Skip to content
This repository has been archived by the owner on Nov 8, 2023. It is now read-only.

Android msm flo 3.4 lollipop release #2

Closed
wants to merge 3 commits into from
Closed

Android msm flo 3.4 lollipop release #2

wants to merge 3 commits into from

Conversation

Flex1911
Copy link

No description provided.

@Flex1911 Flex1911 closed this Nov 14, 2014
victormlourenco pushed a commit to victormlourenco/kernel_msm that referenced this pull request Nov 15, 2014
An inactive timer's base can refer to a offline cpu's base.

In the current code, cpu_base's lock is blindly reinitialized
each time a CPU is brought up. If a CPU is brought online
during the period that another thread is trying to modify an
inactive timer on that CPU with holding its timer base lock,
then the lock will be reinitialized under its feet. This leads
to following SPIN_BUG().

<0> BUG: spinlock already unlocked on CPU#3, kworker/u:3/1466
<0> lock: 0xe3ebe000, .magic: dead4ead, .owner: kworker/u:3/1466,
 .owner_cpu: 1
<4> [<c0013dc4>] (unwind_backtrace+0x0/0x11c) from [<c026e794>]
(do_raw_spin_unlock+0x40/0xcc)
<4> [<c026e794>] (do_raw_spin_unlock+0x40/0xcc) from [<c076c160>]
(_raw_spin_unlock+0x8/0x30)
<4> [<c076c160>] (_raw_spin_unlock+0x8/0x30) from [<c009b858>]
(mod_timer+0x294/0x310)
<4> [<c009b858>] (mod_timer+0x294/0x310) from [<c00a5e04>]
(queue_delayed_work_on+0x104/0x120)
<4> [<c00a5e04>] (queue_delayed_work_on+0x104/0x120) from [<c04eae00>]
(sdhci_msm_bus_voting+0x88/0x9c)
<4> [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c) from [<c04d8780>]
(sdhci_disable+0x40/0x48)
<4> [<c04d8780>] (sdhci_disable+0x40/0x48) from [<c04bf300>]
(mmc_release_host+0x4c/0xb0)
<4> [<c04bf300>] (mmc_release_host+0x4c/0xb0) from [<c04c7aac>]
(mmc_sd_detect+0x90/0xfc)
<4> [<c04c7aac>] (mmc_sd_detect+0x90/0xfc) from [<c04c2504>]
(mmc_rescan+0x7c/0x2c4)
<4> [<c04c2504>] (mmc_rescan+0x7c/0x2c4) from [<c00a6a7c>]
(process_one_work+0x27c/0x484)
<4> [<c00a6a7c>] (process_one_work+0x27c/0x484) from [<c00a6e94>]
(worker_thread+0x210/0x3b0)
<4> [<c00a6e94>] (worker_thread+0x210/0x3b0) from [<c00aad9c>]
(kthread+0x80/0x8c)
<4> [<c00aad9c>] (kthread+0x80/0x8c) from [<c000ea80>]
(kernel_thread_exit+0x0/0x8)

As an example, this particular crash occurred when CPU aosp-mirror#3 is executing
mod_timer() on an inactive timer whose base is refered to offlined CPU aosp-mirror#2.
The code locked the timer_base corresponding to CPU aosp-mirror#2. Before it could
proceed, CPU aosp-mirror#2 came online and reinitialized the spinlock corresponding
to its base. Thus now CPU aosp-mirror#3 held a lock which was reinitialized. When
CPU aosp-mirror#3 finally ended up unlocking the old cpu_base corresponding to CPU aosp-mirror#2,
we hit the above SPIN_BUG().

CPU #0			CPU aosp-mirror#3				       CPU aosp-mirror#2
------			-------				       -------
.....			 ......				      <Offline>
			mod_timer()
			 lock_timer_base
			  spin_lock_irqsave(&base->lock)

cpu_up(2)		 .....				        ......
							 init_timers_cpu()
.....		 	 spin_unlock_irqrestore(&base->lock)     ......
			   <spin_bug>

Allocation of per_cpu timer vector bases is done only once under
"tvec_base_done[]" check. In the current code, spinlock_initialization
of base->lock isn't under this check. When a CPU is up each time the base
lock is reinitialized. Move base spinlock initialization under the check.

CRs-Fixed: 471127
Change-Id: I73b48440fffb227a60af9180e318c851048530dd
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
Signed-off-by: Ed Tam <etam@google.com>
victormlourenco pushed a commit to victormlourenco/kernel_msm that referenced this pull request Nov 15, 2014
msm_sat_enqueue() calls spin_lock() and msm_sat_dequeue() calls
spin_lock_irqsave(). This leads to lockdep warnings about the
same lock being taken in interrupts on and interrupts off context
which can lead to a potential deadlock.

=================================
[ INFO: inconsistent lock state ]
3.4.0+ #382 Tainted: G        W
---------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
kworker/u:2/94 [HC1[1]:SC0[0]:HE0:SE1] takes:
 (&(&sat->lock)->rlock){?.+...}, at: [<c0348b80>] msm_sat_enqueue+0x20/0xb0
{HARDIRQ-ON-W} state was registered at:
  [<c00bd290>] __lock_acquire+0x664/0x8d8
  [<c00bd690>] lock_acquire+0x18c/0x1e8
  [<c06989a4>] _raw_spin_lock+0x38/0x48
  [<c0348b80>] msm_sat_enqueue+0x20/0xb0
  [<c0349338>] msm_slim_rxwq+0x278/0x42c
  [<c0349580>] msm_slim_rx_msgq_thread+0x94/0x1f8
  [<c008e480>] kthread+0x90/0xa0
  [<c000f438>] kernel_thread_exit+0x0/0x8
irq event stamp: 24219
hardirqs last  enabled at (24218): [<c0699188>] _raw_spin_unlock_irqrestore+0x3c/0x68
hardirqs last disabled at (24219): [<c06993f4>] __irq_svc+0x34/0x78
softirqs last  enabled at (24129): [<c00738a8>] irq_exit+0x54/0xa8
softirqs last disabled at (24108): [<c00738a8>] irq_exit+0x54/0xa8

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&sat->lock)->rlock);
  <Interrupt>
    lock(&(&sat->lock)->rlock);

 *** DEADLOCK ***

3 locks held by kworker/u:2/94:
 #0:  ((sat->satcl.name)){.+.+.+}, at: [<c0087124>] process_one_work+0x1e8/0x648
 aosp-mirror#1:  ((&sat->wd)){+.+.+.}, at: [<c0087124>] process_one_work+0x1e8/0x648
 aosp-mirror#2:  (&dev->tx_lock){+.+...}, at: [<c0349cac>] msm_xfer_msg+0xb4/0x51c

stack backtrace:
[<c00151b0>] (unwind_backtrace+0x0/0x120) from [<c00b9d48>] (print_usage_bug+0x258/0x2c0)
[<c00b9d48>] (print_usage_bug+0x258/0x2c0) from [<c00ba12c>] (mark_lock+0x37c/0x68c)
[<c00ba12c>] (mark_lock+0x37c/0x68c) from [<c00bd20c>] (__lock_acquire+0x5e0/0x8d8)
[<c00bd20c>] (__lock_acquire+0x5e0/0x8d8) from [<c00bd690>] (lock_acquire+0x18c/0x1e8)
[<c00bd690>] (lock_acquire+0x18c/0x1e8) from [<c06989a4>] (_raw_spin_lock+0x38/0x48)
[<c06989a4>] (_raw_spin_lock+0x38/0x48) from [<c0348b80>] (msm_sat_enqueue+0x20/0xb0)
[<c0348b80>] (msm_sat_enqueue+0x20/0xb0) from [<c0348dc8>] (msm_slim_interrupt+0x1b8/0x4b0)
[<c0348dc8>] (msm_slim_interrupt+0x1b8/0x4b0) from [<c00d2ccc>] (handle_irq_event_percpu+0x118/0x3a4)
[<c00d2ccc>] (handle_irq_event_percpu+0x118/0x3a4) from [<c00d2f94>] (handle_irq_event+0x3c/0x5c)
[<c00d2f94>] (handle_irq_event+0x3c/0x5c) from [<c00d5c4c>] (handle_fasteoi_irq+0xd0/0x11c)
[<c00d5c4c>] (handle_fasteoi_irq+0xd0/0x11c) from [<c00d2ae4>] (generic_handle_irq+0x24/0x2c)
[<c00d2ae4>] (generic_handle_irq+0x24/0x2c) from [<c000f370>] (handle_IRQ+0x7c/0xc0)
[<c000f370>] (handle_IRQ+0x7c/0xc0) from [<c0008774>] (gic_handle_irq+0x6c/0xc4)
[<c0008774>] (gic_handle_irq+0x6c/0xc4) from [<c0699404>] (__irq_svc+0x44/0x78)
Exception stack(0xee061cd8 to 0xee061d20)
1cc0:                                                       00000001 eebda7c8
1ce0: 00000000 eebda400 20000013 c12b5430 ec96c168 c12b542c c12b5430 00000001
1d00: 20000013 ee061e14 3eb13eb1 ee061d20 c00ba520 c069918c 20000013 ffffffff
[<c0699404>] (__irq_svc+0x44/0x78) from [<c069918c>] (_raw_spin_unlock_irqrestore+0x40/0x68)
[<c069918c>] (_raw_spin_unlock_irqrestore+0x40/0x68) from [<c0279f2c>] (__debug_object_init+0x30c/0x344)
[<c0279f2c>] (__debug_object_init+0x30c/0x344) from [<c007b068>] (init_timer_on_stack_key+0x18/0x30)
[<c007b068>] (init_timer_on_stack_key+0x18/0x30) from [<c0695248>] (schedule_timeout+0x8c/0x4c0)
[<c0695248>] (schedule_timeout+0x8c/0x4c0) from [<c069768c>] (wait_for_common+0xec/0x164)
[<c069768c>] (wait_for_common+0xec/0x164) from [<c0349fc4>] (msm_xfer_msg+0x3cc/0x51c)
[<c0349fc4>] (msm_xfer_msg+0x3cc/0x51c) from [<c034a358>] (slim_sat_rxprocess+0x244/0x664)
[<c034a358>] (slim_sat_rxprocess+0x244/0x664) from [<c0087290>] (process_one_work+0x354/0x648)
[<c0087290>] (process_one_work+0x354/0x648) from [<c0089754>] (worker_thread+0x1a8/0x2a8)
[<c0089754>] (worker_thread+0x1a8/0x2a8) from [<c008e480>] (kthread+0x90/0xa0)
[<c008e480>] (kthread+0x90/0xa0) from [<c000f438>] (kernel_thread_exit+0x0/0x8)

Make this lock irqsafe as well so that this potential bug doesn't
occur.

Change-Id: Icbef6d1d749ee6ee81b079e19e57f22c38f00c68
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
…rror#2)

commit 2608bee upstream.

As observed and suggested by Tushar Gosavi...

---------
readdir calls these function to send TRANS2_FIND_FIRST and
TRANS2_FIND_NEXT command to the server. The current cifs module is
not specifying CIFS_SEARCH_BACKUP_SEARCH flag while sending these
command when backupuid/backupgid is specified. This can be resolved
by specifying CIFS_SEARCH_BACKUP_SEARCH flag.
---------

Reported-and-Tested-by: Tushar Gosavi <tugosavi@in.ibm.com>
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit e5851da upstream.

Remove spinlock as atomic_t can be used instead. Note we use only 16
lower bits, upper bits are changed but we impilcilty cast to u16.

This fix possible deadlock on IBSS mode reproted by lockdep:

=================================
[ INFO: inconsistent lock state ]
3.4.0-wl+ aosp-mirror#4 Not tainted
---------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
kworker/u:2/30374 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (&(&intf->seqlock)->rlock){+.?...}, at: [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
{IN-SOFTIRQ-W} state was registered at:
  [<c04978ab>] __lock_acquire+0x47b/0x1050
  [<c0498504>] lock_acquire+0x84/0xf0
  [<c0835733>] _raw_spin_lock+0x33/0x40
  [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
  [<f9979f2a>] rt2x00queue_write_tx_frame+0x1a/0x300 [rt2x00lib]
  [<f997834f>] rt2x00mac_tx+0x7f/0x380 [rt2x00lib]
  [<f98fe363>] __ieee80211_tx+0x1b3/0x300 [mac80211]
  [<f98ffdf5>] ieee80211_tx+0x105/0x130 [mac80211]
  [<f99000dd>] ieee80211_xmit+0xad/0x100 [mac80211]
  [<f9900519>] ieee80211_subif_start_xmit+0x2d9/0x930 [mac80211]
  [<c0782e87>] dev_hard_start_xmit+0x307/0x660
  [<c079bb71>] sch_direct_xmit+0xa1/0x1e0
  [<c0784bb3>] dev_queue_xmit+0x183/0x730
  [<c078c27a>] neigh_resolve_output+0xfa/0x1e0
  [<c07b436a>] ip_finish_output+0x24a/0x460
  [<c07b4897>] ip_output+0xb7/0x100
  [<c07b2d60>] ip_local_out+0x20/0x60
  [<c07e01ff>] igmpv3_sendpack+0x4f/0x60
  [<c07e108f>] igmp_ifc_timer_expire+0x29f/0x330
  [<c04520fc>] run_timer_softirq+0x15c/0x2f0
  [<c0449e3e>] __do_softirq+0xae/0x1e0
irq event stamp: 18380437
hardirqs last  enabled at (18380437): [<c0526027>] __slab_alloc.clone.3+0x67/0x5f0
hardirqs last disabled at (18380436): [<c0525ff3>] __slab_alloc.clone.3+0x33/0x5f0
softirqs last  enabled at (18377616): [<c0449eb3>] __do_softirq+0x123/0x1e0
softirqs last disabled at (18377611): [<c041278d>] do_softirq+0x9d/0xe0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&intf->seqlock)->rlock);
  <Interrupt>
    lock(&(&intf->seqlock)->rlock);

 *** DEADLOCK ***

4 locks held by kworker/u:2/30374:
 #0:  (wiphy_name(local->hw.wiphy)){++++.+}, at: [<c045cf99>] process_one_work+0x109/0x3f0
 aosp-mirror#1:  ((&sdata->work)){+.+.+.}, at: [<c045cf99>] process_one_work+0x109/0x3f0
 aosp-mirror#2:  (&ifibss->mtx){+.+.+.}, at: [<f98f005b>] ieee80211_ibss_work+0x1b/0x470 [mac80211]
 aosp-mirror#3:  (&intf->beacon_skb_mutex){+.+...}, at: [<f997a644>] rt2x00queue_update_beacon+0x24/0x50 [rt2x00lib]

stack backtrace:
Pid: 30374, comm: kworker/u:2 Not tainted 3.4.0-wl+ aosp-mirror#4
Call Trace:
 [<c04962a6>] print_usage_bug+0x1f6/0x220
 [<c0496a12>] mark_lock+0x2c2/0x300
 [<c0495ff0>] ? check_usage_forwards+0xc0/0xc0
 [<c04978ec>] __lock_acquire+0x4bc/0x1050
 [<c0527890>] ? __kmalloc_track_caller+0x1c0/0x1d0
 [<c0777fb6>] ? copy_skb_header+0x26/0x90
 [<c0498504>] lock_acquire+0x84/0xf0
 [<f9979a20>] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
 [<c0835733>] _raw_spin_lock+0x33/0x40
 [<f9979a20>] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
 [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
 [<f997a5cf>] rt2x00queue_update_beacon_locked+0x5f/0xb0 [rt2x00lib]
 [<f997a64d>] rt2x00queue_update_beacon+0x2d/0x50 [rt2x00lib]
 [<f9977e3a>] rt2x00mac_bss_info_changed+0x1ca/0x200 [rt2x00lib]
 [<f9977c70>] ? rt2x00mac_remove_interface+0x70/0x70 [rt2x00lib]
 [<f98e4dd0>] ieee80211_bss_info_change_notify+0xe0/0x1d0 [mac80211]
 [<f98ef7b8>] __ieee80211_sta_join_ibss+0x3b8/0x610 [mac80211]
 [<c0496ab4>] ? mark_held_locks+0x64/0xc0
 [<c0440012>] ? virt_efi_query_capsule_caps+0x12/0x50
 [<f98efb09>] ieee80211_sta_join_ibss+0xf9/0x140 [mac80211]
 [<f98f0456>] ieee80211_ibss_work+0x416/0x470 [mac80211]
 [<c0496d8b>] ? trace_hardirqs_on+0xb/0x10
 [<c077683b>] ? skb_dequeue+0x4b/0x70
 [<f98f207f>] ieee80211_iface_work+0x13f/0x230 [mac80211]
 [<c045cf99>] ? process_one_work+0x109/0x3f0
 [<c045d015>] process_one_work+0x185/0x3f0
 [<c045cf99>] ? process_one_work+0x109/0x3f0
 [<f98f1f40>] ? ieee80211_teardown_sdata+0xa0/0xa0 [mac80211]
 [<c045ed86>] worker_thread+0x116/0x270
 [<c045ec70>] ? manage_workers+0x1e0/0x1e0
 [<c0462f64>] kthread+0x84/0x90
 [<c0462ee0>] ? __init_kthread_worker+0x60/0x60
 [<c083d382>] kernel_thread_helper+0x6/0x10

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit e35fca4 upstream.

Some edac drivers register themselves as mce decoders via
notifier_chain. But in current notifier_chain implementation logic,
it doesn't accept same notifier registered twice. If so, it will be
wrong when adding/removing the element from the list. For example,
on one SandyBridge platform, remove module sb_edac and then trigger
one error, it will hit oops because it has no mce decoder registered
but related notifier_chain still points to an invalid callback
function. Here is an example:

Call Trace:
 [<ffffffff8150ef6a>] atomic_notifier_call_chain+0x1a/0x20
 [<ffffffff8102b936>] mce_log+0x46/0x180
 [<ffffffff8102eaea>] apei_mce_report_mem_error+0x4a/0x60
 [<ffffffff812e19d2>] ghes_do_proc+0x192/0x210
 [<ffffffff812e2066>] ghes_proc+0x46/0x70
 [<ffffffff812e20d8>] ghes_notify_sci+0x48/0x80
 [<ffffffff8150ef05>] notifier_call_chain+0x55/0x80
 [<ffffffff81076f1a>] __blocking_notifier_call_chain+0x5a/0x80
 [<ffffffff812aea11>] ? acpi_os_wait_events_complete+0x23/0x23
 [<ffffffff81076f56>] blocking_notifier_call_chain+0x16/0x20
 [<ffffffff812ddc4d>] acpi_hed_notify+0x19/0x1b
 [<ffffffff812b16bd>] acpi_device_notify+0x19/0x1b
 [<ffffffff812beb38>] acpi_ev_notify_dispatch+0x67/0x7f
 [<ffffffff812aea3a>] acpi_os_execute_deferred+0x29/0x36
 [<ffffffff81069dc2>] process_one_work+0x132/0x450
 [<ffffffff8106bbcb>] worker_thread+0x17b/0x3c0
 [<ffffffff8106ba50>] ? manage_workers+0x120/0x120
 [<ffffffff81070aee>] kthread+0x9e/0xb0
 [<ffffffff81514724>] kernel_thread_helper+0x4/0x10
 [<ffffffff81070a50>] ? kthread_freezable_should_stop+0x70/0x70
 [<ffffffff81514720>] ? gs_change+0x13/0x13
Code: f3 49 89 d4 45 85 ed 4d 89 c6 48 8b 0f 74 48 48 85 c9 75 17 eb 41
0f 1f 80 00 00 00 00 41 83 ed 01 4c 89 f9 74 22 4d 85 ff 74 1d <4c> 8b
79 08 4c 89 e2 48 89 de 48 89 cf ff 11 4d 85 f6 74 04 41
RIP  [<ffffffff8150eef6>] notifier_call_chain+0x46/0x80
 RSP <ffff88042868fb20>
CR2: ffffffffa01af838
---[ end trace 0100930068e73e6f ]---
BUG: unable to handle kernel paging request at fffffffffffffff8
IP: [<ffffffff810705b0>] kthread_data+0x10/0x20
PGD 1a0d067 PUD 1a0e067 PMD 0
Oops: 0000 [aosp-mirror#2] SMP

Only i7core_edac and sb_edac have such issues because they have more
than one memory controller which means they have to register mce
decoder many times.

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit fe20b39 upstream.

reg_timeout_work() calls restore_regulatory_settings() which
takes cfg80211_mutex.

reg_set_request_processed() already holds cfg80211_mutex
before calling cancel_delayed_work_sync(reg_timeout),
so it might deadlock.

Call the async cancel_delayed_work instead, in order
to avoid the potential deadlock.

This is the relevant lockdep warning:

cfg80211: Calling CRDA for country: XX

======================================================
[ INFO: possible circular locking dependency detected ]
3.4.0-rc5-wl+ #26 Not tainted
-------------------------------------------------------
kworker/0:2/1391 is trying to acquire lock:
 (cfg80211_mutex){+.+.+.}, at: [<bf28ae00>] restore_regulatory_settings+0x34/0x418 [cfg80211]

but task is already holding lock:
 ((reg_timeout).work){+.+...}, at: [<c0059e94>] process_one_work+0x1f0/0x480

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> aosp-mirror#2 ((reg_timeout).work){+.+...}:
       [<c008fd44>] validate_chain+0xb94/0x10f0
       [<c0090b68>] __lock_acquire+0x8c8/0x9b0
       [<c0090d40>] lock_acquire+0xf0/0x114
       [<c005b600>] wait_on_work+0x4c/0x154
       [<c005c000>] __cancel_work_timer+0xd4/0x11c
       [<c005c064>] cancel_delayed_work_sync+0x1c/0x20
       [<bf28b274>] reg_set_request_processed+0x50/0x78 [cfg80211]
       [<bf28bd84>] set_regdom+0x550/0x600 [cfg80211]
       [<bf294cd8>] nl80211_set_reg+0x218/0x258 [cfg80211]
       [<c03c7738>] genl_rcv_msg+0x1a8/0x1e8
       [<c03c6a00>] netlink_rcv_skb+0x5c/0xc0
       [<c03c7584>] genl_rcv+0x28/0x34
       [<c03c6720>] netlink_unicast+0x15c/0x228
       [<c03c6c7c>] netlink_sendmsg+0x218/0x298
       [<c03933c8>] sock_sendmsg+0xa4/0xc0
       [<c039406c>] __sys_sendmsg+0x1e4/0x268
       [<c0394228>] sys_sendmsg+0x4c/0x70
       [<c0013840>] ret_fast_syscall+0x0/0x3c

-> aosp-mirror#1 (reg_mutex){+.+.+.}:
       [<c008fd44>] validate_chain+0xb94/0x10f0
       [<c0090b68>] __lock_acquire+0x8c8/0x9b0
       [<c0090d40>] lock_acquire+0xf0/0x114
       [<c04734dc>] mutex_lock_nested+0x48/0x320
       [<bf28b2cc>] reg_todo+0x30/0x538 [cfg80211]
       [<c0059f44>] process_one_work+0x2a0/0x480
       [<c005a4b4>] worker_thread+0x1bc/0x2bc
       [<c0061148>] kthread+0x98/0xa4
       [<c0014af4>] kernel_thread_exit+0x0/0x8

-> #0 (cfg80211_mutex){+.+.+.}:
       [<c008ed58>] print_circular_bug+0x68/0x2cc
       [<c008fb28>] validate_chain+0x978/0x10f0
       [<c0090b68>] __lock_acquire+0x8c8/0x9b0
       [<c0090d40>] lock_acquire+0xf0/0x114
       [<c04734dc>] mutex_lock_nested+0x48/0x320
       [<bf28ae00>] restore_regulatory_settings+0x34/0x418 [cfg80211]
       [<bf28b200>] reg_timeout_work+0x1c/0x20 [cfg80211]
       [<c0059f44>] process_one_work+0x2a0/0x480
       [<c005a4b4>] worker_thread+0x1bc/0x2bc
       [<c0061148>] kthread+0x98/0xa4
       [<c0014af4>] kernel_thread_exit+0x0/0x8

other info that might help us debug this:

Chain exists of:
  cfg80211_mutex --> reg_mutex --> (reg_timeout).work

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock((reg_timeout).work);
                               lock(reg_mutex);
                               lock((reg_timeout).work);
  lock(cfg80211_mutex);

 *** DEADLOCK ***

2 locks held by kworker/0:2/1391:
 #0:  (events){.+.+.+}, at: [<c0059e94>] process_one_work+0x1f0/0x480
 aosp-mirror#1:  ((reg_timeout).work){+.+...}, at: [<c0059e94>] process_one_work+0x1f0/0x480

stack backtrace:
[<c001b928>] (unwind_backtrace+0x0/0x12c) from [<c0471d3c>] (dump_stack+0x20/0x24)
[<c0471d3c>] (dump_stack+0x20/0x24) from [<c008ef70>] (print_circular_bug+0x280/0x2cc)
[<c008ef70>] (print_circular_bug+0x280/0x2cc) from [<c008fb28>] (validate_chain+0x978/0x10f0)
[<c008fb28>] (validate_chain+0x978/0x10f0) from [<c0090b68>] (__lock_acquire+0x8c8/0x9b0)
[<c0090b68>] (__lock_acquire+0x8c8/0x9b0) from [<c0090d40>] (lock_acquire+0xf0/0x114)
[<c0090d40>] (lock_acquire+0xf0/0x114) from [<c04734dc>] (mutex_lock_nested+0x48/0x320)
[<c04734dc>] (mutex_lock_nested+0x48/0x320) from [<bf28ae00>] (restore_regulatory_settings+0x34/0x418 [cfg80211])
[<bf28ae00>] (restore_regulatory_settings+0x34/0x418 [cfg80211]) from [<bf28b200>] (reg_timeout_work+0x1c/0x20 [cfg80211])
[<bf28b200>] (reg_timeout_work+0x1c/0x20 [cfg80211]) from [<c0059f44>] (process_one_work+0x2a0/0x480)
[<c0059f44>] (process_one_work+0x2a0/0x480) from [<c005a4b4>] (worker_thread+0x1bc/0x2bc)
[<c005a4b4>] (worker_thread+0x1bc/0x2bc) from [<c0061148>] (kthread+0x98/0xa4)
[<c0061148>] (kthread+0x98/0xa4) from [<c0014af4>] (kernel_thread_exit+0x0/0x8)
cfg80211: Calling CRDA to update world regulatory domain
cfg80211: World regulatory domain updated:
cfg80211:   (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211:   (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
cfg80211:   (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211:   (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit b9f90eb upstream.

Ignoring interfaces with additional descriptors is not a reliable
method for locating the correct interface on Gobi devices.  There
is at least one device where this method fails:
https://bbs.archlinux.org/viewtopic.php?id=143506

The result is that the AT command port (interface aosp-mirror#2) is hidden
from qcserial, preventing traditional serial modem usage:

[   15.562552] qmi_wwan 4-1.6:1.0: cdc-wdm0: USB WDM device
[   15.562691] qmi_wwan 4-1.6:1.0: wwan0: register 'qmi_wwan' at usb-0000:00:1d.0-1.6, Qualcomm Gobi wwan/QMI device, 1e:df:3c:3a:4e:3b
[   15.563383] qmi_wwan: probe of 4-1.6:1.1 failed with error -22
[   15.564189] qmi_wwan 4-1.6:1.2: cdc-wdm1: USB WDM device
[   15.564302] qmi_wwan 4-1.6:1.2: wwan1: register 'qmi_wwan' at usb-0000:00:1d.0-1.6, Qualcomm Gobi wwan/QMI device, 1e:df:3c:3a:4e:3b
[   15.564328] qmi_wwan: probe of 4-1.6:1.3 failed with error -22
[   15.569376] qcserial 4-1.6:1.1: Qualcomm USB modem converter detected
[   15.569440] usb 4-1.6: Qualcomm USB modem converter now attached to ttyUSB0
[   15.570372] qcserial 4-1.6:1.3: Qualcomm USB modem converter detected
[   15.570430] usb 4-1.6: Qualcomm USB modem converter now attached to ttyUSB1

Use static interface numbers taken from the interface map in
qcserial for all Gobi devices instead:

	Gobi 1K USB layout:
	0: serial port (doesn't respond)
	1: serial port (doesn't respond)
	2: AT-capable modem port
	3: QMI/net

	Gobi 2K+ USB layout:
	0: QMI/net
	1: DM/DIAG (use libqcdm from ModemManager for communication)
	2: AT-capable modem port
	3: NMEA

This should be more reliable over all, and will also prevent the
noisy "probe failed" messages.  The whitelisting logic is expected
to be replaced by direct interface number matching in 3.6.

Reported-by: Heinrich Siebmanns (Harvey) <H.Siebmanns@t-online.de>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
…condition

commit 26c1917 upstream.

When holding the mmap_sem for reading, pmd_offset_map_lock should only
run on a pmd_t that has been read atomically from the pmdp pointer,
otherwise we may read only half of it leading to this crash.

PID: 11679  TASK: f06e8000  CPU: 3   COMMAND: "do_race_2_panic"
 #0 [f06a9dd8] crash_kexec at c049b5ec
 aosp-mirror#1 [f06a9e2c] oops_end at c083d1c2
 aosp-mirror#2 [f06a9e40] no_context at c0433ded
 aosp-mirror#3 [f06a9e64] bad_area_nosemaphore at c043401a
 aosp-mirror#4 [f06a9e6c] __do_page_fault at c0434493
 aosp-mirror#5 [f06a9eec] do_page_fault at c083eb45
 aosp-mirror#6 [f06a9f04] error_code (via page_fault) at c083c5d5
    EAX: 01fb470c EBX: fff35000 ECX: 00000003 EDX: 00000100 EBP:
    00000000
    DS:  007b     ESI: 9e201000 ES:  007b     EDI: 01fb4700 GS:  00e0
    CS:  0060     EIP: c083bc14 ERR: ffffffff EFLAGS: 00010246
 aosp-mirror#7 [f06a9f38] _spin_lock at c083bc14
 aosp-mirror#8 [f06a9f44] sys_mincore at c0507b7d
 aosp-mirror#9 [f06a9fb0] system_call at c083becd
                         start           len
    EAX: ffffffda  EBX: 9e200000  ECX: 00001000  EDX: 6228537f
    DS:  007b      ESI: 00000000  ES:  007b      EDI: 003d0f00
    SS:  007b      ESP: 62285354  EBP: 62285388  GS:  0033
    CS:  0073      EIP: 00291416  ERR: 000000da  EFLAGS: 00000286

This should be a longstanding bug affecting x86 32bit PAE without THP.
Only archs with 64bit large pmd_t and 32bit unsigned long should be
affected.

With THP enabled the barrier() in pmd_none_or_trans_huge_or_clear_bad()
would partly hide the bug when the pmd transition from none to stable,
by forcing a re-read of the *pmd in pmd_offset_map_lock, but when THP is
enabled a new set of problem arises by the fact could then transition
freely in any of the none, pmd_trans_huge or pmd_trans_stable states.
So making the barrier in pmd_none_or_trans_huge_or_clear_bad()
unconditional isn't good idea and it would be a flakey solution.

This should be fully fixed by introducing a pmd_read_atomic that reads
the pmd in order with THP disabled, or by reading the pmd atomically
with cmpxchg8b with THP enabled.

Luckily this new race condition only triggers in the places that must
already be covered by pmd_none_or_trans_huge_or_clear_bad() so the fix
is localized there but this bug is not related to THP.

NOTE: this can trigger on x86 32bit systems with PAE enabled with more
than 4G of ram, otherwise the high part of the pmd will never risk to be
truncated because it would be zero at all times, in turn so hiding the
SMP race.

This bug was discovered and fully debugged by Ulrich, quote:

----
[..]
pmd_none_or_trans_huge_or_clear_bad() loads the content of edx and
eax.

    496 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t
    *pmd)
    497 {
    498         /* depend on compiler for an atomic pmd read */
    499         pmd_t pmdval = *pmd;

                                // edi = pmd pointer
0xc0507a74 <sys_mincore+548>:   mov    0x8(%esp),%edi
...
                                // edx = PTE page table high address
0xc0507a84 <sys_mincore+564>:   mov    0x4(%edi),%edx
...
                                // eax = PTE page table low address
0xc0507a8e <sys_mincore+574>:   mov    (%edi),%eax

[..]

Please note that the PMD is not read atomically. These are two "mov"
instructions where the high order bits of the PMD entry are fetched
first. Hence, the above machine code is prone to the following race.

-  The PMD entry {high|low} is 0x0000000000000000.
   The "mov" at 0xc0507a84 loads 0x00000000 into edx.

-  A page fault (on another CPU) sneaks in between the two "mov"
   instructions and instantiates the PMD.

-  The PMD entry {high|low} is now 0x00000003fda38067.
   The "mov" at 0xc0507a8e loads 0xfda38067 into eax.
----

Reported-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit 3cf003c upstream.

[The async read code was broadened to include uncached reads in 3.5, so
the mainline patch did not apply directly. This patch is just a backport
to account for that change.]

Jian found that when he ran fsx on a 32 bit arch with a large wsize the
process and one of the bdi writeback kthreads would sometimes deadlock
with a stack trace like this:

crash> bt
PID: 2789   TASK: f02edaa0  CPU: 3   COMMAND: "fsx"
 #0 [eed63cbc] schedule at c083c5b3
 aosp-mirror#1 [eed63d80] kmap_high at c0500ec8
 aosp-mirror#2 [eed63db0] cifs_async_writev at f7fabcd7 [cifs]
 aosp-mirror#3 [eed63df0] cifs_writepages at f7fb7f5c [cifs]
 aosp-mirror#4 [eed63e50] do_writepages at c04f3e32
 aosp-mirror#5 [eed63e54] __filemap_fdatawrite_range at c04e152a
 aosp-mirror#6 [eed63ea4] filemap_fdatawrite at c04e1b3e
 aosp-mirror#7 [eed63eb4] cifs_file_aio_write at f7fa111a [cifs]
 aosp-mirror#8 [eed63ecc] do_sync_write at c052d202
 aosp-mirror#9 [eed63f74] vfs_write at c052d4ee
#10 [eed63f94] sys_write at c052df4c
#11 [eed63fb0] ia32_sysenter_target at c0409a98
    EAX: 00000004  EBX: 00000003  ECX: abd73b73  EDX: 012a65c6
    DS:  007b      ESI: 012a65c6  ES:  007b      EDI: 00000000
    SS:  007b      ESP: bf8db178  EBP: bf8db1f8  GS:  0033
    CS:  0073      EIP: 40000424  ERR: 00000004  EFLAGS: 00000246

Each task would kmap part of its address array before getting stuck, but
not enough to actually issue the write.

This patch fixes this by serializing the marshal_iov operations for
async reads and writes. The idea here is to ensure that cifs
aggressively tries to populate a request before attempting to fulfill
another one. As soon as all of the pages are kmapped for a request, then
we can unlock and allow another one to proceed.

There's no need to do this serialization on non-CONFIG_HIGHMEM arches
however, so optimize all of this out when CONFIG_HIGHMEM isn't set.

Reported-by: Jian Li <jiali@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
…d reasons

commit 5cf02d0 upstream.

We've had some reports of a deadlock where rpciod ends up with a stack
trace like this:

    PID: 2507   TASK: ffff88103691ab40  CPU: 14  COMMAND: "rpciod/14"
     #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9
     aosp-mirror#1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs]
     aosp-mirror#2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f
     aosp-mirror#3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8
     aosp-mirror#4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs]
     aosp-mirror#5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs]
     aosp-mirror#6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670
     aosp-mirror#7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271
     aosp-mirror#8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638
     aosp-mirror#9 [ffff8810343bf818] shrink_zone at ffffffff8112788f
    #10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e
    #11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f
    #12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad
    #13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942
    #14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a
    #15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9
    #16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b
    #17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808
    #18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c
    #19 [ffff8810343bfce8] inet_create at ffffffff81483ba6
    #20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7
    #21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc]
    #22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc]
    #23 [ffff8810343bfe38] worker_thread at ffffffff810887d0
    #24 [ffff8810343bfee8] kthread at ffffffff8108dd96
    #25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca

rpciod is trying to allocate memory for a new socket to talk to the
server. The VM ends up calling ->releasepage to get more memory, and it
tries to do a blocking commit. That commit can't succeed however without
a connected socket, so we deadlock.

Fix this by setting PF_FSTRANS on the workqueue task prior to doing the
socket allocation, and having nfs_release_page check for that flag when
deciding whether to do a commit call. Also, set PF_FSTRANS
unconditionally in rpc_async_schedule since that function can also do
allocations sometimes.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit bea6832 upstream.

On architectures where cputime_t is 64 bit type, is possible to trigger
divide by zero on do_div(temp, (__force u32) total) line, if total is a
non zero number but has lower 32 bit's zeroed. Removing casting is not
a good solution since some do_div() implementations do cast to u32
internally.

This problem can be triggered in practice on very long lived processes:

  PID: 2331   TASK: ffff880472814b00  CPU: 2   COMMAND: "oraagent.bin"
   #0 [ffff880472a51b70] machine_kexec at ffffffff8103214b
   aosp-mirror#1 [ffff880472a51bd0] crash_kexec at ffffffff810b91c2
   aosp-mirror#2 [ffff880472a51ca0] oops_end at ffffffff814f0b00
   aosp-mirror#3 [ffff880472a51cd0] die at ffffffff8100f26b
   aosp-mirror#4 [ffff880472a51d00] do_trap at ffffffff814f03f4
   aosp-mirror#5 [ffff880472a51d60] do_divide_error at ffffffff8100cfff
   aosp-mirror#6 [ffff880472a51e00] divide_error at ffffffff8100be7b
      [exception RIP: thread_group_times+0x56]
      RIP: ffffffff81056a16  RSP: ffff880472a51eb8  RFLAGS: 00010046
      RAX: bc3572c9fe12d194  RBX: ffff880874150800  RCX: 0000000110266fad
      RDX: 0000000000000000  RSI: ffff880472a51eb8  RDI: 001038ae7d9633dc
      RBP: ffff880472a51ef8   R8: 00000000b10a3a64   R9: ffff880874150800
      R10: 00007fcba27ab680  R11: 0000000000000202  R12: ffff880472a51f08
      R13: ffff880472a51f10  R14: 0000000000000000  R15: 0000000000000007
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   aosp-mirror#7 [ffff880472a51f00] do_sys_times at ffffffff8108845d
   aosp-mirror#8 [ffff880472a51f40] sys_times at ffffffff81088524
   aosp-mirror#9 [ffff880472a51f80] system_call_fastpath at ffffffff8100b0f2
      RIP: 0000003808caac3a  RSP: 00007fcba27ab6d8  RFLAGS: 00000202
      RAX: 0000000000000064  RBX: ffffffff8100b0f2  RCX: 0000000000000000
      RDX: 00007fcba27ab6e0  RSI: 000000000076d58e  RDI: 00007fcba27ab6e0
      RBP: 00007fcba27ab700   R8: 0000000000000020   R9: 000000000000091b
      R10: 00007fcba27ab680  R11: 0000000000000202  R12: 00007fff9ca41940
      R13: 0000000000000000  R14: 00007fcba27ac9c0  R15: 00007fff9ca41940
      ORIG_RAX: 0000000000000064  CS: 0033  SS: 002b

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120808092714.GA3580@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit d653220 upstream.

This patch fixes the following kernel panic invoked by uninitialized fields
in the chip initialization for the 1G bnx2 iSCSI offload.

One of the bits in the chip initialization is being used by the latest
firmware to control overflow packets.  When this control bit gets enabled
erroneously, it would ultimately result in a bad packet placement which would
cause the bnx2 driver to dereference a NULL ptr in the placement handler.

This can happen under certain stress I/O environment under the Linux
iSCSI offload operation.

This change only affects Broadcom's 5709 chipset.

Unable to handle kernel NULL pointer dereference at 0000000000000008 RIP:
 [<ffffffff881f0e7d>] :bnx2:bnx2_poll_work+0xd0d/0x13c5
Pid: 0, comm: swapper Tainted: G     ---- 2.6.18-333.el5debug aosp-mirror#2
RIP: 0010:[<ffffffff881f0e7d>]  [<ffffffff881f0e7d>] :bnx2:bnx2_poll_work+0xd0d/0x13c5
RSP: 0018:ffff8101b575bd50  EFLAGS: 00010216
RAX: 0000000000000005 RBX: ffff81007c5fb180 RCX: 0000000000000000
RDX: 0000000000000ffc RSI: 00000000817e8000 RDI: 0000000000000220
RBP: ffff81015bbd7ec0 R08: ffff8100817e9000 R09: 0000000000000000
R10: ffff81007c5fb180 R11: 00000000000000c8 R12: 000000007a25a010
R13: 0000000000000000 R14: 0000000000000005 R15: ffff810159f80558
FS:  0000000000000000(0000) GS:ffff8101afebc240(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000008 CR3: 0000000000201000 CR4: 00000000000006a0
Process swapper (pid: 0, threadinfo ffff8101b5754000, task ffff8101afebd820)
Stack:  000000000000000b ffff810159f80000 0000000000000040 ffff810159f80520
 ffff810159f80500 00cf00cf8008e84b ffffc200100939e0 ffff810009035b20
 0000502900000000 000000be00000001 ffff8100817e7810 00d08101b575bea8
Call Trace:
 <IRQ>  [<ffffffff8008e0d0>] show_schedstat+0x1c2/0x25b
 [<ffffffff881f1886>] :bnx2:bnx2_poll+0xf6/0x231
 [<ffffffff8000c9b9>] net_rx_action+0xac/0x1b1
 [<ffffffff800125a0>] __do_softirq+0x89/0x133
 [<ffffffff8005e30c>] call_softirq+0x1c/0x28
 [<ffffffff8006d5de>] do_softirq+0x2c/0x7d
 [<ffffffff8006d46e>] do_IRQ+0xee/0xf7
 [<ffffffff8005d625>] ret_from_intr+0x0/0xa
 <EOI>  [<ffffffff801a5780>] acpi_processor_idle_simple+0x1c5/0x341
 [<ffffffff801a573d>] acpi_processor_idle_simple+0x182/0x341
 [<ffffffff801a55bb>] acpi_processor_idle_simple+0x0/0x341
 [<ffffffff80049560>] cpu_idle+0x95/0xb8
 [<ffffffff80078b1c>] start_secondary+0x479/0x488

Signed-off-by: Eddie Wai <eddie.wai@broadcom.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit a85d0d7 upstream.

When call_crda() is called we kick off a witch hunt search
for the same regulatory domain on our internal regulatory
database and that work gets kicked off on a workqueue, this
is done while the cfg80211_mutex is held. If that workqueue
kicks off it will first lock reg_regdb_search_mutex and
later cfg80211_mutex but to ensure two CPUs will not contend
against cfg80211_mutex the right thing to do is to have the
reg_regdb_search() wait until the cfg80211_mutex is let go.

The lockdep report is pasted below.

cfg80211: Calling CRDA to update world regulatory domain

======================================================
[ INFO: possible circular locking dependency detected ]
3.3.8 aosp-mirror#3 Tainted: G           O
-------------------------------------------------------
kworker/0:1/235 is trying to acquire lock:
 (cfg80211_mutex){+.+...}, at: [<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

but task is already holding lock:
 (reg_regdb_search_mutex){+.+...}, at: [<81646828>] set_regdom+0x710/0x808 [cfg80211]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> aosp-mirror#2 (reg_regdb_search_mutex){+.+...}:
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<81645778>] is_world_regdom+0x9f8/0xc74 [cfg80211]

-> aosp-mirror#1 (reg_mutex#2){+.+...}:
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<8164539c>] is_world_regdom+0x61c/0xc74 [cfg80211]

-> #0 (cfg80211_mutex){+.+...}:
       [<800a77b8>] __lock_acquire+0x10d4/0x17bc
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

other info that might help us debug this:

Chain exists of:
  cfg80211_mutex --> reg_mutex#2 --> reg_regdb_search_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(reg_regdb_search_mutex);
                               lock(reg_mutex#2);
                               lock(reg_regdb_search_mutex);
  lock(cfg80211_mutex);

 *** DEADLOCK ***

3 locks held by kworker/0:1/235:
 #0:  (events){.+.+..}, at: [<80089a00>] process_one_work+0x230/0x460
 aosp-mirror#1:  (reg_regdb_work){+.+...}, at: [<80089a00>] process_one_work+0x230/0x460
 aosp-mirror#2:  (reg_regdb_search_mutex){+.+...}, at: [<81646828>] set_regdom+0x710/0x808 [cfg80211]

stack backtrace:
Call Trace:
[<80290fd4>] dump_stack+0x8/0x34
[<80291bc4>] print_circular_bug+0x2ac/0x2d8
[<800a77b8>] __lock_acquire+0x10d4/0x17bc
[<800a8384>] lock_acquire+0x60/0x88
[<802950a8>] mutex_lock_nested+0x54/0x31c
[<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

Reported-by: Felix Fietkau <nbd@openwrt.org>
Tested-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
[ Upstream commit c254637 ]

When dump_one_policy() returns an error, e.g. because of a too small
buffer to dump the whole xfrm policy, xfrm_policy_netlink() returns
NULL instead of an error pointer. But its caller expects an error
pointer and therefore continues to operate on a NULL skbuff.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
…2012-4461)

commit 6d1068b upstream.

On hosts without the XSAVE support unprivileged local user can trigger
oops similar to the one below by setting X86_CR4_OSXSAVE bit in guest
cr4 register using KVM_SET_SREGS ioctl and later issuing KVM_RUN
ioctl.

invalid opcode: 0000 [aosp-mirror#2] SMP
Modules linked in: tun ip6table_filter ip6_tables ebtable_nat ebtables
...
Pid: 24935, comm: zoog_kvm_monito Tainted: G      D      3.2.0-3-686-pae
EIP: 0060:[<f8b9550c>] EFLAGS: 00210246 CPU: 0
EIP is at kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm]
EAX: 00000001 EBX: 000f387e ECX: 00000000 EDX: 00000000
ESI: 00000000 EDI: 00000000 EBP: ef5a0060 ESP: d7c63e70
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process zoog_kvm_monito (pid: 24935, ti=d7c62000 task=ed84a0c0
task.ti=d7c62000)
Stack:
 00000001 f70a1200 f8b940a9 ef5a0060 00000000 00200202 f8769009 00000000
 ef5a0060 000f387e eda5c020 8722f9c8 00015bae 00000000 ed84a0c0 ed84a0c0
 c12bf02d 0000ae80 ef7f8740 fffffffb f359b740 ef5a0060 f8b85dc1 0000ae80
Call Trace:
 [<f8b940a9>] ? kvm_arch_vcpu_ioctl_set_sregs+0x2fe/0x308 [kvm]
...
 [<c12bfb44>] ? syscall_call+0x7/0xb
Code: 89 e8 e8 14 ee ff ff ba 00 00 04 00 89 e8 e8 98 48 ff ff 85 c0 74
1e 83 7d 48 00 75 18 8b 85 08 07 00 00 31 c9 8b 95 0c 07 00 00 <0f> 01
d1 c7 45 48 01 00 00 00 c7 45 1c 01 00 00 00 0f ae f0 89
EIP: [<f8b9550c>] kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm] SS:ESP
0068:d7c63e70

QEMU first retrieves the supported features via KVM_GET_SUPPORTED_CPUID
and then sets them later. So guest's X86_FEATURE_XSAVE should be masked
out on hosts without X86_FEATURE_XSAVE, making kvm_set_cr4 with
X86_CR4_OSXSAVE fail. Userspaces that allow specifying guest cpuid with
X86_FEATURE_XSAVE even on hosts that do not support it, might be
susceptible to this attack from inside the guest as well.

Allow setting X86_CR4_OSXSAVE bit only if host has XSAVE support.

Signed-off-by: Petr Matousek <pmatouse@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit 412d32e upstream.

A rescue thread exiting TASK_INTERRUPTIBLE can lead to a task scheduling
off, never to be seen again.  In the case where this occurred, an exiting
thread hit reiserfs homebrew conditional resched while holding a mutex,
bringing the box to its knees.

PID: 18105  TASK: ffff8807fd412180  CPU: 5   COMMAND: "kdmflush"
 #0 [ffff8808157e7670] schedule at ffffffff8143f489
 aosp-mirror#1 [ffff8808157e77b8] reiserfs_get_block at ffffffffa038ab2d [reiserfs]
 aosp-mirror#2 [ffff8808157e79a8] __block_write_begin at ffffffff8117fb14
 aosp-mirror#3 [ffff8808157e7a98] reiserfs_write_begin at ffffffffa0388695 [reiserfs]
 aosp-mirror#4 [ffff8808157e7ad8] generic_perform_write at ffffffff810ee9e2
 aosp-mirror#5 [ffff8808157e7b58] generic_file_buffered_write at ffffffff810eeb41
 aosp-mirror#6 [ffff8808157e7ba8] __generic_file_aio_write at ffffffff810f1a3a
 aosp-mirror#7 [ffff8808157e7c58] generic_file_aio_write at ffffffff810f1c88
 aosp-mirror#8 [ffff8808157e7cc8] do_sync_write at ffffffff8114f850
 aosp-mirror#9 [ffff8808157e7dd8] do_acct_process at ffffffff810a268f
    [exception RIP: kernel_thread_helper]
    RIP: ffffffff8144a5c0  RSP: ffff8808157e7f58  RFLAGS: 00000202
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: 0000000000000000
    RDX: 0000000000000000  RSI: ffffffff8107af60  RDI: ffff8803ee491d18
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000000  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018

Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit b8f2c21 upstream.

Update efi_call_phys_prelog to install an identity mapping of all available
memory.  This corrects a bug on very large systems with more then 512 GB in
which bios would not be able to access addresses above not in the mapping.

The result is a crash that looks much like this.

BUG: unable to handle kernel paging request at 000000effd870020
IP: [<0000000078bce331>] 0x78bce330
PGD 0
Oops: 0000 [aosp-mirror#1] SMP
Modules linked in:
CPU 0
Pid: 0, comm: swapper/0 Tainted: G        W    3.8.0-rc1-next-20121224-medusa_ntz+ aosp-mirror#2 Intel Corp. Stoutland Platform
RIP: 0010:[<0000000078bce331>]  [<0000000078bce331>] 0x78bce330
RSP: 0000:ffffffff81601d28  EFLAGS: 00010006
RAX: 0000000078b80e18 RBX: 0000000000000004 RCX: 0000000000000004
RDX: 0000000078bcf958 RSI: 0000000000002400 RDI: 8000000000000000
RBP: 0000000078bcf760 R08: 000000effd870000 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000000c3 R12: 0000000000000030
R13: 000000effd870000 R14: 0000000000000000 R15: ffff88effd870000
FS:  0000000000000000(0000) GS:ffff88effe400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000effd870020 CR3: 000000000160c000 CR4: 00000000000006b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper/0 (pid: 0, threadinfo ffffffff81600000, task ffffffff81614400)
Stack:
 0000000078b80d18 0000000000000004 0000000078bced7b ffff880078b81fff
 0000000000000000 0000000000000082 0000000078bce3a8 0000000000002400
 0000000060000202 0000000078b80da0 0000000078bce45d ffffffff8107cb5a
Call Trace:
 [<ffffffff8107cb5a>] ? on_each_cpu+0x77/0x83
 [<ffffffff8102f4eb>] ? change_page_attr_set_clr+0x32f/0x3ed
 [<ffffffff81035946>] ? efi_call4+0x46/0x80
 [<ffffffff816c5abb>] ? efi_enter_virtual_mode+0x1f5/0x305
 [<ffffffff816aeb24>] ? start_kernel+0x34a/0x3d2
 [<ffffffff816ae5ed>] ? repair_env_string+0x60/0x60
 [<ffffffff816ae2be>] ? x86_64_start_reservations+0xba/0xc1
 [<ffffffff816ae120>] ? early_idt_handlers+0x120/0x120
 [<ffffffff816ae419>] ? x86_64_start_kernel+0x154/0x163
Code:  Bad RIP value.
RIP  [<0000000078bce331>] 0x78bce330
 RSP <ffffffff81601d28>
CR2: 000000effd870020
---[ end trace ead828934fef5eab ]---

Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit 13d2b4d upstream.

This fixes CVE-2013-0228 / XSA-42

Drew Jones while working on CVE-2013-0190 found that that unprivileged guest user
in 32bit PV guest can use to crash the > guest with the panic like this:

-------------
general protection fault: 0000 [aosp-mirror#1] SMP
last sysfs file: /sys/devices/vbd-51712/block/xvda/dev
Modules linked in: sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4
iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6
xt_state nf_conntrack ip6table_filter ip6_tables ipv6 xen_netfront ext4
mbcache jbd2 xen_blkfront dm_mirror dm_region_hash dm_log dm_mod [last
unloaded: scsi_wait_scan]

Pid: 1250, comm: r Not tainted 2.6.32-356.el6.i686 aosp-mirror#1
EIP: 0061:[<c0407462>] EFLAGS: 00010086 CPU: 0
EIP is at xen_iret+0x12/0x2b
EAX: eb8d0000 EBX: 00000001 ECX: 08049860 EDX: 00000010
ESI: 00000000 EDI: 003d0f00 EBP: b77f8388 ESP: eb8d1fe0
 DS: 0000 ES: 007b FS: 0000 GS: 00e0 SS: 0069
Process r (pid: 1250, ti=eb8d0000 task=c2953550 task.ti=eb8d0000)
Stack:
 00000000 0027f416 00000073 00000206 b77f8364 0000007b 00000000 00000000
Call Trace:
Code: c3 8b 44 24 18 81 4c 24 38 00 02 00 00 8d 64 24 30 e9 03 00 00 00
8d 76 00 f7 44 24 08 00 00 02 80 75 33 50 b8 00 e0 ff ff 21 e0 <8b> 40
10 8b 04 85 a0 f6 ab c0 8b 80 0c b0 b3 c0 f6 44 24 0d 02
EIP: [<c0407462>] xen_iret+0x12/0x2b SS:ESP 0069:eb8d1fe0
general protection fault: 0000 [aosp-mirror#2]
---[ end trace ab0d29a492dcd330 ]---
Kernel panic - not syncing: Fatal exception
Pid: 1250, comm: r Tainted: G      D    ---------------
2.6.32-356.el6.i686 aosp-mirror#1
Call Trace:
 [<c08476df>] ? panic+0x6e/0x122
 [<c084b63c>] ? oops_end+0xbc/0xd0
 [<c084b260>] ? do_general_protection+0x0/0x210
 [<c084a9b7>] ? error_code+0x73/
-------------

Petr says: "
 I've analysed the bug and I think that xen_iret() cannot cope with
 mangled DS, in this case zeroed out (null selector/descriptor) by either
 xen_failsafe_callback() or RESTORE_REGS because the corresponding LDT
 entry was invalidated by the reproducer. "

Jan took a look at the preliminary patch and came up a fix that solves
this problem:

"This code gets called after all registers other than those handled by
IRET got already restored, hence a null selector in %ds or a non-null
one that got loaded from a code or read-only data descriptor would
cause a kernel mode fault (with the potential of crashing the kernel
as a whole, if panic_on_oops is set)."

The way to fix this is to realize that the we can only relay on the
registers that IRET restores. The two that are guaranteed are the
%cs and %ss as they are always fixed GDT selectors. Also they are
inaccessible from user mode - so they cannot be altered. This is
the approach taken in this patch.

Another alternative option suggested by Jan would be to relay on
the subtle realization that using the %ebp or %esp relative references uses
the %ss segment.  In which case we could switch from using %eax to %ebp and
would not need the %ss over-rides. That would also require one extra
instruction to compensate for the one place where the register is used
as scaled index. However Andrew pointed out that is too subtle and if
further work was to be done in this code-path it could escape folks attention
and lead to accidents.

Reviewed-by: Petr Matousek <pmatouse@redhat.com>
Reported-by: Petr Matousek <pmatouse@redhat.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit d990434 upstream.

An earlier commit cd00608 ("ata_piix:
defer disks to the Hyper-V drivers by default") broke MS Virtual PC
guests. Hyper-V guests and Virtual PC guests have nearly identical DMI
info. As a result the driver does currently ignore the emulated hardware
in Virtual PC guests and defers the handling to hv_blkvsc. Since Virtual
PC does not offer paravirtualized drivers no disks will be found in the
guest.

One difference in the DMI info is the product version. This patch adds a
match for MS Virtual PC 2007 and "unignores" the emulated hardware.

This was reported for openSuSE 12.1 in bugzilla:
https://bugzilla.novell.com/show_bug.cgi?id=737532

Here is a detailed list of DMI info from example guests:

hwinfo --bios:

virtual pc guest:

  System Info: aosp-mirror#1
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "VS2005R2"
    Serial: "3178-9905-1533-4840-9282-0569-59"
    UUID: undefined, but settable
    Wake-up: 0x06 (Power Switch)
  Board Info: aosp-mirror#2
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "5.0"
    Serial: "3178-9905-1533-4840-9282-0569-59"
  Chassis Info: aosp-mirror#3
    Manufacturer: "Microsoft Corporation"
    Version: "5.0"
    Serial: "3178-9905-1533-4840-9282-0569-59"
    Asset Tag: "7188-3705-6309-9738-9645-0364-00"
    Type: 0x03 (Desktop)
    Bootup State: 0x03 (Safe)
    Power Supply State: 0x03 (Safe)
    Thermal State: 0x01 (Other)
    Security Status: 0x01 (Other)

win2k8 guest:

  System Info: aosp-mirror#1
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "7.0"
    Serial: "9106-3420-9819-5495-1514-2075-48"
    UUID: undefined, but settable
    Wake-up: 0x06 (Power Switch)
  Board Info: aosp-mirror#2
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "7.0"
    Serial: "9106-3420-9819-5495-1514-2075-48"
  Chassis Info: aosp-mirror#3
    Manufacturer: "Microsoft Corporation"
    Version: "7.0"
    Serial: "9106-3420-9819-5495-1514-2075-48"
    Asset Tag: "7076-9522-6699-1042-9501-1785-77"
    Type: 0x03 (Desktop)
    Bootup State: 0x03 (Safe)
    Power Supply State: 0x03 (Safe)
    Thermal State: 0x01 (Other)
    Security Status: 0x01 (Other)

win2k12 guest:

  System Info: aosp-mirror#1
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "7.0"
    Serial: "8179-1954-0187-0085-3868-2270-14"
    UUID: undefined, but settable
    Wake-up: 0x06 (Power Switch)
  Board Info: aosp-mirror#2
    Manufacturer: "Microsoft Corporation"
    Product: "Virtual Machine"
    Version: "7.0"
    Serial: "8179-1954-0187-0085-3868-2270-14"
  Chassis Info: aosp-mirror#3
    Manufacturer: "Microsoft Corporation"
    Version: "7.0"
    Serial: "8179-1954-0187-0085-3868-2270-14"
    Asset Tag: "8374-0485-4557-6331-0620-5845-25"
    Type: 0x03 (Desktop)
    Bootup State: 0x03 (Safe)
    Power Supply State: 0x03 (Safe)
    Thermal State: 0x01 (Other)
    Security Status: 0x01 (Other)

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit 5370019 upstream.

bd_mutex and lo_ctl_mutex can be held in different order.

Path aosp-mirror#1:

blkdev_open
 blkdev_get
  __blkdev_get (hold bd_mutex)
   lo_open (hold lo_ctl_mutex)

Path aosp-mirror#2:

blkdev_ioctl
 lo_ioctl (hold lo_ctl_mutex)
  lo_set_capacity (hold bd_mutex)

Lockdep does not report it, because path aosp-mirror#2 actually holds a subclass of
lo_ctl_mutex.  This subclass seems creep into the code by mistake.  The
patch author actually just mentioned it in the changelog, see commit
f028f3b ("loop: fix circular locking in loop_clr_fd()"), also see:

	http://marc.info/?l=linux-kernel&m=123806169129727&w=2

Path aosp-mirror#2 hold bd_mutex to call bd_set_size(), I've protected it
with i_mutex in a previous patch, so drop bd_mutex at this site.

Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: M. Hindess <hindessm@uk.ibm.com>
Cc: Nikanth Karthikesan <knikanth@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit a1cbcaa upstream.

The sched_clock_remote() implementation has the following inatomicity
problem on 32bit systems when accessing the remote scd->clock, which
is a 64bit value.

CPU0			CPU1

sched_clock_local()	sched_clock_remote(CPU0)
...
			remote_clock = scd[CPU0]->clock
			    read_low32bit(scd[CPU0]->clock)
cmpxchg64(scd->clock,...)
			    read_high32bit(scd[CPU0]->clock)

While the update of scd->clock is using an atomic64 mechanism, the
readout on the remote cpu is not, which can cause completely bogus
readouts.

It is a quite rare problem, because it requires the update to hit the
narrow race window between the low/high readout and the update must go
across the 32bit boundary.

The resulting misbehaviour is, that CPU1 will see the sched_clock on
CPU1 ~4 seconds ahead of it's own and update CPU1s sched_clock value
to this bogus timestamp. This stays that way due to the clamping
implementation for about 4 seconds until the synchronization with
CLOCK_MONOTONIC undoes the problem.

The issue is hard to observe, because it might only result in a less
accurate SCHED_OTHER timeslicing behaviour. To create observable
damage on realtime scheduling classes, it is necessary that the bogus
update of CPU1 sched_clock happens in the context of an realtime
thread, which then gets charged 4 seconds of RT runtime, which results
in the RT throttler mechanism to trigger and prevent scheduling of RT
tasks for a little less than 4 seconds. So this is quite unlikely as
well.

The issue was quite hard to decode as the reproduction time is between
2 days and 3 weeks and intrusive tracing makes it less likely, but the
following trace recorded with trace_clock=global, which uses
sched_clock_local(), gave the final hint:

  <idle>-0   0d..30 400269.477150: hrtimer_cancel: hrtimer=0xf7061e80
  <idle>-0   0d..30 400269.477151: hrtimer_start:  hrtimer=0xf7061e80 ...
irq/20-S-587 1d..32 400273.772118: sched_wakeup:   comm= ... target_cpu=0
  <idle>-0   0dN.30 400273.772118: hrtimer_cancel: hrtimer=0xf7061e80

What happens is that CPU0 goes idle and invokes
sched_clock_idle_sleep_event() which invokes sched_clock_local() and
CPU1 runs a remote wakeup for CPU0 at the same time, which invokes
sched_remote_clock(). The time jump gets propagated to CPU0 via
sched_remote_clock() and stays stale on both cores for ~4 seconds.

There are only two other possibilities, which could cause a stale
sched clock:

1) ktime_get() which reads out CLOCK_MONOTONIC returns a sporadic
   wrong value.

2) sched_clock() which reads the TSC returns a sporadic wrong value.

aosp-mirror#1 can be excluded because sched_clock would continue to increase for
   one jiffy and then go stale.

aosp-mirror#2 can be excluded because it would not make the clock jump
   forward. It would just result in a stale sched_clock for one jiffy.

After quite some brain twisting and finding the same pattern on other
traces, sched_clock_remote() remained the only place which could cause
such a problem and as explained above it's indeed racy on 32bit
systems.

So while on 64bit systems the readout is atomic, we need to verify the
remote readout on 32bit machines. We need to protect the local->clock
readout in sched_clock_remote() on 32bit as well because an NMI could
hit between the low and the high readout, call sched_clock_local() and
modify local->clock.

Thanks to Siegfried Wulsch for bearing with my debug requests and
going through the tedious tasks of running a bunch of reproducer
systems to generate the debug information which let me decode the
issue.

Reported-by: Siegfried Wulsch <Siegfried.Wulsch@rovema.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304051544160.21884@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit 734df5a upstream.

Currently when the child context for inherited events is
created, it's based on the pmu object of the first event
of the parent context.

This is wrong for the following scenario:

  - HW context having HW and SW event
  - HW event got removed (closed)
  - SW event stays in HW context as the only event
    and its pmu is used to clone the child context

The issue starts when the cpu context object is touched
based on the pmu context object (__get_cpu_context). In
this case the HW context will work with SW cpu context
ending up with following WARN below.

Fixing this by using parent context pmu object to clone
from child context.

Addresses the following warning reported by Vince Weaver:

[ 2716.472065] ------------[ cut here ]------------
[ 2716.476035] WARNING: at kernel/events/core.c:2122 task_ctx_sched_out+0x3c/0x)
[ 2716.476035] Modules linked in: nfsd auth_rpcgss oid_registry nfs_acl nfs locn
[ 2716.476035] CPU: 0 PID: 3164 Comm: perf_fuzzer Not tainted 3.10.0-rc4 aosp-mirror#2
[ 2716.476035] Hardware name: AOpen   DE7000/nMCP7ALPx-DE R1.06 Oct.19.2012, BI2
[ 2716.476035]  0000000000000000 ffffffff8102e215 0000000000000000 ffff88011fc18
[ 2716.476035]  ffff8801175557f0 0000000000000000 ffff880119fda88c ffffffff810ad
[ 2716.476035]  ffff880119fda880 ffffffff810af02a 0000000000000009 ffff880117550
[ 2716.476035] Call Trace:
[ 2716.476035]  [<ffffffff8102e215>] ? warn_slowpath_common+0x5b/0x70
[ 2716.476035]  [<ffffffff810ab2bd>] ? task_ctx_sched_out+0x3c/0x5f
[ 2716.476035]  [<ffffffff810af02a>] ? perf_event_exit_task+0xbf/0x194
[ 2716.476035]  [<ffffffff81032a37>] ? do_exit+0x3e7/0x90c
[ 2716.476035]  [<ffffffff810cd5ab>] ? __do_fault+0x359/0x394
[ 2716.476035]  [<ffffffff81032fe6>] ? do_group_exit+0x66/0x98
[ 2716.476035]  [<ffffffff8103dbcd>] ? get_signal_to_deliver+0x479/0x4ad
[ 2716.476035]  [<ffffffff810ac05c>] ? __perf_event_task_sched_out+0x230/0x2d1
[ 2716.476035]  [<ffffffff8100205d>] ? do_signal+0x3c/0x432
[ 2716.476035]  [<ffffffff810abbf9>] ? ctx_sched_in+0x43/0x141
[ 2716.476035]  [<ffffffff810ac2ca>] ? perf_event_context_sched_in+0x7a/0x90
[ 2716.476035]  [<ffffffff810ac311>] ? __perf_event_task_sched_in+0x31/0x118
[ 2716.476035]  [<ffffffff81050dd9>] ? mmdrop+0xd/0x1c
[ 2716.476035]  [<ffffffff81051a39>] ? finish_task_switch+0x7d/0xa6
[ 2716.476035]  [<ffffffff81002473>] ? do_notify_resume+0x20/0x5d
[ 2716.476035]  [<ffffffff813654f5>] ? retint_signal+0x3d/0x78
[ 2716.476035] ---[ end trace 827178d8a5966c3d ]---

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1373384651-6109-1-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit 058ebd0 upstream.

Jiri managed to trigger this warning:

 [] ======================================================
 [] [ INFO: possible circular locking dependency detected ]
 [] 3.10.0+ #228 Tainted: G        W
 [] -------------------------------------------------------
 [] p/6613 is trying to acquire lock:
 []  (rcu_node_0){..-...}, at: [<ffffffff810ca797>] rcu_read_unlock_special+0xa7/0x250
 []
 [] but task is already holding lock:
 []  (&ctx->lock){-.-...}, at: [<ffffffff810f2879>] perf_lock_task_context+0xd9/0x2c0
 []
 [] which lock already depends on the new lock.
 []
 [] the existing dependency chain (in reverse order) is:
 []
 [] -> aosp-mirror#4 (&ctx->lock){-.-...}:
 [] -> aosp-mirror#3 (&rq->lock){-.-.-.}:
 [] -> aosp-mirror#2 (&p->pi_lock){-.-.-.}:
 [] -> aosp-mirror#1 (&rnp->nocb_gp_wq[1]){......}:
 [] -> #0 (rcu_node_0){..-...}:

Paul was quick to explain that due to preemptible RCU we cannot call
rcu_read_unlock() while holding scheduler (or nested) locks when part
of the read side critical section was preemptible.

Therefore solve it by making the entire RCU read side non-preemptible.

Also pull out the retry from under the non-preempt to play nice with RT.

Reported-by: Jiri Olsa <jolsa@redhat.com>
Helped-out-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit 9edf7d7 upstream.

Commit 64deb6e
"[SCSI] zfcp: Use status_read_buf_num provided by FCP channel"
started using a value returned by the channel but only evaluated the value
if the fabric link is up.
Commit 8d88cf3
"[SCSI] zfcp: Update status read mempool"
introduced mempool resizings based on the above value.
On setting an FCP device online for the very first time since boot, a new
zeroed adapter object is allocated. If the link is down, the number of
status read requests remains zero. Since just the config data exchange is
incomplete, we proceed with adapter open recovery. However, we
unconditionally call mempool_resize with adapter->stat_read_buf_num == 0 in
this case.

This causes a kernel message "kernel BUG at mm/mempool.c:131!" in process
"zfcperp<FCP-device-bus-ID>" with last function mempool_resize in Krnl PSW
and zfcp_erp_thread in the Call Trace.

Don't evaluate channel values which are invalid on link down. The number of
status read requests is always valid, evaluated, and set to a positive
minimum greater than zero. The adapter open recovery can proceed and the
channel has status read buffers to inform us on a future link up event.
While we are not aware of any other code path that could result in mempool
resize attempts of size zero, we still also initialize the number of status
read buffers to be posted to a static minimum number on adapter object
allocation.

Backported for 3.4-stable. commit a53c8fa since v3.6-rc1 unified
copyright messages, e.g: revise such messages 'Copyright IBM Corporation'
as 'Copyright IBM Corp', so updated the messages as a53c8fa did.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> aosp-mirror#2.6.35+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Zhouping Liu <zliu@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit ea3768b upstream.

We used to keep the port's char device structs and the /sys entries
around till the last reference to the port was dropped.  This is
actually unnecessary, and resulted in buggy behaviour:

1. Open port in guest
2. Hot-unplug port
3. Hot-plug a port with the same 'name' property as the unplugged one

This resulted in hot-plug being unsuccessful, as a port with the same
name already exists (even though it was unplugged).

This behaviour resulted in a warning message like this one:

-------------------8<---------------------------------------
WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted)
Hardware name: KVM
sysfs: cannot create duplicate filename
'/devices/pci0000:00/0000:00:04.0/virtio0/virtio-ports/vport0p1'

Call Trace:
 [<ffffffff8106b607>] ? warn_slowpath_common+0x87/0xc0
 [<ffffffff8106b6f6>] ? warn_slowpath_fmt+0x46/0x50
 [<ffffffff811f2319>] ? sysfs_add_one+0xc9/0x130
 [<ffffffff811f23e8>] ? create_dir+0x68/0xb0
 [<ffffffff811f2469>] ? sysfs_create_dir+0x39/0x50
 [<ffffffff81273129>] ? kobject_add_internal+0xb9/0x260
 [<ffffffff812733d8>] ? kobject_add_varg+0x38/0x60
 [<ffffffff812734b4>] ? kobject_add+0x44/0x70
 [<ffffffff81349de4>] ? get_device_parent+0xf4/0x1d0
 [<ffffffff8134b389>] ? device_add+0xc9/0x650

-------------------8<---------------------------------------

Instead of relying on guest applications to release all references to
the ports, we should go ahead and unregister the port from all the core
layers.  Any open/read calls on the port will then just return errors,
and an unplug/plug operation on the host will succeed as expected.

This also caused buggy behaviour in case of the device removal (not just
a port): when the device was removed (which means all ports on that
device are removed automatically as well), the ports with active
users would clean up only when the last references were dropped -- and
it would be too late then to be referencing char device pointers,
resulting in oopses:

-------------------8<---------------------------------------
PID: 6162   TASK: ffff8801147ad500  CPU: 0   COMMAND: "cat"
 #0 [ffff88011b9d5a90] machine_kexec at ffffffff8103232b
 aosp-mirror#1 [ffff88011b9d5af0] crash_kexec at ffffffff810b9322
 aosp-mirror#2 [ffff88011b9d5bc0] oops_end at ffffffff814f4a50
 aosp-mirror#3 [ffff88011b9d5bf0] die at ffffffff8100f26b
 aosp-mirror#4 [ffff88011b9d5c20] do_general_protection at ffffffff814f45e2
 aosp-mirror#5 [ffff88011b9d5c50] general_protection at ffffffff814f3db5
    [exception RIP: strlen+2]
    RIP: ffffffff81272ae2  RSP: ffff88011b9d5d00  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff880118901c18  RCX: 0000000000000000
    RDX: ffff88011799982c  RSI: 00000000000000d0  RDI: 3a303030302f3030
    RBP: ffff88011b9d5d38   R8: 0000000000000006   R9: ffffffffa0134500
    R10: 0000000000001000  R11: 0000000000001000  R12: ffff880117a1cc10
    R13: 00000000000000d0  R14: 0000000000000017  R15: ffffffff81aff700
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 aosp-mirror#6 [ffff88011b9d5d00] kobject_get_path at ffffffff8126dc5d
 aosp-mirror#7 [ffff88011b9d5d40] kobject_uevent_env at ffffffff8126e551
 aosp-mirror#8 [ffff88011b9d5dd0] kobject_uevent at ffffffff8126e9eb
 aosp-mirror#9 [ffff88011b9d5de0] device_del at ffffffff813440c7

-------------------8<---------------------------------------

So clean up when we have all the context, and all that's left to do when
the references to the port have dropped is to free up the port struct
itself.

Reported-by: chayang <chayang@redhat.com>
Reported-by: YOGANANTH SUBRAMANIAN <anantyog@in.ibm.com>
Reported-by: FuXiangChun <xfu@redhat.com>
Reported-by: Qunfang Zhang <qzhang@redhat.com>
Reported-by: Sibiao Luo <sluo@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
poondog pushed a commit to poondog/kernel_msm that referenced this pull request Nov 19, 2014
commit 06a8566 upstream.

This patch fixes the issues indicated by the test results that
ipmi_msg_handler() is invoked in atomic context.

BUG: scheduling while atomic: kipmi0/18933/0x10000100
Modules linked in: ipmi_si acpi_ipmi ...
CPU: 3 PID: 18933 Comm: kipmi0 Tainted: G       AW    3.10.0-rc7+ aosp-mirror#2
Hardware name: QCI QSSC-S4R/QSSC-S4R, BIOS QSSC-S4R.QCI.01.00.0027.070120100606 07/01/2010
 ffff8838245eea00 ffff88103fc63c98 ffffffff814c4a1e ffff88103fc63ca8
 ffffffff814bfbab ffff88103fc63d28 ffffffff814c73e0 ffff88103933cbd4
 0000000000000096 ffff88103fc63ce8 ffff88102f618000 ffff881035c01fd8
Call Trace:
 <IRQ>  [<ffffffff814c4a1e>] dump_stack+0x19/0x1b
 [<ffffffff814bfbab>] __schedule_bug+0x46/0x54
 [<ffffffff814c73e0>] __schedule+0x83/0x59c
 [<ffffffff81058853>] __cond_resched+0x22/0x2d
 [<ffffffff814c794b>] _cond_resched+0x14/0x1d
 [<ffffffff814c6d82>] mutex_lock+0x11/0x32
 [<ffffffff8101e1e9>] ? __default_send_IPI_dest_field.constprop.0+0x53/0x58
 [<ffffffffa09e3f9c>] ipmi_msg_handler+0x23/0x166 [ipmi_si]
 [<ffffffff812bf6e4>] deliver_response+0x55/0x5a
 [<ffffffff812c0fd4>] handle_new_recv_msgs+0xb67/0xc65
 [<ffffffff81007ad1>] ? read_tsc+0x9/0x19
 [<ffffffff814c8620>] ? _raw_spin_lock_irq+0xa/0xc
 [<ffffffffa09e1128>] ipmi_thread+0x5c/0x146 [ipmi_si]
 ...

Also Tony Camuso says:

 We were getting occasional "Scheduling while atomic" call traces
 during boot on some systems. Problem was first seen on a Cisco C210
 but we were able to reproduce it on a Cisco c220m3. Setting
 CONFIG_LOCKDEP and LOCKDEP_SUPPORT to 'y' exposed a lockdep around
 tx_msg_lock in acpi_ipmi.c struct acpi_ipmi_device.

 =================================
 [ INFO: inconsistent lock state ]
 2.6.32-415.el6.x86_64-debug-splck aosp-mirror#1
 ---------------------------------
 inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
 ksoftirqd/3/17 [HC0[0]:SC1[1]:HE1:SE0] takes:
  (&ipmi_device->tx_msg_lock){+.?...}, at: [<ffffffff81337a27>] ipmi_msg_handler+0x71/0x126
 {SOFTIRQ-ON-W} state was registered at:
   [<ffffffff810ba11c>] __lock_acquire+0x63c/0x1570
   [<ffffffff810bb0f4>] lock_acquire+0xa4/0x120
   [<ffffffff815581cc>] __mutex_lock_common+0x4c/0x400
   [<ffffffff815586ea>] mutex_lock_nested+0x4a/0x60
   [<ffffffff8133789d>] acpi_ipmi_space_handler+0x11b/0x234
   [<ffffffff81321c62>] acpi_ev_address_space_dispatch+0x170/0x1be

The fix implemented by this change has been tested by Tony:

 Tested the patch in a boot loop with lockdep debug enabled and never
 saw the problem in over 400 reboots.

Reported-and-tested-by: Tony Camuso <tcamuso@redhat.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Reviewed-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request Feb 22, 2019
commit d5afb6f upstream.

The code where sk_clone() came from created a new socket and locked it,
but then, on the error path didn't unlock it.

This problem stayed there for a long while, till b0691c8 ("net:
Unlock sock before calling sk_free()") fixed it, but unfortunately the
callers of sk_clone() (now sk_clone_locked()) were not audited and the
one in dccp_create_openreq_child() remained.

Now in the age of the syskaller fuzzer, this was finally uncovered, as
reported by Dmitry:

 ---- 8< ----

I've got the following report while running syzkaller fuzzer on
86292b3 ("Merge branch 'akpm' (patches from Andrew)")

  [ BUG: held lock freed! ]
  4.10.0+ #234 Not tainted
  -------------------------
  syz-executor6/6898 is freeing memory
  ffff88006286cac0-ffff88006286d3b7, with a lock still held there!
   (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock
  include/linux/spinlock.h:299 [inline]
   (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>]
  sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504
  5 locks held by syz-executor6/6898:
   #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] lock_sock
  include/net/sock.h:1460 [inline]
   #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>]
  inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681
   aosp-mirror#1:  (rcu_read_lock){......}, at: [<ffffffff83bc1c2a>]
  inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126
   aosp-mirror#2:  (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_unlink
  include/linux/skbuff.h:1767 [inline]
   aosp-mirror#2:  (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_dequeue
  include/linux/skbuff.h:1783 [inline]
   aosp-mirror#2:  (rcu_read_lock){......}, at: [<ffffffff8369b424>]
  process_backlog+0x264/0x730 net/core/dev.c:4835
   aosp-mirror#3:  (rcu_read_lock){......}, at: [<ffffffff83aeb5c0>]
  ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59
   aosp-mirror#4:  (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock
  include/linux/spinlock.h:299 [inline]
   aosp-mirror#4:  (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>]
  sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504

Fix it just like was done by b0691c8 ("net: Unlock sock before calling
sk_free()").

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170301153510.GE15145@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request Feb 22, 2019
commit 71b8e45 upstream.

Since commit db007fc ("[SCSI] Command protection operation"),
scsi_eh_prep_cmnd() saves scmd->prot_op and temporarily resets it to
SCSI_PROT_NORMAL.
Other FCP LLDDs such as qla2xxx and lpfc shield their queuecommand()
to only access any of scsi_prot_sg...() if
(scsi_get_prot_op(cmd) != SCSI_PROT_NORMAL).

Do the same thing for zfcp, which introduced DIX support with
commit ef3eb71 ("[SCSI] zfcp: Introduce experimental support for
DIF/DIX").

Otherwise, TUR SCSI commands as part of scsi_eh likely fail in zfcp,
because the regular SCSI command with DIX protection data, that scsi_eh
re-uses in scsi_send_eh_cmnd(), of course still has
(scsi_prot_sg_count() != 0) and so zfcp sends down bogus requests to the
FCP channel hardware.

This causes scsi_eh_test_devices() to have (finish_cmds == 0)
[not SCSI device is online or not scsi_eh_tur() failed]
so regular SCSI commands, that caused / were affected by scsi_eh,
are moved to work_q and scsi_eh_test_devices() itself returns false.
In turn, it unnecessarily escalates in our case in scsi_eh_ready_devs()
beyond host reset to finally scsi_eh_offline_sdevs()
which sets affected SCSI devices offline with the following kernel message:

"kernel: sd H:0:T:L: Device offlined - not ready after error recovery"

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: ef3eb71 ("[SCSI] zfcp: Introduce experimental support for DIF/DIX")
Cc: <stable@vger.kernel.org> aosp-mirror#2.6.36+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request Feb 22, 2019
commit a099b7b upstream.

Up until now zfcp would just ignore the FCP_RESID_OVER flag in the FCP
response IU. When this flag is set, it is possible, in regards to the
FCP standard, that the storage-server processes the command normally, up
to the point where data is missing and simply ignores those.

In this case no CHECK CONDITION would be set, and because we ignored the
FCP_RESID_OVER flag we resulted in at least a data loss or even
-corruption as a follow-up error, depending on how the
applications/layers on top behave. To prevent this, we now set the
host-byte of the corresponding scsi_cmnd to DID_ERROR.

Other storage-behaviors, where the same condition results in a CHECK
CONDITION set in the answer, don't need to be changed as they are
handled in the mid-layer already.

Following is an example trace record decoded with zfcpdbf from the
s390-tools package. We forcefully injected a fc_dl which is one byte too
small:

Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 3
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : rsl_err
Request ID     : 0x...
SCSI ID        : 0x...
SCSI LUN       : 0x...
SCSI result    : 0x00070000
                     ^^DID_ERROR
SCSI retries   : 0x..
SCSI allowed   : 0x..
SCSI scribble  : 0x...
SCSI opcode    : 2a000000 00000000 08000000 00000000
FCP rsp inf cod: 0x00
FCP rsp IU     : 00000000 00000000 00000400 00000001
                                       ^^fr_flags==FCP_RESID_OVER
                                         ^^fr_status==SAM_STAT_GOOD
                                            ^^^^^^^^fr_resid
                 00000000 00000000

As of now, we don't actively handle to possibility that a response IU
has both flags - FCP_RESID_OVER and FCP_RESID_UNDER - set at once.

Reported-by: Luke M. Hopkins <lmhopkin@us.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 553448f ("[SCSI] zfcp: Message cleanup")
Fixes: ea127f975424 ("[PATCH] s390 (7/7): zfcp host adapter.") (tglx/history.git)
Cc: <stable@vger.kernel.org> aosp-mirror#2.6.33+
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request Feb 22, 2019
…dlers

commit 1a5d999 upstream.

For problem determination we need to see that we were in scsi_eh
as well as whether and why we were successful or not.

The following commits introduced new early returns without adding
a trace record:

v2.6.35 commit a1dbfdd
("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
on fc_block_scsi_eh() returning != 0 which is FAST_IO_FAIL,

v2.6.30 commit 63caf36
("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp")
on not having gotten an FSF request after the maximum number of retry
attempts and thus could not issue a TMF and has to return FAILED.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: a1dbfdd ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
Fixes: 63caf36 ("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp")
Cc: <stable@vger.kernel.org> aosp-mirror#2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request Feb 22, 2019
commit 12c3e57 upstream.

If the FCP_RSP UI has optional parts (FCP_SNS_INFO or FCP_RSP_INFO) and
thus does not fit into the fsp_rsp field built into a SCSI trace record,
trace the full FCP_RSP UI with all optional parts as payload record
instead of just FCP_SNS_INFO as payload and
a 1 byte RSP_INFO_CODE part of FCP_RSP_INFO built into the SCSI record.

That way we would also get the full FCP_SNS_INFO in case a
target would ever send more than
min(SCSI_SENSE_BUFFERSIZE==96, ZFCP_DBF_PAY_MAX_REC==256)==96.

The mandatory part of FCP_RSP IU is only 24 bytes.
PAYload costs at least one full PAY record of 256 bytes anyway.
We cap to the hardware response size which is only FSF_FCP_RSP_SIZE==128.
So we can just put the whole FCP_RSP IU with any optional parts into
PAYload similarly as we do for SAN PAY since v4.9 commit aceeffb
("zfcp: trace full payload of all SAN records (req,resp,iels)").
This does not cause any additional trace records wasting memory.

Decoded trace records were confusing because they showed a hard-coded
sense data length of 96 even if the FCP_RSP_IU field FCP_SNS_LEN showed
actually less.

Since the same commit, we set pl_len for SAN traces to the full length of a
request/response even if we cap the corresponding trace.
In contrast, here for SCSI traces we set pl_len to the pre-computed
length of FCP_RSP IU considering SNS_LEN or RSP_LEN if valid.
Nonetheless we trace a hardcoded payload of length FSF_FCP_RSP_SIZE==128
if there were optional parts.
This makes it easier for the zfcpdbf tool to format only the relevant
part of the long FCP_RSP UI buffer. And any trailing information is still
available in the payload trace record just in case.

Rename the payload record tag from "fcp_sns" to "fcp_riu" to make the new
content explicit to zfcpdbf which can then pick a suitable field name such
as "FCP rsp IU all:" instead of "Sense info :"
Also, the same zfcpdbf can still be backwards compatible with "fcp_sns".

Old example trace record before this fix, formatted with the tool zfcpdbf
from s390-tools:

Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 3
Exception      : -
CPU id         : ..
Caller         : 0x...
Record id      : 1
Tag            : rsl_err
Request id     : 0x<request_id>
SCSI ID        : 0x...
SCSI LUN       : 0x...
SCSI result    : 0x00000002
SCSI retries   : 0x00
SCSI allowed   : 0x05
SCSI scribble  : 0x<request_id>
SCSI opcode    : 00000000 00000000 00000000 00000000
FCP rsp inf cod: 0x00
FCP rsp IU     : 00000000 00000000 00000202 00000000
                                       ^^==FCP_SNS_LEN_VALID
                 00000020 00000000
                 ^^^^^^^^==FCP_SNS_LEN==32
Sense len      : 96 <==min(SCSI_SENSE_BUFFERSIZE,ZFCP_DBF_PAY_MAX_REC)
Sense info     : 70000600 00000018 00000000 29000000
                 00000400 00000000 00000000 00000000
                 00000000 00000000 00000000 00000000<==superfluous
                 00000000 00000000 00000000 00000000<==superfluous
                 00000000 00000000 00000000 00000000<==superfluous
                 00000000 00000000 00000000 00000000<==superfluous

New example trace records with this fix:

Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 3
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : rsl_err
Request ID     : 0x<request_id>
SCSI ID        : 0x...
SCSI LUN       : 0x...
SCSI result    : 0x00000002
SCSI retries   : 0x00
SCSI allowed   : 0x03
SCSI scribble  : 0x<request_id>
SCSI opcode    : a30c0112 00000000 02000000 00000000
FCP rsp inf cod: 0x00
FCP rsp IU     : 00000000 00000000 00000a02 00000200
                 00000020 00000000
FCP rsp IU len : 56
FCP rsp IU all : 00000000 00000000 00000a02 00000200
                                       ^^=FCP_RESID_UNDER|FCP_SNS_LEN_VALID
                 00000020 00000000 70000500 00000018
                 ^^^^^^^^==FCP_SNS_LEN
                                   ^^^^^^^^^^^^^^^^^
                 00000000 240000cb 00011100 00000000
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                 00000000 00000000
                 ^^^^^^^^^^^^^^^^^==FCP_SNS_INFO

Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : lr_okay
Request ID     : 0x<request_id>
SCSI ID        : 0x...
SCSI LUN       : 0x...
SCSI result    : 0x00000000
SCSI retries   : 0x00
SCSI allowed   : 0x05
SCSI scribble  : 0x<request_id>
SCSI opcode    : <CDB of unrelated SCSI command passed to eh handler>
FCP rsp inf cod: 0x00
FCP rsp IU     : 00000000 00000000 00000100 00000000
                 00000000 00000008
FCP rsp IU len : 32
FCP rsp IU all : 00000000 00000000 00000100 00000000
                                       ^^==FCP_RSP_LEN_VALID
                 00000000 00000008 00000000 00000000
                          ^^^^^^^^==FCP_RSP_LEN
                                   ^^^^^^^^^^^^^^^^^==FCP_RSP_INFO

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 250a135 ("[SCSI] zfcp: Redesign of the debug tracing for SCSI records.")
Cc: <stable@vger.kernel.org> aosp-mirror#2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request Feb 22, 2019
…late response

commit fdb7cee upstream.

At the default trace level, we only trace unsuccessful events including
FSF responses.

zfcp_dbf_hba_fsf_response() only used protocol status and FSF status to
decide on an unsuccessful response. However, this is only one of multiple
possible sources determining a failed struct zfcp_fsf_req.

An FSF request can also "fail" if its response runs into an ERP timeout
or if it gets dismissed because a higher level recovery was triggered
[trace tags "erscf_1" or "erscf_2" in zfcp_erp_strategy_check_fsfreq()].
FSF requests with ERP timeout are:
FSF_QTCB_EXCHANGE_CONFIG_DATA, FSF_QTCB_EXCHANGE_PORT_DATA,
FSF_QTCB_OPEN_PORT_WITH_DID or FSF_QTCB_CLOSE_PORT or
FSF_QTCB_CLOSE_PHYSICAL_PORT for target ports,
FSF_QTCB_OPEN_LUN, FSF_QTCB_CLOSE_LUN.
One example is slow queue processing which can cause follow-on errors,
e.g. FSF_PORT_ALREADY_OPEN after FSF_QTCB_OPEN_PORT_WITH_DID timed out.
In order to see the root cause, we need to see late responses even if the
channel presented them successfully with FSF_PROT_GOOD and FSF_GOOD.
Example trace records formatted with zfcpdbf from the s390-tools package:

Timestamp      : ...
Area           : REC
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : ...
Record ID      : 1
Tag            : fcegpf1
LUN            : 0xffffffffffffffff
WWPN           : 0x<WWPN>
D_ID           : 0x00<D_ID>
Adapter status : 0x5400050b
Port status    : 0x41200000
LUN status     : 0x00000000
Ready count    : 0x00000001
Running count  : 0x...
ERP want       : 0x02				ZFCP_ERP_ACTION_REOPEN_PORT
ERP need       : 0x02				ZFCP_ERP_ACTION_REOPEN_PORT
|
Timestamp      : ...				30 seconds later
Area           : REC
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : ...
Record ID      : 2
Tag            : erscf_2
LUN            : 0xffffffffffffffff
WWPN           : 0x<WWPN>
D_ID           : 0x00<D_ID>
Adapter status : 0x5400050b
Port status    : 0x41200000
LUN status     : 0x00000000
Request ID     : 0x<request_ID>
ERP status     : 0x10000000			ZFCP_STATUS_ERP_TIMEDOUT
ERP step       : 0x0800				ZFCP_ERP_STEP_PORT_OPENING
ERP action     : 0x02				ZFCP_ERP_ACTION_REOPEN_PORT
ERP count      : 0x00
|
Timestamp      : ...				later than previous record
Area           : HBA
Subarea        : 00
Level          : 5	> default level		=> 3	<= default level
Exception      : -
CPU ID         : 00
Caller         : ...
Record ID      : 1
Tag            : fs_qtcb			=> fs_rerr
Request ID     : 0x<request_ID>
Request status : 0x00001010			ZFCP_STATUS_FSFREQ_DISMISSED
						| ZFCP_STATUS_FSFREQ_CLEANUP
FSF cmnd       : 0x00000005
FSF sequence no: 0x...
FSF issued     : ...				> 30 seconds ago
FSF stat       : 0x00000000			FSF_GOOD
FSF stat qual  : 00000000 00000000 00000000 00000000
Prot stat      : 0x00000001			FSF_PROT_GOOD
Prot stat qual : 00000000 00000000 00000000 00000000
Port handle    : 0x...
LUN handle     : 0x00000000
QTCB log length: ...
QTCB log info  : ...

In case of problems detecting that new responses are waiting on the input
queue, we sooner or later trigger adapter recovery due to an FSF request
timeout (trace tag "fsrth_1").
FSF requests with FSF request timeout are:
typically FSF_QTCB_ABORT_FCP_CMND; but theoretically also
FSF_QTCB_EXCHANGE_CONFIG_DATA or FSF_QTCB_EXCHANGE_PORT_DATA via sysfs,
FSF_QTCB_OPEN_PORT_WITH_DID or FSF_QTCB_CLOSE_PORT for WKA ports,
FSF_QTCB_FCP_CMND for task management function (LUN / target reset).
One or more pending requests can meanwhile have FSF_PROT_GOOD and FSF_GOOD
because the channel filled in the response via DMA into the request's QTCB.

In a theroretical case, inject code can create an erroneous FSF request
on purpose. If data router is enabled, it uses deferred error reporting.
A READ SCSI command can succeed with FSF_PROT_GOOD, FSF_GOOD, and
SAM_STAT_GOOD. But on writing the read data to host memory via DMA,
it can still fail, e.g. if an intentionally wrong scatter list does not
provide enough space. Rather than getting an unsuccessful response,
we get a QDIO activate check which in turn triggers adapter recovery.
One or more pending requests can meanwhile have FSF_PROT_GOOD and FSF_GOOD
because the channel filled in the response via DMA into the request's QTCB.
Example trace records formatted with zfcpdbf from the s390-tools package:

Timestamp      : ...
Area           : HBA
Subarea        : 00
Level          : 6	> default level		=> 3	<= default level
Exception      : -
CPU ID         : ..
Caller         : ...
Record ID      : 1
Tag            : fs_norm			=> fs_rerr
Request ID     : 0x<request_ID2>
Request status : 0x00001010			ZFCP_STATUS_FSFREQ_DISMISSED
						| ZFCP_STATUS_FSFREQ_CLEANUP
FSF cmnd       : 0x00000001
FSF sequence no: 0x...
FSF issued     : ...
FSF stat       : 0x00000000			FSF_GOOD
FSF stat qual  : 00000000 00000000 00000000 00000000
Prot stat      : 0x00000001			FSF_PROT_GOOD
Prot stat qual : ........ ........ 00000000 00000000
Port handle    : 0x...
LUN handle     : 0x...
|
Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 3
Exception      : -
CPU ID         : ..
Caller         : ...
Record ID      : 1
Tag            : rsl_err
Request ID     : 0x<request_ID2>
SCSI ID        : 0x...
SCSI LUN       : 0x...
SCSI result    : 0x000e0000			DID_TRANSPORT_DISRUPTED
SCSI retries   : 0x00
SCSI allowed   : 0x05
SCSI scribble  : 0x<request_ID2>
SCSI opcode    : 28...				Read(10)
FCP rsp inf cod: 0x00
FCP rsp IU     : 00000000 00000000 00000000 00000000
                                         ^^	SAM_STAT_GOOD
                 00000000 00000000

Only with luck in both above cases, we could see a follow-on trace record
of an unsuccesful event following a successful but late FSF response with
FSF_PROT_GOOD and FSF_GOOD. Typically this was the case for I/O requests
resulting in a SCSI trace record "rsl_err" with DID_TRANSPORT_DISRUPTED
[On ZFCP_STATUS_FSFREQ_DISMISSED, zfcp_fsf_protstatus_eval() sets
ZFCP_STATUS_FSFREQ_ERROR seen by the request handler functions as failure].
However, the reason for this follow-on trace was invisible because the
corresponding HBA trace record was missing at the default trace level
(by default hidden records with tags "fs_norm", "fs_qtcb", or "fs_open").

On adapter recovery, after we had shut down the QDIO queues, we perform
unsuccessful pseudo completions with flag ZFCP_STATUS_FSFREQ_DISMISSED
for each pending FSF request in zfcp_fsf_req_dismiss_all().
In order to find the root cause, we need to see all pseudo responses even
if the channel presented them successfully with FSF_PROT_GOOD and FSF_GOOD.

Therefore, check zfcp_fsf_req.status for ZFCP_STATUS_FSFREQ_DISMISSED
or ZFCP_STATUS_FSFREQ_ERROR and trace with a new tag "fs_rerr".

It does not matter that there are numerous places which set
ZFCP_STATUS_FSFREQ_ERROR after the location where we trace an FSF response
early. These cases are based on protocol status != FSF_PROT_GOOD or
== FSF_PROT_FSF_STATUS_PRESENTED and are thus already traced by default
as trace tag "fs_perr" or "fs_ferr" respectively.

NB: The trace record with tag "fssrh_1" for status read buffers on dismiss
all remains. zfcp_fsf_req_complete() handles this and returns early.
All other FSF request types are handled separately and as described above.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 8a36e45 ("[SCSI] zfcp: enhancement of zfcp debug features")
Fixes: 2e261af ("[SCSI] zfcp: Only collect FSF/HBA debug data for matching trace levels")
Cc: <stable@vger.kernel.org> aosp-mirror#2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request May 27, 2019
commit 0b462c8 upstream.

While a queue is being destroyed, all the blkgs are destroyed and its
->root_blkg pointer is set to NULL.  If someone else starts to drain
while the queue is in this state, the following oops happens.

  NULL pointer dereference at 0000000000000028
  IP: [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230
  PGD e4a1067 PUD b773067 PMD 0
  Oops: 0000 [aosp-mirror#1] PREEMPT SMP DEBUG_PAGEALLOC
  Modules linked in: cfq_iosched(-) [last unloaded: cfq_iosched]
  CPU: 1 PID: 537 Comm: bash Not tainted 3.16.0-rc3-work+ aosp-mirror#2
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff88000e222250 ti: ffff88000efd4000 task.ti: ffff88000efd4000
  RIP: 0010:[<ffffffff8144e944>]  [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230
  RSP: 0018:ffff88000efd7bf0  EFLAGS: 00010046
  RAX: 0000000000000000 RBX: ffff880015091450 RCX: 0000000000000001
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
  RBP: ffff88000efd7c10 R08: 0000000000000000 R09: 0000000000000001
  R10: ffff88000e222250 R11: 0000000000000000 R12: ffff880015091450
  R13: ffff880015092e00 R14: ffff880015091d70 R15: ffff88001508fc28
  FS:  00007f1332650740(0000) GS:ffff88001fa80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000000000000028 CR3: 0000000009446000 CR4: 00000000000006e0
  Stack:
   ffffffff8144e8f6 ffff880015091450 0000000000000000 ffff880015091d80
   ffff88000efd7c28 ffffffff8144ae2f ffff880015091450 ffff88000efd7c58
   ffffffff81427641 ffff880015091450 ffffffff82401f00 ffff880015091450
  Call Trace:
   [<ffffffff8144ae2f>] blkcg_drain_queue+0x1f/0x60
   [<ffffffff81427641>] __blk_drain_queue+0x71/0x180
   [<ffffffff81429b3e>] blk_queue_bypass_start+0x6e/0xb0
   [<ffffffff814498b8>] blkcg_deactivate_policy+0x38/0x120
   [<ffffffff8144ec44>] blk_throtl_exit+0x34/0x50
   [<ffffffff8144aea5>] blkcg_exit_queue+0x35/0x40
   [<ffffffff8142d476>] blk_release_queue+0x26/0xd0
   [<ffffffff81454968>] kobject_cleanup+0x38/0x70
   [<ffffffff81454848>] kobject_put+0x28/0x60
   [<ffffffff81427505>] blk_put_queue+0x15/0x20
   [<ffffffff817d07bb>] scsi_device_dev_release_usercontext+0x16b/0x1c0
   [<ffffffff810bc339>] execute_in_process_context+0x89/0xa0
   [<ffffffff817d064c>] scsi_device_dev_release+0x1c/0x20
   [<ffffffff817930e2>] device_release+0x32/0xa0
   [<ffffffff81454968>] kobject_cleanup+0x38/0x70
   [<ffffffff81454848>] kobject_put+0x28/0x60
   [<ffffffff817934d7>] put_device+0x17/0x20
   [<ffffffff817d11b9>] __scsi_remove_device+0xa9/0xe0
   [<ffffffff817d121b>] scsi_remove_device+0x2b/0x40
   [<ffffffff817d1257>] sdev_store_delete+0x27/0x30
   [<ffffffff81792ca8>] dev_attr_store+0x18/0x30
   [<ffffffff8126f75e>] sysfs_kf_write+0x3e/0x50
   [<ffffffff8126ea87>] kernfs_fop_write+0xe7/0x170
   [<ffffffff811f5e9f>] vfs_write+0xaf/0x1d0
   [<ffffffff811f69bd>] SyS_write+0x4d/0xc0
   [<ffffffff81d24692>] system_call_fastpath+0x16/0x1b

776687b ("block, blk-mq: draining can't be skipped even if
bypass_depth was non-zero") made it easier to trigger this bug by
making blk_queue_bypass_start() drain even when it loses the first
bypass test to blk_cleanup_queue(); however, the bug has always been
there even before the commit as blk_queue_bypass_start() could race
against queue destruction, win the initial bypass test but perform the
actual draining after blk_cleanup_queue() already destroyed all blkgs.

Fix it by skippping calling into policy draining if all the blkgs are
already gone.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Shirish Pargaonkar <spargaonkar@suse.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Reported-by: Jet Chen <jet.chen@intel.com>
Tested-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request May 27, 2019
commit 504d587 upstream.

clockevents_increase_min_delta() calls printk() from under
hrtimer_bases.lock. That causes lock inversion on scheduler locks because
printk() can call into the scheduler. Lockdep puts it as:

======================================================
[ INFO: possible circular locking dependency detected ]
3.15.0-rc8-06195-g939f04b aosp-mirror#2 Not tainted
-------------------------------------------------------
trinity-main/74 is trying to acquire lock:
 (&port_lock_key){-.....}, at: [<811c60be>] serial8250_console_write+0x8c/0x10c

but task is already holding lock:
 (hrtimer_bases.lock){-.-...}, at: [<8103caeb>] hrtimer_try_to_cancel+0x13/0x66

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> aosp-mirror#5 (hrtimer_bases.lock){-.-...}:
       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
       [<8103c918>] __hrtimer_start_range_ns+0x1c/0x197
       [<8107ec20>] perf_swevent_start_hrtimer.part.41+0x7a/0x85
       [<81080792>] task_clock_event_start+0x3a/0x3f
       [<810807a4>] task_clock_event_add+0xd/0x14
       [<8108259a>] event_sched_in+0xb6/0x17a
       [<810826a2>] group_sched_in+0x44/0x122
       [<81082885>] ctx_sched_in.isra.67+0x105/0x11f
       [<810828e6>] perf_event_sched_in.isra.70+0x47/0x4b
       [<81082bf6>] __perf_install_in_context+0x8b/0xa3
       [<8107eb8e>] remote_function+0x12/0x2a
       [<8105f5af>] smp_call_function_single+0x2d/0x53
       [<8107e17d>] task_function_call+0x30/0x36
       [<8107fb82>] perf_install_in_context+0x87/0xbb
       [<810852c9>] SYSC_perf_event_open+0x5c6/0x701
       [<810856f9>] SyS_perf_event_open+0x17/0x19
       [<8142f8ee>] syscall_call+0x7/0xb

-> aosp-mirror#4 (&ctx->lock){......}:
       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f04c>] _raw_spin_lock+0x21/0x30
       [<81081df3>] __perf_event_task_sched_out+0x1dc/0x34f
       [<8142cacc>] __schedule+0x4c6/0x4cb
       [<8142cae0>] schedule+0xf/0x11
       [<8142f9a6>] work_resched+0x5/0x30

-> aosp-mirror#3 (&rq->lock){-.-.-.}:
       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f04c>] _raw_spin_lock+0x21/0x30
       [<81040873>] __task_rq_lock+0x33/0x3a
       [<8104184c>] wake_up_new_task+0x25/0xc2
       [<8102474b>] do_fork+0x15c/0x2a0
       [<810248a9>] kernel_thread+0x1a/0x1f
       [<814232a2>] rest_init+0x1a/0x10e
       [<817af949>] start_kernel+0x303/0x308
       [<817af2ab>] i386_start_kernel+0x79/0x7d

-> aosp-mirror#2 (&p->pi_lock){-.-...}:
       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
       [<810413dd>] try_to_wake_up+0x1d/0xd6
       [<810414cd>] default_wake_function+0xb/0xd
       [<810461f3>] __wake_up_common+0x39/0x59
       [<81046346>] __wake_up+0x29/0x3b
       [<811b8733>] tty_wakeup+0x49/0x51
       [<811c3568>] uart_write_wakeup+0x17/0x19
       [<811c5dc1>] serial8250_tx_chars+0xbc/0xfb
       [<811c5f28>] serial8250_handle_irq+0x54/0x6a
       [<811c5f57>] serial8250_default_handle_irq+0x19/0x1c
       [<811c56d8>] serial8250_interrupt+0x38/0x9e
       [<810510e7>] handle_irq_event_percpu+0x5f/0x1e2
       [<81051296>] handle_irq_event+0x2c/0x43
       [<81052cee>] handle_level_irq+0x57/0x80
       [<81002a72>] handle_irq+0x46/0x5c
       [<810027df>] do_IRQ+0x32/0x89
       [<8143036e>] common_interrupt+0x2e/0x33
       [<8142f23c>] _raw_spin_unlock_irqrestore+0x3f/0x49
       [<811c25a4>] uart_start+0x2d/0x32
       [<811c2c04>] uart_write+0xc7/0xd6
       [<811bc6f6>] n_tty_write+0xb8/0x35e
       [<811b9beb>] tty_write+0x163/0x1e4
       [<811b9cd9>] redirected_tty_write+0x6d/0x75
       [<810b6ed6>] vfs_write+0x75/0xb0
       [<810b7265>] SyS_write+0x44/0x77
       [<8142f8ee>] syscall_call+0x7/0xb

-> aosp-mirror#1 (&tty->write_wait){-.....}:
       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
       [<81046332>] __wake_up+0x15/0x3b
       [<811b8733>] tty_wakeup+0x49/0x51
       [<811c3568>] uart_write_wakeup+0x17/0x19
       [<811c5dc1>] serial8250_tx_chars+0xbc/0xfb
       [<811c5f28>] serial8250_handle_irq+0x54/0x6a
       [<811c5f57>] serial8250_default_handle_irq+0x19/0x1c
       [<811c56d8>] serial8250_interrupt+0x38/0x9e
       [<810510e7>] handle_irq_event_percpu+0x5f/0x1e2
       [<81051296>] handle_irq_event+0x2c/0x43
       [<81052cee>] handle_level_irq+0x57/0x80
       [<81002a72>] handle_irq+0x46/0x5c
       [<810027df>] do_IRQ+0x32/0x89
       [<8143036e>] common_interrupt+0x2e/0x33
       [<8142f23c>] _raw_spin_unlock_irqrestore+0x3f/0x49
       [<811c25a4>] uart_start+0x2d/0x32
       [<811c2c04>] uart_write+0xc7/0xd6
       [<811bc6f6>] n_tty_write+0xb8/0x35e
       [<811b9beb>] tty_write+0x163/0x1e4
       [<811b9cd9>] redirected_tty_write+0x6d/0x75
       [<810b6ed6>] vfs_write+0x75/0xb0
       [<810b7265>] SyS_write+0x44/0x77
       [<8142f8ee>] syscall_call+0x7/0xb

-> #0 (&port_lock_key){-.....}:
       [<8104a62d>] __lock_acquire+0x9ea/0xc6d
       [<8104a942>] lock_acquire+0x92/0x101
       [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
       [<811c60be>] serial8250_console_write+0x8c/0x10c
       [<8104e402>] call_console_drivers.constprop.31+0x87/0x118
       [<8104f5d5>] console_unlock+0x1d7/0x398
       [<8104fb70>] vprintk_emit+0x3da/0x3e4
       [<81425f76>] printk+0x17/0x19
       [<8105bfa0>] clockevents_program_min_delta+0x104/0x116
       [<8105c548>] clockevents_program_event+0xe7/0xf3
       [<8105cc1c>] tick_program_event+0x1e/0x23
       [<8103c43c>] hrtimer_force_reprogram+0x88/0x8f
       [<8103c49e>] __remove_hrtimer+0x5b/0x79
       [<8103cb21>] hrtimer_try_to_cancel+0x49/0x66
       [<8103cb4b>] hrtimer_cancel+0xd/0x18
       [<8107f102>] perf_swevent_cancel_hrtimer.part.60+0x2b/0x30
       [<81080705>] task_clock_event_stop+0x20/0x64
       [<81080756>] task_clock_event_del+0xd/0xf
       [<81081350>] event_sched_out+0xab/0x11e
       [<810813e0>] group_sched_out+0x1d/0x66
       [<81081682>] ctx_sched_out+0xaf/0xbf
       [<81081e04>] __perf_event_task_sched_out+0x1ed/0x34f
       [<8142cacc>] __schedule+0x4c6/0x4cb
       [<8142cae0>] schedule+0xf/0x11
       [<8142f9a6>] work_resched+0x5/0x30

other info that might help us debug this:

Chain exists of:
  &port_lock_key --> &ctx->lock --> hrtimer_bases.lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(hrtimer_bases.lock);
                               lock(&ctx->lock);
                               lock(hrtimer_bases.lock);
  lock(&port_lock_key);

 *** DEADLOCK ***

4 locks held by trinity-main/74:
 #0:  (&rq->lock){-.-.-.}, at: [<8142c6f3>] __schedule+0xed/0x4cb
 aosp-mirror#1:  (&ctx->lock){......}, at: [<81081df3>] __perf_event_task_sched_out+0x1dc/0x34f
 aosp-mirror#2:  (hrtimer_bases.lock){-.-...}, at: [<8103caeb>] hrtimer_try_to_cancel+0x13/0x66
 aosp-mirror#3:  (console_lock){+.+...}, at: [<8104fb5d>] vprintk_emit+0x3c7/0x3e4

stack backtrace:
CPU: 0 PID: 74 Comm: trinity-main Not tainted 3.15.0-rc8-06195-g939f04b aosp-mirror#2
 00000000 81c3a310 8b995c14 81426f69 8b995c44 81425a99 8161f671 8161f570
 8161f538 8161f559 8161f538 8b995c78 8b142bb0 00000004 8b142fdc 8b142bb0
 8b995ca8 8104a62d 8b142fac 000016f2 81c3a310 00000001 00000001 00000003
Call Trace:
 [<81426f69>] dump_stack+0x16/0x18
 [<81425a99>] print_circular_bug+0x18f/0x19c
 [<8104a62d>] __lock_acquire+0x9ea/0xc6d
 [<8104a942>] lock_acquire+0x92/0x101
 [<811c60be>] ? serial8250_console_write+0x8c/0x10c
 [<811c6032>] ? wait_for_xmitr+0x76/0x76
 [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e
 [<811c60be>] ? serial8250_console_write+0x8c/0x10c
 [<811c60be>] serial8250_console_write+0x8c/0x10c
 [<8104af87>] ? lock_release+0x191/0x223
 [<811c6032>] ? wait_for_xmitr+0x76/0x76
 [<8104e402>] call_console_drivers.constprop.31+0x87/0x118
 [<8104f5d5>] console_unlock+0x1d7/0x398
 [<8104fb70>] vprintk_emit+0x3da/0x3e4
 [<81425f76>] printk+0x17/0x19
 [<8105bfa0>] clockevents_program_min_delta+0x104/0x116
 [<8105cc1c>] tick_program_event+0x1e/0x23
 [<8103c43c>] hrtimer_force_reprogram+0x88/0x8f
 [<8103c49e>] __remove_hrtimer+0x5b/0x79
 [<8103cb21>] hrtimer_try_to_cancel+0x49/0x66
 [<8103cb4b>] hrtimer_cancel+0xd/0x18
 [<8107f102>] perf_swevent_cancel_hrtimer.part.60+0x2b/0x30
 [<81080705>] task_clock_event_stop+0x20/0x64
 [<81080756>] task_clock_event_del+0xd/0xf
 [<81081350>] event_sched_out+0xab/0x11e
 [<810813e0>] group_sched_out+0x1d/0x66
 [<81081682>] ctx_sched_out+0xaf/0xbf
 [<81081e04>] __perf_event_task_sched_out+0x1ed/0x34f
 [<8104416d>] ? __dequeue_entity+0x23/0x27
 [<81044505>] ? pick_next_task_fair+0xb1/0x120
 [<8142cacc>] __schedule+0x4c6/0x4cb
 [<81047574>] ? trace_hardirqs_off_caller+0xd7/0x108
 [<810475b0>] ? trace_hardirqs_off+0xb/0xd
 [<81056346>] ? rcu_irq_exit+0x64/0x77

Fix the problem by using printk_deferred() which does not call into the
scheduler.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request May 27, 2019
commit 2a1b4cf upstream.

While a queue is being destroyed, all the blkgs are destroyed and its
->root_blkg pointer is set to NULL.  If someone else starts to drain
while the queue is in this state, the following oops happens.

  NULL pointer dereference at 0000000000000028
  IP: [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230
  PGD e4a1067 PUD b773067 PMD 0
  Oops: 0000 [aosp-mirror#1] PREEMPT SMP DEBUG_PAGEALLOC
  Modules linked in: cfq_iosched(-) [last unloaded: cfq_iosched]
  CPU: 1 PID: 537 Comm: bash Not tainted 3.16.0-rc3-work+ aosp-mirror#2
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff88000e222250 ti: ffff88000efd4000 task.ti: ffff88000efd4000
  RIP: 0010:[<ffffffff8144e944>]  [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230
  RSP: 0018:ffff88000efd7bf0  EFLAGS: 00010046
  RAX: 0000000000000000 RBX: ffff880015091450 RCX: 0000000000000001
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
  RBP: ffff88000efd7c10 R08: 0000000000000000 R09: 0000000000000001
  R10: ffff88000e222250 R11: 0000000000000000 R12: ffff880015091450
  R13: ffff880015092e00 R14: ffff880015091d70 R15: ffff88001508fc28
  FS:  00007f1332650740(0000) GS:ffff88001fa80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000000000000028 CR3: 0000000009446000 CR4: 00000000000006e0
  Stack:
   ffffffff8144e8f6 ffff880015091450 0000000000000000 ffff880015091d80
   ffff88000efd7c28 ffffffff8144ae2f ffff880015091450 ffff88000efd7c58
   ffffffff81427641 ffff880015091450 ffffffff82401f00 ffff880015091450
  Call Trace:
   [<ffffffff8144ae2f>] blkcg_drain_queue+0x1f/0x60
   [<ffffffff81427641>] __blk_drain_queue+0x71/0x180
   [<ffffffff81429b3e>] blk_queue_bypass_start+0x6e/0xb0
   [<ffffffff814498b8>] blkcg_deactivate_policy+0x38/0x120
   [<ffffffff8144ec44>] blk_throtl_exit+0x34/0x50
   [<ffffffff8144aea5>] blkcg_exit_queue+0x35/0x40
   [<ffffffff8142d476>] blk_release_queue+0x26/0xd0
   [<ffffffff81454968>] kobject_cleanup+0x38/0x70
   [<ffffffff81454848>] kobject_put+0x28/0x60
   [<ffffffff81427505>] blk_put_queue+0x15/0x20
   [<ffffffff817d07bb>] scsi_device_dev_release_usercontext+0x16b/0x1c0
   [<ffffffff810bc339>] execute_in_process_context+0x89/0xa0
   [<ffffffff817d064c>] scsi_device_dev_release+0x1c/0x20
   [<ffffffff817930e2>] device_release+0x32/0xa0
   [<ffffffff81454968>] kobject_cleanup+0x38/0x70
   [<ffffffff81454848>] kobject_put+0x28/0x60
   [<ffffffff817934d7>] put_device+0x17/0x20
   [<ffffffff817d11b9>] __scsi_remove_device+0xa9/0xe0
   [<ffffffff817d121b>] scsi_remove_device+0x2b/0x40
   [<ffffffff817d1257>] sdev_store_delete+0x27/0x30
   [<ffffffff81792ca8>] dev_attr_store+0x18/0x30
   [<ffffffff8126f75e>] sysfs_kf_write+0x3e/0x50
   [<ffffffff8126ea87>] kernfs_fop_write+0xe7/0x170
   [<ffffffff811f5e9f>] vfs_write+0xaf/0x1d0
   [<ffffffff811f69bd>] SyS_write+0x4d/0xc0
   [<ffffffff81d24692>] system_call_fastpath+0x16/0x1b

776687b ("block, blk-mq: draining can't be skipped even if
bypass_depth was non-zero") made it easier to trigger this bug by
making blk_queue_bypass_start() drain even when it loses the first
bypass test to blk_cleanup_queue(); however, the bug has always been
there even before the commit as blk_queue_bypass_start() could race
against queue destruction, win the initial bypass test but perform the
actual draining after blk_cleanup_queue() already destroyed all blkgs.

Fix it by skippping calling into policy draining if all the blkgs are
already gone.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Shirish Pargaonkar <spargaonkar@suse.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Reported-by: Jet Chen <jet.chen@intel.com>
Tested-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
timocapa pushed a commit to timocapa/kernel_lenok that referenced this pull request May 27, 2019
commit 35425ea upstream.

Christopher Head 2014-06-28 05:26:20 UTC described:
"I tried to reproduce this on 3.12.21. Instead, when I do "echo hello > foo"
in an ecryptfs mount with ecryptfs_xattr specified, I get a kernel crash:

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff8110eb39>] fsstack_copy_attr_all+0x2/0x61
PGD d7840067 PUD b2c3c067 PMD 0
Oops: 0002 [aosp-mirror#1] SMP
Modules linked in: nvidia(PO)
CPU: 3 PID: 3566 Comm: bash Tainted: P           O 3.12.21-gentoo-r1 aosp-mirror#2
Hardware name: ASUSTek Computer Inc. G60JX/G60JX, BIOS 206 03/15/2010
task: ffff8801948944c0 ti: ffff8800bad70000 task.ti: ffff8800bad70000
RIP: 0010:[<ffffffff8110eb39>]  [<ffffffff8110eb39>] fsstack_copy_attr_all+0x2/0x61
RSP: 0018:ffff8800bad71c10  EFLAGS: 00010246
RAX: 00000000000181a4 RBX: ffff880198648480 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffff880172010450 RDI: 0000000000000000
RBP: ffff880198490e40 R08: 0000000000000000 R09: 0000000000000000
R10: ffff880172010450 R11: ffffea0002c51e80 R12: 0000000000002000
R13: 000000000000001a R14: 0000000000000000 R15: ffff880198490e40
FS:  00007ff224caa700(0000) GS:ffff88019fcc0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000bb07f000 CR4: 00000000000007e0
Stack:
ffffffff811826e8 ffff8800a39d8000 0000000000000000 000000000000001a
ffff8800a01d0000 ffff8800a39d8000 ffffffff81185fd5 ffffffff81082c2c
00000001a39d8000 53d0abbc98490e40 0000000000000037 ffff8800a39d8220
Call Trace:
[<ffffffff811826e8>] ? ecryptfs_setxattr+0x40/0x52
[<ffffffff81185fd5>] ? ecryptfs_write_metadata+0x1b3/0x223
[<ffffffff81082c2c>] ? should_resched+0x5/0x23
[<ffffffff8118322b>] ? ecryptfs_initialize_file+0xaf/0xd4
[<ffffffff81183344>] ? ecryptfs_create+0xf4/0x142
[<ffffffff810f8c0d>] ? vfs_create+0x48/0x71
[<ffffffff810f9c86>] ? do_last.isra.68+0x559/0x952
[<ffffffff810f7ce7>] ? link_path_walk+0xbd/0x458
[<ffffffff810fa2a3>] ? path_openat+0x224/0x472
[<ffffffff810fa7bd>] ? do_filp_open+0x2b/0x6f
[<ffffffff81103606>] ? __alloc_fd+0xd6/0xe7
[<ffffffff810ee6ab>] ? do_sys_open+0x65/0xe9
[<ffffffff8157d022>] ? system_call_fastpath+0x16/0x1b
RIP  [<ffffffff8110eb39>] fsstack_copy_attr_all+0x2/0x61
RSP <ffff8800bad71c10>
CR2: 0000000000000000
---[ end trace df9dba5f1ddb8565 ]---"

If we create a file when we mount with ecryptfs_xattr_metadata option, we will
encounter a crash in this path:
->ecryptfs_create
  ->ecryptfs_initialize_file
    ->ecryptfs_write_metadata
      ->ecryptfs_write_metadata_to_xattr
        ->ecryptfs_setxattr
          ->fsstack_copy_attr_all
It's because our dentry->d_inode used in fsstack_copy_attr_all is NULL, and it
will be initialized when ecryptfs_initialize_file finish.

So we should skip copying attr from lower inode when the value of ->d_inode is
invalid.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
michalgr pushed a commit to michalgr/kernel_msm that referenced this pull request Oct 3, 2019
[ Upstream commit 5845f70 ]

It can be reproduced by following steps:
1. virtio_net NIC is configured with gso/tso on
2. configure nginx as http server with an index file bigger than 1M bytes
3. use tc netem to produce duplicate packets and delay:
   tc qdisc add dev eth0 root netem delay 100ms 10ms 30% duplicate 90%
4. continually curl the nginx http server to get index file on client
5. BUG_ON is seen quickly

[10258690.371129] kernel BUG at net/core/skbuff.c:4028!
[10258690.371748] invalid opcode: 0000 [aosp-mirror#1] SMP PTI
[10258690.372094] CPU: 5 PID: 0 Comm: swapper/5 Tainted: G        W         5.0.0-rc6 aosp-mirror#2
[10258690.372094] RSP: 0018:ffffa05797b43da0 EFLAGS: 00010202
[10258690.372094] RBP: 00000000000005ea R08: 0000000000000000 R09: 00000000000005ea
[10258690.372094] R10: ffffa0579334d800 R11: 00000000000002c0 R12: 0000000000000002
[10258690.372094] R13: 0000000000000000 R14: ffffa05793122900 R15: ffffa0578f7cb028
[10258690.372094] FS:  0000000000000000(0000) GS:ffffa05797b40000(0000) knlGS:0000000000000000
[10258690.372094] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[10258690.372094] CR2: 00007f1a6dc00868 CR3: 000000001000e000 CR4: 00000000000006e0
[10258690.372094] Call Trace:
[10258690.372094]  <IRQ>
[10258690.372094]  skb_to_sgvec+0x11/0x40
[10258690.372094]  start_xmit+0x38c/0x520 [virtio_net]
[10258690.372094]  dev_hard_start_xmit+0x9b/0x200
[10258690.372094]  sch_direct_xmit+0xff/0x260
[10258690.372094]  __qdisc_run+0x15e/0x4e0
[10258690.372094]  net_tx_action+0x137/0x210
[10258690.372094]  __do_softirq+0xd6/0x2a9
[10258690.372094]  irq_exit+0xde/0xf0
[10258690.372094]  smp_apic_timer_interrupt+0x74/0x140
[10258690.372094]  apic_timer_interrupt+0xf/0x20
[10258690.372094]  </IRQ>

In __skb_to_sgvec(), the skb->len is not equal to the sum of the skb's
linear data size and nonlinear data size, thus BUG_ON triggered.
Because the skb is cloned and a part of nonlinear data is split off.

Duplicate packet is cloned in netem_enqueue() and may be delayed
some time in qdisc. When qdisc len reached the limit and returns
NET_XMIT_DROP, the skb will be retransmit later in write queue.
the skb will be fragmented by tso_fragment(), the limit size
that depends on cwnd and mss decrease, the skb's nonlinear
data will be split off. The length of the skb cloned by netem
will not be updated. When we use virtio_net NIC and invoke skb_to_sgvec(),
the BUG_ON trigger.

To fix it, netem returns NET_XMIT_SUCCESS to upper stack
when it clones a duplicate packet.

Fixes: 35d889d ("sch_netem: fix skb leak in netem_enqueue()")
Signed-off-by: Sheng Lan <lansheng@huawei.com>
Reported-by: Qin Ji <jiqin.ji@huawei.com>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
michalgr pushed a commit to michalgr/kernel_msm that referenced this pull request Oct 3, 2019
[ Upstream commit afc9f65 ]

When building the kernel as Thumb-2 with binutils 2.29 or newer, if the
assembler has seen the .type directive (via ENDPROC()) for a symbol, it
automatically handles the setting of the lowest bit when the symbol is
used with ADR.  The badr macro on the other hand handles this lowest bit
manually.  This leads to a jump to a wrong address in the wrong state
in the syscall return path:

 Internal error: Oops - undefined instruction: 0 [aosp-mirror#2] SMP THUMB2
 Modules linked in:
 CPU: 0 PID: 652 Comm: modprobe Tainted: G      D           4.18.0-rc3+ aosp-mirror#8
 PC is at ret_fast_syscall+0x4/0x62
 LR is at sys_brk+0x109/0x128
 pc : [<80101004>]    lr : [<801c8a35>]    psr: 60000013
 Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
 Control: 50c5387d  Table: 9e82006a  DAC: 00000051
 Process modprobe (pid: 652, stack limit = 0x(ptrval))

 80101000 <ret_fast_syscall>:
 80101000:       b672            cpsid   i
 80101002:       f8d9 2008       ldr.w   r2, [r9, aosp-mirror#8]
 80101006:       f1b2 4ffe       cmp.w   r2, #2130706432 ; 0x7f000000

 80101184 <local_restart>:
 80101184:       f8d9 a000       ldr.w   sl, [r9]
 80101188:       e92d 0030       stmdb   sp!, {r4, r5}
 8010118c:       f01a 0ff0       tst.w   sl, #240        ; 0xf0
 80101190:       d117            bne.n   801011c2 <__sys_trace>
 80101192:       46ba            mov     sl, r7
 80101194:       f5ba 7fc8       cmp.w   sl, #400        ; 0x190
 80101198:       bf28            it      cs
 8010119a:       f04f 0a00       movcs.w sl, #0
 8010119e:       f3af 8014       nop.w   {20}
 801011a2:       f2af 1ea2       subw    lr, pc, #418    ; 0x1a2

To fix this, add a new symbol name which doesn't have ENDPROC used on it
and use that with badr.  We can't remove the badr usage since that would
would cause breakage with older binutils.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
michalgr pushed a commit to michalgr/kernel_msm that referenced this pull request Oct 3, 2019
[ Upstream commit a843dc4 ]

In func check_6rd,tunnel->ip6rd.relay_prefixlen may equal to
32,so UBSAN complain about it.

UBSAN: Undefined behaviour in net/ipv6/sit.c:781:47
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 6 PID: 20036 Comm: syz-executor.0 Not tainted 4.19.27 aosp-mirror#2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1
04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
ubsan_epilogue+0xe/0x81 lib/ubsan.c:159
__ubsan_handle_shift_out_of_bounds+0x293/0x2e8 lib/ubsan.c:425
check_6rd.constprop.9+0x433/0x4e0 net/ipv6/sit.c:781
try_6rd net/ipv6/sit.c:806 [inline]
ipip6_tunnel_xmit net/ipv6/sit.c:866 [inline]
sit_tunnel_xmit+0x141c/0x2720 net/ipv6/sit.c:1033
__netdev_start_xmit include/linux/netdevice.h:4300 [inline]
netdev_start_xmit include/linux/netdevice.h:4309 [inline]
xmit_one net/core/dev.c:3243 [inline]
dev_hard_start_xmit+0x17c/0x780 net/core/dev.c:3259
__dev_queue_xmit+0x1656/0x2500 net/core/dev.c:3829
neigh_output include/net/neighbour.h:501 [inline]
ip6_finish_output2+0xa36/0x2290 net/ipv6/ip6_output.c:120
ip6_finish_output+0x3e7/0xa20 net/ipv6/ip6_output.c:154
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip6_output+0x1e2/0x720 net/ipv6/ip6_output.c:171
dst_output include/net/dst.h:444 [inline]
ip6_local_out+0x99/0x170 net/ipv6/output_core.c:176
ip6_send_skb+0x9d/0x2f0 net/ipv6/ip6_output.c:1697
ip6_push_pending_frames+0xc0/0x100 net/ipv6/ip6_output.c:1717
rawv6_push_pending_frames net/ipv6/raw.c:616 [inline]
rawv6_sendmsg+0x2435/0x3530 net/ipv6/raw.c:946
inet_sendmsg+0xf8/0x5c0 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg+0xc8/0x110 net/socket.c:631
___sys_sendmsg+0x6cf/0x890 net/socket.c:2114
__sys_sendmsg+0xf0/0x1b0 net/socket.c:2152
do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: linmiaohe <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jackerghan pushed a commit to jackerghan/kernel_msm that referenced this pull request Jan 6, 2020
[ Upstream commit a843dc4 ]

In func check_6rd,tunnel->ip6rd.relay_prefixlen may equal to
32,so UBSAN complain about it.

UBSAN: Undefined behaviour in net/ipv6/sit.c:781:47
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 6 PID: 20036 Comm: syz-executor.0 Not tainted 4.19.27 aosp-mirror#2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1
04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
ubsan_epilogue+0xe/0x81 lib/ubsan.c:159
__ubsan_handle_shift_out_of_bounds+0x293/0x2e8 lib/ubsan.c:425
check_6rd.constprop.9+0x433/0x4e0 net/ipv6/sit.c:781
try_6rd net/ipv6/sit.c:806 [inline]
ipip6_tunnel_xmit net/ipv6/sit.c:866 [inline]
sit_tunnel_xmit+0x141c/0x2720 net/ipv6/sit.c:1033
__netdev_start_xmit include/linux/netdevice.h:4300 [inline]
netdev_start_xmit include/linux/netdevice.h:4309 [inline]
xmit_one net/core/dev.c:3243 [inline]
dev_hard_start_xmit+0x17c/0x780 net/core/dev.c:3259
__dev_queue_xmit+0x1656/0x2500 net/core/dev.c:3829
neigh_output include/net/neighbour.h:501 [inline]
ip6_finish_output2+0xa36/0x2290 net/ipv6/ip6_output.c:120
ip6_finish_output+0x3e7/0xa20 net/ipv6/ip6_output.c:154
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip6_output+0x1e2/0x720 net/ipv6/ip6_output.c:171
dst_output include/net/dst.h:444 [inline]
ip6_local_out+0x99/0x170 net/ipv6/output_core.c:176
ip6_send_skb+0x9d/0x2f0 net/ipv6/ip6_output.c:1697
ip6_push_pending_frames+0xc0/0x100 net/ipv6/ip6_output.c:1717
rawv6_push_pending_frames net/ipv6/raw.c:616 [inline]
rawv6_sendmsg+0x2435/0x3530 net/ipv6/raw.c:946
inet_sendmsg+0xf8/0x5c0 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg+0xc8/0x110 net/socket.c:631
___sys_sendmsg+0x6cf/0x890 net/socket.c:2114
__sys_sendmsg+0xf0/0x1b0 net/socket.c:2152
do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: linmiaohe <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 5, 2020
[ Upstream commit 16f6b67 ]

With large memory (8TB and more) hotplug, we can get soft lockup
warnings as below. These were caused by a long loop without any
explicit cond_resched which is a problem for !PREEMPT kernels.

Avoid this using cond_resched() while inserting hash page table
entries. We already do similar cond_resched() in __add_pages(), see
commit f64ac5e ("mm, memory_hotplug: add scheduling point to
__add_pages").

  rcu:     3-....: (24002 ticks this GP) idle=13e/1/0x4000000000000002 softirq=722/722 fqs=12001
   (t=24003 jiffies g=4285 q=2002)
  NMI backtrace for cpu 3
  CPU: 3 PID: 3870 Comm: ndctl Not tainted 5.3.0-197.18-default+ aosp-mirror#2
  Call Trace:
    dump_stack+0xb0/0xf4 (unreliable)
    nmi_cpu_backtrace+0x124/0x130
    nmi_trigger_cpumask_backtrace+0x1ac/0x1f0
    arch_trigger_cpumask_backtrace+0x28/0x3c
    rcu_dump_cpu_stacks+0xf8/0x154
    rcu_sched_clock_irq+0x878/0xb40
    update_process_times+0x48/0x90
    tick_sched_handle.isra.16+0x4c/0x80
    tick_sched_timer+0x68/0xe0
    __hrtimer_run_queues+0x180/0x430
    hrtimer_interrupt+0x110/0x300
    timer_interrupt+0x108/0x2f0
    decrementer_common+0x114/0x120
  --- interrupt: 901 at arch_add_memory+0xc0/0x130
      LR = arch_add_memory+0x74/0x130
    memremap_pages+0x494/0x650
    devm_memremap_pages+0x3c/0xa0
    pmem_attach_disk+0x188/0x750
    nvdimm_bus_probe+0xac/0x2c0
    really_probe+0x148/0x570
    driver_probe_device+0x19c/0x1d0
    device_driver_attach+0xcc/0x100
    bind_store+0x134/0x1c0
    drv_attr_store+0x44/0x60
    sysfs_kf_write+0x64/0x90
    kernfs_fop_write+0x1a0/0x270
    __vfs_write+0x3c/0x70
    vfs_write+0xd0/0x260
    ksys_write+0xdc/0x130
    system_call+0x5c/0x68

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191001084656.31277-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 5, 2020
[ Upstream commit cfcbae3 ]

In function __ufshcd_query_descriptor(), in the event of an error
happening, we directly goto out_unlock and forget to invaliate
hba->dev_cmd.query.descriptor pointer. This results in this pointer still
valid in ufshcd_copy_query_response() for other query requests which go
through ufshcd_exec_raw_upiu_cmd(). This will cause __memcpy() crash and
system hangs. Log as shown below:

Unable to handle kernel paging request at virtual address
ffff000012233c40
Mem abort info:
   ESR = 0x96000047
   Exception class = DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
Data abort info:
   ISV = 0, ISS = 0x00000047
   CM = 0, WnR = 1
swapper pgtable: 4k pages, 48-bit VAs, pgdp = 0000000028cc735c
[ffff000012233c40] pgd=00000000bffff003, pud=00000000bfffe003,
pmd=00000000ba8b8003, pte=0000000000000000
 Internal error: Oops: 96000047 [aosp-mirror#2] PREEMPT SMP
 ...
 Call trace:
  __memcpy+0x74/0x180
  ufshcd_issue_devman_upiu_cmd+0x250/0x3c0
  ufshcd_exec_raw_upiu_cmd+0xfc/0x1a8
  ufs_bsg_request+0x178/0x3b0
  bsg_queue_rq+0xc0/0x118
  blk_mq_dispatch_rq_list+0xb0/0x538
  blk_mq_sched_dispatch_requests+0x18c/0x1d8
  __blk_mq_run_hw_queue+0xb4/0x118
  blk_mq_run_work_fn+0x28/0x38
  process_one_work+0x1ec/0x470
  worker_thread+0x48/0x458
  kthread+0x130/0x138
  ret_from_fork+0x10/0x1c
 Code: 540000ab a8c12027 a88120c7 a8c12027 (a88120c7)
 ---[ end trace 793e1eb5dff69f2d ]---
 note: kworker/0:2H[2054] exited with preempt_count 1

This patch is to move "descriptor = NULL" down to below the label
"out_unlock".

Fixes: d44a5f9(ufs: query descriptor API)
Link: https://lore.kernel.org/r/20191112223436.27449-3-huobean@gmail.com
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 5, 2020
commit 5c9934b upstream.

We got another syzbot report [1] that tells us we must use
write_lock_irq()/write_unlock_irq() to avoid possible deadlock.

[1]

WARNING: inconsistent lock state
5.5.0-rc1-syzkaller #0 Not tainted
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-R} usage.
syz-executor826/9605 [HC1[1]:SC0[0]:HE0:SE1] takes:
ffffffff8a128718 (disc_data_lock){+-..}, at: sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138
{HARDIRQ-ON-W} state was registered at:
  lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
  __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
  _raw_write_lock_bh+0x33/0x50 kernel/locking/spinlock.c:319
  sixpack_close+0x1d/0x250 drivers/net/hamradio/6pack.c:657
  tty_ldisc_close.isra.0+0x119/0x1a0 drivers/tty/tty_ldisc.c:489
  tty_set_ldisc+0x230/0x6b0 drivers/tty/tty_ldisc.c:585
  tiocsetd drivers/tty/tty_io.c:2337 [inline]
  tty_ioctl+0xe8d/0x14f0 drivers/tty/tty_io.c:2597
  vfs_ioctl fs/ioctl.c:47 [inline]
  file_ioctl fs/ioctl.c:545 [inline]
  do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
  ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
  __do_sys_ioctl fs/ioctl.c:756 [inline]
  __se_sys_ioctl fs/ioctl.c:754 [inline]
  __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
irq event stamp: 3946
hardirqs last  enabled at (3945): [<ffffffff87c86e43>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
hardirqs last  enabled at (3945): [<ffffffff87c86e43>] _raw_spin_unlock_irq+0x23/0x80 kernel/locking/spinlock.c:199
hardirqs last disabled at (3946): [<ffffffff8100675f>] trace_hardirqs_off_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:42
softirqs last  enabled at (2658): [<ffffffff86a8b4df>] spin_unlock_bh include/linux/spinlock.h:383 [inline]
softirqs last  enabled at (2658): [<ffffffff86a8b4df>] clusterip_netdev_event+0x46f/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:222
softirqs last disabled at (2656): [<ffffffff86a8b22b>] spin_lock_bh include/linux/spinlock.h:343 [inline]
softirqs last disabled at (2656): [<ffffffff86a8b22b>] clusterip_netdev_event+0x1bb/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:196

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(disc_data_lock);
  <Interrupt>
    lock(disc_data_lock);

 *** DEADLOCK ***

5 locks held by syz-executor826/9605:
 #0: ffff8880a905e198 (&tty->legacy_mutex){+.+.}, at: tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19
 aosp-mirror#1: ffffffff899a56c0 (rcu_read_lock){....}, at: mutex_spin_on_owner+0x0/0x330 kernel/locking/mutex.c:413
 aosp-mirror#2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: spin_lock include/linux/spinlock.h:338 [inline]
 aosp-mirror#2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: serial8250_interrupt+0x2d/0x1a0 drivers/tty/serial/8250/8250_core.c:116
 aosp-mirror#3: ffffffff8c104048 (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x24/0x330 drivers/tty/serial/8250/8250_port.c:1823
 aosp-mirror#4: ffff8880a905e090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref+0x22/0x90 drivers/tty/tty_ldisc.c:288

stack backtrace:
CPU: 1 PID: 9605 Comm: syz-executor826 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_usage_bug.cold+0x327/0x378 kernel/locking/lockdep.c:3101
 valid_state kernel/locking/lockdep.c:3112 [inline]
 mark_lock_irq kernel/locking/lockdep.c:3309 [inline]
 mark_lock+0xbb4/0x1220 kernel/locking/lockdep.c:3666
 mark_usage kernel/locking/lockdep.c:3554 [inline]
 __lock_acquire+0x1e55/0x4a00 kernel/locking/lockdep.c:3909
 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
 _raw_read_lock+0x32/0x50 kernel/locking/spinlock.c:223
 sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138
 sixpack_write_wakeup+0x25/0x340 drivers/net/hamradio/6pack.c:402
 tty_wakeup+0xe9/0x120 drivers/tty/tty_io.c:536
 tty_port_default_wakeup+0x2b/0x40 drivers/tty/tty_port.c:50
 tty_port_tty_wakeup+0x57/0x70 drivers/tty/tty_port.c:387
 uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:104
 serial8250_tx_chars+0x495/0xaf0 drivers/tty/serial/8250/8250_port.c:1761
 serial8250_handle_irq.part.0+0x2a2/0x330 drivers/tty/serial/8250/8250_port.c:1834
 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1820 [inline]
 serial8250_default_handle_irq+0xc0/0x150 drivers/tty/serial/8250/8250_port.c:1850
 serial8250_interrupt+0xf1/0x1a0 drivers/tty/serial/8250/8250_core.c:126
 __handle_irq_event_percpu+0x15d/0x970 kernel/irq/handle.c:149
 handle_irq_event_percpu+0x74/0x160 kernel/irq/handle.c:189
 handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206
 handle_edge_irq+0x25e/0x8d0 kernel/irq/chip.c:830
 generic_handle_irq_desc include/linux/irqdesc.h:156 [inline]
 do_IRQ+0xde/0x280 arch/x86/kernel/irq.c:250
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:607
 </IRQ>
RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:685 [inline]
RIP: 0010:mutex_spin_on_owner+0x247/0x330 kernel/locking/mutex.c:579
Code: c3 be 08 00 00 00 4c 89 e7 e8 e5 06 59 00 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 0f 85 e1 00 00 00 49 8b 04 24 a8 01 75 96 f3 90 <e9> 2f fe ff ff 0f 0b e8 0d 19 09 00 84 c0 0f 85 ff fd ff ff 48 c7
RSP: 0018:ffffc90001eafa20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffd7
RAX: 0000000000000000 RBX: ffff88809fd9e0c0 RCX: 1ffffffff13266dd
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: ffffc90001eafa60 R08: 1ffff11013d22898 R09: ffffed1013d22899
R10: ffffed1013d22898 R11: ffff88809e9144c7 R12: ffff8880a905e138
R13: ffff88809e9144c0 R14: 0000000000000000 R15: dffffc0000000000
 mutex_optimistic_spin kernel/locking/mutex.c:673 [inline]
 __mutex_lock_common kernel/locking/mutex.c:962 [inline]
 __mutex_lock+0x32b/0x13c0 kernel/locking/mutex.c:1106
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1121
 tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19
 tty_release+0xb5/0xe90 drivers/tty/tty_io.c:1665
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x8e7/0x2ef0 kernel/exit.c:797
 do_group_exit+0x135/0x360 kernel/exit.c:895
 __do_sys_exit_group kernel/exit.c:906 [inline]
 __se_sys_exit_group kernel/exit.c:904 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:904
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43fef8
Code: Bad RIP value.
RSP: 002b:00007ffdb07d2338 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fef8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004bf730 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000

Fixes: 6e4e2f8 ("6pack,mkiss: fix lock inconsistency")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 5, 2020
commit 334b0f4 upstream.

There is a race condition which results in a deadlock when rmdir and
mkdir execute concurrently:

$ ls /sys/fs/resctrl/c1/mon_groups/m1/
cpus  cpus_list  mon_data  tasks

Thread 1: rmdir /sys/fs/resctrl/c1
Thread 2: mkdir /sys/fs/resctrl/c1/mon_groups/m1

3 locks held by mkdir/48649:
 #0:  (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50
 aosp-mirror#1:  (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c13b>] filename_create+0x7b/0x170
 aosp-mirror#2:  (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70

4 locks held by rmdir/48652:
 #0:  (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50
 aosp-mirror#1:  (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c3cf>] do_rmdir+0x13f/0x1e0
 aosp-mirror#2:  (&type->i_mutex_dir_key#8){++++}, at: [<ffffffffb4c86d5d>] vfs_rmdir+0x4d/0x120
 aosp-mirror#3:  (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70

Thread 1 is deleting control group "c1". Holding rdtgroup_mutex,
kernfs_remove() removes all kernfs nodes under directory "c1"
recursively, then waits for sub kernfs node "mon_groups" to drop active
reference.

Thread 2 is trying to create a subdirectory "m1" in the "mon_groups"
directory. The wrapper kernfs_iop_mkdir() takes an active reference to
the "mon_groups" directory but the code drops the active reference to
the parent directory "c1" instead.

As a result, Thread 1 is blocked on waiting for active reference to drop
and never release rdtgroup_mutex, while Thread 2 is also blocked on
trying to get rdtgroup_mutex.

Thread 1 (rdtgroup_rmdir)   Thread 2 (rdtgroup_mkdir)
(rmdir /sys/fs/resctrl/c1)  (mkdir /sys/fs/resctrl/c1/mon_groups/m1)
-------------------------   -------------------------
                            kernfs_iop_mkdir
                              /*
                               * kn: "m1", parent_kn: "mon_groups",
                               * prgrp_kn: parent_kn->parent: "c1",
                               *
                               * "mon_groups", parent_kn->active++: 1
                               */
                              kernfs_get_active(parent_kn)
kernfs_iop_rmdir
  /* "c1", kn->active++ */
  kernfs_get_active(kn)

  rdtgroup_kn_lock_live
    atomic_inc(&rdtgrp->waitcount)
    /* "c1", kn->active-- */
    kernfs_break_active_protection(kn)
    mutex_lock

  rdtgroup_rmdir_ctrl
    free_all_child_rdtgrp
      sentry->flags = RDT_DELETED

    rdtgroup_ctrl_remove
      rdtgrp->flags = RDT_DELETED
      kernfs_get(kn)
      kernfs_remove(rdtgrp->kn)
        __kernfs_remove
          /* "mon_groups", sub_kn */
          atomic_add(KN_DEACTIVATED_BIAS, &sub_kn->active)
          kernfs_drain(sub_kn)
            /*
             * sub_kn->active == KN_DEACTIVATED_BIAS + 1,
             * waiting on sub_kn->active to drop, but it
             * never drops in Thread 2 which is blocked
             * on getting rdtgroup_mutex.
             */
Thread 1 hangs here ---->
            wait_event(sub_kn->active == KN_DEACTIVATED_BIAS)
            ...
                              rdtgroup_mkdir
                                rdtgroup_mkdir_mon(parent_kn, prgrp_kn)
                                  mkdir_rdt_prepare(parent_kn, prgrp_kn)
                                    rdtgroup_kn_lock_live(prgrp_kn)
                                      atomic_inc(&rdtgrp->waitcount)
                                      /*
                                       * "c1", prgrp_kn->active--
                                       *
                                       * The active reference on "c1" is
                                       * dropped, but not matching the
                                       * actual active reference taken
                                       * on "mon_groups", thus causing
                                       * Thread 1 to wait forever while
                                       * holding rdtgroup_mutex.
                                       */
                                      kernfs_break_active_protection(
                                                               prgrp_kn)
                                      /*
                                       * Trying to get rdtgroup_mutex
                                       * which is held by Thread 1.
                                       */
Thread 2 hangs here ---->             mutex_lock
                                      ...

The problem is that the creation of a subdirectory in the "mon_groups"
directory incorrectly releases the active protection of its parent
directory instead of itself before it starts waiting for rdtgroup_mutex.
This is triggered by the rdtgroup_mkdir() flow calling
rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() with kernfs node of the
parent control group ("c1") as argument. It should be called with kernfs
node "mon_groups" instead. What is currently missing is that the
kn->priv of "mon_groups" is NULL instead of pointing to the rdtgrp.

Fix it by pointing kn->priv to rdtgrp when "mon_groups" is created. Then
it could be passed to rdtgroup_kn_lock_live()/rdtgroup_kn_unlock()
instead. And then it operates on the same rdtgroup structure but handles
the active reference of kernfs node "mon_groups" to prevent deadlock.
The same changes are also made to the "mon_data" directories.

This results in some unused function parameters that will be cleaned up
in follow-up patch as the focus here is on the fix only in support of
backporting efforts.

Backporting notes:

Since upstream commit fa7d949 ("x86/resctrl: Rename and move rdt
files to a separate directory"), the file
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to
arch/x86/kernel/cpu/resctrl/rdtgroup.c.
Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
for older stable trees.

Fixes: c7d9aac ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-4-git-send-email-xiaochen.shen@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 5, 2020
commit e8c75a3 upstream.

sel_lock cannot nest in the console lock. Thanks to syzkaller, the
kernel states firmly:

> WARNING: possible circular locking dependency detected
> 5.6.0-rc3-syzkaller #0 Not tainted
> ------------------------------------------------------
> syz-executor.4/20336 is trying to acquire lock:
> ffff8880a2e952a0 (&tty->termios_rwsem){++++}, at: tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136
>
> but task is already holding lock:
> ffffffff89462e70 (sel_lock){+.+.}, at: paste_selection+0x118/0x470 drivers/tty/vt/selection.c:374
>
> which lock already depends on the new lock.
>
> the existing dependency chain (in reverse order) is:
>
> -> aosp-mirror#2 (sel_lock){+.+.}:
>        mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118
>        set_selection_kernel+0x3b8/0x18a0 drivers/tty/vt/selection.c:217
>        set_selection_user+0x63/0x80 drivers/tty/vt/selection.c:181
>        tioclinux+0x103/0x530 drivers/tty/vt/vt.c:3050
>        vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364

This is ioctl(TIOCL_SETSEL).
Locks held on the path: console_lock -> sel_lock

> -> aosp-mirror#1 (console_lock){+.+.}:
>        console_lock+0x46/0x70 kernel/printk/printk.c:2289
>        con_flush_chars+0x50/0x650 drivers/tty/vt/vt.c:3223
>        n_tty_write+0xeae/0x1200 drivers/tty/n_tty.c:2350
>        do_tty_write drivers/tty/tty_io.c:962 [inline]
>        tty_write+0x5a1/0x950 drivers/tty/tty_io.c:1046

This is write().
Locks held on the path: termios_rwsem -> console_lock

> -> #0 (&tty->termios_rwsem){++++}:
>        down_write+0x57/0x140 kernel/locking/rwsem.c:1534
>        tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136
>        mkiss_receive_buf+0x12aa/0x1340 drivers/net/hamradio/mkiss.c:902
>        tty_ldisc_receive_buf+0x12f/0x170 drivers/tty/tty_buffer.c:465
>        paste_selection+0x346/0x470 drivers/tty/vt/selection.c:389
>        tioclinux+0x121/0x530 drivers/tty/vt/vt.c:3055
>        vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364

This is ioctl(TIOCL_PASTESEL).
Locks held on the path: sel_lock -> termios_rwsem

> other info that might help us debug this:
>
> Chain exists of:
>   &tty->termios_rwsem --> console_lock --> sel_lock

Clearly. From the above, we have:
 console_lock -> sel_lock
 sel_lock -> termios_rwsem
 termios_rwsem -> console_lock

Fix this by reversing the console_lock -> sel_lock dependency in
ioctl(TIOCL_SETSEL). First, lock sel_lock, then console_lock.

Bug: 149079230

Change-Id: I0f60c98750e977a3a70824225d0cac1302e4d70d
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: syzbot+26183d9746e62da329b8@syzkaller.appspotmail.com
Fixes: 07e6124 ("vt: selection, close sel_buffer race")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Harrison Lingren <hlingren@google.com>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 22, 2020
The lock debug output in print_lock() has a few shortcomings:

 - It prints the hlock->acquire_ip field in %px and %pS format. That's
   redundant information.

 - It lacks information about the lock object itself. The lock class is
   not helpful to identify a particular instance of a lock.

Change the output so it prints:

 - hlock->instance to allow identification of a particular lock instance.

 - only the %pS format of hlock->ip_acquire which is sufficient to decode
   the actual code line with faddr2line.

The resulting output is:

3 locks held by a.out/31106:
#0: 00000000b0f753ba (&mm->mmap_sem){++++}, at: copy_process.part.41+0x10d5/0x1fe0
aosp-mirror#1: 00000000ef64d539 (&mm->mmap_sem/1){+.+.}, at: copy_process.part.41+0x10fe/0x1fe0
aosp-mirror#2: 00000000b41a282e (&mapping->i_mmap_rwsem){++++}, at: copy_process.part.41+0x12f2/0x1fe0

[ tglx: Massaged changelog ]

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: linux-mm@kvack.org
Cc: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/201803271941.GBE57310.tVSOJLQOFFOHFM@I-love.SAKURA.ne.jp

Signed-off-by: celtare21 <celtare21@gmail.com>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 22, 2020
The following lockdep report can be triggered by writing to /sys/kernel/debug/sched_features:

  ======================================================
  WARNING: possible circular locking dependency detected
  4.18.0-rc6-00152-gcd3f77d74ac3-dirty #18 Not tainted
  ------------------------------------------------------
  sh/3358 is trying to acquire lock:
  000000004ad3989d (cpu_hotplug_lock.rw_sem){++++}, at: static_key_enable+0x14/0x30
  but task is already holding lock:
  00000000c1b31a88 (&sb->s_type->i_mutex_key#3){+.+.}, at: sched_feat_write+0x160/0x428
  which lock already depends on the new lock.
  the existing dependency chain (in reverse order) is:
  -> aosp-mirror#3 (&sb->s_type->i_mutex_key#3){+.+.}:
         lock_acquire+0xb8/0x148
         down_write+0xac/0x140
         start_creating+0x5c/0x168
         debugfs_create_dir+0x18/0x220
         opp_debug_register+0x8c/0x120
         _add_opp_dev+0x104/0x1f8
         dev_pm_opp_get_opp_table+0x174/0x340
         _of_add_opp_table_v2+0x110/0x760
         dev_pm_opp_of_add_table+0x5c/0x240
         dev_pm_opp_of_cpumask_add_table+0x5c/0x100
         cpufreq_init+0x160/0x430
         cpufreq_online+0x1cc/0xe30
         cpufreq_add_dev+0x78/0x198
         subsys_interface_register+0x168/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> aosp-mirror#2 (opp_table_lock){+.+.}:
         lock_acquire+0xb8/0x148
         __mutex_lock+0x104/0xf50
         mutex_lock_nested+0x1c/0x28
         _of_add_opp_table_v2+0xb4/0x760
         dev_pm_opp_of_add_table+0x5c/0x240
         dev_pm_opp_of_cpumask_add_table+0x5c/0x100
         cpufreq_init+0x160/0x430
         cpufreq_online+0x1cc/0xe30
         cpufreq_add_dev+0x78/0x198
         subsys_interface_register+0x168/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> aosp-mirror#1 (subsys mutex#6){+.+.}:
         lock_acquire+0xb8/0x148
         __mutex_lock+0x104/0xf50
         mutex_lock_nested+0x1c/0x28
         subsys_interface_register+0xd8/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> #0 (cpu_hotplug_lock.rw_sem){++++}:
         __lock_acquire+0x203c/0x21d0
         lock_acquire+0xb8/0x148
         cpus_read_lock+0x58/0x1c8
         static_key_enable+0x14/0x30
         sched_feat_write+0x314/0x428
         full_proxy_write+0xa0/0x138
         __vfs_write+0xd8/0x388
         vfs_write+0xdc/0x318
         ksys_write+0xb4/0x138
         sys_write+0xc/0x18
         __sys_trace_return+0x0/0x4
  other info that might help us debug this:
  Chain exists of:
    cpu_hotplug_lock.rw_sem --> opp_table_lock --> &sb->s_type->i_mutex_key#3
   Possible unsafe locking scenario:
         CPU0                    CPU1
         ----                    ----
    lock(&sb->s_type->i_mutex_key#3);
                                 lock(opp_table_lock);
                                 lock(&sb->s_type->i_mutex_key#3);
    lock(cpu_hotplug_lock.rw_sem);
   *** DEADLOCK ***
  2 locks held by sh/3358:
   #0: 00000000a8c4b363 (sb_writers#10){.+.+}, at: vfs_write+0x238/0x318
   aosp-mirror#1: 00000000c1b31a88 (&sb->s_type->i_mutex_key#3){+.+.}, at: sched_feat_write+0x160/0x428
  stack backtrace:
  CPU: 5 PID: 3358 Comm: sh Not tainted 4.18.0-rc6-00152-gcd3f77d74ac3-dirty #18
  Hardware name: Renesas H3ULCB Kingfisher board based on r8a7795 ES2.0+ (DT)
  Call trace:
   dump_backtrace+0x0/0x288
   show_stack+0x14/0x20
   dump_stack+0x13c/0x1ac
   print_circular_bug.isra.10+0x270/0x438
   check_prev_add.constprop.16+0x4dc/0xb98
   __lock_acquire+0x203c/0x21d0
   lock_acquire+0xb8/0x148
   cpus_read_lock+0x58/0x1c8
   static_key_enable+0x14/0x30
   sched_feat_write+0x314/0x428
   full_proxy_write+0xa0/0x138
   __vfs_write+0xd8/0x388
   vfs_write+0xdc/0x318
   ksys_write+0xb4/0x138
   sys_write+0xc/0x18
   __sys_trace_return+0x0/0x4

This is because when loading the cpufreq_dt module we first acquire
cpu_hotplug_lock.rw_sem lock, then in cpufreq_init(), we are taking
the &sb->s_type->i_mutex_key lock.

But when writing to /sys/kernel/debug/sched_features, the
cpu_hotplug_lock.rw_sem lock depends on the &sb->s_type->i_mutex_key lock.

To fix this bug, reverse the lock acquisition order when writing to
sched_features, this way cpu_hotplug_lock.rw_sem no longer depends on
&sb->s_type->i_mutex_key.

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Eugeniu Rosca <erosca@de.adit-jv.com>
Cc: George G. Davis <george_davis@mentor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180731121222.26195-1-jiada_wang@mentor.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: celtare21 <celtare21@gmail.com>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 22, 2020
The lock debug output in print_lock() has a few shortcomings:

 - It prints the hlock->acquire_ip field in %px and %pS format. That's
   redundant information.

 - It lacks information about the lock object itself. The lock class is
   not helpful to identify a particular instance of a lock.

Change the output so it prints:

 - hlock->instance to allow identification of a particular lock instance.

 - only the %pS format of hlock->ip_acquire which is sufficient to decode
   the actual code line with faddr2line.

The resulting output is:

3 locks held by a.out/31106:
#0: 00000000b0f753ba (&mm->mmap_sem){++++}, at: copy_process.part.41+0x10d5/0x1fe0
aosp-mirror#1: 00000000ef64d539 (&mm->mmap_sem/1){+.+.}, at: copy_process.part.41+0x10fe/0x1fe0
aosp-mirror#2: 00000000b41a282e (&mapping->i_mmap_rwsem){++++}, at: copy_process.part.41+0x12f2/0x1fe0

[ tglx: Massaged changelog ]

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: linux-mm@kvack.org
Cc: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/201803271941.GBE57310.tVSOJLQOFFOHFM@I-love.SAKURA.ne.jp

Signed-off-by: celtare21 <celtare21@gmail.com>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 24, 2020
Refine to tune or skip min freq, to let little cluster
boost to a bit higher freq than lowest at touch time.
Keep big cluster touch min boosts skipped.
This is to avoid rare lags in refresh rate, when CPU
cores have very little load/idling.
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 24, 2020
…irror#2

add divider param, divide top-app boosting to allow more idle freq
timespans while casual usage is present, like reading, sliding.
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 24, 2020
Refine to tune or skip min freq, to let little cluster
boost to a bit higher freq than lowest at touch time.
Keep big cluster touch min boosts skipped.
This is to avoid rare lags in refresh rate, when CPU
cores have very little load/idling.
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 24, 2020
…irror#2

add divider param, divide top-app boosting to allow more idle freq
timespans while casual usage is present, like reading, sliding.
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 24, 2020
Refine to tune or skip min freq, to let little cluster
boost to a bit higher freq than lowest at touch time.
Keep big cluster touch min boosts skipped.
This is to avoid rare lags in refresh rate, when CPU
cores have very little load/idling.
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 24, 2020
…irror#2

add divider param, divide top-app boosting to allow more idle freq
timespans while casual usage is present, like reading, sliding.
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 27, 2020
The following lockdep report can be triggered by writing to /sys/kernel/debug/sched_features:

  ======================================================
  WARNING: possible circular locking dependency detected
  4.18.0-rc6-00152-gcd3f77d74ac3-dirty #18 Not tainted
  ------------------------------------------------------
  sh/3358 is trying to acquire lock:
  000000004ad3989d (cpu_hotplug_lock.rw_sem){++++}, at: static_key_enable+0x14/0x30
  but task is already holding lock:
  00000000c1b31a88 (&sb->s_type->i_mutex_key#3){+.+.}, at: sched_feat_write+0x160/0x428
  which lock already depends on the new lock.
  the existing dependency chain (in reverse order) is:
  -> aosp-mirror#3 (&sb->s_type->i_mutex_key#3){+.+.}:
         lock_acquire+0xb8/0x148
         down_write+0xac/0x140
         start_creating+0x5c/0x168
         debugfs_create_dir+0x18/0x220
         opp_debug_register+0x8c/0x120
         _add_opp_dev+0x104/0x1f8
         dev_pm_opp_get_opp_table+0x174/0x340
         _of_add_opp_table_v2+0x110/0x760
         dev_pm_opp_of_add_table+0x5c/0x240
         dev_pm_opp_of_cpumask_add_table+0x5c/0x100
         cpufreq_init+0x160/0x430
         cpufreq_online+0x1cc/0xe30
         cpufreq_add_dev+0x78/0x198
         subsys_interface_register+0x168/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> aosp-mirror#2 (opp_table_lock){+.+.}:
         lock_acquire+0xb8/0x148
         __mutex_lock+0x104/0xf50
         mutex_lock_nested+0x1c/0x28
         _of_add_opp_table_v2+0xb4/0x760
         dev_pm_opp_of_add_table+0x5c/0x240
         dev_pm_opp_of_cpumask_add_table+0x5c/0x100
         cpufreq_init+0x160/0x430
         cpufreq_online+0x1cc/0xe30
         cpufreq_add_dev+0x78/0x198
         subsys_interface_register+0x168/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> aosp-mirror#1 (subsys mutex#6){+.+.}:
         lock_acquire+0xb8/0x148
         __mutex_lock+0x104/0xf50
         mutex_lock_nested+0x1c/0x28
         subsys_interface_register+0xd8/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> #0 (cpu_hotplug_lock.rw_sem){++++}:
         __lock_acquire+0x203c/0x21d0
         lock_acquire+0xb8/0x148
         cpus_read_lock+0x58/0x1c8
         static_key_enable+0x14/0x30
         sched_feat_write+0x314/0x428
         full_proxy_write+0xa0/0x138
         __vfs_write+0xd8/0x388
         vfs_write+0xdc/0x318
         ksys_write+0xb4/0x138
         sys_write+0xc/0x18
         __sys_trace_return+0x0/0x4
  other info that might help us debug this:
  Chain exists of:
    cpu_hotplug_lock.rw_sem --> opp_table_lock --> &sb->s_type->i_mutex_key#3
   Possible unsafe locking scenario:
         CPU0                    CPU1
         ----                    ----
    lock(&sb->s_type->i_mutex_key#3);
                                 lock(opp_table_lock);
                                 lock(&sb->s_type->i_mutex_key#3);
    lock(cpu_hotplug_lock.rw_sem);
   *** DEADLOCK ***
  2 locks held by sh/3358:
   #0: 00000000a8c4b363 (sb_writers#10){.+.+}, at: vfs_write+0x238/0x318
   aosp-mirror#1: 00000000c1b31a88 (&sb->s_type->i_mutex_key#3){+.+.}, at: sched_feat_write+0x160/0x428
  stack backtrace:
  CPU: 5 PID: 3358 Comm: sh Not tainted 4.18.0-rc6-00152-gcd3f77d74ac3-dirty #18
  Hardware name: Renesas H3ULCB Kingfisher board based on r8a7795 ES2.0+ (DT)
  Call trace:
   dump_backtrace+0x0/0x288
   show_stack+0x14/0x20
   dump_stack+0x13c/0x1ac
   print_circular_bug.isra.10+0x270/0x438
   check_prev_add.constprop.16+0x4dc/0xb98
   __lock_acquire+0x203c/0x21d0
   lock_acquire+0xb8/0x148
   cpus_read_lock+0x58/0x1c8
   static_key_enable+0x14/0x30
   sched_feat_write+0x314/0x428
   full_proxy_write+0xa0/0x138
   __vfs_write+0xd8/0x388
   vfs_write+0xdc/0x318
   ksys_write+0xb4/0x138
   sys_write+0xc/0x18
   __sys_trace_return+0x0/0x4

This is because when loading the cpufreq_dt module we first acquire
cpu_hotplug_lock.rw_sem lock, then in cpufreq_init(), we are taking
the &sb->s_type->i_mutex_key lock.

But when writing to /sys/kernel/debug/sched_features, the
cpu_hotplug_lock.rw_sem lock depends on the &sb->s_type->i_mutex_key lock.

To fix this bug, reverse the lock acquisition order when writing to
sched_features, this way cpu_hotplug_lock.rw_sem no longer depends on
&sb->s_type->i_mutex_key.

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Eugeniu Rosca <erosca@de.adit-jv.com>
Cc: George G. Davis <george_davis@mentor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180731121222.26195-1-jiada_wang@mentor.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: celtare21 <celtare21@gmail.com>
reaqon pushed a commit to reaqon/kernel_msm that referenced this pull request Jun 27, 2020
The following lockdep report can be triggered by writing to /sys/kernel/debug/sched_features:

  ======================================================
  WARNING: possible circular locking dependency detected
  4.18.0-rc6-00152-gcd3f77d74ac3-dirty #18 Not tainted
  ------------------------------------------------------
  sh/3358 is trying to acquire lock:
  000000004ad3989d (cpu_hotplug_lock.rw_sem){++++}, at: static_key_enable+0x14/0x30
  but task is already holding lock:
  00000000c1b31a88 (&sb->s_type->i_mutex_key#3){+.+.}, at: sched_feat_write+0x160/0x428
  which lock already depends on the new lock.
  the existing dependency chain (in reverse order) is:
  -> aosp-mirror#3 (&sb->s_type->i_mutex_key#3){+.+.}:
         lock_acquire+0xb8/0x148
         down_write+0xac/0x140
         start_creating+0x5c/0x168
         debugfs_create_dir+0x18/0x220
         opp_debug_register+0x8c/0x120
         _add_opp_dev+0x104/0x1f8
         dev_pm_opp_get_opp_table+0x174/0x340
         _of_add_opp_table_v2+0x110/0x760
         dev_pm_opp_of_add_table+0x5c/0x240
         dev_pm_opp_of_cpumask_add_table+0x5c/0x100
         cpufreq_init+0x160/0x430
         cpufreq_online+0x1cc/0xe30
         cpufreq_add_dev+0x78/0x198
         subsys_interface_register+0x168/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> aosp-mirror#2 (opp_table_lock){+.+.}:
         lock_acquire+0xb8/0x148
         __mutex_lock+0x104/0xf50
         mutex_lock_nested+0x1c/0x28
         _of_add_opp_table_v2+0xb4/0x760
         dev_pm_opp_of_add_table+0x5c/0x240
         dev_pm_opp_of_cpumask_add_table+0x5c/0x100
         cpufreq_init+0x160/0x430
         cpufreq_online+0x1cc/0xe30
         cpufreq_add_dev+0x78/0x198
         subsys_interface_register+0x168/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> aosp-mirror#1 (subsys mutex#6){+.+.}:
         lock_acquire+0xb8/0x148
         __mutex_lock+0x104/0xf50
         mutex_lock_nested+0x1c/0x28
         subsys_interface_register+0xd8/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> #0 (cpu_hotplug_lock.rw_sem){++++}:
         __lock_acquire+0x203c/0x21d0
         lock_acquire+0xb8/0x148
         cpus_read_lock+0x58/0x1c8
         static_key_enable+0x14/0x30
         sched_feat_write+0x314/0x428
         full_proxy_write+0xa0/0x138
         __vfs_write+0xd8/0x388
         vfs_write+0xdc/0x318
         ksys_write+0xb4/0x138
         sys_write+0xc/0x18
         __sys_trace_return+0x0/0x4
  other info that might help us debug this:
  Chain exists of:
    cpu_hotplug_lock.rw_sem --> opp_table_lock --> &sb->s_type->i_mutex_key#3
   Possible unsafe locking scenario:
         CPU0                    CPU1
         ----                    ----
    lock(&sb->s_type->i_mutex_key#3);
                                 lock(opp_table_lock);
                                 lock(&sb->s_type->i_mutex_key#3);
    lock(cpu_hotplug_lock.rw_sem);
   *** DEADLOCK ***
  2 locks held by sh/3358:
   #0: 00000000a8c4b363 (sb_writers#10){.+.+}, at: vfs_write+0x238/0x318
   aosp-mirror#1: 00000000c1b31a88 (&sb->s_type->i_mutex_key#3){+.+.}, at: sched_feat_write+0x160/0x428
  stack backtrace:
  CPU: 5 PID: 3358 Comm: sh Not tainted 4.18.0-rc6-00152-gcd3f77d74ac3-dirty #18
  Hardware name: Renesas H3ULCB Kingfisher board based on r8a7795 ES2.0+ (DT)
  Call trace:
   dump_backtrace+0x0/0x288
   show_stack+0x14/0x20
   dump_stack+0x13c/0x1ac
   print_circular_bug.isra.10+0x270/0x438
   check_prev_add.constprop.16+0x4dc/0xb98
   __lock_acquire+0x203c/0x21d0
   lock_acquire+0xb8/0x148
   cpus_read_lock+0x58/0x1c8
   static_key_enable+0x14/0x30
   sched_feat_write+0x314/0x428
   full_proxy_write+0xa0/0x138
   __vfs_write+0xd8/0x388
   vfs_write+0xdc/0x318
   ksys_write+0xb4/0x138
   sys_write+0xc/0x18
   __sys_trace_return+0x0/0x4

This is because when loading the cpufreq_dt module we first acquire
cpu_hotplug_lock.rw_sem lock, then in cpufreq_init(), we are taking
the &sb->s_type->i_mutex_key lock.

But when writing to /sys/kernel/debug/sched_features, the
cpu_hotplug_lock.rw_sem lock depends on the &sb->s_type->i_mutex_key lock.

To fix this bug, reverse the lock acquisition order when writing to
sched_features, this way cpu_hotplug_lock.rw_sem no longer depends on
&sb->s_type->i_mutex_key.

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Eugeniu Rosca <erosca@de.adit-jv.com>
Cc: George G. Davis <george_davis@mentor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180731121222.26195-1-jiada_wang@mentor.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: celtare21 <celtare21@gmail.com>
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Labels
None yet
5 participants