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Merge pull request #1 from torvalds/master #47

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lenb pushed a commit to lenb/linux that referenced this pull request Sep 14, 2013
When a probe is being removed, it cleans up the event files that correspond
to the probe. But there is a race between writing to one of these files
and deleting the probe. This is especially true for the "enable" file.

	CPU 0				CPU 1
	-----				-----

				  fd = open("enable",O_WRONLY);

  probes_open()
  release_all_trace_probes()
  unregister_trace_probe()
  if (trace_probe_is_enabled(tp))
	return -EBUSY

				   write(fd, "1", 1)
				   __ftrace_set_clr_event()
				   call->class->reg()
				    (kprobe_register)
				     enable_trace_probe(tp)

  __unregister_trace_probe(tp);
  list_del(&tp->list)
  unregister_probe_event(tp) <-- fails!
  free_trace_probe(tp)

				   write(fd, "0", 1)
				   __ftrace_set_clr_event()
				   call->class->unreg
				    (kprobe_register)
				    disable_trace_probe(tp) <-- BOOM!

A test program was written that used two threads to simulate the
above scenario adding a nanosleep() interval to change the timings
and after several thousand runs, it was able to trigger this bug
and crash:

BUG: unable to handle kernel paging request at 00000005000000f9
IP: [<ffffffff810dee70>] probes_open+0x3b/0xa7
PGD 7808a067 PUD 0
Oops: 0000 [#1] PREEMPT SMP
Dumping ftrace buffer:
---------------------------------
Modules linked in: ipt_MASQUERADE sunrpc ip6t_REJECT nf_conntrack_ipv6
CPU: 1 PID: 2070 Comm: test-kprobe-rem Not tainted 3.11.0-rc3-test+ torvalds#47
Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
task: ffff880077756440 ti: ffff880076e52000 task.ti: ffff880076e52000
RIP: 0010:[<ffffffff810dee70>]  [<ffffffff810dee70>] probes_open+0x3b/0xa7
RSP: 0018:ffff880076e53c38  EFLAGS: 00010203
RAX: 0000000500000001 RBX: ffff88007844f440 RCX: 0000000000000003
RDX: 0000000000000003 RSI: 0000000000000003 RDI: ffff880076e52000
RBP: ffff880076e53c58 R08: ffff880076e53bd8 R09: 0000000000000000
R10: ffff880077756440 R11: 0000000000000006 R12: ffffffff810dee35
R13: ffff880079250418 R14: 0000000000000000 R15: ffff88007844f450
FS:  00007f87a276f700(0000) GS:ffff88007d480000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000005000000f9 CR3: 0000000077262000 CR4: 00000000000007e0
Stack:
 ffff880076e53c58 ffffffff81219ea0 ffff88007844f440 ffffffff810dee35
 ffff880076e53ca8 ffffffff81130f78 ffff8800772986c0 ffff8800796f93a0
 ffffffff81d1b5d8 ffff880076e53e04 0000000000000000 ffff88007844f440
Call Trace:
 [<ffffffff81219ea0>] ? security_file_open+0x2c/0x30
 [<ffffffff810dee35>] ? unregister_trace_probe+0x4b/0x4b
 [<ffffffff81130f78>] do_dentry_open+0x162/0x226
 [<ffffffff81131186>] finish_open+0x46/0x54
 [<ffffffff8113f30b>] do_last+0x7f6/0x996
 [<ffffffff8113cc6f>] ? inode_permission+0x42/0x44
 [<ffffffff8113f6dd>] path_openat+0x232/0x496
 [<ffffffff8113fc30>] do_filp_open+0x3a/0x8a
 [<ffffffff8114ab32>] ? __alloc_fd+0x168/0x17a
 [<ffffffff81131f4e>] do_sys_open+0x70/0x102
 [<ffffffff8108f06e>] ? trace_hardirqs_on_caller+0x160/0x197
 [<ffffffff81131ffe>] SyS_open+0x1e/0x20
 [<ffffffff81522742>] system_call_fastpath+0x16/0x1b
Code: e5 41 54 53 48 89 f3 48 83 ec 10 48 23 56 78 48 39 c2 75 6c 31 f6 48 c7
RIP  [<ffffffff810dee70>] probes_open+0x3b/0xa7
 RSP <ffff880076e53c38>
CR2: 00000005000000f9
---[ end trace 35f17d68fc569897 ]---

The unregister_trace_probe() must be done first, and if it fails it must
fail the removal of the kprobe.

Several changes have already been made by Oleg Nesterov and Masami Hiramatsu
to allow moving the unregister_probe_event() before the removal of
the probe and exit the function if it fails. This prevents the tp
structure from being used after it is freed.

Link: http://lkml.kernel.org/r/20130704034038.819592356@goodmis.org

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
codyps pushed a commit to codyps/linux that referenced this pull request Sep 25, 2013
ERROR: "(foo*)" should be "(foo *)"
torvalds#47: FILE: ipc/util.c:493:
+	struct ipc_rcu *p = ((struct ipc_rcu*)ptr)-1;

ERROR: "(foo*)" should be "(foo *)"
#58: FILE: ipc/util.c:509:
+	struct ipc_rcu *p = ((struct ipc_rcu*)ptr)-1;

total: 2 errors, 0 warnings, 34 lines checked

./patches/ipc-utilc-ipc_rcu_alloc-cacheline-align-allocation.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dormando pushed a commit to fastly/linux that referenced this pull request Oct 3, 2013
commit 40c3259 upstream.

When a probe is being removed, it cleans up the event files that correspond
to the probe. But there is a race between writing to one of these files
and deleting the probe. This is especially true for the "enable" file.

	CPU 0				CPU 1
	-----				-----

				  fd = open("enable",O_WRONLY);

  probes_open()
  release_all_trace_probes()
  unregister_trace_probe()
  if (trace_probe_is_enabled(tp))
	return -EBUSY

				   write(fd, "1", 1)
				   __ftrace_set_clr_event()
				   call->class->reg()
				    (kprobe_register)
				     enable_trace_probe(tp)

  __unregister_trace_probe(tp);
  list_del(&tp->list)
  unregister_probe_event(tp) <-- fails!
  free_trace_probe(tp)

				   write(fd, "0", 1)
				   __ftrace_set_clr_event()
				   call->class->unreg
				    (kprobe_register)
				    disable_trace_probe(tp) <-- BOOM!

A test program was written that used two threads to simulate the
above scenario adding a nanosleep() interval to change the timings
and after several thousand runs, it was able to trigger this bug
and crash:

BUG: unable to handle kernel paging request at 00000005000000f9
IP: [<ffffffff810dee70>] probes_open+0x3b/0xa7
PGD 7808a067 PUD 0
Oops: 0000 [#1] PREEMPT SMP
Dumping ftrace buffer:
---------------------------------
Modules linked in: ipt_MASQUERADE sunrpc ip6t_REJECT nf_conntrack_ipv6
CPU: 1 PID: 2070 Comm: test-kprobe-rem Not tainted 3.11.0-rc3-test+ torvalds#47
Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
task: ffff880077756440 ti: ffff880076e52000 task.ti: ffff880076e52000
RIP: 0010:[<ffffffff810dee70>]  [<ffffffff810dee70>] probes_open+0x3b/0xa7
RSP: 0018:ffff880076e53c38  EFLAGS: 00010203
RAX: 0000000500000001 RBX: ffff88007844f440 RCX: 0000000000000003
RDX: 0000000000000003 RSI: 0000000000000003 RDI: ffff880076e52000
RBP: ffff880076e53c58 R08: ffff880076e53bd8 R09: 0000000000000000
R10: ffff880077756440 R11: 0000000000000006 R12: ffffffff810dee35
R13: ffff880079250418 R14: 0000000000000000 R15: ffff88007844f450
FS:  00007f87a276f700(0000) GS:ffff88007d480000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000005000000f9 CR3: 0000000077262000 CR4: 00000000000007e0
Stack:
 ffff880076e53c58 ffffffff81219ea0 ffff88007844f440 ffffffff810dee35
 ffff880076e53ca8 ffffffff81130f78 ffff8800772986c0 ffff8800796f93a0
 ffffffff81d1b5d8 ffff880076e53e04 0000000000000000 ffff88007844f440
Call Trace:
 [<ffffffff81219ea0>] ? security_file_open+0x2c/0x30
 [<ffffffff810dee35>] ? unregister_trace_probe+0x4b/0x4b
 [<ffffffff81130f78>] do_dentry_open+0x162/0x226
 [<ffffffff81131186>] finish_open+0x46/0x54
 [<ffffffff8113f30b>] do_last+0x7f6/0x996
 [<ffffffff8113cc6f>] ? inode_permission+0x42/0x44
 [<ffffffff8113f6dd>] path_openat+0x232/0x496
 [<ffffffff8113fc30>] do_filp_open+0x3a/0x8a
 [<ffffffff8114ab32>] ? __alloc_fd+0x168/0x17a
 [<ffffffff81131f4e>] do_sys_open+0x70/0x102
 [<ffffffff8108f06e>] ? trace_hardirqs_on_caller+0x160/0x197
 [<ffffffff81131ffe>] SyS_open+0x1e/0x20
 [<ffffffff81522742>] system_call_fastpath+0x16/0x1b
Code: e5 41 54 53 48 89 f3 48 83 ec 10 48 23 56 78 48 39 c2 75 6c 31 f6 48 c7
RIP  [<ffffffff810dee70>] probes_open+0x3b/0xa7
 RSP <ffff880076e53c38>
CR2: 00000005000000f9
---[ end trace 35f17d68fc569897 ]---

The unregister_trace_probe() must be done first, and if it fails it must
fail the removal of the kprobe.

Several changes have already been made by Oleg Nesterov and Masami Hiramatsu
to allow moving the unregister_probe_event() before the removal of
the probe and exit the function if it fails. This prevents the tp
structure from being used after it is freed.

Link: http://lkml.kernel.org/r/20130704034038.819592356@goodmis.org

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
swarren pushed a commit to swarren/linux-tegra that referenced this pull request Oct 14, 2013
As the new x86 CPU bootup printout format code maintainer, I am
taking immediate action to improve and clean (and thus indulge
my OCD) the reporting of the cores when coming up online.

Fix padding to a right-hand alignment, cleanup code and bind
reporting width to the max number of supported CPUs on the
system, like this:

 [    0.074509] smpboot: Booting Node   0, Processors:      #1  #2  #3  #4  #5  torvalds#6  torvalds#7 OK
 [    0.644008] smpboot: Booting Node   1, Processors:  torvalds#8  torvalds#9 torvalds#10 torvalds#11 torvalds#12 torvalds#13 torvalds#14 torvalds#15 OK
 [    1.245006] smpboot: Booting Node   2, Processors: torvalds#16 torvalds#17 torvalds#18 torvalds#19 torvalds#20 torvalds#21 torvalds#22 torvalds#23 OK
 [    1.864005] smpboot: Booting Node   3, Processors: torvalds#24 torvalds#25 torvalds#26 torvalds#27 torvalds#28 torvalds#29 torvalds#30 torvalds#31 OK
 [    2.489005] smpboot: Booting Node   4, Processors: torvalds#32 torvalds#33 torvalds#34 torvalds#35 torvalds#36 torvalds#37 torvalds#38 torvalds#39 OK
 [    3.093005] smpboot: Booting Node   5, Processors: torvalds#40 torvalds#41 torvalds#42 torvalds#43 torvalds#44 torvalds#45 torvalds#46 torvalds#47 OK
 [    3.698005] smpboot: Booting Node   6, Processors: torvalds#48 torvalds#49 torvalds#50 torvalds#51 #52 #53 torvalds#54 torvalds#55 OK
 [    4.304005] smpboot: Booting Node   7, Processors: torvalds#56 torvalds#57 #58 torvalds#59 torvalds#60 torvalds#61 torvalds#62 torvalds#63 OK
 [    4.961413] Brought up 64 CPUs

and this:

 [    0.072367] smpboot: Booting Node   0, Processors:    #1 #2 #3 #4 #5 torvalds#6 torvalds#7 OK
 [    0.686329] Brought up 8 CPUs

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Libin <huawei.libin@huawei.com>
Cc: wangyijing@huawei.com
Cc: fenghua.yu@intel.com
Cc: guohanjun@huawei.com
Cc: paul.gortmaker@windriver.com
Link: http://lkml.kernel.org/r/20130927143554.GF4422@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
swarren pushed a commit to swarren/linux-tegra that referenced this pull request Oct 14, 2013
Turn it into (for example):

[    0.073380] x86: Booting SMP configuration:
[    0.074005] .... node   #0, CPUs:          #1   #2   #3   #4   #5   torvalds#6   torvalds#7
[    0.603005] .... node   #1, CPUs:     torvalds#8   torvalds#9  torvalds#10  torvalds#11  torvalds#12  torvalds#13  torvalds#14  torvalds#15
[    1.200005] .... node   #2, CPUs:    torvalds#16  torvalds#17  torvalds#18  torvalds#19  torvalds#20  torvalds#21  torvalds#22  torvalds#23
[    1.796005] .... node   #3, CPUs:    torvalds#24  torvalds#25  torvalds#26  torvalds#27  torvalds#28  torvalds#29  torvalds#30  torvalds#31
[    2.393005] .... node   #4, CPUs:    torvalds#32  torvalds#33  torvalds#34  torvalds#35  torvalds#36  torvalds#37  torvalds#38  torvalds#39
[    2.996005] .... node   #5, CPUs:    torvalds#40  torvalds#41  torvalds#42  torvalds#43  torvalds#44  torvalds#45  torvalds#46  torvalds#47
[    3.600005] .... node   torvalds#6, CPUs:    torvalds#48  torvalds#49  torvalds#50  torvalds#51  #52  #53  torvalds#54  torvalds#55
[    4.202005] .... node   torvalds#7, CPUs:    torvalds#56  torvalds#57  #58  torvalds#59  torvalds#60  torvalds#61  torvalds#62  torvalds#63
[    4.811005] .... node   torvalds#8, CPUs:    torvalds#64  torvalds#65  torvalds#66  torvalds#67  torvalds#68  torvalds#69  #70  torvalds#71
[    5.421006] .... node   torvalds#9, CPUs:    torvalds#72  torvalds#73  torvalds#74  torvalds#75  torvalds#76  torvalds#77  torvalds#78  torvalds#79
[    6.032005] .... node  torvalds#10, CPUs:    torvalds#80  torvalds#81  torvalds#82  torvalds#83  torvalds#84  torvalds#85  torvalds#86  torvalds#87
[    6.648006] .... node  torvalds#11, CPUs:    torvalds#88  torvalds#89  torvalds#90  torvalds#91  torvalds#92  torvalds#93  torvalds#94  torvalds#95
[    7.262005] .... node  torvalds#12, CPUs:    torvalds#96  torvalds#97  torvalds#98  torvalds#99 torvalds#100 torvalds#101 torvalds#102 torvalds#103
[    7.865005] .... node  torvalds#13, CPUs:   torvalds#104 torvalds#105 torvalds#106 torvalds#107 torvalds#108 torvalds#109 torvalds#110 torvalds#111
[    8.466005] .... node  torvalds#14, CPUs:   torvalds#112 torvalds#113 torvalds#114 torvalds#115 torvalds#116 torvalds#117 torvalds#118 torvalds#119
[    9.073006] .... node  torvalds#15, CPUs:   torvalds#120 torvalds#121 torvalds#122 torvalds#123 torvalds#124 torvalds#125 torvalds#126 torvalds#127
[    9.679901] x86: Booted up 16 nodes, 128 CPUs

and drop useless elements.

Change num_digits() to hpa's division-avoiding, cell-phone-typed
version which he went at great lengths and pains to submit on a
Saturday evening.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: huawei.libin@huawei.com
Cc: wangyijing@huawei.com
Cc: fenghua.yu@intel.com
Cc: guohanjun@huawei.com
Cc: paul.gortmaker@windriver.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20130930095624.GB16383@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
torvalds pushed a commit that referenced this pull request Dec 2, 2013
The patch fixes the following lockdep warning, which is 100%
reproducible on network restart:

======================================================
[ INFO: possible circular locking dependency detected ]
3.12.0+ #47 Tainted: GF
-------------------------------------------------------
kworker/1:1/27 is trying to acquire lock:
 ((&(&adapter->watchdog_task)->work)){+.+...}, at: [<ffffffff8108a5b0>] flush_work+0x0/0x70

but task is already holding lock:
 (&adapter->mutex){+.+...}, at: [<ffffffffa0177c0a>] e1000_reset_task+0x4a/0xa0 [e1000]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&adapter->mutex){+.+...}:
       [<ffffffff810bdb5d>] lock_acquire+0x9d/0x120
       [<ffffffff816b8cbc>] mutex_lock_nested+0x4c/0x390
       [<ffffffffa017233d>] e1000_watchdog+0x7d/0x5b0 [e1000]
       [<ffffffff8108b972>] process_one_work+0x1d2/0x510
       [<ffffffff8108ca80>] worker_thread+0x120/0x3a0
       [<ffffffff81092c1e>] kthread+0xee/0x110
       [<ffffffff816c3d7c>] ret_from_fork+0x7c/0xb0

-> #0 ((&(&adapter->watchdog_task)->work)){+.+...}:
       [<ffffffff810bd9c0>] __lock_acquire+0x1710/0x1810
       [<ffffffff810bdb5d>] lock_acquire+0x9d/0x120
       [<ffffffff8108a5eb>] flush_work+0x3b/0x70
       [<ffffffff8108b5d8>] __cancel_work_timer+0x98/0x140
       [<ffffffff8108b693>] cancel_delayed_work_sync+0x13/0x20
       [<ffffffffa0170cec>] e1000_down_and_stop+0x3c/0x60 [e1000]
       [<ffffffffa01775b1>] e1000_down+0x131/0x220 [e1000]
       [<ffffffffa0177c12>] e1000_reset_task+0x52/0xa0 [e1000]
       [<ffffffff8108b972>] process_one_work+0x1d2/0x510
       [<ffffffff8108ca80>] worker_thread+0x120/0x3a0
       [<ffffffff81092c1e>] kthread+0xee/0x110
       [<ffffffff816c3d7c>] ret_from_fork+0x7c/0xb0

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&adapter->mutex);
                               lock((&(&adapter->watchdog_task)->work));
                               lock(&adapter->mutex);
  lock((&(&adapter->watchdog_task)->work));

 *** DEADLOCK ***

3 locks held by kworker/1:1/27:
 #0:  (events){.+.+.+}, at: [<ffffffff8108b906>] process_one_work+0x166/0x510
 #1:  ((&adapter->reset_task)){+.+...}, at: [<ffffffff8108b906>] process_one_work+0x166/0x510
 #2:  (&adapter->mutex){+.+...}, at: [<ffffffffa0177c0a>] e1000_reset_task+0x4a/0xa0 [e1000]

stack backtrace:
CPU: 1 PID: 27 Comm: kworker/1:1 Tainted: GF            3.12.0+ #47
Hardware name: System manufacturer System Product Name/P5B-VM SE, BIOS 0501    05/31/2007
Workqueue: events e1000_reset_task [e1000]
 ffffffff820f6000 ffff88007b9dba98 ffffffff816b54a2 0000000000000002
 ffffffff820f5e50 ffff88007b9dbae8 ffffffff810ba936 ffff88007b9dbac8
 ffff88007b9dbb48 ffff88007b9d8f00 ffff88007b9d8780 ffff88007b9d8f00
Call Trace:
 [<ffffffff816b54a2>] dump_stack+0x49/0x5f
 [<ffffffff810ba936>] print_circular_bug+0x216/0x310
 [<ffffffff810bd9c0>] __lock_acquire+0x1710/0x1810
 [<ffffffff8108a5b0>] ? __flush_work+0x250/0x250
 [<ffffffff810bdb5d>] lock_acquire+0x9d/0x120
 [<ffffffff8108a5b0>] ? __flush_work+0x250/0x250
 [<ffffffff8108a5eb>] flush_work+0x3b/0x70
 [<ffffffff8108a5b0>] ? __flush_work+0x250/0x250
 [<ffffffff8108b5d8>] __cancel_work_timer+0x98/0x140
 [<ffffffff8108b693>] cancel_delayed_work_sync+0x13/0x20
 [<ffffffffa0170cec>] e1000_down_and_stop+0x3c/0x60 [e1000]
 [<ffffffffa01775b1>] e1000_down+0x131/0x220 [e1000]
 [<ffffffffa0177c12>] e1000_reset_task+0x52/0xa0 [e1000]
 [<ffffffff8108b972>] process_one_work+0x1d2/0x510
 [<ffffffff8108b906>] ? process_one_work+0x166/0x510
 [<ffffffff8108ca80>] worker_thread+0x120/0x3a0
 [<ffffffff8108c960>] ? manage_workers+0x2c0/0x2c0
 [<ffffffff81092c1e>] kthread+0xee/0x110
 [<ffffffff81092b30>] ? __init_kthread_worker+0x70/0x70
 [<ffffffff816c3d7c>] ret_from_fork+0x7c/0xb0
 [<ffffffff81092b30>] ? __init_kthread_worker+0x70/0x70

== The issue background ==

The problem occurs, because e1000_down(), which is called under
adapter->mutex by e1000_reset_task(), tries to synchronously cancel
e1000 auxiliary works (reset_task, watchdog_task, phy_info_task,
fifo_stall_task), which take adapter->mutex in their handlers. So the
question is what does adapter->mutex protect there?

The adapter->mutex was introduced by commit 0ef4ee ("e1000: convert to
private mutex from rtnl") as a replacement for rtnl_lock() taken in the
asynchronous handlers. It targeted on fixing a similar lockdep warning
issued when e1000_down() was called under rtnl_lock(), and it fixed it,
but unfortunately it introduced the lockdep warning described above.
Anyway, that said the source of this bug is that the asynchronous works
were made to take rtnl_lock() some time ago, so let's look deeper and
find why it was added there.

The rtnl_lock() was added to asynchronous handlers by commit 338c15
("e1000: fix occasional panic on unload") in order to prevent
asynchronous handlers from execution after the module is unloaded
(e1000_down() is called) as it follows from the comment to the commit:

> Net drivers in general have an issue where timers fired
> by mod_timer or work threads with schedule_work are running
> outside of the rtnl_lock.
>
> With no other lock protection these routines are vulnerable
> to races with driver unload or reset paths.
>
> The longer term solution to this might be a redesign with
> safer locks being taken in the driver to guarantee no
> reentrance, but for now a safe and effective fix is
> to take the rtnl_lock in these routines.

I'm not sure if this locking scheme fixed the problem or just made it
unlikely, although I incline to the latter. Anyway, this was long time
ago when e1000 auxiliary works were implemented as timers scheduling
real work handlers in their routines. The e1000_down() function only
canceled the timers, but left the real handlers running if they were
running, which could result in work execution after module unload.
Today, the e1000 driver uses sane delayed works instead of the pair
timer+work to implement its delayed asynchronous handlers, and the
e1000_down() synchronously cancels all the works so that the problem
that commit 338c15 tried to cope with disappeared, and we don't need any
locks in the handlers any more. Moreover, any locking there can
potentially result in a deadlock.

So, this patch reverts commits 0ef4ee and 338c15.

Fixes: 0ef4eed ("e1000: convert to private mutex from rtnl")
Fixes: 338c15e ("e1000: fix occasional panic on unload")
Cc: Tushar Dave <tushar.n.dave@intel.com>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
torvalds pushed a commit that referenced this pull request Feb 24, 2014
If we cannot calibrate TSC via MSR based calibration
try_msr_calibrate_tsc() stores zero to fast_calibrate and returns that
to the caller. This value gets then propagated further to clockevents
code resulting division by zero oops like the one below:

 divide error: 0000 [#1] PREEMPT SMP
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W    3.13.0+ #47
 task: ffff880075508000 ti: ffff880075506000 task.ti: ffff880075506000
 RIP: 0010:[<ffffffff810aec14>]  [<ffffffff810aec14>] clockevents_config.part.3+0x24/0xa0
 RSP: 0000:ffff880075507e58  EFLAGS: 00010246
 RAX: ffffffffffffffff RBX: ffff880079c0cd80 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffffffffff
 RBP: ffff880075507e70 R08: 0000000000000001 R09: 00000000000000be
 R10: 00000000000000bd R11: 0000000000000003 R12: 000000000000b008
 R13: 0000000000000008 R14: 000000000000b010 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff880079c00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffff880079fff000 CR3: 0000000001c0b000 CR4: 00000000001006f0
 Stack:
  ffff880079c0cd80 000000000000b008 0000000000000008 ffff880075507e88
  ffffffff810aecb0 ffff880079c0cd80 ffff880075507e98 ffffffff81030168
  ffff880075507ed8 ffffffff81d1104f 00000000000000c3 0000000000000000
 Call Trace:
  [<ffffffff810aecb0>] clockevents_config_and_register+0x20/0x30
  [<ffffffff81030168>] setup_APIC_timer+0xc8/0xd0
  [<ffffffff81d1104f>] setup_boot_APIC_clock+0x4cc/0x4d8
  [<ffffffff81d0f5de>] native_smp_prepare_cpus+0x3dd/0x3f0
  [<ffffffff81d02ee9>] kernel_init_freeable+0xc3/0x205
  [<ffffffff8177c910>] ? rest_init+0x90/0x90
  [<ffffffff8177c91e>] kernel_init+0xe/0x120
  [<ffffffff8178deec>] ret_from_fork+0x7c/0xb0
  [<ffffffff8177c910>] ? rest_init+0x90/0x90

Prevent this from happening by:
 1) Modifying try_msr_calibrate_tsc() to return calibration value or zero
    if it fails.
 2) Check this return value in native_calibrate_tsc() and in case of zero
    fallback to use normal non-MSR based calibration.

[mw: Added subject and changelog]

Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bin Gao <bin.gao@linux.intel.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1392810750-18660-1-git-send-email-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
aryabinin pushed a commit to aryabinin/linux that referenced this pull request Aug 14, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
torvalds pushed a commit that referenced this pull request Aug 14, 2014
This patch disables the branch target address CAM which under specific
circumstances may cause the processor to skip execution of 1-4
instructions. This fixes IBM Erratum #47.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
andy-shev pushed a commit to andy-shev/linux that referenced this pull request Aug 26, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
aryabinin pushed a commit to aryabinin/linux that referenced this pull request Sep 3, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
swarren pushed a commit to swarren/linux-tegra that referenced this pull request Sep 3, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
andy-shev pushed a commit to andy-shev/linux that referenced this pull request Sep 5, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
aryabinin pushed a commit to aryabinin/linux that referenced this pull request Sep 10, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
koct9i pushed a commit to koct9i/linux that referenced this pull request Sep 23, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
aryabinin pushed a commit to aryabinin/linux that referenced this pull request Sep 24, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ddstreet pushed a commit to ddstreet/linux that referenced this pull request Sep 25, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
koct9i pushed a commit to koct9i/linux that referenced this pull request Sep 27, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
tom3q pushed a commit to tom3q/linux that referenced this pull request Oct 2, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
aryabinin pushed a commit to aryabinin/linux that referenced this pull request Oct 3, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
bengal pushed a commit to bengal/linux that referenced this pull request Oct 7, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
swarren pushed a commit to swarren/linux-tegra that referenced this pull request Oct 16, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
aryabinin pushed a commit to aryabinin/linux that referenced this pull request Oct 27, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
bengal pushed a commit to bengal/linux that referenced this pull request Nov 9, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
aryabinin pushed a commit to aryabinin/linux that referenced this pull request Nov 18, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
aryabinin pushed a commit to aryabinin/linux that referenced this pull request Nov 24, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
aryabinin pushed a commit to aryabinin/linux that referenced this pull request Nov 27, 2014
…kpatch-fixes

WARNING: else is not generally useful after a break or return
torvalds#47: FILE: fs/ocfs2/dlm/dlmast.c:392:
+				break;
+			else

total: 0 errors, 1 warnings, 15 lines checked

./patches/o2dlm-fix-null-pointer-dereference-in-o2dlm_blocking_ast_wrapper.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
gthelen pushed a commit to gthelen/linux that referenced this pull request Apr 1, 2015
Sumeone needs to buy a tab key.

WARNING: please, no spaces at the start of a line
torvalds#29: FILE: security/tomoyo/util.c:951:
+       struct file *exe_file;$

WARNING: please, no spaces at the start of a line
torvalds#30: FILE: security/tomoyo/util.c:952:
+       const char *cp;$

WARNING: please, no spaces at the start of a line
torvalds#31: FILE: security/tomoyo/util.c:953:
+       struct mm_struct *mm = current->mm;$

WARNING: please, no spaces at the start of a line
torvalds#40: FILE: security/tomoyo/util.c:955:
+       if (!mm)$

WARNING: suspect code indent for conditional statements (7, 15)
torvalds#40: FILE: security/tomoyo/util.c:955:
+       if (!mm)
+	       return NULL;

WARNING: please, no spaces at the start of a line
torvalds#42: FILE: security/tomoyo/util.c:957:
+       exe_file = get_mm_exe_file(mm);$

WARNING: please, no spaces at the start of a line
torvalds#43: FILE: security/tomoyo/util.c:958:
+       if (!exe_file)$

WARNING: suspect code indent for conditional statements (7, 15)
torvalds#43: FILE: security/tomoyo/util.c:958:
+       if (!exe_file)
+	       return NULL;

WARNING: please, no spaces at the start of a line
torvalds#46: FILE: security/tomoyo/util.c:961:
+       cp = tomoyo_realpath_from_path(&exe_file->f_path);$

WARNING: please, no spaces at the start of a line
torvalds#47: FILE: security/tomoyo/util.c:962:
+       fput(exe_file);$

WARNING: please, no spaces at the start of a line
torvalds#48: FILE: security/tomoyo/util.c:963:
+       return cp;$

total: 0 errors, 11 warnings, 28 lines checked

./patches/tomoyo-reduce-mmap_sem-hold-for-mm-exe_file.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: James Morris <jmorris@namei.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Oct 22, 2023
commit 72377ab upstream.

Christoph reported that the MPTCP protocol can find the subflow-level
write queue unexpectedly not empty while crafting a zero-window probe,
hitting a warning:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 188 at net/mptcp/protocol.c:1312 mptcp_sendmsg_frag+0xc06/0xe70
Modules linked in:
CPU: 0 PID: 188 Comm: kworker/0:2 Not tainted 6.6.0-rc2-g1176aa719d7a torvalds#47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_sendmsg_frag+0xc06/0xe70 net/mptcp/protocol.c:1312
RAX: 47d0530de347ff6a RBX: 47d0530de347ff6b RCX: ffff8881015d3c00
RDX: ffff8881015d3c00 RSI: 47d0530de347ff6b RDI: 47d0530de347ff6b
RBP: 47d0530de347ff6b R08: ffffffff8243c6a8 R09: ffffffff82042d9c
R10: 0000000000000002 R11: ffffffff82056850 R12: ffff88812a13d580
R13: 0000000000000001 R14: ffff88812b375e50 R15: ffff88812bbf3200
FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000695118 CR3: 0000000115dfc001 CR4: 0000000000170ef0
Call Trace:
 <TASK>
 __subflow_push_pending+0xa4/0x420 net/mptcp/protocol.c:1545
 __mptcp_push_pending+0x128/0x3b0 net/mptcp/protocol.c:1614
 mptcp_release_cb+0x218/0x5b0 net/mptcp/protocol.c:3391
 release_sock+0xf6/0x100 net/core/sock.c:3521
 mptcp_worker+0x6e8/0x8f0 net/mptcp/protocol.c:2746
 process_scheduled_works+0x341/0x690 kernel/workqueue.c:2630
 worker_thread+0x3a7/0x610 kernel/workqueue.c:2784
 kthread+0x143/0x180 kernel/kthread.c:388
 ret_from_fork+0x4d/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304
 </TASK>

The root cause of the issue is that expectations are wrong: e.g. due
to MPTCP-level re-injection we can hit the critical condition.

Explicitly avoid the zero-window probe when the subflow write queue
is not empty and drop the related warnings.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: multipath-tcp/mptcp_net-next#444
Fixes: f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-3-17ecb002e41d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Oct 23, 2023
commit 72377ab upstream.

Christoph reported that the MPTCP protocol can find the subflow-level
write queue unexpectedly not empty while crafting a zero-window probe,
hitting a warning:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 188 at net/mptcp/protocol.c:1312 mptcp_sendmsg_frag+0xc06/0xe70
Modules linked in:
CPU: 0 PID: 188 Comm: kworker/0:2 Not tainted 6.6.0-rc2-g1176aa719d7a torvalds#47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_sendmsg_frag+0xc06/0xe70 net/mptcp/protocol.c:1312
RAX: 47d0530de347ff6a RBX: 47d0530de347ff6b RCX: ffff8881015d3c00
RDX: ffff8881015d3c00 RSI: 47d0530de347ff6b RDI: 47d0530de347ff6b
RBP: 47d0530de347ff6b R08: ffffffff8243c6a8 R09: ffffffff82042d9c
R10: 0000000000000002 R11: ffffffff82056850 R12: ffff88812a13d580
R13: 0000000000000001 R14: ffff88812b375e50 R15: ffff88812bbf3200
FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000695118 CR3: 0000000115dfc001 CR4: 0000000000170ef0
Call Trace:
 <TASK>
 __subflow_push_pending+0xa4/0x420 net/mptcp/protocol.c:1545
 __mptcp_push_pending+0x128/0x3b0 net/mptcp/protocol.c:1614
 mptcp_release_cb+0x218/0x5b0 net/mptcp/protocol.c:3391
 release_sock+0xf6/0x100 net/core/sock.c:3521
 mptcp_worker+0x6e8/0x8f0 net/mptcp/protocol.c:2746
 process_scheduled_works+0x341/0x690 kernel/workqueue.c:2630
 worker_thread+0x3a7/0x610 kernel/workqueue.c:2784
 kthread+0x143/0x180 kernel/kthread.c:388
 ret_from_fork+0x4d/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304
 </TASK>

The root cause of the issue is that expectations are wrong: e.g. due
to MPTCP-level re-injection we can hit the critical condition.

Explicitly avoid the zero-window probe when the subflow write queue
is not empty and drop the related warnings.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: multipath-tcp/mptcp_net-next#444
Fixes: f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-3-17ecb002e41d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kaz205 pushed a commit to Kaz205/linux that referenced this pull request Oct 25, 2023
commit 72377ab upstream.

Christoph reported that the MPTCP protocol can find the subflow-level
write queue unexpectedly not empty while crafting a zero-window probe,
hitting a warning:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 188 at net/mptcp/protocol.c:1312 mptcp_sendmsg_frag+0xc06/0xe70
Modules linked in:
CPU: 0 PID: 188 Comm: kworker/0:2 Not tainted 6.6.0-rc2-g1176aa719d7a torvalds#47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_sendmsg_frag+0xc06/0xe70 net/mptcp/protocol.c:1312
RAX: 47d0530de347ff6a RBX: 47d0530de347ff6b RCX: ffff8881015d3c00
RDX: ffff8881015d3c00 RSI: 47d0530de347ff6b RDI: 47d0530de347ff6b
RBP: 47d0530de347ff6b R08: ffffffff8243c6a8 R09: ffffffff82042d9c
R10: 0000000000000002 R11: ffffffff82056850 R12: ffff88812a13d580
R13: 0000000000000001 R14: ffff88812b375e50 R15: ffff88812bbf3200
FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000695118 CR3: 0000000115dfc001 CR4: 0000000000170ef0
Call Trace:
 <TASK>
 __subflow_push_pending+0xa4/0x420 net/mptcp/protocol.c:1545
 __mptcp_push_pending+0x128/0x3b0 net/mptcp/protocol.c:1614
 mptcp_release_cb+0x218/0x5b0 net/mptcp/protocol.c:3391
 release_sock+0xf6/0x100 net/core/sock.c:3521
 mptcp_worker+0x6e8/0x8f0 net/mptcp/protocol.c:2746
 process_scheduled_works+0x341/0x690 kernel/workqueue.c:2630
 worker_thread+0x3a7/0x610 kernel/workqueue.c:2784
 kthread+0x143/0x180 kernel/kthread.c:388
 ret_from_fork+0x4d/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304
 </TASK>

The root cause of the issue is that expectations are wrong: e.g. due
to MPTCP-level re-injection we can hit the critical condition.

Explicitly avoid the zero-window probe when the subflow write queue
is not empty and drop the related warnings.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: multipath-tcp/mptcp_net-next#444
Fixes: f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-3-17ecb002e41d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
intersectRaven pushed a commit to intersectRaven/linux that referenced this pull request Oct 25, 2023
commit 72377ab upstream.

Christoph reported that the MPTCP protocol can find the subflow-level
write queue unexpectedly not empty while crafting a zero-window probe,
hitting a warning:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 188 at net/mptcp/protocol.c:1312 mptcp_sendmsg_frag+0xc06/0xe70
Modules linked in:
CPU: 0 PID: 188 Comm: kworker/0:2 Not tainted 6.6.0-rc2-g1176aa719d7a torvalds#47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_sendmsg_frag+0xc06/0xe70 net/mptcp/protocol.c:1312
RAX: 47d0530de347ff6a RBX: 47d0530de347ff6b RCX: ffff8881015d3c00
RDX: ffff8881015d3c00 RSI: 47d0530de347ff6b RDI: 47d0530de347ff6b
RBP: 47d0530de347ff6b R08: ffffffff8243c6a8 R09: ffffffff82042d9c
R10: 0000000000000002 R11: ffffffff82056850 R12: ffff88812a13d580
R13: 0000000000000001 R14: ffff88812b375e50 R15: ffff88812bbf3200
FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000695118 CR3: 0000000115dfc001 CR4: 0000000000170ef0
Call Trace:
 <TASK>
 __subflow_push_pending+0xa4/0x420 net/mptcp/protocol.c:1545
 __mptcp_push_pending+0x128/0x3b0 net/mptcp/protocol.c:1614
 mptcp_release_cb+0x218/0x5b0 net/mptcp/protocol.c:3391
 release_sock+0xf6/0x100 net/core/sock.c:3521
 mptcp_worker+0x6e8/0x8f0 net/mptcp/protocol.c:2746
 process_scheduled_works+0x341/0x690 kernel/workqueue.c:2630
 worker_thread+0x3a7/0x610 kernel/workqueue.c:2784
 kthread+0x143/0x180 kernel/kthread.c:388
 ret_from_fork+0x4d/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304
 </TASK>

The root cause of the issue is that expectations are wrong: e.g. due
to MPTCP-level re-injection we can hit the critical condition.

Explicitly avoid the zero-window probe when the subflow write queue
is not empty and drop the related warnings.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: multipath-tcp/mptcp_net-next#444
Fixes: f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-3-17ecb002e41d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1054009064 pushed a commit to 1054009064/linux that referenced this pull request Oct 25, 2023
commit 72377ab upstream.

Christoph reported that the MPTCP protocol can find the subflow-level
write queue unexpectedly not empty while crafting a zero-window probe,
hitting a warning:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 188 at net/mptcp/protocol.c:1312 mptcp_sendmsg_frag+0xc06/0xe70
Modules linked in:
CPU: 0 PID: 188 Comm: kworker/0:2 Not tainted 6.6.0-rc2-g1176aa719d7a torvalds#47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_sendmsg_frag+0xc06/0xe70 net/mptcp/protocol.c:1312
RAX: 47d0530de347ff6a RBX: 47d0530de347ff6b RCX: ffff8881015d3c00
RDX: ffff8881015d3c00 RSI: 47d0530de347ff6b RDI: 47d0530de347ff6b
RBP: 47d0530de347ff6b R08: ffffffff8243c6a8 R09: ffffffff82042d9c
R10: 0000000000000002 R11: ffffffff82056850 R12: ffff88812a13d580
R13: 0000000000000001 R14: ffff88812b375e50 R15: ffff88812bbf3200
FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000695118 CR3: 0000000115dfc001 CR4: 0000000000170ef0
Call Trace:
 <TASK>
 __subflow_push_pending+0xa4/0x420 net/mptcp/protocol.c:1545
 __mptcp_push_pending+0x128/0x3b0 net/mptcp/protocol.c:1614
 mptcp_release_cb+0x218/0x5b0 net/mptcp/protocol.c:3391
 release_sock+0xf6/0x100 net/core/sock.c:3521
 mptcp_worker+0x6e8/0x8f0 net/mptcp/protocol.c:2746
 process_scheduled_works+0x341/0x690 kernel/workqueue.c:2630
 worker_thread+0x3a7/0x610 kernel/workqueue.c:2784
 kthread+0x143/0x180 kernel/kthread.c:388
 ret_from_fork+0x4d/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304
 </TASK>

The root cause of the issue is that expectations are wrong: e.g. due
to MPTCP-level re-injection we can hit the critical condition.

Explicitly avoid the zero-window probe when the subflow write queue
is not empty and drop the related warnings.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: multipath-tcp/mptcp_net-next#444
Fixes: f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-3-17ecb002e41d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
intel-lab-lkp pushed a commit to intel-lab-lkp/linux that referenced this pull request Nov 7, 2023
The cloned child of ahash that uses shash under the hood should use
shash helpers (like crypto_shash_setkey()).

The following panic may be observed on TCP-AO selftests:

> ==================================================================
> BUG: KASAN: wild-memory-access in crypto_mod_get+0x1b/0x60
> Write of size 4 at addr 5d5be0ff5c415e14 by task connect_ipv4/1397
>
> CPU: 0 PID: 1397 Comm: connect_ipv4 Tainted: G        W          6.6.0+ torvalds#47
> Call Trace:
>  <TASK>
>  dump_stack_lvl+0x46/0x70
>  kasan_report+0xc3/0xf0
>  kasan_check_range+0xec/0x190
>  crypto_mod_get+0x1b/0x60
>  crypto_spawn_alg+0x53/0x140
>  crypto_spawn_tfm2+0x13/0x60
>  hmac_init_tfm+0x25/0x60
>  crypto_ahash_setkey+0x8b/0x100
>  tcp_ao_add_cmd+0xe7a/0x1120
>  do_tcp_setsockopt+0x5ed/0x12a0
>  do_sock_setsockopt+0x82/0x100
>  __sys_setsockopt+0xe9/0x160
>  __x64_sys_setsockopt+0x60/0x70
>  do_syscall_64+0x3c/0xe0
>  entry_SYSCALL_64_after_hwframe+0x46/0x4e
> ==================================================================
> general protection fault, probably for non-canonical address 0x5d5be0ff5c415e14: 0000 [#1] PREEMPT SMP KASAN
> CPU: 0 PID: 1397 Comm: connect_ipv4 Tainted: G    B   W          6.6.0+ torvalds#47
> Call Trace:
>  <TASK>
>  ? die_addr+0x3c/0xa0
>  ? exc_general_protection+0x144/0x210
>  ? asm_exc_general_protection+0x22/0x30
>  ? add_taint+0x26/0x90
>  ? crypto_mod_get+0x20/0x60
>  ? crypto_mod_get+0x1b/0x60
>  ? ahash_def_finup_done1+0x58/0x80
>  crypto_spawn_alg+0x53/0x140
>  crypto_spawn_tfm2+0x13/0x60
>  hmac_init_tfm+0x25/0x60
>  crypto_ahash_setkey+0x8b/0x100
>  tcp_ao_add_cmd+0xe7a/0x1120
>  do_tcp_setsockopt+0x5ed/0x12a0
>  do_sock_setsockopt+0x82/0x100
>  __sys_setsockopt+0xe9/0x160
>  __x64_sys_setsockopt+0x60/0x70
>  do_syscall_64+0x3c/0xe0
>  entry_SYSCALL_64_after_hwframe+0x46/0x4e
>  </TASK>
> RIP: 0010:crypto_mod_get+0x20/0x60

Make sure that the child/clone has using_shash set when parent is
an shash user.

Fixes: 2f1f34c ("crypto: ahash - optimize performance when wrapping shash")
Cc: David Ahern <dsahern@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Francesco Ruggeri <fruggeri05@gmail.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Salam Noureddine <noureddine@arista.com>
Cc: netdev@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
roxell pushed a commit to roxell/linux that referenced this pull request Nov 8, 2023
The cloned child of ahash that uses shash under the hood should use
shash helpers (like crypto_shash_setkey()).

The following panic may be observed on TCP-AO selftests:

> ==================================================================
> BUG: KASAN: wild-memory-access in crypto_mod_get+0x1b/0x60
> Write of size 4 at addr 5d5be0ff5c415e14 by task connect_ipv4/1397
>
> CPU: 0 PID: 1397 Comm: connect_ipv4 Tainted: G        W          6.6.0+ torvalds#47
> Call Trace:
>  <TASK>
>  dump_stack_lvl+0x46/0x70
>  kasan_report+0xc3/0xf0
>  kasan_check_range+0xec/0x190
>  crypto_mod_get+0x1b/0x60
>  crypto_spawn_alg+0x53/0x140
>  crypto_spawn_tfm2+0x13/0x60
>  hmac_init_tfm+0x25/0x60
>  crypto_ahash_setkey+0x8b/0x100
>  tcp_ao_add_cmd+0xe7a/0x1120
>  do_tcp_setsockopt+0x5ed/0x12a0
>  do_sock_setsockopt+0x82/0x100
>  __sys_setsockopt+0xe9/0x160
>  __x64_sys_setsockopt+0x60/0x70
>  do_syscall_64+0x3c/0xe0
>  entry_SYSCALL_64_after_hwframe+0x46/0x4e
> ==================================================================
> general protection fault, probably for non-canonical address 0x5d5be0ff5c415e14: 0000 [#1] PREEMPT SMP KASAN
> CPU: 0 PID: 1397 Comm: connect_ipv4 Tainted: G    B   W          6.6.0+ torvalds#47
> Call Trace:
>  <TASK>
>  ? die_addr+0x3c/0xa0
>  ? exc_general_protection+0x144/0x210
>  ? asm_exc_general_protection+0x22/0x30
>  ? add_taint+0x26/0x90
>  ? crypto_mod_get+0x20/0x60
>  ? crypto_mod_get+0x1b/0x60
>  ? ahash_def_finup_done1+0x58/0x80
>  crypto_spawn_alg+0x53/0x140
>  crypto_spawn_tfm2+0x13/0x60
>  hmac_init_tfm+0x25/0x60
>  crypto_ahash_setkey+0x8b/0x100
>  tcp_ao_add_cmd+0xe7a/0x1120
>  do_tcp_setsockopt+0x5ed/0x12a0
>  do_sock_setsockopt+0x82/0x100
>  __sys_setsockopt+0xe9/0x160
>  __x64_sys_setsockopt+0x60/0x70
>  do_syscall_64+0x3c/0xe0
>  entry_SYSCALL_64_after_hwframe+0x46/0x4e
>  </TASK>
> RIP: 0010:crypto_mod_get+0x20/0x60

Make sure that the child/clone has using_shash set when parent is
an shash user.

Fixes: 2f1f34c ("crypto: ahash - optimize performance when wrapping shash")
Cc: David Ahern <dsahern@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Francesco Ruggeri <fruggeri05@gmail.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Salam Noureddine <noureddine@arista.com>
Cc: netdev@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
1054009064 pushed a commit to 1054009064/linux that referenced this pull request Nov 8, 2023
[ Upstream commit 72377ab ]

Christoph reported that the MPTCP protocol can find the subflow-level
write queue unexpectedly not empty while crafting a zero-window probe,
hitting a warning:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 188 at net/mptcp/protocol.c:1312 mptcp_sendmsg_frag+0xc06/0xe70
Modules linked in:
CPU: 0 PID: 188 Comm: kworker/0:2 Not tainted 6.6.0-rc2-g1176aa719d7a torvalds#47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_sendmsg_frag+0xc06/0xe70 net/mptcp/protocol.c:1312
RAX: 47d0530de347ff6a RBX: 47d0530de347ff6b RCX: ffff8881015d3c00
RDX: ffff8881015d3c00 RSI: 47d0530de347ff6b RDI: 47d0530de347ff6b
RBP: 47d0530de347ff6b R08: ffffffff8243c6a8 R09: ffffffff82042d9c
R10: 0000000000000002 R11: ffffffff82056850 R12: ffff88812a13d580
R13: 0000000000000001 R14: ffff88812b375e50 R15: ffff88812bbf3200
FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000695118 CR3: 0000000115dfc001 CR4: 0000000000170ef0
Call Trace:
 <TASK>
 __subflow_push_pending+0xa4/0x420 net/mptcp/protocol.c:1545
 __mptcp_push_pending+0x128/0x3b0 net/mptcp/protocol.c:1614
 mptcp_release_cb+0x218/0x5b0 net/mptcp/protocol.c:3391
 release_sock+0xf6/0x100 net/core/sock.c:3521
 mptcp_worker+0x6e8/0x8f0 net/mptcp/protocol.c:2746
 process_scheduled_works+0x341/0x690 kernel/workqueue.c:2630
 worker_thread+0x3a7/0x610 kernel/workqueue.c:2784
 kthread+0x143/0x180 kernel/kthread.c:388
 ret_from_fork+0x4d/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304
 </TASK>

The root cause of the issue is that expectations are wrong: e.g. due
to MPTCP-level re-injection we can hit the critical condition.

Explicitly avoid the zero-window probe when the subflow write queue
is not empty and drop the related warnings.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: multipath-tcp/mptcp_net-next#444
Fixes: f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-3-17ecb002e41d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
MingcongBai pushed a commit to AOSC-Tracking/linux that referenced this pull request Dec 24, 2023
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
shikongzhineng pushed a commit to shikongzhineng/linux that referenced this pull request Dec 28, 2023
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
yetist pushed a commit to loongarchlinux/linux that referenced this pull request Jan 9, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
intel-lab-lkp pushed a commit to intel-lab-lkp/linux that referenced this pull request Jan 9, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
arinc9 pushed a commit to arinc9/linux that referenced this pull request Jan 10, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
shikongzhineng pushed a commit to shikongzhineng/linux that referenced this pull request Jan 10, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Gelbpunkt pushed a commit to sm8450-mainline/linux that referenced this pull request Jan 11, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
intel-lab-lkp pushed a commit to intel-lab-lkp/linux that referenced this pull request Jan 12, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
cthbleachbit pushed a commit to AOSC-Tracking/linux that referenced this pull request Jan 17, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
cthbleachbit pushed a commit to AOSC-Tracking/linux that referenced this pull request Jan 17, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
roxell pushed a commit to roxell/linux that referenced this pull request Jan 17, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
cthbleachbit pushed a commit to AOSC-Tracking/linux that referenced this pull request Jan 17, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
logic10492 pushed a commit to logic10492/linux-amd-zen2 that referenced this pull request Jan 18, 2024
scx: Fix p->scx.flags corruption due to unsynchronized writes of SCX_TASK_ON_DSQ_PRIQ
intel-lab-lkp pushed a commit to intel-lab-lkp/linux that referenced this pull request Jan 18, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Jan 24, 2024
[ Upstream commit 36a8738 ]

The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
staging-kernelci-org pushed a commit to kernelci/linux that referenced this pull request Jan 25, 2024
[ Upstream commit 36a8738 ]

The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
intersectRaven pushed a commit to intersectRaven/linux that referenced this pull request Jan 26, 2024
[ Upstream commit 36a8738 ]

The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
1054009064 pushed a commit to 1054009064/linux that referenced this pull request Jan 26, 2024
[ Upstream commit 36a8738 ]

The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gyroninja added a commit to gyroninja/linux that referenced this pull request Jan 28, 2024
KSAN calls into rcu code which then triggers a write that reenters into KSAN
getting the system stuck doing infinite recursion.

#0  kmsan_get_context () at mm/kmsan/kmsan.h:106
#1  __msan_get_context_state () at mm/kmsan/instrumentation.c:331
#2  0xffffffff81495671 in get_current () at ./arch/x86/include/asm/current.h:42
#3  rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
#4  __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
#5  0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#6  pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#7  kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#8  virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#9  0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#10 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#11 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#12 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#13 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#14 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#15 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#16 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#17 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#18 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#19 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#20 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#21 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#22 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#23 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#24 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#25 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#26 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#27 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#28 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#29 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#30 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#31 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#32 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#33 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#34 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#35 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#36 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#37 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#38 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#39 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#40 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#41 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#42 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#43 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#44 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#45 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#46 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#47 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#48 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#49 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#50 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#51 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
#52 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
#53 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#54 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#55 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#56 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#57 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
#58 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#59 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#60 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#61 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#62 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#63 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#64 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#65 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#66 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#67 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#68 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#69 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
#70 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#71 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#72 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#73 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#74 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#75 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#76 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#77 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff86203c90) at ./arch/x86/include/asm/kmsan.h:82
torvalds#78 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff86203c90) at mm/kmsan/shadow.c:75
torvalds#79 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff86203c90, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#80 kmsan_get_shadow_origin_ptr (address=0xffffffff86203c90, size=8, store=false) at mm/kmsan/shadow.c:97
torvalds#81 0xffffffff81b1dc72 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=8, store=false) at mm/kmsan/instrumentation.c:36
torvalds#82 __msan_metadata_ptr_for_load_8 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:92
torvalds#83 0xffffffff814fdb9e in filter_irq_stacks (entries=<optimized out>, nr_entries=4) at kernel/stacktrace.c:397
torvalds#84 0xffffffff829520e8 in stack_depot_save_flags (entries=0xffffffff8620d974 <init_task+1012>, nr_entries=4, alloc_flags=0, depot_flags=0) at lib/stackdepot.c:500
torvalds#85 0xffffffff81b1e560 in __msan_poison_alloca (address=0xffffffff86203da0, size=24, descr=<optimized out>) at mm/kmsan/instrumentation.c:285
torvalds#86 0xffffffff8562821c in _printk (fmt=0xffffffff85f191a5 "\0016Attempting lock1") at kernel/printk/printk.c:2324
torvalds#87 0xffffffff81942aa2 in kmem_cache_create_usercopy (name=0xffffffff85f18903 "mm_struct", size=1296, align=0, flags=270336, useroffset=<optimized out>, usersize=<optimized out>, ctor=0x0 <fixed_percpu_data>) at mm/slab_common.c:296
torvalds#88 0xffffffff86f337a0 in mm_cache_init () at kernel/fork.c:3262
torvalds#89 0xffffffff86eacb8e in start_kernel () at init/main.c:932
torvalds#90 0xffffffff86ecdf94 in x86_64_start_reservations (real_mode_data=0x140e0 <exception_stacks+28896> <error: Cannot access memory at address 0x140e0>) at arch/x86/kernel/head64.c:555
torvalds#91 0xffffffff86ecde9b in x86_64_start_kernel (real_mode_data=0x140e0 <exception_stacks+28896> <error: Cannot access memory at address 0x140e0>) at arch/x86/kernel/head64.c:536
torvalds#92 0xffffffff810001d3 in secondary_startup_64 () at /pool/workspace/linux/arch/x86/kernel/head_64.S:461
torvalds#93 0x0000000000000000 in ??
gyroninja added a commit to gyroninja/linux that referenced this pull request Jan 28, 2024
As of 5ec8e8e(mm/sparsemem: fix race in accessing memory_section->usage) KMSAN
now calls into RCU tree code during kmsan_get_metadata. This will trigger a
write that will reenter into KMSAN getting the system stuck doing infinite
recursion.

#0  kmsan_get_context () at mm/kmsan/kmsan.h:106
#1  __msan_get_context_state () at mm/kmsan/instrumentation.c:331
#2  0xffffffff81495671 in get_current () at ./arch/x86/include/asm/current.h:42
#3  rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
#4  __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
#5  0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#6  pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#7  kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#8  virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#9  0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#10 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#11 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#12 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#13 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#14 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#15 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#16 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#17 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#18 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#19 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#20 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#21 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#22 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#23 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#24 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#25 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#26 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#27 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#28 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#29 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#30 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#31 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#32 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#33 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#34 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#35 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#36 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#37 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#38 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#39 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#40 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#41 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#42 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#43 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#44 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#45 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#46 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#47 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#48 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#49 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#50 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#51 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
#52 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
#53 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#54 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#55 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#56 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#57 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
#58 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#59 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#60 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#61 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#62 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#63 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#64 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#65 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#66 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#67 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82
torvalds#68 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75
torvalds#69 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143
#70 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97
torvalds#71 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36
torvalds#72 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91
torvalds#73 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379
torvalds#74 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402
torvalds#75 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748
torvalds#76 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016
torvalds#77 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff86203c90) at ./arch/x86/include/asm/kmsan.h:82
torvalds#78 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff86203c90) at mm/kmsan/shadow.c:75
torvalds#79 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff86203c90, is_origin=false) at mm/kmsan/shadow.c:143
torvalds#80 kmsan_get_shadow_origin_ptr (address=0xffffffff86203c90, size=8, store=false) at mm/kmsan/shadow.c:97
torvalds#81 0xffffffff81b1dc72 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=8, store=false) at mm/kmsan/instrumentation.c:36
torvalds#82 __msan_metadata_ptr_for_load_8 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:92
torvalds#83 0xffffffff814fdb9e in filter_irq_stacks (entries=<optimized out>, nr_entries=4) at kernel/stacktrace.c:397
torvalds#84 0xffffffff829520e8 in stack_depot_save_flags (entries=0xffffffff8620d974 <init_task+1012>, nr_entries=4, alloc_flags=0, depot_flags=0) at lib/stackdepot.c:500
torvalds#85 0xffffffff81b1e560 in __msan_poison_alloca (address=0xffffffff86203da0, size=24, descr=<optimized out>) at mm/kmsan/instrumentation.c:285
torvalds#86 0xffffffff8562821c in _printk (fmt=0xffffffff85f191a5 "\0016Attempting lock1") at kernel/printk/printk.c:2324
torvalds#87 0xffffffff81942aa2 in kmem_cache_create_usercopy (name=0xffffffff85f18903 "mm_struct", size=1296, align=0, flags=270336, useroffset=<optimized out>, usersize=<optimized out>, ctor=0x0 <fixed_percpu_data>) at mm/slab_common.c:296
torvalds#88 0xffffffff86f337a0 in mm_cache_init () at kernel/fork.c:3262
torvalds#89 0xffffffff86eacb8e in start_kernel () at init/main.c:932
torvalds#90 0xffffffff86ecdf94 in x86_64_start_reservations (real_mode_data=0x140e0 <exception_stacks+28896> <error: Cannot access memory at address 0x140e0>) at arch/x86/kernel/head64.c:555
torvalds#91 0xffffffff86ecde9b in x86_64_start_kernel (real_mode_data=0x140e0 <exception_stacks+28896> <error: Cannot access memory at address 0x140e0>) at arch/x86/kernel/head64.c:536
torvalds#92 0xffffffff810001d3 in secondary_startup_64 () at /pool/workspace/linux/arch/x86/kernel/head_64.S:461
torvalds#93 0x0000000000000000 in ??
NeroReflex pushed a commit to NeroReflex/linux that referenced this pull request Feb 3, 2024
[ Upstream commit 36a8738 ]

The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
yetist pushed a commit to loongarchlinux/linux that referenced this pull request Feb 29, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf torvalds#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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