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Sync up with Linus #22

Merged
merged 268 commits into from
Jan 13, 2015
Merged

Sync up with Linus #22

merged 268 commits into from
Jan 13, 2015

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dabrace
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@dabrace dabrace commented Jan 13, 2015

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dantti and others added 30 commits December 17, 2014 17:23
Allows for HID_BATTERY_STRENGTH config be enabled without the need for HID
module to be built-in, prior to this HID and POWER_SUPPLY had to be equal, and
now we only select POWER_SUPPLY and depend on the HID module.

Signed-off-by: Daniel Nicoletti <dantti12@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
pps_{lock,unlock}() call intel_display_power_{get,put}() outside
pps_mutes to avoid deadlocks with the power_domain mutex. In theory
during aux transfers we should usually have the relevant power domain
references already held by some higher level code, so this should not
result in much overhead (exception being userspace i2c-dev access).
However thanks to the check_power_well() calls in
intel_display_power_{get/put}() we end up doing a few Punit reads for
each aux transfer. Obviously doing this for each byte transferred via
i2c-over-aux is not a good idea.

I can't think of a good way to keep check_power_well() while eliminating
the overhead, so let's just remove check_power_well() entirely.

Fixes a driver init time regression introduced by:
 commit 773538e
 Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
 Date:   Thu Sep 4 14:54:56 2014 +0300

    drm/i915: Reset power sequencer pipe tracking when disp2d is off

Credit goes to Jani for figuring this out.

v2: Add the regression note in the commit message.

Cc: stable@vger.kernel.org (v3.18+)
Cc: Egbert Eich <eich@suse.de>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86201
Tested-by: Wendy Wang <wendy.wang@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
The flip stall detector kicks in when pending>=INTEL_FLIP_COMPLETE. That
means if we first call intel_prepare_page_flip() but don't call
intel_finish_page_flip(), the next stall check will erroneosly think
the page flip was somehow stuck.

With enough debug spew emitted from the interrupt handler my 830 hangs
when this happens. My theory is that the previous vblank interrupt gets
sufficiently delayed that the handler will see the pending bit set in
IIR, but ISR still has the bit set as well (ie. the flip was processed
by CS but didn't complete yet). In this case the handler will proceed
to call intel_check_page_flip() immediately after
intel_prepare_page_flip(). It then tries to print a backtrace for the
stuck flip WARN, which apparetly results in way too much debug spew
delaying interrupt processing further. That then seems to cause an
endless loop in the interrupt handler, and the machine is dead until
the watchdog kicks in and reboots. At least limiting the number of
iterations of the loop in the interrupt handler also prevented the
hang.

So it seems better to not call intel_prepare_page_flip() without
immediately calling intel_finish_page_flip(). The IIR/ISR trickery
avoids races here so this is a perfectly safe thing to do.

v2: Fix typo in commit message (checkpatch)

Cc: stable@vger.kernel.org
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88381
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85888
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
The VGA_2X_MODE bit apparently affects the display even when the VGA
plane is disabled. The bit will set by the BIOS when the panel width
is at least 1280 pixels. So by preserving the bit from the BIOS we
end up with corrupted display on machines with such high res panels.
I only have 1024x768 panels on my gen2 machines so never ran into
this problem.

The original reason for preserving the VGACNTR register was to make
my 830 survive S3 with acpi_sleep=s3_bios option. However after
further 830 fixes that option is no longer needed to make S3 work
and preserving VGACNTR doesn't seem to be necessary without it,
so we can just revert the entire patch.

This reverts
commit 69769f9
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Fri Aug 15 01:22:08 2014 +0300

    drm/i915: Preserve VGACNTR bits from the BIOS

Cc: Bruno Prémont <bonbons@linux-vserver.org>
Cc: stable@vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=87171
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Without this RPM ref we can hit the device suspended WARN via:
i915_gem_object_pin()->ggtt_bind_vma->gen6_ggtt_insert_entries(). I
noticed this on my BYT while keeping the i915 device in runtime
suspended state for a while. I chose this place to take the ref to
avoid the possible deadlock via the mutex_lock taken both later in this
function and in the runtime suspend handler. This can happen if an RPM
suspend event is queued and need to be flushed before taking the RPM
ref.

Testcase: igt/pm_rpm/gem-evict-pwrite
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=87363
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Add a return to avoid a fall-through. Introduced in commit
57ac86c ("HID: logitech-hidpp: add
support of the first Logitech Wireless Touchpad").

Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Current names are reported as "K750", "M705", and it can be misleading
for the users when they look at their input device list.

Prefixing the names with "Logitech " makes things better.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
In mutex destroy code currently we pass to debug_check_no_locks_freed()

    [mem_from, mem_end)

address region. But debug_check_no_locks_freed() accepts

    mem_from, mem_*len*

i.e. second parameter is region length, not end address. And it was
always so, starting from 2006 (fbb9ce9 "lockdep: core").

Fix it, or else on a mutex destroy we wrongly check
much-wider-than-mutex region and can find not-yet-released other locks
there and wrongly report BUGs on them.

Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
The theory behind vdso randomization is that it's mapped at a random
offset above the top of the stack.  To avoid wasting a page of
memory for an extra page table, the vdso isn't supposed to extend
past the lowest PMD into which it can fit.  Other than that, the
address should be a uniformly distributed address that meets all of
the alignment requirements.

The current algorithm is buggy: the vdso has about a 50% probability
of being at the very end of a PMD.  The current algorithm also has a
decent chance of failing outright due to incorrect handling of the
case where the top of the stack is near the top of its PMD.

This fixes the implementation.  The paxtest estimate of vdso
"randomisation" improves from 11 bits to 18 bits.  (Disclaimer: I
don't know what the paxtest code is actually calculating.)

It's worth noting that this algorithm is inherently biased: the vdso
is more likely to end up near the end of its PMD than near the
beginning.  Ideally we would either nix the PMD sharing requirement
or jointly randomize the vdso and the stack to reduce the bias.

In the mean time, this is a considerable improvement with basically
no risk of compatibility issues, since the allowed outputs of the
algorithm are unchanged.

As an easy test, doing this:

for i in `seq 10000`
  do grep -P vdso /proc/self/maps |cut -d- -f1
done |sort |uniq -d

used to produce lots of output (1445 lines on my most recent run).
A tiny subset looks like this:

7fffdfffe000
7fffe01fe000
7fffe05fe000
7fffe07fe000
7fffe09fe000
7fffe0bfe000
7fffe0dfe000

Note the suspicious fe000 endings.  With the fix, I get a much more
palatable 76 repeated addresses.

Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
…x/kernel/git/luto/linux into x86/urgent

Pull a VDSO fix from Andy Lutomirski:

  "One vdso fix for a longstanding ASLR bug that's been in the news lately.

   The vdso base address has always been randomized, and I don't think there's
   anything particularly wrong with the range over which it's randomized,
   but the implementation seems to have been buggy since the very beginning.

   This fixes the implementation to remove a large bias that caused a small
   fraction of possible vdso load addresess to be vastly more likely than
   the rest of the possible addresses."

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
nouveau_ttm_tt_unpopulate() is supposed to return right after calling
ttm_dma_unpopulate() in the case of a coherent buffer. The return
statement was omitted, leading to the pages being unmapped twice. Fix
this.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
The failure paths if we fail to wake the card are less than desirable,
but there's not really a graceful way to handle this case currently.

I'll keep this situation in mind when I get to fixing other vm-related
issues.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Pierre Moreau <pierre.morrow@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Several users have, over time, reported issues with MSI on these IGPs.
They're old, rarely available, and MSI doesn't provide such huge
advantages on them. Just disable.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=87361
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=74492
Fixes: fa8c9ac ("drm/nv4c/mc: nv4x igp's have a different msi rearm register")
Cc: stable@vger.kernel.org
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
On !SMP systems spinlocks do not exist. Thus checking of they
are active will always fail.

Use
  assert_spin_locked(lock);
instead of
  BUG_ON(!spin_is_locked(lock));
to not BUG() on all UP systems.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
AMD GPU devices are dependent on AMD IOMMU controller functionality to allow
the GPU to access a process's virtual memory address space, without the need
for pinning the memory.

This patch changes the order in the drivers makefile, so iommu/ subsystem is
linked before gpu/ subsystem. That way, if the gpu and iommu drivers are
compiled inside the kernel image (not as modules), the correct order of device
loading is still maintained (iommu module is loaded before gpu module).

Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
When amdkfd and radeon are compiled inside the kernel image (not as modules),
radeon will load before amdkfd, which will cause a bug when radeon will probe
the GPUs.

When the two drivers are compiled as modules, amdkfd is loaded after radeon is
loaded but before radeon starts probing the GPUs. This is done because radeon
loads the amdkfd module through symbol_request function.

This patch makes amdkfd load before radeon when they are both compiled inside
the kernel image, which makes the behavior similar to the case when they are
modules, and prevents the kernel bug.

Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
…linux/kernel/git/sashal/linux into core/urgent

Pull a liblockdep fix from Sasha Levin:

 "A small (but important) fix to the way we detect freeing live locks. We would
  pass a wrong memory region when testing for locks inside freed memory spaces,
  which would trigger false positives."

Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is no reason for having it and, with commit 250a1ac ("x86,
smpboot: Remove pointless preempt_disable() in
native_smp_prepare_cpus()"), it prevents HVM guests from booting.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
The old scheme can lead to failure in certain cases - the
problem is that after bumping step_size the next (non-final)
iteration is only guaranteed to make available a memory block
the size of what step_size was before. E.g. for a memory block
[0,3004600000) we'd have:

 iter	start		end		step		amount
 1	3004400000	30045fffff	 2M		  2M
 2	3004000000	30043fffff	64M		  4M
 3	3000000000	3003ffffff	 2G		 64M
 4	2000000000	2fffffffff	64G		 64G

Yet to map 64G with 4k pages (as happens e.g. under PV Xen) we
need slightly over 128M, but the first three iterations made
only about 70M available.

The condition (new_mapped_ram_size > mapped_ram_size) for
bumping step_size is just not suitable. Instead we want to bump
it when we know we have enough memory available to cover a block
of the new step_size. And rather than making that condition more
complicated than needed, simply adjust step_size by the largest
possible factor we know we can cover at that point - which is
shifting it left by one less than the difference between page
table level shifts. (Interestingly the original STEP_SIZE_SHIFT
definition had a comment hinting at that having been the
intention, just that it should have been PUD_SHIFT-PMD_SHIFT-1
instead of (PUD_SHIFT-PMD_SHIFT)/2, and of course for non-PAE
32-bit we can't really use these two constants as they're equal
there.)

Furthermore the comment in get_new_step_size() didn't get
updated when the bottom-down mapping logic got added. Yet while
an overflow (flushing step_size to zero) of the shift doesn't
matter for the top-down method, it does for bottom-up because
round_up(x, 0) = 0, and an upper range boundary of zero can't
really work well.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/54945C1E020000780005114E@mail.emea.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When allocating space for load_balance_mask, in sched_init, when
CPUMASK_OFFSTACK is set, we've managed to spill over
KMALLOC_MAX_SIZE on our 6144 core machine.  The patch below
breaks up the allocations so that they don't overflow the max
alloc size.  It also allocates the masks on the the node from
which they'll most commonly be accessed, to minimize remote
accesses on NUMA machines.

Suggested-by: George Beshers <gbeshers@sgi.com>
Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Cc: George Beshers <gbeshers@sgi.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1418928270-148543-1-git-send-email-athorlton@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Chocked while compiling linux with dash shell instead of bash
shell. See:

   http://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html

Signed-off-by: Sylvain BERTRAND <sylvain.bertrand@gmail.com>
Link: http://lkml.kernel.org/r/20141223123912.GA1386@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 9def39b ("x86: Support compiling out human-friendly
processor feature names") made two source file targets
conditional. Such conditional targets will not be cleaned
automatically by make mrproper.

Fix by adding explicit clean-files targets for the two files.

Fixes: 9def39b ("x86: Support compiling out human-friendly processor feature names")
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Cc: Josh Triplett <josh@joshtriplett.org>
Link: http://lkml.kernel.org/r/1419335863-10608-1-git-send-email-bjorn@mork.no
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Sometimes it takes a long time to resort hist entries for output in case
of a large data file.  Show a progress bar window and inform user.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1419223455-4362-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The output will look like below.  (I added an error into ui__init() for
the test).

  $ perf report
  perf: Segmentation fault
  -------- backtrace --------
  perf[0x503781]
  /usr/lib/libc.so.6(+0x33b20)[0x7f1a14f04b20]
  perf(ui__init+0xd5)[0x503645]
  perf(setup_browser+0x97)[0x4ce4e7]
  perf(cmd_report+0xcea)[0x4392ba]
  perf[0x428493]
  perf(main+0x60a)[0x427c0a]
  /usr/lib/libc.so.6(__libc_start_main+0xf0)[0x7f1a14ef1040]
  perf[0x427d29]
  [0x0]

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1419223455-4362-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf report --children can be called with callchain disabled so no
need to append callchains.  Actually the root of callchain tree is not
initialized properly in this case.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1419223455-4362-7-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
…/scm/linux/kernel/git/xen/tip

Pull xen bug fixes from David Vrabel:
 "Several critical linear p2m fixes that prevented some hosts from
  booting"

* tag 'stable/for-linus-3.19-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: properly retrieve NMI reason
  xen: check for zero sized area when invalidating memory
  xen: use correct type for physical addresses
  xen: correct race in alloc_p2m_pmd()
  xen: correct error for building p2m list on 32 bits
  x86/xen: avoid freeing static 'name' when kasprintf() fails
  x86/xen: add extra memory for remapped frames during setup
  x86/xen: don't count how many PFNs are identity mapped
  x86/xen: Free bootmem in free_p2m_page() during early boot
  x86/xen: Remove unnecessary BUG_ON(preemptible()) in xen_setup_timer()
…/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:
 "This update contains three patches to fix one compile error, and two
  run-time bugs.  One of them fixes infinite loop on ARM"

* tag 'linux-kselftest-3.19-rc-5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/vm: fix link error for transhuge-stress test
  tools: testing: selftests: mq_perf_tests: Fix infinite loop on ARM
  selftests/exec: allow shell return code of 126
dabrace added a commit that referenced this pull request Jan 13, 2015
@dabrace dabrace merged commit ff0c551 into dabrace:master Jan 13, 2015
dabrace pushed a commit that referenced this pull request Feb 21, 2015
This patch addresses a bug reported during iser-target login/logout
stress testing, where iscsit_take_action_for_connection_exit() is
incorrectly invoking iscsit_close_connection() twice during IN_LOGOUT
state, after connection shutdown has already been initiated by
iser-target code.

Here is the backtrace:

BUG: unable to handle kernel NULL pointer dereference at 00000000000001f0
IP: [<ffffffffa033d992>] iscsit_take_action_for_connection_exit+0x62/0x110 [iscsi_target_mod]
PGD 0
Oops: 0000 [#1] SMP
Modules linked in: target_core_pscsi(O) target_core_file(O) target_core_iblock(O) ib_isert(O) iscsi_target_mod(O) ib_srpt(O) tcm_loop(O) tcm_fc(O) target_core_mod(O) mst_pciconf(OE) bonding mlx5_ib(O) mlx5_core libfc scsi_transport_fc netconsole configfs nfsv3 nfs_acl mlx4_ib(O) rdma_ucm(O) ib_ucm(O) rdma_cm(O) iw_cm(O) ib_uverbs(O) libiscsi_tcp libiscsi scsi_transport_iscsi mlx4_en mlx4_core ib_ipoib(O) ib_cm(O) ib_sa(O) ib_umad(O) ib_mad(O) ib_core(O) ib_addr(O) rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs fscache lockd grace autofs4 sunrpc 8021q garp stp llc ipv6 dm_mirror dm_region_hash dm_log dm_multipath uinput ipmi_si ipmi_msghandler acpi_pad iTCO_wdt iTCO_vendor_support dcdbas microcode pcspkr wmi sb_edac edac_core sg lpc_ich mfd_core shpchp tg3 ptp pps_core dm_mod ext3(E) jbd(E) mbcache(E) sr_mod(E) cdrom(E) sd_mod(E) ahci(E) libahci(E) megaraid_sas(E) [last unloaded: target_core_mod]
CPU: 2 PID: 5280 Comm: iscsi_ttx Tainted: G        W  OE  3.18.0-rc2+ #22
Hardware name: Dell Inc. PowerEdge R720/0VWT90, BIOS 2.0.9 03/08/2013
task: ffff8806132f9010 ti: ffff880601d6c000 task.ti: ffff880601d6c000
RIP: 0010:[<ffffffffa033d992>] [<ffffffffa033d992>] iscsit_take_action_for_connection_exit+0x62/0x110 [iscsi_target_mod]
RSP: 0018:ffff880601d6fe18  EFLAGS: 00010296
RAX: 0000000000000000 RBX: ffff8805dc437800 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 0000000000000200 RDI: ffffffffa033d98b
RBP: ffff880601d6fe28 R08: 0000000000000000 R09: 000000000000dd37
R10: 00000000ec5d4202 R11: 0000000000000001 R12: ffff8805dc437bf4
R13: ffff88061b831600 R14: ffff880601d6fe58 R15: ffff8806132f9010
FS:  0000000000000000(0000) GS:ffff88032fa20000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000001f0 CR3: 0000000001a14000 CR4: 00000000000407e0
Stack:
ffff8805dc437800 fffffffffffffe00 ffff880601d6feb8 ffffffffa034ed40
ffff8806132f9010 ffff880601d6fe70 0f00000000000000 ffff8805d51fbef0
0000000000000000 ffff8806132f9010 ffffffff8108e7f0 ffff880601d6fe70
Call Trace:
[<ffffffffa034ed40>] iscsi_target_tx_thread+0x160/0x220 [iscsi_target_mod]
[<ffffffff8108e7f0>] ? bit_waitqueue+0xb0/0xb0
[<ffffffffa034ebe0>] ? iscsit_handle_snack+0x190/0x190 [iscsi_target_mod]
[<ffffffff8107017e>] kthread+0xce/0xf0
[<ffffffff810700b0>] ? kthread_freezable_should_stop+0x70/0x70
[<ffffffff815a0b6c>] ret_from_fork+0x7c/0xb0
[<ffffffff810700b0>] ? kthread_freezable_should_stop+0x70/0x70
Code: 06 0f 84 82 00 00 00 3c 08 74 4e f6 05 39 e6 02 00 04 0f 85 9e 00 00 00 c6 43 19 08 4c 89 e7 e8 65 2a 26 e1 48 8b 83 a0 04 00 00 <48> 8b 88 f0 01 00 00 80 b9 d8 04 00 00 02 74 2e f6 05 31 e6 02
RIP  [<ffffffffa033d992>] iscsit_take_action_for_connection_exit+0x62/0x110 [iscsi_target_mod]
RSP <ffff880601d6fe18>
CR2: 00000000000001f0
---[ end trace a0c33436cd0836b4 ]---

This special case is still required by ISCSI_TCP transport during a
iscsit_handle_logout_cmd() failure case in iscsi_target_rx_opcode(),
but must be avoided for iser-target.

Reported-by: Sagi Grimberg <sagig@mellanox.com>
Reported-by: Slava Shwartsman <valyushash@gmail.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Slava Shwartsman <valyushash@gmail.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
dabrace pushed a commit that referenced this pull request Apr 7, 2015
If register_shrinker() failed, nfsd will cause a NULL pointer access as,

[ 9250.875465] nfsd: last server has exited, flushing export cache
[ 9251.427270] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 9251.427393] IP: [<ffffffff8136fc29>] __list_del_entry+0x29/0xd0
[ 9251.427579] PGD 13e4d067 PUD 13e4c067 PMD 0
[ 9251.427633] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 9251.427706] Modules linked in: ip6t_rpfilter ip6t_REJECT bnep bluetooth xt_conntrack cfg80211 rfkill ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw btrfs xfs microcode ppdev serio_raw pcspkr xor libcrc32c raid6_pq e1000 parport_pc parport i2c_piix4 i2c_core nfsd(OE-) auth_rpcgss nfs_acl lockd sunrpc(E) ata_generic pata_acpi
[ 9251.428240] CPU: 0 PID: 1557 Comm: rmmod Tainted: G           OE 3.16.0-rc2+ #22
[ 9251.428366] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
[ 9251.428496] task: ffff880000849540 ti: ffff8800136f4000 task.ti: ffff8800136f4000
[ 9251.428593] RIP: 0010:[<ffffffff8136fc29>]  [<ffffffff8136fc29>] __list_del_entry+0x29/0xd0
[ 9251.428696] RSP: 0018:ffff8800136f7ea0  EFLAGS: 00010207
[ 9251.428751] RAX: 0000000000000000 RBX: ffffffffa0116d48 RCX: dead000000200200
[ 9251.428814] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa0116d48
[ 9251.428876] RBP: ffff8800136f7ea0 R08: ffff8800136f4000 R09: 0000000000000001
[ 9251.428939] R10: 8080808080808080 R11: 0000000000000000 R12: ffffffffa011a5a0
[ 9251.429002] R13: 0000000000000800 R14: 0000000000000000 R15: 00000000018ac090
[ 9251.429064] FS:  00007fb9acef0740(0000) GS:ffff88003fa00000(0000) knlGS:0000000000000000
[ 9251.429164] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9251.429221] CR2: 0000000000000000 CR3: 0000000031a17000 CR4: 00000000001407f0
[ 9251.429306] Stack:
[ 9251.429410]  ffff8800136f7eb8 ffffffff8136fcdd ffffffffa0116d20 ffff8800136f7ed0
[ 9251.429511]  ffffffff8118a0f2 0000000000000000 ffff8800136f7ee0 ffffffffa00eb765
[ 9251.429610]  ffff8800136f7ef0 ffffffffa010e93c ffff8800136f7f78 ffffffff81104ac2
[ 9251.429709] Call Trace:
[ 9251.429755]  [<ffffffff8136fcdd>] list_del+0xd/0x30
[ 9251.429896]  [<ffffffff8118a0f2>] unregister_shrinker+0x22/0x40
[ 9251.430037]  [<ffffffffa00eb765>] nfsd_reply_cache_shutdown+0x15/0x90 [nfsd]
[ 9251.430106]  [<ffffffffa010e93c>] exit_nfsd+0x9/0x6cd [nfsd]
[ 9251.430192]  [<ffffffff81104ac2>] SyS_delete_module+0x162/0x200
[ 9251.430280]  [<ffffffff81013b69>] ? do_notify_resume+0x59/0x90
[ 9251.430395]  [<ffffffff816f2369>] system_call_fastpath+0x16/0x1b
[ 9251.430457] Code: 00 00 55 48 8b 17 48 b9 00 01 10 00 00 00 ad de 48 8b 47 08 48 89 e5 48 39 ca 74 29 48 b9 00 02 20 00 00 00 ad de 48 39 c8 74 7a <4c> 8b 00 4c 39 c7 75 53 4c 8b 42 08 4c 39 c7 75 2b 48 89 42 08
[ 9251.430691] RIP  [<ffffffff8136fc29>] __list_del_entry+0x29/0xd0
[ 9251.430755]  RSP <ffff8800136f7ea0>
[ 9251.430805] CR2: 0000000000000000
[ 9251.431033] ---[ end trace 080f3050d082b4ea ]---

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
dabrace pushed a commit that referenced this pull request Aug 5, 2015
Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  #1 schedule at ffffffff815ab76e
  #2 schedule_timeout at ffffffff815ae5e5
  #3 io_schedule_timeout at ffffffff815aad6a
  #4 bit_wait_io at ffffffff815abfc6
  #5 __wait_on_bit at ffffffff815abda5
  #6 wait_on_page_bit at ffffffff8111fd4f
  #7 shrink_page_list at ffffffff81135445
  #8 shrink_inactive_list at ffffffff81135845
  #9 shrink_lruvec at ffffffff81135ead
 #10 shrink_zone at ffffffff811360c3
 #11 shrink_zones at ffffffff81136eff
 #12 do_try_to_free_pages at ffffffff8113712f
 #13 try_to_free_mem_cgroup_pages at ffffffff811372be
 #14 try_charge at ffffffff81189423
 #15 mem_cgroup_try_charge at ffffffff8118c6f5
 #16 __add_to_page_cache_locked at ffffffff8112137d
 #17 add_to_page_cache_lru at ffffffff81121618
 #18 pagecache_get_page at ffffffff8112170b
 #19 grow_dev_page at ffffffff811c8297
 #20 __getblk_slow at ffffffff811c91d6
 #21 __getblk_gfp at ffffffff811c92c1
 #22 ext4_ext_grow_indepth at ffffffff8124565c
 #23 ext4_ext_create_new_leaf at ffffffff81246ca8
 #24 ext4_ext_insert_extent at ffffffff81246f09
 #25 ext4_ext_map_blocks at ffffffff8124a848
 #26 ext4_map_blocks at ffffffff8121a5b7
 #27 mpage_map_one_extent at ffffffff8121b1fa
 #28 mpage_map_and_submit_extent at ffffffff8121f07b
 #29 ext4_writepages at ffffffff8121f6d5
 #30 do_writepages at ffffffff8112c490
 #31 __filemap_fdatawrite_range at ffffffff81120199
 #32 filemap_flush at ffffffff8112041c
 #33 ext4_alloc_da_blocks at ffffffff81219da1
 #34 ext4_rename at ffffffff81229b91
 #35 ext4_rename2 at ffffffff81229e32
 #36 vfs_rename at ffffffff811a08a5
 #37 SYSC_renameat2 at ffffffff811a3ffc
 #38 sys_renameat2 at ffffffff811a408e
 #39 sys_rename at ffffffff8119e51e
 #40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384 ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f4 ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

Cc: stable@vger.kernel.org # 3.9+
[tytso@mit.edu: corrected the control flow]
Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dabrace pushed a commit that referenced this pull request Oct 7, 2015
it was broken by 35d5d20
"mtd: mxc_nand: cleanup copy_spare function"

else we get the following error :
[   22.709507] ubi0: attaching mtd3
[   23.613470] ubi0: scanning is finished
[   23.617278] ubi0: empty MTD device detected
[   23.623219] Unhandled fault: imprecise external abort (0x1c06) at 0x9e62f0ec
[   23.630291] pgd = 9df80000
[   23.633005] [9e62f0ec] *pgd=8e60041e(bad)
[   23.637064] Internal error: : 1c06 [#1] SMP ARM
[   23.641605] Modules linked in:
[   23.644687] CPU: 0 PID: 99 Comm: ubiattach Not tainted 4.2.0-dirty #22
[   23.651222] Hardware name: Freescale i.MX53 (Device Tree Support)
[   23.657322] task: 9e687300 ti: 9dcfc000 task.ti: 9dcfc000
[   23.662744] PC is at memcpy16_toio+0x4c/0x74
[   23.667026] LR is at mxc_nand_command+0x484/0x640
[   23.671739] pc : [<803f9c08>]    lr : [<803faeb0>]    psr: 60000013
[   23.671739] sp : 9dcfdb10  ip : 9e62f0ea  fp : 9dcfdb1c
[   23.683222] r10: a09c1000  r9 : 0000001a  r8 : ffffffff
[   23.688453] r7 : ffffffff  r6 : 9e674810  r5 : 9e674810  r4 : 000000b6
[   23.694985] r3 : a09c16a4  r2 : a09c16a4  r1 : a09c16a4  r0 : 0000ffff
[   23.701521] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   23.708662] Control: 10c5387d  Table: 8df80019  DAC: 00000015
[   23.714413] Process ubiattach (pid: 99, stack limit = 0x9dcfc210)
[   23.720514] Stack: (0x9dcfdb10 to 0x9dcfe000)
[   23.724881] db00:                                     9dcfdb6c 9dcfdb20 803faeb0 803f9bc8
[   23.733069] db20: 803f227c 803f9b74 ffffffff 9e674810 9e674810 9e674810 00000040 9e62f010
[   23.741255] db40: 803faa2c 9e674b40 9e674810 803faa2c 00000400 803faa2c 00000000 9df42800
[   23.749441] db60: 9dcfdb9c 9dcfdb70 803f2024 803faa38 9e4201cc 00000000 803f0a78 9e674b40
[   23.757627] db80: 803f1f80 9e674810 00000400 00000400 9dcfdc14 9dcfdba0 803f3bd8 803f1f8c
[   23.765814] dba0: 9e4201cc 00000000 00000580 00000000 00000000 800718c0 0000007f 00001000
[   23.774000] dbc0: 9df42800 000000e0 00000000 00000000 9e4201cc 00000000 00000000 00000000
[   23.782186] dbe0: 00000580 00000580 00000000 9e674810 9dcfdc20 9dcfdce8 9df42800 00580000
[   23.790372] dc00: 00000000 00000400 9dcfdc6c 9dcfdc18 803f3f94 803f39a4 9dcfdc20 00000000
[   23.798558] dc20: 00000000 00000400 00000000 00000000 00000000 00000000 9df42800 00000000
[   23.806744] dc40: 9dcfdd0c 00580000 00000000 00000400 00000000 9df42800 9dee1000 9d802000
[   23.814930] dc60: 9dcfdc94 9dcfdc70 803eb63c 803f3f38 00000400 9dcfdce8 9df42800 dead4ead
[   23.823116] dc80: 803eb5f4 00000000 9dcfdcc4 9dcfdc98 803e82ac 803eb600 00000400 9dcfdce8
[   23.831301] dca0: 9df42800 00000400 9dee0000 00000000 00000400 00000000 9dcfdd1c 9dcfdcc8
[   23.839488] dcc0: 80406048 803e8230 00000400 9dcfdce8 9df42800 9dcfdc78 00000008 00000000
[   23.847673] dce0: 00000000 00000000 00000000 00000004 00000000 9df42800 9dee0000 00000000
[   23.855859] dd00: 9d802030 00000000 9dc8b214 9d802000 9dcfdd44 9dcfdd20 804066cc 80405f50
[   23.864047] dd20: 00000400 9dc8b200 9d802030 9df42800 9dee0000 9dc8b200 9dcfdd84 9dcfdd48
[   23.872233] dd40: 8040a544 804065ac 9e401c80 000080d0 9dcfdd84 00000001 800fc828 9df42400
[   23.880418] dd60: 00000000 00000080 9dc8b200 9dc8b200 9dc8b200 9dee0000 9dcfdddc 9dcfdd8
[   23.888605] dd80: 803fb560 8040a440 9dcfddc4 9dcfdd98 800f1428 9dee1000 a0acf000 00000000
[   23.896792] dda0: 00000000 ffffffff 00000006 00000000 9dee0000 9dee0000 00005600 00000080
[   23.904979] ddc0: 9dc8b200 a0acf000 9dc8b200 8112514c 9dcfde24 9dcfdde0 803fc08c 803fb4f0
[   23.913165] dde0: 9e401c80 00000013 9dcfde04 9dcfddf8 8006bbf8 8006ba00 9dcfde24 00000000
[   23.921351] de00: 9dee0000 00000065 9dee0000 00000001 9dc8b200 8112514c 9dcfde84 9dcfde28
[   23.929538] de20: 8040afa0 803fb948 ffffffff 00000000 9dc8b214 9dcfde40 800f1428 800f11dc
[   23.937724] de40: 9dc8b21c 9dc8b20c 9dc8b204 9dee1000 9dc8b214 8069bb60 fffff000 fffff000
[   23.945911] de60: 9e7b5400 00000000 9dee0000 9dee1000 00001000 9e7b5400 9dcfdecc 9dcfde88
[   23.954097] de80: 803ff1bc 8040a630 9dcfdea4 9dcfde98 00000800 00000800 9dcfdecc 9dcfdea8
[   23.962284] dea0: 803e8f6c 00000000 7e87ab70 9e7b5400 80113e30 00000003 9dcfc000 00000000
[   23.970470] dec0: 9dcfdf04 9dcfded0 804008cc 803feb98 ffffffff 00000003 00000000 00000000
[   23.978656] dee0: 00000000 00000000 9e7cb000 9dc193e0 7e87ab70 9dd92140 9dcfdf7c 9dcfdf08
[   23.986842] df00: 80113b5c 8040080c 800fbed8 8006bbf0 9e7cb000 00000003 9e7cb000 9dd92140
[   23.995029] df20: 9dc193e0 9dd92148 9dcfdf4c 9dcfdf38 8011022c 800fbe78 8000f9cc 9e687300
[   24.003216] df40: 9dcfdf6c 9dcfdf50 8011f798 8007ffe8 7e87ab70 9dd92140 00000003 9dd92140
[   24.011402] df60: 40186f40 7e87ab70 9dcfc000 00000000 9dcfdfa4 9dcfdf80 80113e30 8011373c
[   24.019588] df80: 7e87ab70 7e87ab70 7e87aea9 00000036 8000fb8 9dcfc000 00000000 9dcfdfa8
[   24.027775] dfa0: 8000f9a0 80113e00 7e87ab70 7e87ab70 00000003 40186f40 7e87ab70 00000000
[   24.035962] dfc0: 7e87ab70 7e87ab70 7e87aea9 00000036 00000000 00000000 76fd1f70 00000000
[   24.044148] dfe0: 76f80f8c 7e87ab28 00009810 76f80fc4 60000010 00000003 00000000 00000000
[   24.052328] Backtrace:
[   24.054806] [<803f9bbc>] (memcpy16_toio) from [<803faeb0>] (mxc_nand_command+0x484/0x640)
[   24.062996] [<803faa2c>] (mxc_nand_command) from [<803f2024>] (nand_write_page+0xa4/0x154)
[   24.071264]  r10:9df42800 r9:00000000 r8:803faa2c r7:00000400 r6:803faa2c r5:9e674810
[   24.079180]  r4:9e674b40
[   24.081738] [<803f1f80>] (nand_write_page) from [<803f3bd8>] (nand_do_write_ops+0x240/0x444)
[   24.090180]  r8:00000400 r7:00000400 r6:9e674810 r5:803f1f80 r4:9e674b40
[   24.096970] [<803f3998>] (nand_do_write_ops) from [<803f3f94>] (nand_write+0x68/0x88)
[   24.104804]  r10:00000400 r9:00000000 r8:00580000 r7:9df42800 r6:9dcfdce8 r5:9dcfdc20
[   24.112719]  r4:9e674810
[   24.115287] [<803f3f2c>] (nand_write) from [<803eb63c>] (part_write+0x48/0x50)
[   24.122514]  r10:9d802000 r9:9dee1000 r8:9df42800 r7:00000000 r6:00000400 r5:00000000
[   24.130429]  r4:00580000
[   24.132989] [<803eb5f4>] (part_write) from [<803e82ac>] (mtd_write+0x88/0xa0)
[   24.140129]  r5:00000000 r4:803eb5f4
[   24.143748] [<803e8224>] (mtd_write) from [<80406048>] (ubi_io_write+0x104/0x65c)
[   24.151235]  r7:00000000 r6:00000400 r5:00000000 r4:9dee0000
[   24.156968] [<80405f44>] (ubi_io_write) from [<804066cc>] (ubi_io_write_ec_hdr+0x12c/0x190)
[   24.165323]  r10:9d802000 r9:9dc8b214 r8:00000000 r7:9d802030 r6:00000000 r5:9dee0000
[   24.173239]  r4:9df42800
[   24.175798] [<804065a0>] (ubi_io_write_ec_hdr) from [<8040a544>] (ubi_early_get_peb+0x110/0x1f0)
[   24.184587]  r6:9dc8b200 r5:9dee0000 r4:9df42800
[   24.189262] [<8040a434>] (ubi_early_get_peb) from [<803fb560>] (create_vtbl+0x7c/0x238)
[   24.197271]  r10:9dee0000 r9:9dc8b200 r8:9dc8b200 r7:9dc8b200 r6:00000080 r5:00000000
[   24.205187]  r4:9df42400
[   24.207746] [<803fb4e4>] (create_vtbl) from [<803fc08c>] (ubi_read_volume_table+0x750/0xa64)
[   24.216187]  r10:8112514c r9:9dc8b200 r8:a0acf000 r7:9dc8b200 r6:00000080 r5:00005600
[   24.224103]  r4:9dee0000
[   24.226662] [<803fb93c>] (ubi_read_volume_table) from [<8040afa0>] (ubi_attach+0x97c/0x152c)
[   24.235103]  r10:8112514c r9:9dc8b200 r8:00000001 r7:9dee0000 r6:00000065 r5:9dee0000
[   24.243018]  r4:00000000
[   24.245579] [<8040a624>] (ubi_attach) from [<803ff1bc>] (ubi_attach_mtd_dev+0x630/0xbac)
[   24.253673]  r10:9e7b5400 r9:00001000 r8:9dee1000 r7:9dee0000 r6:00000000 r5:9e7b5400
[   24.261588]  r4:fffff000
[   24.264148] [<803feb8c>] (ubi_attach_mtd_dev) from [<804008cc>] (ctrl_cdev_ioctl+0xcc/0x1cc)
[   24.272589]  r10:00000000 r9:9dcfc000 r8:00000003 r7:80113e30 r6:9e7b5400 r5:7e87ab70
[   24.280505]  r4:00000000
[   24.283070] [<80400800>] (ctrl_cdev_ioctl) from [<80113b5c>] (do_vfs_ioctl+0x42c/0x6c4)
[   24.291077]  r6:9dd92140 r5:7e87ab70 r4:9dc193e0
[   24.295753] [<80113730>] (do_vfs_ioctl) from [<80113e30>] (SyS_ioctl+0x3c/0x64)
[   24.303066]  r10:00000000 r9:9dcfc000 r8:7e87ab70 r7:40186f40 r6:9dd92140 r5:00000003
[   24.310981]  r4:9dd92140
[   24.313549] [<80113df4>] (SyS_ioctl) from [<8000f9a0>] (ret_fast_syscall+0x0/0x54)
[   24.321123]  r9:9dcfc000 r8:8000fb84 r7:00000036 r6:7e87aea9 r5:7e87ab70 r4:7e87ab70
[   24.328957] Code: e1c300b0 e1510002 e1a03001 1afffff9 (e89da800)
[   24.335066] ---[ end trace ab1cb17887f21bbb ]---
[   24.340249] Unhandled fault: imprecise external abort (0x1c06) at 0x7ee8bcf0
[   24.347310] pgd = 9df3c000
[   24.350023] [7ee8bcf0] *pgd=8dcbf831, *pte=8eb3334f, *ppte=8eb3383f
Segmentation fault

Fixes: 35d5d20 ("mtd: mxc_nand: cleanup copy_spare function")
Signed-off-by: Eric Bénard <eric@eukrea.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Baruch Siach <baruch@tkos.co.il>
Cc: <stable@vger.kernel.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
dabrace pushed a commit that referenced this pull request Oct 10, 2016
Function ib_create_qp() was failing to return an error when
rdma_rw_init_mrs() fails, causing a crash further down in ib_create_qp()
when trying to dereferece the qp pointer which was actually a negative
errno.

The crash:

crash> log|grep BUG
[  136.458121] BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
crash> bt
PID: 3736   TASK: ffff8808543215c0  CPU: 2   COMMAND: "kworker/u64:2"
 #0 [ffff88084d323340] machine_kexec at ffffffff8105fbb0
 #1 [ffff88084d3233b0] __crash_kexec at ffffffff81116758
 #2 [ffff88084d323480] crash_kexec at ffffffff8111682d
 #3 [ffff88084d3234b0] oops_end at ffffffff81032bd6
 #4 [ffff88084d3234e0] no_context at ffffffff8106e431
 #5 [ffff88084d323530] __bad_area_nosemaphore at ffffffff8106e610
 #6 [ffff88084d323590] bad_area_nosemaphore at ffffffff8106e6f4
 #7 [ffff88084d3235a0] __do_page_fault at ffffffff8106ebdc
 #8 [ffff88084d323620] do_page_fault at ffffffff8106f057
 #9 [ffff88084d323660] page_fault at ffffffff816e3148
    [exception RIP: ib_create_qp+427]
    RIP: ffffffffa02554fb  RSP: ffff88084d323718  RFLAGS: 00010246
    RAX: 0000000000000004  RBX: fffffffffffffff4  RCX: 000000018020001f
    RDX: ffff880830997fc0  RSI: 0000000000000001  RDI: ffff88085f407200
    RBP: ffff88084d323778   R8: 0000000000000001   R9: ffffea0020bae210
    R10: ffffea0020bae218  R11: 0000000000000001  R12: ffff88084d3237c8
    R13: 00000000fffffff4  R14: ffff880859fa5000  R15: ffff88082eb89800
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
#10 [ffff88084d323780] rdma_create_qp at ffffffffa0782681 [rdma_cm]
#11 [ffff88084d3237b0] nvmet_rdma_create_queue_ib at ffffffffa07c43f3 [nvmet_rdma]
#12 [ffff88084d323860] nvmet_rdma_alloc_queue at ffffffffa07c5ba9 [nvmet_rdma]
#13 [ffff88084d323900] nvmet_rdma_queue_connect at ffffffffa07c5c96 [nvmet_rdma]
#14 [ffff88084d323980] nvmet_rdma_cm_handler at ffffffffa07c6450 [nvmet_rdma]
#15 [ffff88084d3239b0] iw_conn_req_handler at ffffffffa0787480 [rdma_cm]
#16 [ffff88084d323a60] cm_conn_req_handler at ffffffffa0775f06 [iw_cm]
#17 [ffff88084d323ab0] process_event at ffffffffa0776019 [iw_cm]
#18 [ffff88084d323af0] cm_work_handler at ffffffffa0776170 [iw_cm]
#19 [ffff88084d323cb0] process_one_work at ffffffff810a1483
#20 [ffff88084d323d90] worker_thread at ffffffff810a211d
#21 [ffff88084d323ec0] kthread at ffffffff810a6c5c
#22 [ffff88084d323f50] ret_from_fork at ffffffff816e1ebf

Fixes: 632bc3f ("IB/core, RDMA RW API: Do not exceed QP SGE send limit")
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Cc: stable@vger.kernel.org
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
dabrace pushed a commit that referenced this pull request Dec 15, 2016
There have been several reports over the years of NULL pointer
dereferences in xfs_trans_log_inode during xfs_fsr processes,
when the process is doing an fput and tearing down extents
on the temporary inode, something like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
PID: 29439  TASK: ffff880550584fa0  CPU: 6   COMMAND: "xfs_fsr"
    [exception RIP: xfs_trans_log_inode+0x10]
 #9 [ffff8800a57bbbe0] xfs_bunmapi at ffffffffa037398e [xfs]
#10 [ffff8800a57bbce8] xfs_itruncate_extents at ffffffffa0391b29 [xfs]
#11 [ffff8800a57bbd88] xfs_inactive_truncate at ffffffffa0391d0c [xfs]
#12 [ffff8800a57bbdb8] xfs_inactive at ffffffffa0392508 [xfs]
#13 [ffff8800a57bbdd8] xfs_fs_evict_inode at ffffffffa035907e [xfs]
#14 [ffff8800a57bbe00] evict at ffffffff811e1b67
#15 [ffff8800a57bbe28] iput at ffffffff811e23a5
#16 [ffff8800a57bbe58] dentry_kill at ffffffff811dcfc8
#17 [ffff8800a57bbe88] dput at ffffffff811dd06c
#18 [ffff8800a57bbea8] __fput at ffffffff811c823b
#19 [ffff8800a57bbef0] ____fput at ffffffff811c846e
#20 [ffff8800a57bbf00] task_work_run at ffffffff81093b27
#21 [ffff8800a57bbf30] do_notify_resume at ffffffff81013b0c
#22 [ffff8800a57bbf50] int_signal at ffffffff8161405d

As it turns out, this is because the i_itemp pointer, along
with the d_ops pointer, has been overwritten with zeros
when we tear down the extents during truncate.  When the in-core
inode fork on the temporary inode used by xfs_fsr was originally
set up during the extent swap, we mistakenly looked at di_nextents
to determine whether all extents fit inline, but this misses extents
generated by speculative preallocation; we should be using if_bytes
instead.

This mistake corrupts the in-memory inode, and code in
xfs_iext_remove_inline eventually gets bad inputs, causing
it to memmove and memset incorrect ranges; this became apparent
because the two values in ifp->if_u2.if_inline_ext[1] contained
what should have been in d_ops and i_itemp; they were memmoved due
to incorrect array indexing and then the original locations
were zeroed with memset, again due to an array overrun.

Fix this by properly using i_df.if_bytes to determine the number
of extents, not di_nextents.

Thanks to dchinner for looking at this with me and spotting the
root cause.

Cc: stable@vger.kernel.org
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
dabrace pushed a commit that referenced this pull request Mar 15, 2017
As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 #8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 #9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <egarver@redhat.com>
Cc: Hannes Sowa <hsowa@redhat.com>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dabrace pushed a commit that referenced this pull request Sep 7, 2017
In case of corrupt images, multiple interrupts may occur
due to different error scenarios.

Since we are removing the src and dest buffers in the first
interrupt itself, crash occurs in the second error interrupts.

Disable the global interrupt before we start processing
the interrupt to avoid the crash.

Disable System interrupt in isr to avoid the crash below.

Unable to handle kernel NULL pointer dereference at virtual address 000000c8
pgd = ffffffc0007db000
[000000c8] *pgd=00000000fb006003, *pud=00000000fb006003, *pmd=00000000fb007003, *pte=0060000011001707
Internal error: Oops: 96000007 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.18.0-next-20141210+ #22
Hardware name: Samsung Exynos7 Espresso board based on EXYNOS7 (DT)
task: ffffffc00075e5c0 ti: ffffffc00074c000 task.ti: ffffffc00074c000
PC is at exynos4_jpeg_irq+0x30/0x15c
LR is at exynos4_jpeg_irq+0x2c/0x15c
pc : [<ffffffc00040873c>] lr : [<ffffffc000408738>] pstate: 800001c5
sp : ffffffc00074fc60
x29: ffffffc00074fc60 x28: 0000004040000000
x27: ffffffc000673928 x26: ffffffc000673940
x25: ffffffc0007a030c x24: ffffffc0bb20a400
x23: 0000000000000030 x22: ffffffc0ba56ba40
x21: 0000000000000000 x20: 0000000000000000
x19: ffffffc0ba56ba18 x18: 0000000000000000
x17: 0000000000000000 x16: ffffffc00018b508
x15: 0000000000000000 x14: 0000000000000000
x13: 0098968000000000 x12: 0000000000989680
x11: 0000000000000004 x10: 0101010101010101
x9 : 00000020a285a9ea x8 : ffffffc0007af880
x7 : ffffffc0bac001a8 x6 : ffffffc0bac00000
x5 : 00000000fffffffa x4 : ffffffc00040870c
x3 : 0000000000000003 x2 : 0000000000010003
x1 : 0000000000010002 x0 : 0000000000000000

Process swapper/0 (pid: 0, stack limit = 0xffffffc00074c058)
Stack: (0xffffffc00074fc60 to 0xffffffc000750000)
fc60: 0074fca0 ffffffc0 000e4508 ffffffc0 bb225300 ffffffc0 bb20a494 ffffffc0
fc80: 00000000 00000000 00000000 00000000 00000030 00000000 000f8c6c ffffffc0
fca0: 0074fd00 ffffffc0 000e4644 ffffffc0 bb20a400 ffffffc0 bb20a494 ffffffc0
fcc0: 00776a00 ffffffc0 00670da8 ffffffc0 00000000 00000000 00000001 00000000
fce0: bb008000 ffffffc0 407db000 00000000 00081230 ffffffc0 000e4638 ffffffc0
fd00: 0074fd40 ffffffc0 000e7338 ffffffc0 bb20a400 ffffffc0 bb20a494 ffffffc0
fd20: 00776a00 ffffffc0 000e7280 ffffffc0 bb225300 ffffffc0 000e72e0 ffffffc0
fd40: 0074fd70 ffffffc0 000e3d60 ffffffc0 00000030 00000000 00743000 ffffffc0
fd60: 0066e000 ffffffc0 006c2000 ffffffc0 0074fd90 ffffffc0 000e3e90 ffffffc0
fd80: 007437c8 ffffffc0 000e3e6c ffffffc0 0074fdf0 ffffffc0 00082404 ffffffc0
fda0: 0074fe20 ffffffc0 0075a000 ffffffc0 0000200c ffffff80 00002010 ffffff80
fdc0: 60000145 00000000 00672cc8 ffffffc0 407d9000 00000000 befb9b40 ffffffc0
fde0: 0074fe20 ffffffc0 000001d2 00000000 0074ff40 ffffffc0 00085da8 ffffffc0
fe00: 00758584 ffffffc0 0052c000 ffffffc0 0074ff40 ffffffc0 00087114 ffffffc0
fe20: 00000000 00000000 0074ff50 ffffffc0 0067d760 ffffffc0 befb9adc ffffffc0
fe40: 00000001 00000000 d4414200 00000020 d6a39c00 00000020 007a6a18 ffffffc0
fe60: 0075eb00 ffffffc0 0074fd60 ffffffc0 ffffc185 00000000 00000020 00000000
fe80: 0052d340 ffffffc0 00000030 00000000 fffffffe 0fffffff 00000000 00000000
fea0: 0018b508 ffffffc0 00000000 00000000 00000000 00000000 00758584 ffffffc0
fec0: 0052c000 ffffffc0 006c24e8 ffffffc0 007a030a ffffffc0 00000001 00000000
fee0: 00672cc8 ffffffc0 407d9000 00000000 407db000 00000000 00081230 ffffffc0
ff00: 40000000 00000040 0074ff40 ffffffc0 00087110 ffffffc0 0074ff40 ffffffc0
ff20: 00087114 ffffffc0 60000145 00000000 00758584 ffffffc0 0052c000 ffffffc0
ff40: 0074ff50 ffffffc0 000db568 ffffffc0 0074ff90 ffffffc0 00515fdc ffffffc0
ff60: 00758000 ffffffc0 007a3000 ffffffc0 007a3000 ffffffc0 befc8940 ffffffc0
ff80: 40760000 00000000 40000000 00000000 0074ffb0 ffffffc0 006ff998 ffffffc0
ffa0: 00000002 00000000 006ff988 ffffffc0 00000000 00000000 400826c0 00000000
ffc0: 8f03a688 00000000 00000e11 00000000 48000000 00000000 410fd030 00000000
ffe0: 0072c250 ffffffc0 00000000 00000000 00000000 00000000 00000000 00000000
Call trace:
[<ffffffc00040873c>] exynos4_jpeg_irq+0x30/0x15c
[<ffffffc0000e4504>] handle_irq_event_percpu+0x6c/0x160
[<ffffffc0000e4640>] handle_irq_event+0x48/0x78
[<ffffffc0000e7334>] handle_fasteoi_irq+0xe0/0x198
[<ffffffc0000e3d5c>] generic_handle_irq+0x24/0x40
[<ffffffc0000e3e8c>] __handle_domain_irq+0x80/0xf0
[<ffffffc000082400>] gic_handle_irq+0x30/0x80
Exception stack(0xffffffc00074fe00 to 0xffffffc00074ff20)
fe00: 00758584 ffffffc0 0052c000 ffffffc0 0074ff40 ffffffc0 00087114 ffffffc0
fe20: 00000000 00000000 0074ff50 ffffffc0 0067d760 ffffffc0 befb9adc ffffffc0
fe40: 00000001 00000000 d4414200 00000020 d6a39c00 00000020 007a6a18 ffffffc0
fe60: 0075eb00 ffffffc0 0074fd60 ffffffc0 ffffc185 00000000 00000020 00000000
fe80: 0052d340 ffffffc0 00000030 00000000 fffffffe 0fffffff 00000000 00000000
fea0: 0018b508 ffffffc0 00000000 00000000 00000000 00000000 00758584 ffffffc0
fec0: 0052c000 ffffffc0 006c24e8 ffffffc0 007a030a ffffffc0 00000001 00000000
fee0: 00672cc8 ffffffc0 407d9000 00000000 407db000 00000000 00081230 ffffffc0
ff00: 40000000 00000040 0074ff40 ffffffc0 00087110 ffffffc0 0074ff40 ffffffc0
[<ffffffc000085da4>] el1_irq+0x64/0xd8
[<ffffffc0000db564>] cpu_startup_entry+0x118/0x168
[<ffffffc000515fd8>] rest_init+0x7c/0x88
[<ffffffc0006ff994>] start_kernel+0x3a8/0x3bc
Code: 94045c34 f9406e60 97ffdc74 aa0003f4 (f9406400)
---[ end trace fa6dc0ea2efad21f ]---
Kernel panic - not syncing: Fatal exception in interrupt
---[ end Kernel panic - not syncing: Fatal exception in interrupt

Signed-off-by: Tony K Nadackal <tony.kn@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
dabrace pushed a commit that referenced this pull request May 21, 2018
syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dabrace pushed a commit that referenced this pull request Jul 1, 2018
Wire up io_pgetevents system call on powerpc.

io_pgetevents is a new syscall to read asynchronous I/O events from the
completion queue.

Tested with libaio branch aio-poll[1] and the io_pgetevents test (#22) passed
on both ppc64 LE and BE modes.

[1] https://pagure.io/libaio/branch/aio-poll

CC: Christoph Hellwig <hch@lst.de>
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
dabrace pushed a commit that referenced this pull request Jul 24, 2018
Crash dump shows following instructions

crash> bt
PID: 0      TASK: ffffffffbe412480  CPU: 0   COMMAND: "swapper/0"
 #0 [ffff891ee0003868] machine_kexec at ffffffffbd063ef1
 #1 [ffff891ee00038c8] __crash_kexec at ffffffffbd12b6f2
 #2 [ffff891ee0003998] crash_kexec at ffffffffbd12c84c
 #3 [ffff891ee00039b8] oops_end at ffffffffbd030f0a
 #4 [ffff891ee00039e0] no_context at ffffffffbd074643
 #5 [ffff891ee0003a40] __bad_area_nosemaphore at ffffffffbd07496e
 #6 [ffff891ee0003a90] bad_area_nosemaphore at ffffffffbd074a64
 #7 [ffff891ee0003aa0] __do_page_fault at ffffffffbd074b0a
 #8 [ffff891ee0003b18] do_page_fault at ffffffffbd074fc8
 #9 [ffff891ee0003b50] page_fault at ffffffffbda01925
    [exception RIP: qlt_schedule_sess_for_deletion+15]
    RIP: ffffffffc02e526f  RSP: ffff891ee0003c08  RFLAGS: 00010046
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: ffffffffc0307847
    RDX: 00000000000020e6  RSI: ffff891edbc377c8  RDI: 0000000000000000
    RBP: ffff891ee0003c18   R8: ffffffffc02f0b20   R9: 0000000000000250
    R10: 0000000000000258  R11: 000000000000b780  R12: ffff891ed9b43000
    R13: 00000000000000f0  R14: 0000000000000006  R15: ffff891edbc377c8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #10 [ffff891ee0003c20] qla2x00_fcport_event_handler at ffffffffc02853d3 [qla2xxx]
 #11 [ffff891ee0003cf0] __dta_qla24xx_async_gnl_sp_done_333 at ffffffffc0285a1d [qla2xxx]
 #12 [ffff891ee0003de8] qla24xx_process_response_queue at ffffffffc02a2eb5 [qla2xxx]
 #13 [ffff891ee0003e88] qla24xx_msix_rsp_q at ffffffffc02a5403 [qla2xxx]
 #14 [ffff891ee0003ec0] __handle_irq_event_percpu at ffffffffbd0f4c59
 #15 [ffff891ee0003f10] handle_irq_event_percpu at ffffffffbd0f4e02
 #16 [ffff891ee0003f40] handle_irq_event at ffffffffbd0f4e90
 #17 [ffff891ee0003f68] handle_edge_irq at ffffffffbd0f8984
 #18 [ffff891ee0003f88] handle_irq at ffffffffbd0305d5
 #19 [ffff891ee0003fb8] do_IRQ at ffffffffbda02a18
 --- <IRQ stack> ---
 #20 [ffffffffbe403d30] ret_from_intr at ffffffffbda0094e
    [exception RIP: unknown or invalid address]
    RIP: 000000000000001f  RSP: 0000000000000000  RFLAGS: fff3b8c2091ebb3f
    RAX: ffffbba5a0000200  RBX: 0000be8cdfa8f9fa  RCX: 0000000000000018
    RDX: 0000000000000101  RSI: 000000000000015d  RDI: 0000000000000193
    RBP: 0000000000000083   R8: ffffffffbe403e38   R9: 0000000000000002
    R10: 0000000000000000  R11: ffffffffbe56b820  R12: ffff891ee001cf00
    R13: ffffffffbd11c0a4  R14: ffffffffbe403d60  R15: 0000000000000001
    ORIG_RAX: ffff891ee0022ac0  CS: 0000  SS: ffffffffffffffb9
 bt: WARNING: possibly bogus exception frame
 #21 [ffffffffbe403dd8] cpuidle_enter_state at ffffffffbd67c6fd
 #22 [ffffffffbe403e40] cpuidle_enter at ffffffffbd67c907
 #23 [ffffffffbe403e50] call_cpuidle at ffffffffbd0d98f3
 #24 [ffffffffbe403e60] do_idle at ffffffffbd0d9b42
 #25 [ffffffffbe403e98] cpu_startup_entry at ffffffffbd0d9da3
 #26 [ffffffffbe403ec0] rest_init at ffffffffbd81d4aa
 #27 [ffffffffbe403ed0] start_kernel at ffffffffbe67d2ca
 #28 [ffffffffbe403f28] x86_64_start_reservations at ffffffffbe67c675
 #29 [ffffffffbe403f38] x86_64_start_kernel at ffffffffbe67c6eb
 #30 [ffffffffbe403f50] secondary_startup_64 at ffffffffbd0000d5

Fixes: 040036b ("scsi: qla2xxx: Delay loop id allocation at login")
Cc: <stable@vger.kernel.org> # v4.17+
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
dabrace pushed a commit that referenced this pull request Nov 12, 2018
Increase kasan instrumented kernel stack size from 32k to 64k. Other
architectures seems to get away with just doubling kernel stack size under
kasan, but on s390 this appears to be not enough due to bigger frame size.
The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE
vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting
stack overflow is fs sync on xfs filesystem:

 #0 [9a0681e8]  704 bytes  check_usage at 34b1fc
 #1 [9a0684a8]  432 bytes  check_usage at 34c710
 #2 [9a068658]  1048 bytes  validate_chain at 35044a
 #3 [9a068a70]  312 bytes  __lock_acquire at 3559fe
 #4 [9a068ba8]  440 bytes  lock_acquire at 3576ee
 #5 [9a068d60]  104 bytes  _raw_spin_lock at 21b44e0
 #6 [9a068dc8]  1992 bytes  enqueue_entity at 2dbf72
 #7 [9a069590]  1496 bytes  enqueue_task_fair at 2df5f0
 #8 [9a069b68]  64 bytes  ttwu_do_activate at 28f438
 #9 [9a069ba8]  552 bytes  try_to_wake_up at 298c4c
 #10 [9a069dd0]  168 bytes  wake_up_worker at 23f97c
 #11 [9a069e78]  200 bytes  insert_work at 23fc2e
 #12 [9a069f40]  648 bytes  __queue_work at 2487c0
 #13 [9a06a1c8]  200 bytes  __queue_delayed_work at 24db28
 #14 [9a06a290]  248 bytes  mod_delayed_work_on at 24de84
 #15 [9a06a388]  24 bytes  kblockd_mod_delayed_work_on at 153e2a0
 #16 [9a06a3a0]  288 bytes  __blk_mq_delay_run_hw_queue at 158168c
 #17 [9a06a4c0]  192 bytes  blk_mq_run_hw_queue at 1581a3c
 #18 [9a06a580]  184 bytes  blk_mq_sched_insert_requests at 15a2192
 #19 [9a06a638]  1024 bytes  blk_mq_flush_plug_list at 1590f3a
 #20 [9a06aa38]  704 bytes  blk_flush_plug_list at 1555028
 #21 [9a06acf8]  320 bytes  schedule at 219e476
 #22 [9a06ae38]  760 bytes  schedule_timeout at 21b0aac
 #23 [9a06b130]  408 bytes  wait_for_common at 21a1706
 #24 [9a06b2c8]  360 bytes  xfs_buf_iowait at fa1540
 #25 [9a06b430]  256 bytes  __xfs_buf_submit at fadae6
 #26 [9a06b530]  264 bytes  xfs_buf_read_map at fae3f6
 #27 [9a06b638]  656 bytes  xfs_trans_read_buf_map at 10ac9a8
 #28 [9a06b8c8]  304 bytes  xfs_btree_kill_root at e72426
 #29 [9a06b9f8]  288 bytes  xfs_btree_lookup_get_block at e7bc5e
 #30 [9a06bb18]  624 bytes  xfs_btree_lookup at e7e1a6
 #31 [9a06bd88]  2664 bytes  xfs_alloc_ag_vextent_near at dfa070
 #32 [9a06c7f0]  144 bytes  xfs_alloc_ag_vextent at dff3ca
 #33 [9a06c880]  1128 bytes  xfs_alloc_vextent at e05fce
 #34 [9a06cce8]  584 bytes  xfs_bmap_btalloc at e58342
 #35 [9a06cf30]  1336 bytes  xfs_bmapi_write at e618de
 #36 [9a06d468]  776 bytes  xfs_iomap_write_allocate at ff678e
 #37 [9a06d770]  720 bytes  xfs_map_blocks at f82af8
 #38 [9a06da40]  928 bytes  xfs_writepage_map at f83cd6
 #39 [9a06dde0]  320 bytes  xfs_do_writepage at f85872
 #40 [9a06df20]  1320 bytes  write_cache_pages at 73dfe8
 #41 [9a06e448]  208 bytes  xfs_vm_writepages at f7f892
 #42 [9a06e518]  88 bytes  do_writepages at 73fe6a
 #43 [9a06e570]  872 bytes  __writeback_single_inode at a20cb6
 #44 [9a06e8d8]  664 bytes  writeback_sb_inodes at a23be2
 #45 [9a06eb70]  296 bytes  __writeback_inodes_wb at a242e0
 #46 [9a06ec98]  928 bytes  wb_writeback at a2500e
 #47 [9a06f038]  848 bytes  wb_do_writeback at a260ae
 #48 [9a06f388]  536 bytes  wb_workfn at a28228
 #49 [9a06f5a0]  1088 bytes  process_one_work at 24a234
 #50 [9a06f9e0]  1120 bytes  worker_thread at 24ba26
 #51 [9a06fe40]  104 bytes  kthread at 26545a
 #52 [9a06fea8]             kernel_thread_starter at 21b6b62

To be able to increase the stack size to 64k reuse LLILL instruction
in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE
(65192) value as unsigned.

Reported-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
dabrace pushed a commit that referenced this pull request Dec 3, 2018
conn_free() holds lock with spin_lock() and it is called by both
nf_conncount_lookup() and nf_conncount_gc_list(). nf_conncount_lookup()
is called from bottom-half context and nf_conncount_gc_list() from
process context. So that spin_lock() call is not safe. Hence
conn_free() should use spin_lock_bh() instead of spin_lock().

test commands:
   %nft add table ip filter
   %nft add chain ip filter input { type filter hook input priority 0\; }
   %nft add rule filter input meter test { ip saddr ct count over 2 } \
	   counter

splat looks like:
[  461.996507] ================================
[  461.998999] WARNING: inconsistent lock state
[  461.998999] 4.19.0-rc6+ #22 Not tainted
[  461.998999] --------------------------------
[  461.998999] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  461.998999] kworker/0:2/134 [HC0[0]:SC0[0]:HE1:SE1] takes:
[  461.998999] 00000000a71a559a (&(&list->list_lock)->rlock){+.?.}, at: conn_free+0x69/0x2b0 [nf_conncount]
[  461.998999] {IN-SOFTIRQ-W} state was registered at:
[  461.998999]   _raw_spin_lock+0x30/0x70
[  461.998999]   nf_conncount_add+0x28a/0x520 [nf_conncount]
[  461.998999]   nft_connlimit_eval+0x401/0x580 [nft_connlimit]
[  461.998999]   nft_dynset_eval+0x32b/0x590 [nf_tables]
[  461.998999]   nft_do_chain+0x497/0x1430 [nf_tables]
[  461.998999]   nft_do_chain_ipv4+0x255/0x330 [nf_tables]
[  461.998999]   nf_hook_slow+0xb1/0x160
[ ... ]
[  461.998999] other info that might help us debug this:
[  461.998999]  Possible unsafe locking scenario:
[  461.998999]
[  461.998999]        CPU0
[  461.998999]        ----
[  461.998999]   lock(&(&list->list_lock)->rlock);
[  461.998999]   <Interrupt>
[  461.998999]     lock(&(&list->list_lock)->rlock);
[  461.998999]
[  461.998999]  *** DEADLOCK ***
[  461.998999]
[ ... ]

Fixes: 5c789e1 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
dabrace pushed a commit that referenced this pull request Dec 3, 2018
nf_conncount_tuple is an element of nft_connlimit and that is deleted by
conn_free(). Elements can be deleted by both GC routine and data path
functions (nf_conncount_lookup, nf_conncount_add) and they call
conn_free() to free elements. But conn_free() only protects lists, not
each element. So that list_del corruption could occurred.

The conn_free() doesn't check whether element is already deleted. In
order to protect elements, dead flag is added. If an element is deleted,
dead flag is set. The only conn_free() can delete elements so that both
list lock and dead flag are enough to protect it.

test commands:
   %nft add table ip filter
   %nft add chain ip filter input { type filter hook input priority 0\; }
   %nft add rule filter input meter test { ip id ct count over 2 } counter

splat looks like:
[ 1779.495778] list_del corruption, ffff8800b6e12008->prev is LIST_POISON2 (dead000000000200)
[ 1779.505453] ------------[ cut here ]------------
[ 1779.506260] kernel BUG at lib/list_debug.c:50!
[ 1779.515831] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 1779.516772] CPU: 0 PID: 33 Comm: kworker/0:2 Not tainted 4.19.0-rc6+ #22
[ 1779.516772] Workqueue: events_power_efficient nft_rhash_gc [nf_tables_set]
[ 1779.516772] RIP: 0010:__list_del_entry_valid+0xd8/0x150
[ 1779.516772] Code: 39 48 83 c4 08 b8 01 00 00 00 5b 5d c3 48 89 ea 48 c7 c7 00 c3 5b 98 e8 0f dc 40 ff 0f 0b 48 c7 c7 60 c3 5b 98 e8 01 dc 40 ff <0f> 0b 48 c7 c7 c0 c3 5b 98 e8 f3 db 40 ff 0f 0b 48 c7 c7 20 c4 5b
[ 1779.516772] RSP: 0018:ffff880119127420 EFLAGS: 00010286
[ 1779.516772] RAX: 000000000000004e RBX: dead000000000200 RCX: 0000000000000000
[ 1779.516772] RDX: 000000000000004e RSI: 0000000000000008 RDI: ffffed0023224e7a
[ 1779.516772] RBP: ffff88011934bc10 R08: ffffed002367cea9 R09: ffffed002367cea9
[ 1779.516772] R10: 0000000000000001 R11: ffffed002367cea8 R12: ffff8800b6e12008
[ 1779.516772] R13: ffff8800b6e12010 R14: ffff88011934bc20 R15: ffff8800b6e12008
[ 1779.516772] FS:  0000000000000000(0000) GS:ffff88011b200000(0000) knlGS:0000000000000000
[ 1779.516772] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1779.516772] CR2: 00007fc876534010 CR3: 000000010da16000 CR4: 00000000001006f0
[ 1779.516772] Call Trace:
[ 1779.516772]  conn_free+0x9f/0x2b0 [nf_conncount]
[ 1779.516772]  ? nf_ct_tmpl_alloc+0x2a0/0x2a0 [nf_conntrack]
[ 1779.516772]  ? nf_conncount_add+0x520/0x520 [nf_conncount]
[ 1779.516772]  ? do_raw_spin_trylock+0x1a0/0x1a0
[ 1779.516772]  ? do_raw_spin_trylock+0x10/0x1a0
[ 1779.516772]  find_or_evict+0xe5/0x150 [nf_conncount]
[ 1779.516772]  nf_conncount_gc_list+0x162/0x360 [nf_conncount]
[ 1779.516772]  ? nf_conncount_lookup+0xee0/0xee0 [nf_conncount]
[ 1779.516772]  ? _raw_spin_unlock_irqrestore+0x45/0x50
[ 1779.516772]  ? trace_hardirqs_off+0x6b/0x220
[ 1779.516772]  ? trace_hardirqs_on_caller+0x220/0x220
[ 1779.516772]  nft_rhash_gc+0x16b/0x540 [nf_tables_set]
[ ... ]

Fixes: 5c789e1 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
dabrace pushed a commit that referenced this pull request Apr 22, 2019
Move ieee80211_tx_status_ext() outside of status_list lock section
in order to avoid locking dependency and possible deadlock reposed by
LOCKDEP in below warning.

Also do mt76_tx_status_lock() just before it's needed.

[  440.224832] WARNING: possible circular locking dependency detected
[  440.224833] 5.1.0-rc2+ #22 Not tainted
[  440.224834] ------------------------------------------------------
[  440.224835] kworker/u16:28/2362 is trying to acquire lock:
[  440.224836] 0000000089b8cacf (&(&q->lock)->rlock#2){+.-.}, at: mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.224842]
               but task is already holding lock:
[  440.224842] 000000002cfedc59 (&(&sta->lock)->rlock){+.-.}, at: ieee80211_stop_tx_ba_cb+0x32/0x1f0 [mac80211]
[  440.224863]
               which lock already depends on the new lock.

[  440.224863]
               the existing dependency chain (in reverse order) is:
[  440.224864]
               -> #3 (&(&sta->lock)->rlock){+.-.}:
[  440.224869]        _raw_spin_lock_bh+0x34/0x40
[  440.224880]        ieee80211_start_tx_ba_session+0xe4/0x3d0 [mac80211]
[  440.224894]        minstrel_ht_get_rate+0x45c/0x510 [mac80211]
[  440.224906]        rate_control_get_rate+0xc1/0x140 [mac80211]
[  440.224918]        ieee80211_tx_h_rate_ctrl+0x195/0x3c0 [mac80211]
[  440.224930]        ieee80211_xmit_fast+0x26d/0xa50 [mac80211]
[  440.224942]        __ieee80211_subif_start_xmit+0xfc/0x310 [mac80211]
[  440.224954]        ieee80211_subif_start_xmit+0x38/0x390 [mac80211]
[  440.224956]        dev_hard_start_xmit+0xb8/0x300
[  440.224957]        __dev_queue_xmit+0x7d4/0xbb0
[  440.224968]        ip6_finish_output2+0x246/0x860 [ipv6]
[  440.224978]        mld_sendpack+0x1bd/0x360 [ipv6]
[  440.224987]        mld_ifc_timer_expire+0x1a4/0x2f0 [ipv6]
[  440.224989]        call_timer_fn+0x89/0x2a0
[  440.224990]        run_timer_softirq+0x1bd/0x4d0
[  440.224992]        __do_softirq+0xdb/0x47c
[  440.224994]        irq_exit+0xfa/0x100
[  440.224996]        smp_apic_timer_interrupt+0x9a/0x220
[  440.224997]        apic_timer_interrupt+0xf/0x20
[  440.224999]        cpuidle_enter_state+0xc1/0x470
[  440.225000]        do_idle+0x21a/0x260
[  440.225001]        cpu_startup_entry+0x19/0x20
[  440.225004]        start_secondary+0x135/0x170
[  440.225006]        secondary_startup_64+0xa4/0xb0
[  440.225007]
               -> #2 (&(&sta->rate_ctrl_lock)->rlock){+.-.}:
[  440.225009]        _raw_spin_lock_bh+0x34/0x40
[  440.225022]        rate_control_tx_status+0x4f/0xb0 [mac80211]
[  440.225031]        ieee80211_tx_status_ext+0x142/0x1a0 [mac80211]
[  440.225035]        mt76x02_send_tx_status+0x2e4/0x340 [mt76x02_lib]
[  440.225037]        mt76x02_tx_status_data+0x31/0x40 [mt76x02_lib]
[  440.225040]        mt76u_tx_status_data+0x51/0xa0 [mt76_usb]
[  440.225042]        process_one_work+0x237/0x5d0
[  440.225043]        worker_thread+0x3c/0x390
[  440.225045]        kthread+0x11d/0x140
[  440.225046]        ret_from_fork+0x3a/0x50
[  440.225047]
               -> #1 (&(&list->lock)->rlock#8){+.-.}:
[  440.225049]        _raw_spin_lock_bh+0x34/0x40
[  440.225052]        mt76_tx_status_skb_add+0x51/0x100 [mt76]
[  440.225054]        mt76x02u_tx_prepare_skb+0xbd/0x116 [mt76x02_usb]
[  440.225056]        mt76u_tx_queue_skb+0x5f/0x180 [mt76_usb]
[  440.225058]        mt76_tx+0x93/0x190 [mt76]
[  440.225070]        ieee80211_tx_frags+0x148/0x210 [mac80211]
[  440.225081]        __ieee80211_tx+0x75/0x1b0 [mac80211]
[  440.225092]        ieee80211_tx+0xde/0x110 [mac80211]
[  440.225105]        __ieee80211_tx_skb_tid_band+0x72/0x90 [mac80211]
[  440.225122]        ieee80211_send_auth+0x1f3/0x360 [mac80211]
[  440.225141]        ieee80211_auth.cold.40+0x6c/0x100 [mac80211]
[  440.225156]        ieee80211_mgd_auth.cold.50+0x132/0x15f [mac80211]
[  440.225171]        cfg80211_mlme_auth+0x149/0x360 [cfg80211]
[  440.225181]        nl80211_authenticate+0x273/0x2e0 [cfg80211]
[  440.225183]        genl_family_rcv_msg+0x196/0x3a0
[  440.225184]        genl_rcv_msg+0x47/0x8e
[  440.225185]        netlink_rcv_skb+0x3a/0xf0
[  440.225187]        genl_rcv+0x24/0x40
[  440.225188]        netlink_unicast+0x16d/0x210
[  440.225189]        netlink_sendmsg+0x204/0x3b0
[  440.225191]        sock_sendmsg+0x36/0x40
[  440.225193]        ___sys_sendmsg+0x259/0x2b0
[  440.225194]        __sys_sendmsg+0x47/0x80
[  440.225196]        do_syscall_64+0x60/0x1f0
[  440.225197]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  440.225198]
               -> #0 (&(&q->lock)->rlock#2){+.-.}:
[  440.225200]        lock_acquire+0xb9/0x1a0
[  440.225202]        _raw_spin_lock_bh+0x34/0x40
[  440.225204]        mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.225215]        ieee80211_agg_start_txq+0xe8/0x2b0 [mac80211]
[  440.225225]        ieee80211_stop_tx_ba_cb+0xb8/0x1f0 [mac80211]
[  440.225235]        ieee80211_ba_session_work+0x1c1/0x2f0 [mac80211]
[  440.225236]        process_one_work+0x237/0x5d0
[  440.225237]        worker_thread+0x3c/0x390
[  440.225239]        kthread+0x11d/0x140
[  440.225240]        ret_from_fork+0x3a/0x50
[  440.225240]
               other info that might help us debug this:

[  440.225241] Chain exists of:
                 &(&q->lock)->rlock#2 --> &(&sta->rate_ctrl_lock)->rlock --> &(&sta->lock)->rlock

[  440.225243]  Possible unsafe locking scenario:

[  440.225244]        CPU0                    CPU1
[  440.225244]        ----                    ----
[  440.225245]   lock(&(&sta->lock)->rlock);
[  440.225245]                                lock(&(&sta->rate_ctrl_lock)->rlock);
[  440.225246]                                lock(&(&sta->lock)->rlock);
[  440.225247]   lock(&(&q->lock)->rlock#2);
[  440.225248]
                *** DEADLOCK ***

[  440.225249] 5 locks held by kworker/u16:28/2362:
[  440.225250]  #0: 0000000048fcd291 ((wq_completion)phy0){+.+.}, at: process_one_work+0x1b5/0x5d0
[  440.225252]  #1: 00000000f1c6828f ((work_completion)(&sta->ampdu_mlme.work)){+.+.}, at: process_one_work+0x1b5/0x5d0
[  440.225254]  #2: 00000000433d2b2c (&sta->ampdu_mlme.mtx){+.+.}, at: ieee80211_ba_session_work+0x5c/0x2f0 [mac80211]
[  440.225265]  #3: 000000002cfedc59 (&(&sta->lock)->rlock){+.-.}, at: ieee80211_stop_tx_ba_cb+0x32/0x1f0 [mac80211]
[  440.225276]  #4: 000000009d7b9a44 (rcu_read_lock){....}, at: ieee80211_agg_start_txq+0x33/0x2b0 [mac80211]
[  440.225286]
               stack backtrace:
[  440.225288] CPU: 2 PID: 2362 Comm: kworker/u16:28 Not tainted 5.1.0-rc2+ #22
[  440.225289] Hardware name: LENOVO 20KGS23S0P/20KGS23S0P, BIOS N23ET55W (1.30 ) 08/31/2018
[  440.225300] Workqueue: phy0 ieee80211_ba_session_work [mac80211]
[  440.225301] Call Trace:
[  440.225304]  dump_stack+0x85/0xc0
[  440.225306]  print_circular_bug.isra.38.cold.58+0x15c/0x195
[  440.225307]  check_prev_add.constprop.48+0x5f0/0xc00
[  440.225309]  ? check_prev_add.constprop.48+0x39d/0xc00
[  440.225311]  ? __lock_acquire+0x41d/0x1100
[  440.225312]  __lock_acquire+0xd98/0x1100
[  440.225313]  ? __lock_acquire+0x41d/0x1100
[  440.225315]  lock_acquire+0xb9/0x1a0
[  440.225317]  ? mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.225319]  _raw_spin_lock_bh+0x34/0x40
[  440.225321]  ? mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.225323]  mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.225334]  ieee80211_agg_start_txq+0xe8/0x2b0 [mac80211]
[  440.225344]  ieee80211_stop_tx_ba_cb+0xb8/0x1f0 [mac80211]
[  440.225354]  ieee80211_ba_session_work+0x1c1/0x2f0 [mac80211]
[  440.225356]  process_one_work+0x237/0x5d0
[  440.225358]  worker_thread+0x3c/0x390
[  440.225359]  ? wq_calc_node_cpumask+0x70/0x70
[  440.225360]  kthread+0x11d/0x140
[  440.225362]  ? kthread_create_on_node+0x40/0x40
[  440.225363]  ret_from_fork+0x3a/0x50

Cc: stable@vger.kernel.org
Fixes: 88046b2 ("mt76: add support for reporting tx status with skb")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
dabrace pushed a commit that referenced this pull request Aug 9, 2019
A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
dabrace pushed a commit that referenced this pull request Sep 16, 2019
KASAN report this:

kernel BUG at net/mac802154/main.c:130!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 19932 Comm: modprobe Not tainted 5.1.0-rc6+ #22
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:ieee802154_free_hw+0x2a/0x30 [mac802154]
Code: 55 48 8d 57 38 48 89 e5 53 48 89 fb 48 8b 47 38 48 39 c2 75 15 48 8d 7f 48 e8 82 85 16 e1 48 8b 7b 28 e8 f9 ef 83 e2 5b 5d c3 <0f> 0b 0f 1f 40 00 55 48 89 e5 53 48 89 fb 0f b6 86 80 00 00 00 88
RSP: 0018:ffffc90001c7b9f0 EFLAGS: 00010206
RAX: ffff88822df3aa80 RBX: ffff88823143d5c0 RCX: 0000000000000002
RDX: ffff88823143d5f8 RSI: ffff88822b1fabc0 RDI: ffff88823143d5c0
RBP: ffffc90001c7b9f8 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000fffffff4
R13: ffff88822dea4f50 R14: ffff88823143d7c0 R15: 00000000fffffff4
FS: 00007ff52e999540(0000) GS:ffff888237a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc06dba768 CR3: 000000023160a000 CR4: 00000000000006f0
Call Trace:
 hwsim_add_one+0x2dd/0x540 [mac802154_hwsim]
 hwsim_probe+0x2f/0xb0 [mac802154_hwsim]
 platform_drv_probe+0x3a/0x90
 ? driver_sysfs_add+0x79/0xb0
 really_probe+0x1d4/0x2d0
 driver_probe_device+0x50/0xf0
 device_driver_attach+0x54/0x60
 __driver_attach+0x7e/0xd0
 ? device_driver_attach+0x60/0x60
 bus_for_each_dev+0x68/0xc0
 driver_attach+0x19/0x20
 bus_add_driver+0x15e/0x200
 driver_register+0x5b/0xf0
 __platform_driver_register+0x31/0x40
 hwsim_init_module+0x74/0x1000 [mac802154_hwsim]
 ? 0xffffffffa00e9000
 do_one_initcall+0x6c/0x3cc
 ? kmem_cache_alloc_trace+0x248/0x3b0
 do_init_module+0x5b/0x1f1
 load_module+0x1db1/0x2690
 ? m_show+0x1d0/0x1d0
 __do_sys_finit_module+0xc5/0xd0
 __x64_sys_finit_module+0x15/0x20
 do_syscall_64+0x6b/0x1d0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7ff52e4a2839
Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffffa7b3c08 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 00005647560a2a00 RCX: 00007ff52e4a2839
RDX: 0000000000000000 RSI: 00005647547f3c2e RDI: 0000000000000003
RBP: 00005647547f3c2e R08: 0000000000000000 R09: 00005647560a2a00
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 00005647560a2c10 R14: 0000000000040000 R15: 00005647560a2a00
Modules linked in: mac802154_hwsim(+) mac802154 [last unloaded: mac802154_hwsim]

In hwsim_add_one, if hwsim_subscribe_all_others fails, we
should call ieee802154_unregister_hw to free resources.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: f25da51 ("ieee802154: hwsim: add replacement for fakelb")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
dabrace pushed a commit that referenced this pull request Jan 13, 2020
'chrdev_open()' calls 'cdev_get()' to obtain a reference to the
'struct cdev *' stashed in the 'i_cdev' field of the target inode
structure. If the pointer is NULL, then it is initialised lazily by
looking up the kobject in the 'cdev_map' and so the whole procedure is
protected by the 'cdev_lock' spinlock to serialise initialisation of
the shared pointer.

Unfortunately, it is possible for the initialising thread to fail *after*
installing the new pointer, for example if the subsequent '->open()' call
on the file fails. In this case, 'cdev_put()' is called, the reference
count on the kobject is dropped and, if nobody else has taken a reference,
the release function is called which finally clears 'inode->i_cdev' from
'cdev_purge()' before potentially freeing the object. The problem here
is that a racing thread can happily take the 'cdev_lock' and see the
non-NULL pointer in the inode, which can result in a refcount increment
from zero and a warning:

  |  ------------[ cut here ]------------
  |  refcount_t: addition on 0; use-after-free.
  |  WARNING: CPU: 2 PID: 6385 at lib/refcount.c:25 refcount_warn_saturate+0x6d/0xf0
  |  Modules linked in:
  |  CPU: 2 PID: 6385 Comm: repro Not tainted 5.5.0-rc2+ #22
  |  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  |  RIP: 0010:refcount_warn_saturate+0x6d/0xf0
  |  Code: 05 55 9a 15 01 01 e8 9d aa c8 ff 0f 0b c3 80 3d 45 9a 15 01 00 75 ce 48 c7 c7 00 9c 62 b3 c6 08
  |  RSP: 0018:ffffb524c1b9bc70 EFLAGS: 00010282
  |  RAX: 0000000000000000 RBX: ffff9e9da1f71390 RCX: 0000000000000000
  |  RDX: ffff9e9dbbd27618 RSI: ffff9e9dbbd18798 RDI: ffff9e9dbbd18798
  |  RBP: 0000000000000000 R08: 000000000000095f R09: 0000000000000039
  |  R10: 0000000000000000 R11: ffffb524c1b9bb20 R12: ffff9e9da1e8c700
  |  R13: ffffffffb25ee8b0 R14: 0000000000000000 R15: ffff9e9da1e8c700
  |  FS:  00007f3b87d26700(0000) GS:ffff9e9dbbd00000(0000) knlGS:0000000000000000
  |  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  |  CR2: 00007fc16909c000 CR3: 000000012df9c000 CR4: 00000000000006e0
  |  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  |  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  |  Call Trace:
  |   kobject_get+0x5c/0x60
  |   cdev_get+0x2b/0x60
  |   chrdev_open+0x55/0x220
  |   ? cdev_put.part.3+0x20/0x20
  |   do_dentry_open+0x13a/0x390
  |   path_openat+0x2c8/0x1470
  |   do_filp_open+0x93/0x100
  |   ? selinux_file_ioctl+0x17f/0x220
  |   do_sys_open+0x186/0x220
  |   do_syscall_64+0x48/0x150
  |   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  |  RIP: 0033:0x7f3b87efcd0e
  |  Code: 89 54 24 08 e8 a3 f4 ff ff 8b 74 24 0c 48 8b 3c 24 41 89 c0 44 8b 54 24 08 b8 01 01 00 00 89 f4
  |  RSP: 002b:00007f3b87d259f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
  |  RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3b87efcd0e
  |  RDX: 0000000000000000 RSI: 00007f3b87d25a80 RDI: 00000000ffffff9c
  |  RBP: 00007f3b87d25e90 R08: 0000000000000000 R09: 0000000000000000
  |  R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe188f504e
  |  R13: 00007ffe188f504f R14: 00007f3b87d26700 R15: 0000000000000000
  |  ---[ end trace 24f53ca58db8180a ]---

Since 'cdev_get()' can already fail to obtain a reference, simply move
it over to use 'kobject_get_unless_zero()' instead of 'kobject_get()',
which will cause the racing thread to return -ENXIO if the initialising
thread fails unexpectedly.

Cc: Hillf Danton <hdanton@sina.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: syzbot+82defefbbd8527e1c2cb@syzkaller.appspotmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191219120203.32691-1-will@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dabrace pushed a commit that referenced this pull request Jan 13, 2020
Starting with commit fa212a9 ("iommu/vt-d: Probe DMA-capable ACPI
name space devices"), we now probe DMA-capable ACPI name
space devices. On Dell XPS 13 9343, which has an Intel LPSS platform
device INTL9C60 enumerated via ACPI, this change leads to the following
warning:

    ------------[ cut here ]------------
    WARNING: CPU: 1 PID: 1 at pci_device_group+0x11a/0x130
    CPU: 1 PID: 1 Comm: swapper/0 Tainted: G                T 5.5.0-rc3+ #22
    Hardware name: Dell Inc. XPS 13 9343/0310JH, BIOS A20 06/06/2019
    RIP: 0010:pci_device_group+0x11a/0x130
    Code: f0 ff ff 48 85 c0 49 89 c4 75 c4 48 8d 74 24 10 48 89 ef e8 48 ef ff ff 48 85 c0 49 89 c4 75 af e8 db f7 ff ff 49 89 c4 eb a5 <0f> 0b 49 c7 c4 ea ff ff ff eb 9a e8 96 1e c7 ff 66 0f 1f 44 00 00
    RSP: 0000:ffffc0d6c0043cb0 EFLAGS: 00010202
    RAX: 0000000000000000 RBX: ffffa3d1d43dd810 RCX: 0000000000000000
    RDX: ffffa3d1d4fecf80 RSI: ffffa3d12943dcc0 RDI: ffffa3d1d43dd810
    RBP: ffffa3d1d43dd810 R08: 0000000000000000 R09: ffffa3d1d4c04a80
    R10: ffffa3d1d4c00880 R11: ffffa3d1d44ba000 R12: 0000000000000000
    R13: ffffa3d1d4383b80 R14: ffffa3d1d4c090d0 R15: ffffa3d1d4324530
    FS:  0000000000000000(0000) GS:ffffa3d1d6700000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 000000000460a001 CR4: 00000000003606e0
    Call Trace:
     ? iommu_group_get_for_dev+0x81/0x1f0
     ? intel_iommu_add_device+0x61/0x170
     ? iommu_probe_device+0x43/0xd0
     ? intel_iommu_init+0x1fa2/0x2235
     ? pci_iommu_init+0x52/0xe7
     ? e820__memblock_setup+0x15c/0x15c
     ? do_one_initcall+0xcc/0x27e
     ? kernel_init_freeable+0x169/0x259
     ? rest_init+0x95/0x95
     ? kernel_init+0x5/0xeb
     ? ret_from_fork+0x35/0x40
    ---[ end trace 28473e7abc25b92c ]---
    DMAR: ACPI name space devices didn't probe correctly

The bug results from the fact that while we now enumerate ACPI devices,
we aren't able to handle any non-PCI device when generating the device
group. Fix the issue by implementing an Intel-specific callback that
returns `pci_device_group` only if the device is a PCI device.
Otherwise, it will return a generic device group.

Fixes: fa212a9 ("iommu/vt-d: Probe DMA-capable ACPI name space devices")
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Cc: stable@vger.kernel.org # v5.3+
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
dabrace pushed a commit that referenced this pull request Apr 21, 2020
Commit

  d9e3d2c ("efi/x86: Don't map the entire kernel text RW for mixed mode")

updated the code that creates the 1:1 memory mapping to use read-only
attributes for the 1:1 alias of the kernel's text and rodata sections, to
protect it from inadvertent modification. However, it failed to take into
account that the unused gap between text and rodata is given to the page
allocator for general use.

If the vmap'ed stack happens to be allocated from this region, any by-ref
output arguments passed to EFI runtime services that are allocated on the
stack (such as the 'datasize' argument taken by GetVariable() when invoked
from efivar_entry_size()) will be referenced via a read-only mapping,
resulting in a page fault if the EFI code tries to write to it:

  BUG: unable to handle page fault for address: 00000000386aae88
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  PGD fd61063 P4D fd61063 PUD fd62063 PMD 386000e1
  Oops: 0003 [#1] SMP PTI
  CPU: 2 PID: 255 Comm: systemd-sysv-ge Not tainted 5.6.0-rc4-default+ #22
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0008:0x3eaeed95
  Code: ...  <89> 03 be 05 00 00 80 a1 74 63 b1 3e 83 c0 48 e8 44 d2 ff ff eb 05
  RSP: 0018:000000000fd73fa0 EFLAGS: 00010002
  RAX: 0000000000000001 RBX: 00000000386aae88 RCX: 000000003e9f1120
  RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001
  RBP: 000000000fd73fd8 R08: 00000000386aae88 R09: 0000000000000000
  R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
  R13: ffffc0f040220000 R14: 0000000000000000 R15: 0000000000000000
  FS:  00007f21160ac940(0000) GS:ffff9cf23d500000(0000) knlGS:0000000000000000
  CS:  0008 DS: 0018 ES: 0018 CR0: 0000000080050033
  CR2: 00000000386aae88 CR3: 000000000fd6c004 CR4: 00000000003606e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
  Modules linked in:
  CR2: 00000000386aae88
  ---[ end trace a8bfbd202e712834 ]---

Let's fix this by remapping text and rodata individually, and leave the
gaps mapped read-write.

Fixes: d9e3d2c ("efi/x86: Don't map the entire kernel text RW for mixed mode")
Reported-by: Jiri Slaby <jslaby@suse.cz>
Tested-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200409130434.6736-10-ardb@kernel.org
dabrace pushed a commit that referenced this pull request Jul 27, 2020
The FD should not be installed until all of the setup is completed as the
fd_install() transfers ownership of the kref to the FD table. A thread can
race a close() and trigger concurrent rdma_alloc_commit_uobject() and
uverbs_uobject_fd_release() which, at least, triggers a safety WARN_ON:

  WARNING: CPU: 4 PID: 6913 at drivers/infiniband/core/rdma_core.c:768 uverbs_uobject_fd_release+0x202/0x230
  Kernel panic - not syncing: panic_on_warn set ...
  CPU: 4 PID: 6913 Comm: syz-executor.3 Not tainted 5.7.0-rc2 #22
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
  [..]
  RIP: 0010:uverbs_uobject_fd_release+0x202/0x230
  Code: fe 4c 89 e7 e8 af 23 fe ff e9 2a ff ff ff e8 c5 fa 61 fe be 03 00 00 00 4c 89 e7 e8 68 eb f5 fe e9 13 ff ff ff e8 ae fa 61 fe <0f> 0b eb ac e8 e5 aa 3c fe e8 50 2b 86 fe e9 6a fe ff ff e8 46 2b
  RSP: 0018:ffffc90008117d88 EFLAGS: 00010293
  RAX: ffff88810e146580 RBX: 1ffff92001022fb1 RCX: ffffffff82d5b902
  RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88811951b040
  RBP: ffff88811951b000 R08: ffffed10232a3609 R09: ffffed10232a3609
  R10: ffff88811951b043 R11: 0000000000000001 R12: ffff888100a7c600
  R13: ffff888100a7c650 R14: ffffc90008117da8 R15: ffffffff82d5b700
   ? __uverbs_cleanup_ufile+0x270/0x270
   ? uverbs_uobject_fd_release+0x202/0x230
   ? uverbs_uobject_fd_release+0x202/0x230
   ? __uverbs_cleanup_ufile+0x270/0x270
   ? locks_remove_file+0x282/0x3d0
   ? security_file_free+0xaa/0xd0
   __fput+0x2be/0x770
   task_work_run+0x10e/0x1b0
   exit_to_usermode_loop+0x145/0x170
   do_syscall_64+0x2d0/0x390
   ? prepare_exit_to_usermode+0x17a/0x230
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x414da7
  Code: 00 00 0f 05 48 3d 00 f0 ff ff 77 3f f3 c3 0f 1f 44 00 00 53 89 fb 48 83 ec 10 e8 f4 fb ff ff 89 df 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2b 89 d7 89 44 24 0c e8 36 fc ff ff 8b 44 24
  RSP: 002b:00007fff39d379d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
  RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000414da7
  RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003
  RBP: 00007fff39d37a3c R08: 0000000400000000 R09: 0000000400000000
  R10: 00007fff39d37910 R11: 0000000000000293 R12: 0000000000000001
  R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000003

Reorder so that fd_install() is the last thing done in
rdma_alloc_commit_uobject().

Fixes: aba9454 ("IB/uverbs: Move the FD uobj type struct file allocation to alloc_commit")
Link: https://lore.kernel.org/r/20200716102059.1420681-1-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
dabrace pushed a commit that referenced this pull request Aug 14, 2020
This patch is to fix a crash:

 #3 [ffffb6580689f898] oops_end at ffffffffa2835bc2
 #4 [ffffb6580689f8b8] no_context at ffffffffa28766e7
 #5 [ffffb6580689f920] async_page_fault at ffffffffa320135e
    [exception RIP: f2fs_is_compressed_page+34]
    RIP: ffffffffa2ba83a2  RSP: ffffb6580689f9d8  RFLAGS: 00010213
    RAX: 0000000000000001  RBX: fffffc0f50b34bc0  RCX: 0000000000002122
    RDX: 0000000000002123  RSI: 0000000000000c00  RDI: fffffc0f50b34bc0
    RBP: ffff97e815a40178   R8: 0000000000000000   R9: ffff97e83ffc9000
    R10: 0000000000032300  R11: 0000000000032380  R12: ffffb6580689fa38
    R13: fffffc0f50b34bc0  R14: ffff97e825cbd000  R15: 0000000000000c00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #6 [ffffb6580689f9d8] __is_cp_guaranteed at ffffffffa2b7ea98
 #7 [ffffb6580689f9f0] f2fs_submit_page_write at ffffffffa2b81a69
 #8 [ffffb6580689fa30] f2fs_do_write_meta_page at ffffffffa2b99777
 #9 [ffffb6580689fae0] __f2fs_write_meta_page at ffffffffa2b75f1a
 #10 [ffffb6580689fb18] f2fs_sync_meta_pages at ffffffffa2b77466
 #11 [ffffb6580689fc98] do_checkpoint at ffffffffa2b78e46
 #12 [ffffb6580689fd88] f2fs_write_checkpoint at ffffffffa2b79c29
 #13 [ffffb6580689fdd0] f2fs_sync_fs at ffffffffa2b69d95
 #14 [ffffb6580689fe20] sync_filesystem at ffffffffa2ad2574
 #15 [ffffb6580689fe30] generic_shutdown_super at ffffffffa2a9b582
 #16 [ffffb6580689fe48] kill_block_super at ffffffffa2a9b6d1
 #17 [ffffb6580689fe60] kill_f2fs_super at ffffffffa2b6abe1
 #18 [ffffb6580689fea0] deactivate_locked_super at ffffffffa2a9afb6
 #19 [ffffb6580689feb8] cleanup_mnt at ffffffffa2abcad4
 #20 [ffffb6580689fee0] task_work_run at ffffffffa28bca28
 #21 [ffffb6580689ff00] exit_to_usermode_loop at ffffffffa28050b7
 #22 [ffffb6580689ff38] do_syscall_64 at ffffffffa280560e
 #23 [ffffb6580689ff50] entry_SYSCALL_64_after_hwframe at ffffffffa320008c

This occurred when umount f2fs if enable F2FS_FS_COMPRESSION
with F2FS_IO_TRACE. Fixes it by adding IS_IO_TRACED_PAGE to check
validity of pid for page_private.

Signed-off-by: Yu Changchun <yuchangchun1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
dabrace pushed a commit that referenced this pull request Aug 14, 2020
Intel document 333717-008, "Intel® Ethernet Controller X550
Specification Update", version 2.7, dated June 2020, includes errata
#22, added in version 2.1, May 2016, indicating X550 NICs suffer from
the same implementation deficiency as the 700-series NICs:

"The Interrupt Status bit in the Status register of the PCIe
 configuration space is not implemented and is not set as described
 in the PCIe specification."

Without the interrupt status bit, vfio-pci cannot determine when
these devices signal INTx.  They are therefore added to the nointx
quirk.

Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
dabrace pushed a commit that referenced this pull request Oct 28, 2020
When an UE or memory error exception is encountered the MCE handler
tries to find the pfn using addr_to_pfn() which takes effective
address as an argument, later pfn is used to poison the page where
memory error occurred, recent rework in this area made addr_to_pfn
to run in real mode, which can be fatal as it may try to access
memory outside RMO region.

Have two helper functions to separate things to be done in real mode
and virtual mode without changing any functionality. This also fixes
the following error as the use of addr_to_pfn is now moved to virtual
mode.

Without this change following kernel crash is seen on hitting UE.

[  485.128036] Oops: Kernel access of bad area, sig: 11 [#1]
[  485.128040] LE SMP NR_CPUS=2048 NUMA pSeries
[  485.128047] Modules linked in:
[  485.128067] CPU: 15 PID: 6536 Comm: insmod Kdump: loaded Tainted: G OE 5.7.0 #22
[  485.128074] NIP:  c00000000009b24c LR: c0000000000398d8 CTR: c000000000cd57c0
[  485.128078] REGS: c000000003f1f970 TRAP: 0300   Tainted: G OE (5.7.0)
[  485.128082] MSR:  8000000000001003 <SF,ME,RI,LE>  CR: 28008284  XER: 00000001
[  485.128088] CFAR: c00000000009b190 DAR: c0000001fab00000 DSISR: 40000000 IRQMASK: 1
[  485.128088] GPR00: 0000000000000001 c000000003f1fbf0 c000000001634300 0000b0fa01000000
[  485.128088] GPR04: d000000002220000 0000000000000000 00000000fab00000 0000000000000022
[  485.128088] GPR08: c0000001fab00000 0000000000000000 c0000001fab00000 c000000003f1fc14
[  485.128088] GPR12: 0000000000000008 c000000003ff5880 d000000002100008 0000000000000000
[  485.128088] GPR16: 000000000000ff20 000000000000fff1 000000000000fff2 d0000000021a1100
[  485.128088] GPR20: d000000002200000 c00000015c893c50 c000000000d49b28 c00000015c893c50
[  485.128088] GPR24: d0000000021a0d08 c0000000014e5da8 d0000000021a0818 000000000000000a
[  485.128088] GPR28: 0000000000000008 000000000000000a c0000000017e2970 000000000000000a
[  485.128125] NIP [c00000000009b24c] __find_linux_pte+0x11c/0x310
[  485.128130] LR [c0000000000398d8] addr_to_pfn+0x138/0x170
[  485.128133] Call Trace:
[  485.128135] Instruction dump:
[  485.128138] 3929ffff 7d4a3378 7c883c36 7d2907b4 794a1564 7d294038 794af082 3900ffff
[  485.128144] 79291f24 790af00e 78e70020 7d095214 <7c69502a> 2fa30000 419e011c 70690040
[  485.128152] ---[ end trace d34b27e29ae0e340 ]---

Fixes: 9ca766f ("powerpc/64s/pseries: machine check convert to use common event code")
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200724063946.21378-1-ganeshgr@linux.ibm.com
dabrace pushed a commit that referenced this pull request Nov 23, 2020
This fix is for a failure that occurred in the DWARF unwind perf test.

Stack unwinders may probe memory when looking for frames.

Memory sanitizer will poison and track uninitialized memory on the
stack, and on the heap if the value is copied to the heap.

This can lead to false memory sanitizer failures for the use of an
uninitialized value.

Avoid this problem by removing the poison on the copied stack.

The full msan failure with track origins looks like:

==2168==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22
    #1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13
    #2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #24 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10
    #1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13
    #2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18
    #3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #25 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3
    #1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2
    #2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9
    #3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6
    #4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #17 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events'
    #0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445

SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: clang-built-linux@googlegroups.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandeep Dasgupta <sdasgup@google.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201113182053.754625-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
dabrace pushed a commit that referenced this pull request Mar 17, 2022
When bringing down the netdevice or system shutdown, a panic can be
triggered while accessing the sysfs path because the device is already
removed.

    [  755.549084] mlx5_core 0000:12:00.1: Shutdown was called
    [  756.404455] mlx5_core 0000:12:00.0: Shutdown was called
    ...
    [  757.937260] BUG: unable to handle kernel NULL pointer dereference at           (null)
    [  758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280

    crash> bt
    ...
    PID: 12649  TASK: ffff8924108f2100  CPU: 1   COMMAND: "amsd"
    ...
     #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778
        [exception RIP: dma_pool_alloc+0x1ab]
        RIP: ffffffff8ee11acb  RSP: ffff89240e1a3968  RFLAGS: 00010046
        RAX: 0000000000000246  RBX: ffff89243d874100  RCX: 0000000000001000
        RDX: 0000000000000000  RSI: 0000000000000246  RDI: ffff89243d874090
        RBP: ffff89240e1a39c0   R8: 000000000001f080   R9: ffff8905ffc03c00
        R10: ffffffffc04680d4  R11: ffffffff8edde9fd  R12: 00000000000080d0
        R13: ffff89243d874090  R14: ffff89243d874080  R15: 0000000000000000
        ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core]
    #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core]
    #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core]
    #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core]
    #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core]
    #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core]
    #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core]
    #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46
    #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208
    #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3
    #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf
    #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596
    #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10
    #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5
    #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff
    #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f
    #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92

    crash> net_device.state ffff89443b0c0000
      state = 0x5  (__LINK_STATE_START| __LINK_STATE_NOCARRIER)

To prevent this scenario, we also make sure that the netdevice is present.

Signed-off-by: suresh kumar <suresh2514@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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