Pull powerpc fixes and cleanups from Ben Herrenschmidt:
"Here are a handful or two of powerpc fixes and simple/trivial
cleanups. A bunch of them fix ftrace with the new ABI v2 in Little
Endian, the rest is a scattering of fairly simple things"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc: Don't skip ePAPR spin-table CPUs
powerpc/module: Fix TOC symbol CRC
powerpc/powernv: Remove OPAL v1 takeover
powerpc/kmemleak: Do not scan the DART table
selftests/powerpc: Use the test harness for the TM DSCR test
powerpc/cell: cbe_thermal.c: Cleaning up a variable is of the wrong type
powerpc/kprobes: Fix jprobes on ABI v2 (LE)
powerpc/ftrace: Use pr_fmt() to namespace error messages
powerpc/ftrace: Fix nop of modules on 64bit LE (ABIv2)
powerpc/ftrace: Fix inverted check of create_branch()
powerpc/ftrace: Fix typo in mask of opcode
powerpc: Add ppc_global_function_entry()
powerpc/macintosh/smu.c: Fix closing brace followed by if
powerpc: Remove __arch_swab*
powerpc: Remove ancient DEBUG_SIG code
powerpc/kerenl: Enable EEH for IO accessors
Two cleanup patches removing code duplication that got introduced by changes in
rc1. Not fixing crashes, but I'd rather not carry the duplicate code until the
next merge window.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull vhost cleanups from Michael S Tsirkin:
"Two cleanup patches removing code duplication that got introduced by
changes in rc1. Not fixing crashes, but I'd rather not carry the
duplicate code until the next merge window"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost-scsi: don't open-code kvfree
vhost-net: don't open-code kvfree
race condition that happens between enabling/disabling syscall tracepoints
and new process creations (the check to go into the ptrace path for a process
can be set when it shouldn't, or not set when it should). Not a major bug
but one that should be fixed and even applied to stable.
The other two patches are cleanup/fixes that are not that critical, but
for an -rc1 release would be nice to have. They both deal with syscall
tracepoints.
It also includes a patch to introduce a new macro for the TRACE_EVENT()
format called __field_struct(). Originally, __field() was used to record
any variable into a trace event, but with the addition of setting the
"is signed" attribute, the check causes anything but a primitive variable
to fail to compile. That is, structs and unions can't be used as they
once were. When the "is signed" check was introduce there were only
primitive variables being recorded. But that will change soon and it
was reported that __field() causes build failures.
To solve the __field() issue, __field_struct() is introduced to allow
trace_events to be able to record complex types too.
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Merge tag 'trace-fixes-v3.16-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing cleanups and fixes from Steven Rostedt:
"This includes three patches from Oleg Nesterov. The first is a fix to
a race condition that happens between enabling/disabling syscall
tracepoints and new process creations (the check to go into the ptrace
path for a process can be set when it shouldn't, or not set when it
should). Not a major bug but one that should be fixed and even
applied to stable.
The other two patches are cleanup/fixes that are not that critical,
but for an -rc1 release would be nice to have. They both deal with
syscall tracepoints.
It also includes a patch to introduce a new macro for the
TRACE_EVENT() format called __field_struct(). Originally, __field()
was used to record any variable into a trace event, but with the
addition of setting the "is signed" attribute, the check causes
anything but a primitive variable to fail to compile. That is,
structs and unions can't be used as they once were. When the "is
signed" check was introduce there were only primitive variables being
recorded. But that will change soon and it was reported that
__field() causes build failures.
To solve the __field() issue, __field_struct() is introduced to allow
trace_events to be able to record complex types too"
* tag 'trace-fixes-v3.16-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Add __field_struct macro for TRACE_EVENT()
tracing: syscall_regfunc() should not skip kernel threads
tracing: Change syscall_*regfunc() to check PF_KTHREAD and use for_each_process_thread()
tracing: Fix syscall_*regfunc() vs copy_process() race
Commit 59a53afe70 "powerpc: Don't setup
CPUs with bad status" broke ePAPR SMP booting. ePAPR says that CPUs
that aren't presently running shall have status of disabled, with
enable-method being used to determine whether the CPU can be enabled.
Fix by checking for spin-table, which is currently the only supported
enable-method.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Emil Medve <Emilian.Medve@Freescale.com>
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The commit 71ec7c55ed introduced the magic symbol ".TOC." for ELFv2 ABI.
This symbol is built manually and has no CRC value computed. A zero value
is put in the CRC section to avoid modpost complaining about a missing CRC.
Unfortunately, this breaks the kernel module loading when the kernel is
relocated (kdump case for instance) because of the relocation applied to
the kcrctab values.
This patch compute a CRC value for the TOC symbol which will match the one
compute by the kernel when it is relocated - aka '0 - relocate_start' done in
maybe_relocated called by check_version (module.c).
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In commit 27f4488872 "Add OPAL takeover from PowerVM" we added support
for "takeover" on OPAL v1 machines.
This was a mode of operation where we would boot under pHyp, and query
for the presence of OPAL. If detected we would then do a special
sequence to take over the machine, and the kernel would end up running
in hypervisor mode.
OPAL v1 was never a supported product, and was never shipped outside
IBM. As far as we know no one is still using it.
Newer versions of OPAL do not use the takeover mechanism. Although the
query for OPAL should be harmless on machines with newer OPAL, we have
seen a machine where it causes a crash in Open Firmware.
The code in early_init_devtree() to copy boot_command_line into cmd_line
was added in commit 817c21ad9a "Get kernel command line accross OPAL
takeover", and AFAIK is only used by takeover, so should also be
removed.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull aio fixes from Ben LaHaise:
"These fix a kernel memory disclosure issue (arbitrary kmap() &
copy_to_user()) revealed in CVE-2014-0206 by changes that were
introduced in v3.10"
* git://git.kvack.org/~bcrl/aio-fixes:
aio: fix kernel memory disclosure in io_getevents() introduced in v3.10
aio: fix aio request leak when events are reaped by userspace
Pull ARM fixes from Russell King:
"A number of low impact fixes, the most noticable one is the thumb2
frame pointer fix. We also fix a regression caused during this merge
window with ARM925 CPUs running with caches disabled, and fix a number
of warnings"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: arm925: ensure assembly sets up writethrough mapping
ARM: perf: fix compiler warning with gcc 4.6.4 (and tidy code)
ARM: l2c: fix dependencies on PL310 errata symbols
ARM: 8069/1: Make thread_save_fp macro aware of THUMB2 mode
ARM: 8068/1: scoop: Remove unused variable
A kernel memory disclosure was introduced in aio_read_events_ring() in v3.10
by commit a31ad380be. The changes made to
aio_read_events_ring() failed to correctly limit the index into
ctx->ring_pages[], allowing an attacked to cause the subsequent kmap() of
an arbitrary page with a copy_to_user() to copy the contents into userspace.
This vulnerability has been assigned CVE-2014-0206. Thanks to Mateusz and
Petr for disclosing this issue.
This patch applies to v3.12+. A separate backport is needed for 3.10/3.11.
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: stable@vger.kernel.org
The aio cleanups and optimizations by kmo that were merged into the 3.10
tree added a regression for userspace event reaping. Specifically, the
reference counts are not decremented if the event is reaped in userspace,
leading to the application being unable to submit further aio requests.
This patch applies to 3.12+. A separate backport is required for 3.10/3.11.
This issue was uncovered as part of CVE-2014-0206.
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: stable@vger.kernel.org
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Petr Matousek <pmatouse@redhat.com>
The DART table allocation is registered to kmemleak via the
memblock_alloc_base() call. However, the DART table is later unmapped
and dart_tablebase VA no longer accessible. This patch tells kmemleak
not to scan this block and avoid an unhandled paging request.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This gives us standardised success/failure output and also handles
killing the test if it runs forever (2 minutes).
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This variable is of the wrong type, everywhere it is used it
should be an unsigned int rather than a int.
Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In commit 721aeaa9 "Build little endian ppc64 kernel with ABIv2", we
missed some updates required in the kprobes code to make jprobes work
when the kernel is built with ABI v2.
Firstly update arch_deref_entry_point() to do the right thing. Now that
we have added ppc_global_function_entry() we can just always use that, it
will do the right thing for 32 & 64 bit and ABI v1 & v2.
Secondly we need to update the code that sets up the register state before
calling the jprobe handler. On ABI v1 we setup r2 to hold the TOC, on ABI
v2 we need to populate r12 with the function entry point address.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The printks() in our ftrace code have no prefix, so they appear on the
console with very little context, eg:
Branch out of range
Use pr_fmt() & pr_err() to add a prefix. While we're at it, collapse a
few split lines that don't need to be, and add a missing newline to one
message.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
There is a bug in the handling of the function entry when we are nopping
out a branch from a module in ftrace.
We compare the result of module_trampoline_target() with the value of
ppc_function_entry(), and expect them to be true. But they never will
be.
module_trampoline_target() will always return the global entry point of
the function, whereas ppc_function_entry() will always return the local.
Fix it by using the newly added ppc_global_function_entry().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In commit 24a1bdc35, "Fix ABIv2 issues with __ftrace_make_call", Anton
changed the logic that creates and patches the branch, and added a
thinko in the check of create_branch(). create_branch() returns the
instruction that was generated, so if we get zero then it succeeded.
The result is we can't ftrace modules:
Branch out of range
WARNING: at ../kernel/trace/ftrace.c:1638
ftrace failed to modify [<d000000004ba001c>] fuse_req_init_context+0x1c/0x90 [fuse]
We should probably fix patch_instruction() to do that check and make the
API saner, but that's a separate patch. For now just invert the test.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In commit 24a1bdc35, "Fix ABIv2 issues with __ftrace_make_call", Anton
changed the logic that checks for the expected code sequence when
patching a module.
We missed the typo in the mask, 0xffff00000 should be 0xffff0000, which
has the effect of making the test always true.
That makes it impossible to ftrace against modules, eg:
Unexpected call sequence: 48000008 e8410018
WARNING: at ../kernel/trace/ftrace.c:1638
ftrace failed to modify [<d000000007cf001c>] rng_dev_open+0x1c/0x70 [rng_core]
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
ABIv2 has the concept of a global and local entry point to a function.
In most cases we are interested in the local entry point, and so that is
what ppc_function_entry() returns.
However we have a case in the ftrace code where we want the global entry
point, and there may be other places we need it too. Rather than special
casing each, add an accessor.
For ABIv1 and 32-bit there is only a single entry point, so we return
that. That means it's safe for the caller to use this without also
checking the ABI version.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
A closing brace followed by "if" is almost certainly a mistake. Maybe
"else if" was meant, but in this case it doesn't really matter.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The generic code uses gcc built-ins which work fine so there's no benefit
in implementing our own anymore.
We can't completely remove the ld/st_le* functions as some historical
cruft still uses them, but that's next on the radar
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We have some compile-time disabled debug code in signal_xx.c. It's from
some ancient time BG, almost certainly part of the original port, given
the very similar code on other arches.
The show_unhandled_signal logic, added in d0c3d534a4 (2.6.24) is
cleaner and prints more useful information, so drop the debug code.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In arch/powerpc/kernel/iomap.c, lots of IO reading accessors missed
to check EEH error as Ben pointed. The patch fixes it.
For the writing accessors, we change the called functions only for
making them look similar to the reading counterparts.
Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Here are two bugfixes for some compression functions that resolve some
errors when uncompressing some pathalogical data. Both were found by
Don A. Bailey.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'compress-3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull compress bugfixes from Greg KH:
"Here are two bugfixes for some compression functions that resolve some
errors when uncompressing some pathalogical data. Both were found by
Don A Bailey"
* tag 'compress-3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
lz4: ensure length does not wrap
lzo: properly check for overruns
Merge fixes from Andrew Morton:
"The nmi patch and watchdog patch aren't actually fixes - they're
features which needed a few last-minutes touchups.
Otherwise, a rather large batch of fixes - ocfs2 review takes a while
and I got distracted and missed last week's batch"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (31 commits)
ocfs2/dlm: do not purge lockres that is queued for assert master
ocfs2: do not return DLM_MIGRATE_RESPONSE_MASTERY_REF to avoid endless,loop during umount
ocfs2: manually do the iput once ocfs2_add_entry failed in ocfs2_symlink and ocfs2_mknod
ocfs2: fix a tiny race when running dirop_fileop_racer
ocfs2/dlm: fix misuse of list_move_tail() in dlm_run_purge_list()
ocfs2: refcount: take rw_lock in ocfs2_reflink
ocfs2: revert "ocfs2: fix NULL pointer dereference when dismount and ocfs2rec simultaneously"
ocfs2: fix deadlock when two nodes are converting same lock from PR to EX and idletimeout closes conn
ocfs2: should add inode into orphan dir after updating entry in ocfs2_rename()
mm: fix crashes from mbind() merging vmas
checkpatch: reduce false positives when checking void function return statements
ia64: arch/ia64/include/uapi/asm/fcntl.h needs personality.h
DMA, CMA: fix possible memory leak
slab: fix oops when reading /proc/slab_allocators
shmem: fix faulting into a hole while it's punched
mm: let mm_find_pmd fix buggy race with THP fault
mm: thp: fix DEBUG_PAGEALLOC oops in copy_page_rep()
kernel/watchdog.c: print traces for all cpus on lockup detection
nmi: provide the option to issue an NMI back trace to every cpu but current
Documentation/accounting/getdelays.c: add missing null-terminate after strncpy call
...
When workqueue is delayed, it may occur that a lockres is purged while it
is still queued for master assert. it may trigger BUG() as follows.
N1 N2
dlm_get_lockres()
->dlm_do_master_requery
is the master of lockres,
so queue assert_master work
dlm_thread() start running
and purge the lockres
dlm_assert_master_worker()
send assert master message
to other nodes
receiving the assert_master
message, set master to N2
dlmlock_remote() send create_lock message to N2, but receive DLM_IVLOCKID,
if it is RECOVERY lockres, it triggers the BUG().
Another BUG() is triggered when N3 become the new master and send
assert_master to N1, N1 will trigger the BUG() because owner doesn't
match. So we should not purge lockres when it is queued for assert
master.
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following case may lead to endless loop during umount.
node A node B node C node D
umount volume,
migrate lockres1
to B
want to lock lockres1,
send
MASTER_REQUEST_MSG
to C
init block mle
send
MIGRATE_REQUEST_MSG
to C
find a block
mle, and then
return
DLM_MIGRATE_RESPONSE_MASTERY_REF
to B
set C in refmap
umount successfully
try to umount, endless
loop occurs when migrate
lockres1 since C is in
refmap
So we can fix this endless loop case by only returning
DLM_MIGRATE_RESPONSE_MASTERY_REF if it has a mastery mle when receiving
MIGRATE_REQUEST_MSG.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: jiangyiwen <jiangyiwen@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Xue jiufei <xuejiufei@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the call to ocfs2_add_entry() failed in ocfs2_symlink() and
ocfs2_mknod(), iput() will not be called during dput(dentry) because no
d_instantiate(), and this will lead to umount hung.
Signed-off-by: jiangyiwen <jiangyiwen@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When running dirop_fileop_racer we found a dead lock case.
2 nodes, say Node A and Node B, mount the same ocfs2 volume. Create
/race/16/1 in the filesystem, and let the inode number of dir 16 is less
than the inode number of dir race.
Node A Node B
mv /race/16/1 /race/
right after Node A has got the
EX mode of /race/16/, and tries to
get EX mode of /race
ls /race/16/
In this case, Node A has got the EX mode of /race/16/, and wants to get EX
mode of /race/. Node B has got the PR mode of /race/, and wants to get
the PR mode of /race/16/. Since EX and PR are mutually exclusive, dead
lock happens.
This patch fixes this case by locking in ancestor order before trying
inode number order.
Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a lockres in purge list but is still in use, it should be moved to
the tail of purge list. dlm_thread will continue to check next lockres in
purge list. However, code list_move_tail(&dlm->purge_list,
&lockres->purge) will do *no* movements, so dlm_thread will purge the same
lockres in this loop again and again. If it is in use for a long time,
other lockres will not be processed.
Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch tries to fix this crash:
#5 [ffff88003c1cd690] do_invalid_op at ffffffff810166d5
#6 [ffff88003c1cd730] invalid_op at ffffffff8159b2de
[exception RIP: ocfs2_direct_IO_get_blocks+359]
RIP: ffffffffa05dfa27 RSP: ffff88003c1cd7e8 RFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff88003c1cdaa8 RCX: 0000000000000000
RDX: 000000000000000c RSI: ffff880027a95000 RDI: ffff88003c79b540
RBP: ffff88003c1cd858 R8: 0000000000000000 R9: ffffffff815f6ba0
R10: 00000000000001c9 R11: 00000000000001c9 R12: ffff88002d271500
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000001000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#7 [ffff88003c1cd860] do_direct_IO at ffffffff811cd31b
#8 [ffff88003c1cd950] direct_IO_iovec at ffffffff811cde9c
#9 [ffff88003c1cd9b0] do_blockdev_direct_IO at ffffffff811ce764
#10 [ffff88003c1cdb80] __blockdev_direct_IO at ffffffff811ce7cc
#11 [ffff88003c1cdbb0] ocfs2_direct_IO at ffffffffa05df756 [ocfs2]
#12 [ffff88003c1cdbe0] generic_file_direct_write_iter at ffffffff8112f935
#13 [ffff88003c1cdc40] ocfs2_file_write_iter at ffffffffa0600ccc [ocfs2]
#14 [ffff88003c1cdd50] do_aio_write at ffffffff8119126c
#15 [ffff88003c1cddc0] aio_rw_vect_retry at ffffffff811d9bb4
#16 [ffff88003c1cddf0] aio_run_iocb at ffffffff811db880
#17 [ffff88003c1cde30] io_submit_one at ffffffff811dc238
#18 [ffff88003c1cde80] do_io_submit at ffffffff811dc437
#19 [ffff88003c1cdf70] sys_io_submit at ffffffff811dc530
#20 [ffff88003c1cdf80] system_call_fastpath at ffffffff8159a159
It crashes at
BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED));
in ocfs2_direct_IO_get_blocks.
ocfs2_direct_IO_get_blocks is expecting the OCFS2_EXT_REFCOUNTED be removed in
ocfs2_prepare_inode_for_write() if it was there. But no cluster lock is taken
during the time before (or inside) ocfs2_prepare_inode_for_write() and after
ocfs2_direct_IO_get_blocks().
It can happen in this case:
Node A(which crashes) Node B
------------------------ ---------------------------
ocfs2_file_aio_write
ocfs2_prepare_inode_for_write
ocfs2_inode_lock
...
ocfs2_inode_unlock
#no refcount found
.... ocfs2_reflink
ocfs2_inode_lock
...
ocfs2_inode_unlock
#now, refcount flag set on extent
...
flush change to disk
ocfs2_direct_IO_get_blocks
ocfs2_get_clusters
#extent map miss
#buffer_head miss
read extents from disk
found refcount flag on extent
crash..
Fix:
Take rw_lock in ocfs2_reflink path
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
75f82eaa50 ("ocfs2: fix NULL pointer dereference when dismount and
ocfs2rec simultaneously") may cause umount hang while shutting down
truncate log.
The situation is as followes:
ocfs2_dismout_volume
-> ocfs2_recovery_exit
-> free osb->recovery_map
-> ocfs2_truncate_shutdown
-> lock global bitmap inode
-> ocfs2_wait_for_recovery
-> check whether osb->recovery_map->rm_used is zero
Because osb->recovery_map is already freed, rm_used can be any other
values, so it may yield umount hang.
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Orabug: 18639535
Two node cluster and both nodes hold a lock at PR level and both want to
convert to EX at the same time. Master node 1 has sent BAST and then
closes the connection due to idletime out. Node 0 receives BAST, sends
unlock req with cancel flag but gets error -ENOTCONN. The problem is
this error is ignored in dlm_send_remote_unlock_request() on the
**incorrect** assumption that the master is dead. See NOTE in comment
why it returns DLM_NORMAL. Upon getting DLM_NORMAL, node 0 proceeds to
sends convert (without cancel flg) which fails with -ENOTCONN. waits 5
sec and resends.
This time gets DLM_IVLOCKID from the master since lock not found in
grant, it had been moved to converting queue in response to conv PR->EX
req. No way out.
Node 1 (master) Node 0
============== ======
lock mode PR PR
convert PR -> EX
mv grant -> convert and que BAST
...
<-------- convert PR -> EX
convert que looks like this: ((node 1, PR -> EX) (node 0, PR -> EX))
...
BAST (want PR -> NL)
------------------>
...
idle timout, conn closed
...
In response to BAST,
sends unlock with cancel convert flag
gets -ENOTCONN. Ignores and
sends remote convert request
gets -ENOTCONN, waits 5 Sec, retries
...
reconnects
<----------------- convert req goes through on next try
does not find lock on grant que
status DLM_IVLOCKID
------------------>
...
No way out. Fix is to keep retrying unlock with cancel flag until it
succeeds or the master dies.
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are two files a and b in dir /mnt/ocfs2.
node A node B
mv a b
In ocfs2_rename(), after calling
ocfs2_orphan_add(), the inode of
file b will be added into orphan
dir.
If ocfs2_update_entry() fails,
ocfs2_rename return error and mv
operation fails. But file b still
exists in the parent dir.
ocfs2_queue_orphan_scan
-> ocfs2_queue_recovery_completion
-> ocfs2_complete_recovery
-> ocfs2_recover_orphans
The inode of the file b will be
put with iput().
ocfs2_evict_inode
-> ocfs2_delete_inode
-> ocfs2_wipe_inode
-> ocfs2_remove_inode
OCFS2_VALID_FL in the inode
i_flags will be cleared.
The file b still can be accessed
on node B.
ls /mnt/ocfs2
When first read the file b with
ocfs2_read_inode_block(). It will
validate the inode using
ocfs2_validate_inode_block().
Because OCFS2_VALID_FL not set in
the inode i_flags, so the file
system will be readonly.
So we should add inode into orphan dir after updating entry in
ocfs2_rename().
Signed-off-by: alex.chen <alex.chen@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In v2.6.34 commit 9d8cebd4bc ("mm: fix mbind vma merge problem")
introduced vma merging to mbind(), but it should have also changed the
convention of passing start vma from queue_pages_range() (formerly
check_range()) to new_vma_page(): vma merging may have already freed
that structure, resulting in BUG at mm/mempolicy.c:1738 and probably
worse crashes.
Fixes: 9d8cebd4bc ("mm: fix mbind vma merge problem")
Reported-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Tested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: <stable@vger.kernel.org> [2.6.34+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The previous patch had a few too many false positives on styles that
should be acceptable.
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/notify/fanotify/fanotify_user.c: In function 'SYSC_fanotify_init':
fs/notify/fanotify/fanotify_user.c:726: error: implicit declaration of function 'personality'
fs/notify/fanotify/fanotify_user.c:726: error: 'PER_LINUX32' undeclared (first use in this function)
fs/notify/fanotify/fanotify_user.c:726: error: (Each undeclared identifier is reported only once
fs/notify/fanotify/fanotify_user.c:726: error: for each function it appears in.)
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Will Woods <wwoods@redhat.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: <stable@vger.kernel.org> [3.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We should free memory for bitmap when we find zone mismatch, otherwise
this memory will leak.
Additionally, I copy code comment from PPC KVM's CMA code to inform why
we need to check zone mis-match.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Reviewed-by: Michal Nazarewicz <mina86@mina86.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Alexander Graf <agraf@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit b1cb0982bd ("change the management method of free objects of
the slab") introduced a bug on slab leak detector
('/proc/slab_allocators'). This detector works like as following
decription.
1. traverse all objects on all the slabs.
2. determine whether it is active or not.
3. if active, print who allocate this object.
but that commit changed the way how to manage free objects, so the logic
determining whether it is active or not is also changed. In before, we
regard object in cpu caches as inactive one, but, with this commit, we
mistakenly regard object in cpu caches as active one.
This intoduces kernel oops if DEBUG_PAGEALLOC is enabled. If
DEBUG_PAGEALLOC is enabled, kernel_map_pages() is used to detect who
corrupt free memory in the slab. It unmaps page table mapping if object
is free and map it if object is active. When slab leak detector check
object in cpu caches, it mistakenly think this object active so try to
access object memory to retrieve caller of allocation. At this point,
page table mapping to this object doesn't exist, so oops occurs.
Following is oops message reported from Dave.
It blew up when something tried to read /proc/slab_allocators
(Just cat it, and you should see the oops below)
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in:
[snip...]
CPU: 1 PID: 9386 Comm: trinity-c33 Not tainted 3.14.0-rc5+ #131
task: ffff8801aa46e890 ti: ffff880076924000 task.ti: ffff880076924000
RIP: 0010:[<ffffffffaa1a8f4a>] [<ffffffffaa1a8f4a>] handle_slab+0x8a/0x180
RSP: 0018:ffff880076925de0 EFLAGS: 00010002
RAX: 0000000000001000 RBX: 0000000000000000 RCX: 000000005ce85ce7
RDX: ffffea00079be100 RSI: 0000000000001000 RDI: ffff880107458000
RBP: ffff880076925e18 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000000000f R12: ffff8801e6f84000
R13: ffffea00079be100 R14: ffff880107458000 R15: ffff88022bb8d2c0
FS: 00007fb769e45740(0000) GS:ffff88024d040000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8801e6f84ff8 CR3: 00000000a22db000 CR4: 00000000001407e0
DR0: 0000000002695000 DR1: 0000000002695000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000070602
Call Trace:
leaks_show+0xce/0x240
seq_read+0x28e/0x490
proc_reg_read+0x3d/0x80
vfs_read+0x9b/0x160
SyS_read+0x58/0xb0
tracesys+0xd4/0xd9
Code: f5 00 00 00 0f 1f 44 00 00 48 63 c8 44 3b 0c 8a 0f 84 e3 00 00 00 83 c0 01 44 39 c0 72 eb 41 f6 47 1a 01 0f 84 e9 00 00 00 89 f0 <4d> 8b 4c 04 f8 4d 85 c9 0f 84 88 00 00 00 49 8b 7e 08 4d 8d 46
RIP handle_slab+0x8a/0x180
To fix the problem, I introduce an object status buffer on each slab.
With this, we can track object status precisely, so slab leak detector
would not access active object and no kernel oops would occur. Memory
overhead caused by this fix is only imposed to CONFIG_DEBUG_SLAB_LEAK
which is mainly used for debugging, so memory overhead isn't big
problem.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Trinity finds that mmap access to a hole while it's punched from shmem
can prevent the madvise(MADV_REMOVE) or fallocate(FALLOC_FL_PUNCH_HOLE)
from completing, until the reader chooses to stop; with the puncher's
hold on i_mutex locking out all other writers until it can complete.
It appears that the tmpfs fault path is too light in comparison with its
hole-punching path, lacking an i_data_sem to obstruct it; but we don't
want to slow down the common case.
Extend shmem_fallocate()'s existing range notification mechanism, so
shmem_fault() can refrain from faulting pages into the hole while it's
punched, waiting instead on i_mutex (when safe to sleep; or repeatedly
faulting when not).
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Trinity has reported:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
IP: __lock_acquire (kernel/locking/lockdep.c:3070 (discriminator 1))
CPU: 6 PID: 16173 Comm: trinity-c364 Tainted: G W
3.15.0-rc1-next-20140415-sasha-00020-gaa90d09 #398
lock_acquire (arch/x86/include/asm/current.h:14
kernel/locking/lockdep.c:3602)
_raw_spin_lock (include/linux/spinlock_api_smp.h:143
kernel/locking/spinlock.c:151)
remove_migration_pte (mm/migrate.c:137)
rmap_walk (mm/rmap.c:1628 mm/rmap.c:1699)
remove_migration_ptes (mm/migrate.c:224)
migrate_pages (mm/migrate.c:922 mm/migrate.c:960 mm/migrate.c:1126)
migrate_misplaced_page (mm/migrate.c:1733)
__handle_mm_fault (mm/memory.c:3762 mm/memory.c:3812 mm/memory.c:3925)
handle_mm_fault (mm/memory.c:3948)
__get_user_pages (mm/memory.c:1851)
__mlock_vma_pages_range (mm/mlock.c:255)
__mm_populate (mm/mlock.c:711)
SyS_mlockall (include/linux/mm.h:1799 mm/mlock.c:817 mm/mlock.c:791)
I believe this comes about because, whereas collapsing and splitting THP
functions take anon_vma lock in write mode (which excludes concurrent
rmap walks), faulting THP functions (write protection and misplaced
NUMA) do not - and mostly they do not need to.
But they do use a pmdp_clear_flush(), set_pmd_at() sequence which, for
an instant (indeed, for a long instant, given the inter-CPU TLB flush in
there), leaves *pmd neither present not trans_huge.
Which can confuse a concurrent rmap walk, as when removing migration
ptes, seen in the dumped trace. Although that rmap walk has a 4k page
to insert, anon_vmas containing THPs are in no way segregated from
4k-page anon_vmas, so the 4k-intent mm_find_pmd() does need to cope with
that instant when a trans_huge pmd is temporarily absent.
I don't think we need strengthen the locking at the THP end: it's easily
handled with an ACCESS_ONCE() before testing both conditions.
And since mm_find_pmd() had only one caller who wanted a THP rather than
a pmd, let's slightly repurpose it to fail when it hits a THP or
non-present pmd, and open code split_huge_page_address() again.
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Christoph Lameter <cl@gentwo.org>
Cc: Dave Jones <davej@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Trinity has for over a year been reporting a CONFIG_DEBUG_PAGEALLOC oops
in copy_page_rep() called from copy_user_huge_page() called from
do_huge_pmd_wp_page().
I believe this is a DEBUG_PAGEALLOC false positive, due to the source
page being split, and a tail page freed, while copy is in progress; and
not a problem without DEBUG_PAGEALLOC, since the pmd_same() check will
prevent a miscopy from being made visible.
Fix by adding get_user_huge_page() and put_user_huge_page(): reducing to
the usual get_page() and put_page() on head page in the usual config;
but get and put references to all of the tail pages when
DEBUG_PAGEALLOC.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A 'softlockup' is defined as a bug that causes the kernel to loop in
kernel mode for more than a predefined period to time, without giving
other tasks a chance to run.
Currently, upon detection of this condition by the per-cpu watchdog
task, debug information (including a stack trace) is sent to the system
log.
On some occasions, we have observed that the "victim" rather than the
actual "culprit" (i.e. the owner/holder of the contended resource) is
reported to the user. Often this information has proven to be
insufficient to assist debugging efforts.
To avoid loss of useful debug information, for architectures which
support NMI, this patch makes it possible to improve soft lockup
reporting. This is accomplished by issuing an NMI to each cpu to obtain
a stack trace.
If NMI is not supported we just revert back to the old method. A sysctl
and boot-time parameter is available to toggle this feature.
[dzickus@redhat.com: add CONFIG_SMP in certain areas]
[akpm@linux-foundation.org: additional CONFIG_SMP=n optimisations]
[mq@suse.cz: fix warning]
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jan Moskyto Matejka <mq@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sometimes it is preferred not to use the trigger_all_cpu_backtrace()
routine when one wants to avoid capturing a back trace for current. For
instance if one was previously captured recently.
This patch provides a new routine namely
trigger_allbutself_cpu_backtrace() which offers the flexibility to issue
an NMI to every cpu but current and capture a back trace accordingly.
Patch x86 and sparc to support new routine.
[dzickus@redhat.com: add stub in #else clause]
[dzickus@redhat.com: don't print message in single processor case, wrap with get/put_cpu based on Oleg's suggestion]
[sfr@canb.auug.org.au: undo C99ism]
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Added a guaranteed null-terminate after call to strncpy.
This was partly found using a static code analysis program called
cppcheck.
Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add cancel_work_sync() in rtsx_pci_ms_drv_remove() to cancel pending
request work when removing the driver.
Signed-off-by: Micky Ching <micky_ching@realsil.com.cn>
Cc: Samuel Ortiz <sameo@linux.intel.com> says:
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Roger Tseng <rogerable@realtek.com>
Cc: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg reports a division by zero error on zero-length write() to the
percpu_pagelist_fraction sysctl:
divide error: 0000 [#1] SMP DEBUG_PAGEALLOC
CPU: 1 PID: 9142 Comm: badarea_io Not tainted 3.15.0-rc2-vm-nfs+ #19
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
task: ffff8800d5aeb6e0 ti: ffff8800d87a2000 task.ti: ffff8800d87a2000
RIP: 0010: percpu_pagelist_fraction_sysctl_handler+0x84/0x120
RSP: 0018:ffff8800d87a3e78 EFLAGS: 00010246
RAX: 0000000000000f89 RBX: ffff88011f7fd000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000010
RBP: ffff8800d87a3e98 R08: ffffffff81d002c8 R09: ffff8800d87a3f50
R10: 000000000000000b R11: 0000000000000246 R12: 0000000000000060
R13: ffffffff81c3c3e0 R14: ffffffff81cfddf8 R15: ffff8801193b0800
FS: 00007f614f1e9740(0000) GS:ffff88011f440000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f614f1fa000 CR3: 00000000d9291000 CR4: 00000000000006e0
Call Trace:
proc_sys_call_handler+0xb3/0xc0
proc_sys_write+0x14/0x20
vfs_write+0xba/0x1e0
SyS_write+0x46/0xb0
tracesys+0xe1/0xe6
However, if the percpu_pagelist_fraction sysctl is set by the user, it
is also impossible to restore it to the kernel default since the user
cannot write 0 to the sysctl.
This patch allows the user to write 0 to restore the default behavior.
It still requires a fraction equal to or larger than 8, however, as
stated by the documentation for sanity. If a value in the range [1, 7]
is written, the sysctl will return EINVAL.
This successfully solves the divide by zero issue at the same time.
Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Oleg Drokin <green@linuxhacker.ru>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Peter Wu noticed the following splat on his machine when updating
/proc/sys/kernel/watchdog_thresh:
BUG: sleeping function called from invalid context at mm/slub.c:965
in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: init
3 locks held by init/1:
#0: (sb_writers#3){.+.+.+}, at: [<ffffffff8117b663>] vfs_write+0x143/0x180
#1: (watchdog_proc_mutex){+.+.+.}, at: [<ffffffff810e02d3>] proc_dowatchdog+0x33/0x110
#2: (cpu_hotplug.lock){.+.+.+}, at: [<ffffffff810589c2>] get_online_cpus+0x32/0x80
Preemption disabled at:[<ffffffff810e0384>] proc_dowatchdog+0xe4/0x110
CPU: 0 PID: 1 Comm: init Not tainted 3.16.0-rc1-testing #34
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x4e/0x7a
__might_sleep+0x11d/0x190
kmem_cache_alloc_trace+0x4e/0x1e0
perf_event_alloc+0x55/0x440
perf_event_create_kernel_counter+0x26/0xe0
watchdog_nmi_enable+0x75/0x140
update_timers_all_cpus+0x53/0xa0
proc_dowatchdog+0xe4/0x110
proc_sys_call_handler+0xb3/0xc0
proc_sys_write+0x14/0x20
vfs_write+0xad/0x180
SyS_write+0x49/0xb0
system_call_fastpath+0x16/0x1b
NMI watchdog: disabled (cpu0): hardware events not enabled
What happened is after updating the watchdog_thresh, the lockup detector
is restarted to utilize the new value. Part of this process involved
disabling preemption. Once preemption was disabled, perf tried to
allocate a new event (as part of the restart). This caused the above
BUG_ON as you can't sleep with preemption disabled.
The preemption restriction seemed agressive as we are not doing anything
on that particular cpu, but with all the online cpus (which are
protected by the get_online_cpus lock). Remove the restriction and the
BUG_ON goes away.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Peter Wu <peter@lekensteyn.nl>
Tested-by: Peter Wu <peter@lekensteyn.nl>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org> [3.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As discussed in various threads on the side:
Remove one inactive maintainer, add two new ones and update my email
address. Plus add Andrew. And fix the glob to include files like
mm/slab_common.c
Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
