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commit 6d7225f0cc1a1fc32cf5dd01b4ab4b8a34c7cdb4 upstream.
Patch series "scope GFP_NOFS api", v5.
This patch (of 7):
Commit 21caf2fc1931 ("mm: teach mm by current context info to not do I/O
during memory allocation") added the memalloc_noio_(save|restore)
functions to enable people to modify the MM behavior by disabling I/O
during memory allocation.
This was further extended in commit 934f3072c17c ("mm: clear __GFP_FS
when PF_MEMALLOC_NOIO is set").
memalloc_noio_* functions prevent allocation paths recursing back into
the filesystem without explicitly changing the flags for every
allocation site.
However, lockdep hasn't been keeping up with the changes and it entirely
misses handling the memalloc_noio adjustments. Instead, it is left to
the callers of __lockdep_trace_alloc to call the function after they
have shaven the respective GFP flags which can lead to false positives:
=================================
[ INFO: inconsistent lock state ]
4.10.0-nbor #134 Not tainted
---------------------------------
inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
fsstress/3365 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&xfs_nondir_ilock_class){++++?.}, at: xfs_ilock+0x141/0x230
{IN-RECLAIM_FS-W} state was registered at:
__lock_acquire+0x62a/0x17c0
lock_acquire+0xc5/0x220
down_write_nested+0x4f/0x90
xfs_ilock+0x141/0x230
xfs_reclaim_inode+0x12a/0x320
xfs_reclaim_inodes_ag+0x2c8/0x4e0
xfs_reclaim_inodes_nr+0x33/0x40
xfs_fs_free_cached_objects+0x19/0x20
super_cache_scan+0x191/0x1a0
shrink_slab+0x26f/0x5f0
shrink_node+0xf9/0x2f0
kswapd+0x356/0x920
kthread+0x10c/0x140
ret_from_fork+0x31/0x40
irq event stamp: 173777
hardirqs last enabled at (173777): __local_bh_enable_ip+0x70/0xc0
hardirqs last disabled at (173775): __local_bh_enable_ip+0x37/0xc0
softirqs last enabled at (173776): _xfs_buf_find+0x67a/0xb70
softirqs last disabled at (173774): _xfs_buf_find+0x5db/0xb70
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&xfs_nondir_ilock_class);
<Interrupt>
lock(&xfs_nondir_ilock_class);
*** DEADLOCK ***
4 locks held by fsstress/3365:
#0: (sb_writers#10){++++++}, at: mnt_want_write+0x24/0x50
#1: (&sb->s_type->i_mutex_key#12){++++++}, at: vfs_setxattr+0x6f/0xb0
#2: (sb_internal#2){++++++}, at: xfs_trans_alloc+0xfc/0x140
#3: (&xfs_nondir_ilock_class){++++?.}, at: xfs_ilock+0x141/0x230
stack backtrace:
CPU: 0 PID: 3365 Comm: fsstress Not tainted 4.10.0-nbor #134
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
Call Trace:
kmem_cache_alloc_node_trace+0x3a/0x2c0
vm_map_ram+0x2a1/0x510
_xfs_buf_map_pages+0x77/0x140
xfs_buf_get_map+0x185/0x2a0
xfs_attr_rmtval_set+0x233/0x430
xfs_attr_leaf_addname+0x2d2/0x500
xfs_attr_set+0x214/0x420
xfs_xattr_set+0x59/0xb0
__vfs_setxattr+0x76/0xa0
__vfs_setxattr_noperm+0x5e/0xf0
vfs_setxattr+0xae/0xb0
setxattr+0x15e/0x1a0
path_setxattr+0x8f/0xc0
SyS_lsetxattr+0x11/0x20
entry_SYSCALL_64_fastpath+0x23/0xc6
Let's fix this by making lockdep explicitly do the shaving of respective
GFP flags.
Fixes: 934f3072c17c ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set")
Link: http://lkml.kernel.org/r/20170306131408.9828-2-mhocko@kernel.org
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: no need to touch #includes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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As requested by Linus add explicit __visible to the asmlinkage users.
This marks functions visible to assembler.
Tree sweep for rest of tree.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1398984278-29319-4-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 LTO changes from Peter Anvin:
"More infrastructure work in preparation for link-time optimization
(LTO). Most of these changes is to make sure symbols accessed from
assembly code are properly marked as visible so the linker doesn't
remove them.
My understanding is that the changes to support LTO are still not
upstream in binutils, but are on the way there. This patchset should
conclude the x86-specific changes, and remaining patches to actually
enable LTO will be fed through the Kbuild tree (other than keeping up
with changes to the x86 code base, of course), although not
necessarily in this merge window"
* 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
Kbuild, lto: Handle basic LTO in modpost
Kbuild, lto: Disable LTO for asm-offsets.c
Kbuild, lto: Add a gcc-ld script to let run gcc as ld
Kbuild, lto: add ld-version and ld-ifversion macros
Kbuild, lto: Drop .number postfixes in modpost
Kbuild, lto, workaround: Don't warn for initcall_reference in modpost
lto: Disable LTO for sys_ni
lto: Handle LTO common symbols in module loader
lto, workaround: Add workaround for initcall reordering
lto: Make asmlinkage __visible
x86, lto: Disable LTO for the x86 VDSO
initconst, x86: Fix initconst mistake in ts5500 code
initconst: Fix initconst mistake in dcdbas
asmlinkage: Make trace_hardirqs_on/off_caller visible
asmlinkage, x86: Fix 32bit memcpy for LTO
asmlinkage Make __stack_chk_failed and memcmp visible
asmlinkage: Mark rwsem functions that can be called from assembler asmlinkage
asmlinkage: Make main_extable_sort_needed visible
asmlinkage, mutex: Mark __visible
asmlinkage: Make trace_hardirq visible
...
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Can be called from assembler code.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391845930-28580-6-git-send-email-ak@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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lockdep_sys_exit can be called from assembler code, so make it
asmlinkage.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391845930-28580-5-git-send-email-ak@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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lockdep_no_validate
The __lockdep_no_validate check in mark_held_locks() adds the subtle
and (afaics) unnecessary difference between no-validate and check==0.
And this looks even more inconsistent because __lock_acquire() skips
mark_irqflags()->mark_lock() if !check.
Change mark_held_locks() to check hlock->check instead.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140120182013.GA26505@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Test-case:
DEFINE_MUTEX(m1);
DEFINE_MUTEX(m2);
DEFINE_MUTEX(mx);
void lockdep_should_complain(void)
{
lockdep_set_novalidate_class(&mx);
// m1 -> mx -> m2
mutex_lock(&m1);
mutex_lock(&mx);
mutex_lock(&m2);
mutex_unlock(&m2);
mutex_unlock(&mx);
mutex_unlock(&m1);
// m2 -> m1 ; should trigger the warning
mutex_lock(&m2);
mutex_lock(&m1);
mutex_unlock(&m1);
mutex_unlock(&m2);
}
this doesn't trigger any warning, lockdep can't detect the trivial
deadlock.
This is because lock(&mx) correctly avoids m1 -> mx dependency, it
skips validate_chain() due to mx->check == 0. But lock(&m2) wrongly
adds mx -> m2 and thus m1 -> m2 is not created.
rcu_lock_acquire()->lock_acquire(check => 0) is fine due to read == 2,
so currently only __lockdep_no_validate__ can trigger this problem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140120182010.GA26498@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The "int check" argument of lock_acquire() and held_lock->check are
misleading. This is actually a boolean: 2 means "true", everything
else is "false".
And there is no need to pass 1 or 0 to lock_acquire() depending on
CONFIG_PROVE_LOCKING, __lock_acquire() checks prove_locking at the
start and clears "check" if !CONFIG_PROVE_LOCKING.
Note: probably we can simply kill this member/arg. The only explicit
user of check => 0 is rcu_lock_acquire(), perhaps we can change it to
use lock_acquire(trylock =>, read => 2). __lockdep_no_validate means
check => 0 implicitly, but we can change validate_chain() to check
hlock->instance->key instead. Not to mention it would be nice to get
rid of lockdep_set_novalidate_class().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140120182006.GA26495@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Lockdep is an awesome piece of code which detects locking issues
which are relevant both to userspace and kernelspace. We can
easily make lockdep work in userspace since there is really no
kernel spacific magic going on in the code.
All we need is to wrap two functions which are used by lockdep
and are very kernel specific.
Doing that will allow tools located in tools/ to easily utilize
lockdep's code for their own use.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: penberg@kernel.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/1352753446-24109-1-git-send-email-sasha.levin@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There are new Sparse warnings:
>> kernel/locking/lockdep.c:1235:15: sparse: symbol '__lockdep_count_forward_deps' was not declared. Should it be static?
>> kernel/locking/lockdep.c:1261:15: sparse: symbol '__lockdep_count_backward_deps' was not declared. Should it be static?
Please consider folding the attached diff :-)
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/527d1787.ThzXGoUspZWehFDl\%fengguang.wu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-wl7s3tta5isufzfguc23et06@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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