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kasan,kmsan: remove __GFP_KSWAPD_RECLAIM usage from kasan/kmsan 

syzbot is reporting lockdep warning in __stack_depot_save(), for
the caller of __stack_depot_save() (i.e. __kasan_record_aux_stack() in
this report) is responsible for masking __GFP_KSWAPD_RECLAIM flag in
order not to wake kswapd which in turn wakes kcompactd.

Since kasan/kmsan functions might be called with arbitrary locks held,
mask __GFP_KSWAPD_RECLAIM flag from all GFP_NOWAIT/GFP_ATOMIC allocations
in kasan/kmsan.

Note that kmsan_save_stack_with_flags() is changed to mask both
__GFP_DIRECT_RECLAIM flag and __GFP_KSWAPD_RECLAIM flag, for
wakeup_kswapd() from wake_all_kswapds() from __alloc_pages_slowpath()
calls wakeup_kcompactd() if __GFP_KSWAPD_RECLAIM flag is set and
__GFP_DIRECT_RECLAIM flag is not set.

Link: https://lkml.kernel.org/r/656cb4f5-998b-c8d7-3c61-c2d37aa90f9a@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+ece2915262061d6e0ac1@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=ece2915262061d6e0ac1
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Tetsuo Handa 2023-05-28 00:25:31 +09:00 committed by Andrew Morton
parent 9721fd8235
commit 726ccdba15
4 changed files with 7 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
mm/kasan/generic.c
View File

@ -488,7 +488,7 @@ static void __kasan_record_aux_stack(void *addr, bool can_alloc)
return;
alloc_meta->aux_stack[1] = alloc_meta->aux_stack[0];
alloc_meta->aux_stack[0] = kasan_save_stack(GFP_NOWAIT, can_alloc);
alloc_meta->aux_stack[0] = kasan_save_stack(0, can_alloc);
}
void kasan_record_aux_stack(void *addr)
@ -518,7 +518,7 @@ void kasan_save_free_info(struct kmem_cache *cache, void *object)
if (!free_meta)
return;
kasan_set_track(&free_meta->free_track, GFP_NOWAIT);
kasan_set_track(&free_meta->free_track, 0);
/* The object was freed and has free track set. */
*(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREETRACK;
}

2
mm/kasan/tags.c
View File

@ -140,5 +140,5 @@ void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
void kasan_save_free_info(struct kmem_cache *cache, void *object)
{
save_stack_info(cache, object, GFP_NOWAIT, true);
save_stack_info(cache, object, 0, true);
}

6
mm/kmsan/core.c
View File

@ -74,7 +74,7 @@ depot_stack_handle_t kmsan_save_stack_with_flags(gfp_t flags,
nr_entries = stack_trace_save(entries, KMSAN_STACK_DEPTH, 0);
/* Don't sleep. */
flags &= ~__GFP_DIRECT_RECLAIM;
flags &= ~(__GFP_DIRECT_RECLAIM | __GFP_KSWAPD_RECLAIM);
handle = __stack_depot_save(entries, nr_entries, flags, true);
return stack_depot_set_extra_bits(handle, extra);
@ -245,7 +245,7 @@ depot_stack_handle_t kmsan_internal_chain_origin(depot_stack_handle_t id)
extra_bits = kmsan_extra_bits(depth, uaf);
entries[0] = KMSAN_CHAIN_MAGIC_ORIGIN;
entries[1] = kmsan_save_stack_with_flags(GFP_ATOMIC, 0);
entries[1] = kmsan_save_stack_with_flags(__GFP_HIGH, 0);
entries[2] = id;
/*
* @entries is a local var in non-instrumented code, so KMSAN does not
@ -253,7 +253,7 @@ depot_stack_handle_t kmsan_internal_chain_origin(depot_stack_handle_t id)
* positives when __stack_depot_save() passes it to instrumented code.
*/
kmsan_internal_unpoison_memory(entries, sizeof(entries), false);
handle = __stack_depot_save(entries, ARRAY_SIZE(entries), GFP_ATOMIC,
handle = __stack_depot_save(entries, ARRAY_SIZE(entries), __GFP_HIGH,
true);
return stack_depot_set_extra_bits(handle, extra_bits);
}

2
mm/kmsan/instrumentation.c
View File

@ -282,7 +282,7 @@ void __msan_poison_alloca(void *address, uintptr_t size, char *descr)
/* stack_depot_save() may allocate memory. */
kmsan_enter_runtime();
handle = stack_depot_save(entries, ARRAY_SIZE(entries), GFP_ATOMIC);
handle = stack_depot_save(entries, ARRAY_SIZE(entries), __GFP_HIGH);
kmsan_leave_runtime();
kmsan_internal_set_shadow_origin(address, size, -1, handle,