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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2023-05-27 18:25:31 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-06-24 02:59:26 +0300
commit726ccdba1521007fab4b2b7565d255fa0f2b770c (patch)
treebadf8cdcdd9c5b281ac44fd961832601dcebfa42 /mm/kmsan
parent9721fd82351d47a37ba982272e128101f24efd7c (diff)
downloadlinux-726ccdba1521007fab4b2b7565d255fa0f2b770c.tar.xz
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>
Diffstat (limited to 'mm/kmsan')
-rw-r--r--mm/kmsan/core.c6
-rw-r--r--mm/kmsan/instrumentation.c2
2 files changed, 4 insertions, 4 deletions
diff --git a/mm/kmsan/core.c b/mm/kmsan/core.c
index 7d1e4aa30bae..3adb4c1d3b19 100644
--- a/mm/kmsan/core.c
+++ b/mm/kmsan/core.c
@@ -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);
}
diff --git a/mm/kmsan/instrumentation.c b/mm/kmsan/instrumentation.c
index cf12e9616b24..cc3907a9c33a 100644
--- a/mm/kmsan/instrumentation.c
+++ b/mm/kmsan/instrumentation.c
@@ -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,