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>

diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 224d161a5a22eff4c13bc4453483c389edac196a..5b4c97baa656497140888b42e5e6a93f281e263d 100644 (file)
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -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;
 }

diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
index 67a222586846e8d86feeb4971dfc1067477791c5..7dcfe341d48e31444b03cf3eb3bbd866a3981d73 100644 (file)
--- a/mm/kasan/tags.c
+++ b/mm/kasan/tags.c
@@ -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);
 }

diff --git a/mm/kmsan/core.c b/mm/kmsan/core.c
index 7d1e4aa30bae6227e8053812cffff78793285a57..3adb4c1d3b1937cb3d5fbf4e6869743156a84e6a 100644 (file)
--- 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 cf12e9616b243dc346b1497af8f2a4199e2580f1..cc3907a9c33a0c3d4e08faaa611b62eb6e2f4282 100644 (file)
--- 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,