+ kasankmsan-remove-__gfp_kswapd_reclaim-usage-from-kasan-kmsan.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: kasan,kmsan: remove __GFP_KSWAPD_RECLAIM usage from kasan/kmsan
has been added to the -mm mm-unstable branch.  Its filename is
     kasankmsan-remove-__gfp_kswapd_reclaim-usage-from-kasan-kmsan.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasankmsan-remove-__gfp_kswapd_reclaim-usage-from-kasan-kmsan.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Subject: kasan,kmsan: remove __GFP_KSWAPD_RECLAIM usage from kasan/kmsan
Date: Sun, 28 May 2023 00:25:31 +0900

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>
Cc: 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>
---

 mm/kasan/generic.c         |    4 ++--
 mm/kasan/tags.c            |    2 +-
 mm/kmsan/core.c            |    6 +++---
 mm/kmsan/instrumentation.c |    2 +-
 4 files changed, 7 insertions(+), 7 deletions(-)

--- a/mm/kasan/generic.c~kasankmsan-remove-__gfp_kswapd_reclaim-usage-from-kasan-kmsan
+++ a/mm/kasan/generic.c
@@ -488,7 +488,7 @@ static void __kasan_record_aux_stack(voi
 		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_ca
 	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;
 }
--- a/mm/kasan/tags.c~kasankmsan-remove-__gfp_kswapd_reclaim-usage-from-kasan-kmsan
+++ a/mm/kasan/tags.c
@@ -140,5 +140,5 @@ void kasan_save_alloc_info(struct kmem_c
 
 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);
 }
--- a/mm/kmsan/core.c~kasankmsan-remove-__gfp_kswapd_reclaim-usage-from-kasan-kmsan
+++ a/mm/kmsan/core.c
@@ -74,7 +74,7 @@ depot_stack_handle_t kmsan_save_stack_wi
 	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_chai
 	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_chai
 	 * 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);
 }
--- a/mm/kmsan/instrumentation.c~kasankmsan-remove-__gfp_kswapd_reclaim-usage-from-kasan-kmsan
+++ a/mm/kmsan/instrumentation.c
@@ -282,7 +282,7 @@ void __msan_poison_alloca(void *address,
 
 	/* 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,
_

Patches currently in -mm which might be from penguin-kernel@I-love.SAKURA.ne.jp are

workingset-refactor-lru-refault-to-expose-refault-recency-check-fix.patch
mm-page_alloc-dont-wake-up-kswapd-from-rmqueue-unless-__gfp_kswapd_reclaim-is-specified.patch
kasankmsan-remove-__gfp_kswapd_reclaim-usage-from-kasan-kmsan.patch
debugobjects-turn-off-debug_objects_enabled-from-debug_objects_oom.patch