From: Mike Galbraith <efault@gmx.de>
To: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>
Cc: linux-rt-users@vger.kernel.org,
Mel Gorman <mgorman@techsingularity.net>,
Vlastimil Babka <vbabka@suse.cz>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [patch] mm/slub: Fix kmem_cache_alloc_bulk() error path
Date: Fri, 09 Jul 2021 07:20:36 +0200 [thread overview]
Message-ID: <966f27f7999acb1db8d60e241a73dfde3344345c.camel@gmx.de> (raw)
In-Reply-To: <87tul5p2fa.ffs@nanos.tec.linutronix.de>
The kmem_cache_alloc_bulk() error exit path double unlocks cpu_slab->lock
instead of making the required slub_put_cpu_ptr() call. Fix that.
Boring details:
1. 12c69bab1ece ("mm, slub: move disabling/enabling irqs to ___slab_alloc())")
adds local_irq_enable() above goto error, leaving the one at error: intact.
2. 2180da7ea70a0 ("mm, slub: use migrate_disable() on PREEMPT_RT") adds
slub_get/put_cpu_ptr() calls, missing the already broken error path,
creating unpaired slub_put_cpu_ptr()/slub_put_cpu_ptr() calls.
3. 340e7c4136c3 ("mm, slub: convert kmem_cpu_slab protection to local_lock")
converts local_irq_enable() to local_unlock_irq(), culminating in a
double unlock and unpaired slub_put_cpu_ptr()/slub_put_cpu_ptr().
Signed-off-by: Mike Galbraith <efault@gmx.de>
---
mm/slub.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3605,7 +3605,7 @@ int kmem_cache_alloc_bulk(struct kmem_ca
slab_want_init_on_alloc(flags, s));
return i;
error:
- local_unlock_irq(&s->cpu_slab->lock);
+ slub_put_cpu_ptr(s->cpu_slab);
slab_post_alloc_hook(s, objcg, flags, i, p, false);
__kmem_cache_free_bulk(s, i, p);
return 0;
next prev parent reply other threads:[~2021-07-09 5:20 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-08 9:42 [ANNOUNCE] v5.13-rt1 Thomas Gleixner
2021-07-09 5:20 ` Mike Galbraith [this message]
2021-07-09 5:20 ` [patch] mm/slub: Replace do_slab_free() local_lock_irqsave/restore() calls in PREEMPT_RT scope Mike Galbraith
2021-07-09 5:21 ` [rfc/patch] mm/slub: restore/expand unfreeze_partials() local exclusion scope Mike Galbraith
2021-07-09 5:25 ` Mike Galbraith
2021-07-09 19:28 ` Thomas Gleixner
2021-07-10 1:12 ` Mike Galbraith
2021-07-15 16:34 ` Mike Galbraith
2021-07-17 14:58 ` [patch] v2 " Mike Galbraith
2021-07-18 7:58 ` Vlastimil Babka
2021-07-18 8:11 ` Mike Galbraith
2021-07-18 15:43 ` Mike Galbraith
2021-07-18 21:19 ` Vlastimil Babka
2021-07-19 4:01 ` Mike Galbraith
2021-07-19 13:15 ` Mike Galbraith
2021-07-20 2:46 ` kernel test robot
2021-07-20 8:56 ` [rfc/patch] " Vlastimil Babka
2021-07-20 11:26 ` Mike Galbraith
2021-07-21 4:56 ` Mike Galbraith
2021-07-21 8:44 ` Vlastimil Babka
2021-07-21 9:33 ` Mike Galbraith
2021-07-23 22:39 ` Vlastimil Babka
2021-07-24 2:25 ` Mike Galbraith
2021-07-25 14:09 ` Mike Galbraith
2021-07-25 14:16 ` Vlastimil Babka
2021-07-25 15:02 ` Mike Galbraith
2021-07-25 16:27 ` Vlastimil Babka
2021-07-25 19:12 ` Vlastimil Babka
2021-07-25 19:34 ` Vlastimil Babka
2021-07-26 10:04 ` Mike Galbraith
2021-07-26 17:00 ` Mike Galbraith
2021-07-26 21:26 ` Vlastimil Babka
2021-07-27 4:09 ` Mike Galbraith
2021-07-28 16:59 ` Vlastimil Babka
2021-07-29 4:51 ` Mike Galbraith
2021-07-29 9:51 ` Vlastimil Babka
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