From: Qian Cai <cai@lca.pw>
To: peterz@infradead.org
Cc: mark.rutland@arm.com, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org, Qian Cai <cai@lca.pw>
Subject: [PATCH -next] fork: silence a false postive warning in __mmdrop
Date: Thu, 4 Jun 2020 11:03:44 -0400 [thread overview]
Message-ID: <20200604150344.1796-1-cai@lca.pw> (raw)
The linux-next commit bf2c59fce407 ("sched/core: Fix illegal RCU from
offline CPUs") delayed,
idle->active_mm = &init_mm;
into finish_cpu() instead of idle_task_exit() which results in a false
positive warning that was originally designed in the commit 3eda69c92d47
("kernel/fork.c: detect early free of a live mm").
WARNING: CPU: 127 PID: 72976 at kernel/fork.c:697
__mmdrop+0x230/0x2c0
do_exit+0x424/0xfa0
Call Trace:
do_exit+0x424/0xfa0
do_group_exit+0x64/0xd0
sys_exit_group+0x24/0x30
system_call_exception+0x108/0x1d0
system_call_common+0xf0/0x278
Fixes: bf2c59fce407 ("sched/core: Fix illegal RCU from offline CPUs")
Signed-off-by: Qian Cai <cai@lca.pw>
---
kernel/fork.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index 142b23645d82..5334efd2a680 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -694,7 +694,6 @@ void __mmdrop(struct mm_struct *mm)
{
BUG_ON(mm == &init_mm);
WARN_ON_ONCE(mm == current->mm);
- WARN_ON_ONCE(mm == current->active_mm);
mm_free_pgd(mm);
destroy_context(mm);
mmu_notifier_subscriptions_destroy(mm);
--
2.21.0 (Apple Git-122.2)
next reply other threads:[~2020-06-04 15:04 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-04 15:03 Qian Cai [this message]
2020-07-21 17:30 ` [PATCH -next] fork: silence a false postive warning in __mmdrop Qian Cai
2020-07-22 10:06 ` peterz
2020-07-22 13:19 ` Qian Cai
2020-07-22 13:44 ` Peter Zijlstra
2020-09-08 16:50 ` Qian Cai
2020-09-08 17:58 ` peterz
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