The patch titled
Subject: printk: avoid double lock acquire
has been added to the -mm tree. Its filename is
printk-avoid-double-lock-acquire.patch
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------------------------------------------------------
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Subject: printk: avoid double lock acquire
Commit 4f2a8d3cf5e ("printk: Fix console_sem vs logbuf_lock unlock race")
introduced another silly bug where we would want to acquire an already
held lock. Avoid this.
Reported-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/printk.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff -puN kernel/printk.c~printk-avoid-double-lock-acquire kernel/printk.c
--- a/kernel/printk.c~printk-avoid-double-lock-acquire
+++ a/kernel/printk.c
@@ -1292,10 +1292,11 @@ again:
raw_spin_lock(&logbuf_lock);
if (con_start != log_end)
retry = 1;
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+
if (retry && console_trylock())
goto again;
- raw_spin_unlock_irqrestore(&logbuf_lock, flags);
if (wake_klogd)
wake_up_klogd();
}
_
Subject: Subject: printk: avoid double lock acquire
Patches currently in -mm which might be from peterz@xxxxxxxxxxxxx are
linux-next.patch
printk-avoid-double-lock-acquire.patch
treewide-remove-useless-noret_type-macro-and-uses.patch
treewide-convert-uses-of-attrib_noreturn-to-__noreturn.patch
mm-memcg-shorten-preempt-disabled-section-around-event-checks.patch
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