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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2015-01-07 10:04:41 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-01-14 15:16:21 +0100 |
| commit | 0f1ba9a2cea52896448ef4e14a4cb1880b8e5bee (patch) | |
| tree | 301b6a4c78620715ea99a35eba30e80a866097e9 | |
| parent | 036cc30c6b6af1cd42de6c34c4461f17da01cbf7 (diff) | |
| download | talos-op-linux-0f1ba9a2cea52896448ef4e14a4cb1880b8e5bee.tar.gz talos-op-linux-0f1ba9a2cea52896448ef4e14a4cb1880b8e5bee.zip | |
softirq/preempt: Add missing current->preempt_disable_ip update
While debugging some "sleeping function called from invalid context" bug I
realized that the debugging message "Preemption disabled at:" pointed to
an incorrect function.
In particular if the last function/action that disabled preemption was
spin_lock_bh() then current->preempt_disable_ip won't be updated.
The reason for this is that __local_bh_disable_ip() will increase
preempt_count manually instead of calling preempt_count_add(), which
would handle the update correctly.
It look like the manual handling was done to work around some lockdep issue.
So add the missing update of current->preempt_disable_ip to
__local_bh_disable_ip() as well.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150107090441.GC4365@osiris
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | kernel/softirq.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c index 501baa9ac1be..b9ae81643f1d 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -114,8 +114,12 @@ void __local_bh_disable_ip(unsigned long ip, unsigned int cnt) trace_softirqs_off(ip); raw_local_irq_restore(flags); - if (preempt_count() == cnt) + if (preempt_count() == cnt) { +#ifdef CONFIG_DEBUG_PREEMPT + current->preempt_disable_ip = get_parent_ip(CALLER_ADDR1); +#endif trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); + } } EXPORT_SYMBOL(__local_bh_disable_ip); #endif /* CONFIG_TRACE_IRQFLAGS */ |
