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authorHeiko Carstens <heiko.carstens@de.ibm.com>2015-01-07 10:04:41 +0100
committerIngo Molnar <mingo@kernel.org>2015-01-14 15:16:21 +0100
commit0f1ba9a2cea52896448ef4e14a4cb1880b8e5bee (patch)
tree301b6a4c78620715ea99a35eba30e80a866097e9 /kernel
parent036cc30c6b6af1cd42de6c34c4461f17da01cbf7 (diff)
downloadlinux-0f1ba9a2cea52896448ef4e14a4cb1880b8e5bee.tar.bz2
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/softirq.c6
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 */