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author | Peter Zijlstra <peterz@infradead.org> | 2020-12-18 18:39:14 +0300 |
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committer | Peter Zijlstra <peterz@infradead.org> | 2020-12-18 18:53:13 +0300 |
commit | 91ea62d58bd661827c328a2c6c02a87fa4aae88b (patch) | |
tree | 531563294d9ea18a4b4797b91fafee39d3a5f720 | |
parent | 441fa3409769180df2fd12fcada35441435a120c (diff) | |
download | linux-91ea62d58bd661827c328a2c6c02a87fa4aae88b.tar.xz |
softirq: Avoid bad tracing / lockdep interaction
Similar to commit:
1a63dcd8765b ("softirq: Reorder trace_softirqs_on to prevent lockdep splat")
__local_bh_enable_ip() can also call into tracing with inconsistent
state. Unlike that commit we don't need to bother about the tracepoint
because 'cnt-1' never matches preempt_count() (by construction).
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lkml.kernel.org/r/20201218154519.GW3092@hirez.programming.kicks-ass.net
-rw-r--r-- | kernel/softirq.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c index 09229ad82209..0f1d3a32d53b 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -185,7 +185,7 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) * Keep preemption disabled until we are done with * softirq processing: */ - preempt_count_sub(cnt - 1); + __preempt_count_sub(cnt - 1); if (unlikely(!in_interrupt() && local_softirq_pending())) { /* |