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| author | Steven Rostedt <rostedt@goodmis.org> | 2016-12-06 17:50:30 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2017-08-02 20:15:31 -0400 |
| commit | 2581273d5e006b7bf26f15a0c1eaeefac1eae1d6 (patch) | |
| tree | 3d9399175113f8f2faf7405aab355f31f8d8f866 /net | |
| parent | 2939759a2215c2a98bf02c2352a4740533257210 (diff) | |
| download | linux-rt-2581273d5e006b7bf26f15a0c1eaeefac1eae1d6.tar.gz | |
net: Have __napi_schedule_irqoff() disable interrupts on RT
A customer hit a crash where the napi sd->poll_list became corrupted.
The customer had the bnx2x driver, which does a
__napi_schedule_irqoff() in its interrupt handler. Unfortunately, when
running with CONFIG_PREEMPT_RT_FULL, this interrupt handler is run as a
thread and is preemptable. The call to ____napi_schedule() must be done
with interrupts disabled to protect the per cpu softnet_data's
"poll_list, which is protected by disabling interrupts (disabling
preemption is enough when all interrupts are threaded and
local_bh_disable() can't preempt)."
As bnx2x isn't the only driver that does this, the safest thing to do
is to make __napi_schedule_irqoff() call __napi_schedule() instead when
CONFIG_PREEMPT_RT_FULL is enabled, which will call local_irq_save()
before calling ____napi_schedule().
Cc: stable-rt@vger.kernel.org
Signed-off-by: Steven Rostedt (Red Hat) <rostedt@goodmis.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/dev.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 319d38c89f12..15b0f54d3145 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4749,6 +4749,7 @@ void __napi_schedule(struct napi_struct *n) } EXPORT_SYMBOL(__napi_schedule); +#ifndef CONFIG_PREEMPT_RT_FULL /** * __napi_schedule_irqoff - schedule for receive * @n: entry to schedule @@ -4760,6 +4761,7 @@ void __napi_schedule_irqoff(struct napi_struct *n) ____napi_schedule(this_cpu_ptr(&softnet_data), n); } EXPORT_SYMBOL(__napi_schedule_irqoff); +#endif void __napi_complete(struct napi_struct *n) { |