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tracing, hardirq: No moar _rcuidle() tracing

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Robot reported that trace_hardirqs_{on,off}() tickle the forbidden
_rcuidle() tracepoint through local_irq_{en,dis}able().

For 'sane' configs, these calls will only happen with RCU enabled and
as such can use the regular tracepoint. This also means it's possible
to trace them from NMI context again.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230112195541.477416709@infradead.org
This commit is contained in:
Peter Zijlstra 2023-01-12 20:43:49 +01:00 committed by Ingo Molnar
parent 408b961146
commit 9aedeaed6f
1 changed files with 18 additions and 8 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

26
kernel/trace/trace_preemptirq.c
View file

@ -19,6 +19,20 @@
/* Per-cpu variable to prevent redundant calls when IRQs already off */
static DEFINE_PER_CPU(int, tracing_irq_cpu);
/*
* Use regular trace points on architectures that implement noinstr
* tooling: these calls will only happen with RCU enabled, which can
* use a regular tracepoint.
*
* On older architectures, use the rcuidle tracing methods (which
* aren't NMI-safe - so exclude NMI contexts):
*/
#ifdef CONFIG_ARCH_WANTS_NO_INSTR
#define trace(point) trace_##point
#else
#define trace(point) if (!in_nmi()) trace_##point##_rcuidle
#endif
/*
* Like trace_hardirqs_on() but without the lockdep invocation. This is
* used in the low level entry code where the ordering vs. RCU is important
@ -28,8 +42,7 @@ static DEFINE_PER_CPU(int, tracing_irq_cpu);
void trace_hardirqs_on_prepare(void)
{
if (this_cpu_read(tracing_irq_cpu)) {
if (!in_nmi())
trace_irq_enable(CALLER_ADDR0, CALLER_ADDR1);
trace(irq_enable)(CALLER_ADDR0, CALLER_ADDR1);
tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
this_cpu_write(tracing_irq_cpu, 0);
}
@ -40,8 +53,7 @@ NOKPROBE_SYMBOL(trace_hardirqs_on_prepare);
void trace_hardirqs_on(void)
{
if (this_cpu_read(tracing_irq_cpu)) {
if (!in_nmi())
trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
trace(irq_enable)(CALLER_ADDR0, CALLER_ADDR1);
tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
this_cpu_write(tracing_irq_cpu, 0);
}
@ -63,8 +75,7 @@ void trace_hardirqs_off_finish(void)
if (!this_cpu_read(tracing_irq_cpu)) {
this_cpu_write(tracing_irq_cpu, 1);
tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
if (!in_nmi())
trace_irq_disable(CALLER_ADDR0, CALLER_ADDR1);
trace(irq_disable)(CALLER_ADDR0, CALLER_ADDR1);
}
}
@ -78,8 +89,7 @@ void trace_hardirqs_off(void)
if (!this_cpu_read(tracing_irq_cpu)) {
this_cpu_write(tracing_irq_cpu, 1);
tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
if (!in_nmi())
trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
trace(irq_disable)(CALLER_ADDR0, CALLER_ADDR1);
}
}
EXPORT_SYMBOL(trace_hardirqs_off);