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| author |   Thomas Gleixner <tglx@linutronix.de> | 2020-03-04 13:09:50 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-05-19 15:47:21 +0200 |
| commit | 0995a5dfbe49badff78e78761fb66f46579f2f9a (patch) | |
| tree | ded1a9f18a2f7a3a700a19cd2d95cf82c1107451 /include/linux/irqflags.h | |
| parent | vmlinux.lds.h: Create section for protection against instrumentation (diff) | |
| download | wireguard-linux-0995a5dfbe49badff78e78761fb66f46579f2f9a.tar.xz wireguard-linux-0995a5dfbe49badff78e78761fb66f46579f2f9a.zip | |
tracing: Provide lockdep less trace_hardirqs_on/off() variants
trace_hardirqs_on/off() is only partially safe vs. RCU idle. The tracer
core itself is safe, but the resulting tracepoints can be utilized by
e.g. BPF which is unsafe.
Provide variants which do not contain the lockdep invocation so the lockdep
and tracer invocations can be split at the call site and placed
properly. This is required because lockdep needs to be aware of the state
before switching away from RCU idle and after switching to RCU idle because
these transitions can take locks.
As these code pathes are going to be non-instrumentable the tracer can be
invoked after RCU is turned on and before the switch to RCU idle. So for
these new variants there is no need to invoke the rcuidle aware tracer
functions.
Name them so they match the lockdep counterparts.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200505134100.270771162@linutronix.de
Diffstat (limited to 'include/linux/irqflags.h')
| -rw-r--r-- | include/linux/irqflags.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index 61a9ced3aa50..f150e69ab81d 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -29,6 +29,8 @@ #endif #ifdef CONFIG_TRACE_IRQFLAGS + extern void trace_hardirqs_on_prepare(void); + extern void trace_hardirqs_off_prepare(void); extern void trace_hardirqs_on(void); extern void trace_hardirqs_off(void); # define lockdep_hardirq_context(p) ((p)->hardirq_context) @@ -96,6 +98,8 @@ do { \ } while (0) #else +# define trace_hardirqs_on_prepare() do { } while (0) +# define trace_hardirqs_off_prepare() do { } while (0) # define trace_hardirqs_on() do { } while (0) # define trace_hardirqs_off() do { } while (0) # define lockdep_hardirq_context(p) 0 |