sched/debug: Fix preempt_disable_ip recording for preempt_disable()
authorSebastian Andrzej Siewior <bigeasy@linutronix.de>
Fri, 26 Feb 2016 13:54:56 +0000 (14:54 +0100)
committerIngo Molnar <mingo@kernel.org>
Mon, 29 Feb 2016 08:53:10 +0000 (09:53 +0100)
commitf904f58263e1df5f70feb8b283f4bbe662847334
tree41c09804a0ee0617cfc32d196709088d9ec2e914
parentff9a9b4c4334b53b52ee9279f30bd5dd92ea9bdd
sched/debug: Fix preempt_disable_ip recording for preempt_disable()

The preempt_disable() invokes preempt_count_add() which saves the caller
in ->preempt_disable_ip. It uses CALLER_ADDR1 which does not look for
its caller but for the parent of the caller. Which means we get the correct
caller for something like spin_lock() unless the architectures inlines
those invocations. It is always wrong for preempt_disable() or
local_bh_disable().

This patch makes the function get_lock_parent_ip() which tries
CALLER_ADDR0,1,2 if the former is a locking function.
This seems to record the preempt_disable() caller properly for
preempt_disable() itself as well as for get_cpu_var() or
local_bh_disable().

Steven asked for the get_parent_ip() -> get_lock_parent_ip() rename.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160226135456.GB18244@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
include/linux/ftrace.h
include/linux/sched.h
kernel/sched/core.c
kernel/softirq.c