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>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6dbb21f..423452c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2946,16 +2946,6 @@
}
#endif
-notrace unsigned long get_parent_ip(unsigned long addr)
-{
- if (in_lock_functions(addr)) {
- addr = CALLER_ADDR2;
- if (in_lock_functions(addr))
- addr = CALLER_ADDR3;
- }
- return addr;
-}
-
#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
defined(CONFIG_PREEMPT_TRACER))
@@ -2977,7 +2967,7 @@
PREEMPT_MASK - 10);
#endif
if (preempt_count() == val) {
- unsigned long ip = get_parent_ip(CALLER_ADDR1);
+ unsigned long ip = get_lock_parent_ip();
#ifdef CONFIG_DEBUG_PREEMPT
current->preempt_disable_ip = ip;
#endif
@@ -3004,7 +2994,7 @@
#endif
if (preempt_count() == val)
- trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
__preempt_count_sub(val);
}
EXPORT_SYMBOL(preempt_count_sub);
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 479e443..8aae49d 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -116,9 +116,9 @@
if (preempt_count() == cnt) {
#ifdef CONFIG_DEBUG_PREEMPT
- current->preempt_disable_ip = get_parent_ip(CALLER_ADDR1);
+ current->preempt_disable_ip = get_lock_parent_ip();
#endif
- trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ trace_preempt_off(CALLER_ADDR0, get_lock_parent_ip());
}
}
EXPORT_SYMBOL(__local_bh_disable_ip);