3.2.77-rt112-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
preempt_disable() invokes preempt_count_add() which saves the caller in
current->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_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().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
include/linux/ftrace.h | 12 ++++++++++++
include/linux/sched.h | 2 --
kernel/sched.c | 14 ++------------
kernel/softirq.c | 2 +-
4 files changed, 15 insertions(+), 15 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index a3ebb09d4283..3c87797e371e 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -341,6 +341,18 @@ static inline void __ftrace_enabled_restore(int enabled)
# endif
#endif /* ifndef HAVE_ARCH_CALLER_ADDR */
+static inline unsigned long get_lock_parent_ip(void)
+{
+ unsigned long addr = CALLER_ADDR0;
+
+ if (!in_lock_functions(addr))
+ return addr;
+ addr = CALLER_ADDR1;
+ if (!in_lock_functions(addr))
+ return addr;
+ return CALLER_ADDR2;
+}
+
#ifdef CONFIG_IRQSOFF_TRACER
extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index a15cfd1bac9f..3cb870f1ffc1 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -149,8 +149,6 @@ extern unsigned long this_cpu_load(void);
extern void calc_global_load(unsigned long ticks);
extern void update_cpu_load_nohz(void);
-extern unsigned long get_parent_ip(unsigned long addr);
-
struct seq_file;
struct cfs_rq;
struct task_group;
diff --git a/kernel/sched.c b/kernel/sched.c
index 24d7256ce0b2..abc27a937c1b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4460,16 +4460,6 @@ void scheduler_tick(void)
#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))
@@ -4491,7 +4481,7 @@ void __kprobes add_preempt_count(int val)
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
@@ -4517,7 +4507,7 @@ void __kprobes sub_preempt_count(int val)
#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() -= val;
}
EXPORT_SYMBOL(sub_preempt_count);
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 61860daa4098..b03c01c77d92 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -207,7 +207,7 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt)
raw_local_irq_restore(flags);
if (preempt_count() == cnt)
- trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ trace_preempt_off(CALLER_ADDR0, get_lock_parent_ip());
}
#else /* !CONFIG_TRACE_IRQFLAGS */
static inline void __local_bh_disable(unsigned long ip, unsigned int cnt)
--
2.7.0
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