3.4.110-rt140-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior 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 Signed-off-by: Steven Rostedt --- include/linux/ftrace.h | 12 ++++++++++++ include/linux/sched.h | 2 -- kernel/sched/core.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 bfbcd439e2c6..93bce698fb86 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -476,6 +476,18 @@ 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 daf469059630..029575fb9bc8 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -148,8 +148,6 @@ 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/core.c b/kernel/sched/core.c index 7d9a53d80d22..ec9bfbef9873 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3241,16 +3241,6 @@ 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)) @@ -3272,7 +3262,7 @@ 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 @@ -3298,7 +3288,7 @@ 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 d2c870a826da..2cdd5102331b 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