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_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 <[email protected]> --- v1…v2: drop the header split and move it to ftrace.h instead include/linux/ftrace.h | 12 ++++++++++++ include/linux/sched.h | 2 -- kernel/sched/core.c | 14 ++------------ kernel/softirq.c | 4 ++-- 4 files changed, 16 insertions(+), 16 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 81de7123959d..f473d9408bc3 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -711,6 +711,18 @@ static inline void __ftrace_enabled_restore(int enabled) #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) +static inline unsigned long get_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 a10494a94cc3..f45f947500c9 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -182,8 +182,6 @@ extern void update_cpu_load_nohz(int active); static inline void update_cpu_load_nohz(int active) { } #endif -extern unsigned long get_parent_ip(unsigned long addr); - extern void dump_cpu_task(int cpu); struct seq_file; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9503d590e5ef..12c2527f5957 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3010,16 +3010,6 @@ u64 scheduler_tick_max_deferment(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)) @@ -3041,7 +3031,7 @@ void preempt_count_add(int val) PREEMPT_MASK - 10); #endif if (preempt_count() == val) { - unsigned long ip = get_parent_ip(CALLER_ADDR1); + unsigned long ip = get_parent_ip(); #ifdef CONFIG_DEBUG_PREEMPT current->preempt_disable_ip = ip; #endif @@ -3068,7 +3058,7 @@ void preempt_count_sub(int val) #endif if (preempt_count() == val) - trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); + trace_preempt_on(CALLER_ADDR0, get_parent_ip()); __preempt_count_sub(val); } EXPORT_SYMBOL(preempt_count_sub); diff --git a/kernel/softirq.c b/kernel/softirq.c index 479e4436f787..ec71033a87a2 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -116,9 +116,9 @@ void __local_bh_disable_ip(unsigned long ip, unsigned int cnt) if (preempt_count() == cnt) { #ifdef CONFIG_DEBUG_PREEMPT - current->preempt_disable_ip = get_parent_ip(CALLER_ADDR1); + current->preempt_disable_ip = get_parent_ip(); #endif - trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); + trace_preempt_off(CALLER_ADDR0, get_parent_ip()); } } EXPORT_SYMBOL(__local_bh_disable_ip); -- 2.7.0
