From 2f5f6ad9390c1ebbf738d130dbfe80b60eaa167e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 8 Aug 2011 16:57:47 -0400 Subject: ftrace: Pass ftrace_ops as third parameter to function trace callback Currently the function trace callback receives only the ip and parent_ip of the function that it traced. It would be more powerful to also return the ops that registered the function as well. This allows the same function to act differently depending on what ftrace_ops registered it. Link: http://lkml.kernel.org/r/20120612225424.267254552@goodmis.org Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 101 ++++++++++++++++++++++++++------------ kernel/trace/trace_event_perf.c | 3 +- kernel/trace/trace_events.c | 3 +- kernel/trace/trace_functions.c | 9 ++-- kernel/trace/trace_irqsoff.c | 3 +- kernel/trace/trace_sched_wakeup.c | 2 +- kernel/trace/trace_selftest.c | 15 ++++-- kernel/trace/trace_stack.c | 2 +- 8 files changed, 94 insertions(+), 44 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b4f20fba09fc..4f2ab9352a68 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -64,12 +64,19 @@ #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL) +static struct ftrace_ops ftrace_list_end __read_mostly = { + .func = ftrace_stub, +}; + /* ftrace_enabled is a method to turn ftrace on or off */ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; /* Quick disabling of function tracer. */ -int function_trace_stop; +int function_trace_stop __read_mostly; + +/* Current function tracing op */ +struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; /* List for set_ftrace_pid's pids. */ LIST_HEAD(ftrace_pids); @@ -86,10 +93,6 @@ static int ftrace_disabled __read_mostly; static DEFINE_MUTEX(ftrace_lock); -static struct ftrace_ops ftrace_list_end __read_mostly = { - .func = ftrace_stub, -}; - static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; @@ -100,8 +103,14 @@ ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; static struct ftrace_ops global_ops; static struct ftrace_ops control_ops; -static void -ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); +#if ARCH_SUPPORTS_FTRACE_OPS +static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op); +#else +/* See comment below, where ftrace_ops_list_func is defined */ +static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); +#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) +#endif /* * Traverse the ftrace_global_list, invoking all entries. The reason that we @@ -112,29 +121,29 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); * * Silly Alpha and silly pointer-speculation compiler optimizations! */ -static void ftrace_global_list_func(unsigned long ip, - unsigned long parent_ip) +static void +ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { - struct ftrace_ops *op; - if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT))) return; trace_recursion_set(TRACE_GLOBAL_BIT); op = rcu_dereference_raw(ftrace_global_list); /*see above*/ while (op != &ftrace_list_end) { - op->func(ip, parent_ip); + op->func(ip, parent_ip, op); op = rcu_dereference_raw(op->next); /*see above*/ }; trace_recursion_clear(TRACE_GLOBAL_BIT); } -static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) +static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { if (!test_tsk_trace_trace(current)) return; - ftrace_pid_function(ip, parent_ip); + ftrace_pid_function(ip, parent_ip, op); } static void set_ftrace_pid_function(ftrace_func_t func) @@ -163,12 +172,13 @@ void clear_ftrace_function(void) * For those archs that do not test ftrace_trace_stop in their * mcount call site, we need to do it from C. */ -static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) +static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { if (function_trace_stop) return; - __ftrace_trace_function(ip, parent_ip); + __ftrace_trace_function(ip, parent_ip, op); } #endif @@ -230,15 +240,24 @@ static void update_ftrace_function(void) /* * If we are at the end of the list and this ops is - * not dynamic, then have the mcount trampoline call - * the function directly + * not dynamic and the arch supports passing ops, then have the + * mcount trampoline call the function directly. */ if (ftrace_ops_list == &ftrace_list_end || (ftrace_ops_list->next == &ftrace_list_end && - !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC))) + !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && + ARCH_SUPPORTS_FTRACE_OPS)) { + /* Set the ftrace_ops that the arch callback uses */ + if (ftrace_ops_list == &global_ops) + function_trace_op = ftrace_global_list; + else + function_trace_op = ftrace_ops_list; func = ftrace_ops_list->func; - else + } else { + /* Just use the default ftrace_ops */ + function_trace_op = &ftrace_list_end; func = ftrace_ops_list_func; + } #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST ftrace_trace_function = func; @@ -773,7 +792,8 @@ ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) } static void -function_profile_call(unsigned long ip, unsigned long parent_ip) +function_profile_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *ops) { struct ftrace_profile_stat *stat; struct ftrace_profile *rec; @@ -803,7 +823,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip) #ifdef CONFIG_FUNCTION_GRAPH_TRACER static int profile_graph_entry(struct ftrace_graph_ent *trace) { - function_profile_call(trace->func, 0); + function_profile_call(trace->func, 0, NULL); return 1; } @@ -2790,8 +2810,8 @@ static int __init ftrace_mod_cmd_init(void) } device_initcall(ftrace_mod_cmd_init); -static void -function_trace_probe_call(unsigned long ip, unsigned long parent_ip) +static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { struct ftrace_func_probe *entry; struct hlist_head *hhd; @@ -3942,10 +3962,9 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) #endif /* CONFIG_DYNAMIC_FTRACE */ static void -ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip) +ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { - struct ftrace_ops *op; - if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) return; @@ -3959,7 +3978,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip) while (op != &ftrace_list_end) { if (!ftrace_function_local_disabled(op) && ftrace_ops_test(op, ip)) - op->func(ip, parent_ip); + op->func(ip, parent_ip, op); op = rcu_dereference_raw(op->next); }; @@ -3971,8 +3990,9 @@ static struct ftrace_ops control_ops = { .func = ftrace_ops_control_func, }; -static void -ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) +static inline void +__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *ignored) { struct ftrace_ops *op; @@ -3988,13 +4008,32 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) op = rcu_dereference_raw(ftrace_ops_list); while (op != &ftrace_list_end) { if (ftrace_ops_test(op, ip)) - op->func(ip, parent_ip); + op->func(ip, parent_ip, op); op = rcu_dereference_raw(op->next); }; preempt_enable_notrace(); trace_recursion_clear(TRACE_INTERNAL_BIT); } +/* + * Some archs only support passing ip and parent_ip. Even though + * the list function ignores the op parameter, we do not want any + * C side effects, where a function is called without the caller + * sending a third parameter. + */ +#if ARCH_SUPPORTS_FTRACE_OPS +static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) +{ + __ftrace_ops_list_func(ip, parent_ip, NULL); +} +#else +static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) +{ + __ftrace_ops_list_func(ip, parent_ip, NULL); +} +#endif + static void clear_ftrace_swapper(void) { struct task_struct *p; diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index fee3752ae8f6..a872a9a298a0 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -258,7 +258,8 @@ EXPORT_SYMBOL_GPL(perf_trace_buf_prepare); #ifdef CONFIG_FUNCTION_TRACER static void -perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip) +perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *ops) { struct ftrace_entry *entry; struct hlist_head *head; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 29111da1d100..88daa5177bf4 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1681,7 +1681,8 @@ static __init void event_trace_self_tests(void) static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable); static void -function_test_events_call(unsigned long ip, unsigned long parent_ip) +function_test_events_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { struct ring_buffer_event *event; struct ring_buffer *buffer; diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index c7b0c6a7db09..fceb7a9aa06d 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -48,7 +48,8 @@ static void function_trace_start(struct trace_array *tr) } static void -function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip) +function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { struct trace_array *tr = func_trace; struct trace_array_cpu *data; @@ -75,7 +76,8 @@ function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip) } static void -function_trace_call(unsigned long ip, unsigned long parent_ip) +function_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { struct trace_array *tr = func_trace; struct trace_array_cpu *data; @@ -106,7 +108,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) } static void -function_stack_trace_call(unsigned long ip, unsigned long parent_ip) +function_stack_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { struct trace_array *tr = func_trace; struct trace_array_cpu *data; diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 99d20e920368..2862c77f95d9 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -136,7 +136,8 @@ static int func_prolog_dec(struct trace_array *tr, * irqsoff uses its own tracer function to keep the overhead down: */ static void -irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip) +irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op) { struct trace_array *tr = irqsoff_trace; struct trace_array_cpu *data; diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index ff791ea48b57..0caf4f5da569 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -108,7 +108,7 @@ out_enable: * wakeup uses its own tracer function to keep the overhead down: */ static void -wakeup_tracer_call(unsigned long ip, unsigned long parent_ip) +wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op) { struct trace_array *tr = wakeup_trace; struct trace_array_cpu *data; diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 288541f977fb..9ae40c823af8 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -103,35 +103,40 @@ static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret) static int trace_selftest_test_probe1_cnt; static void trace_selftest_test_probe1_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op) { trace_selftest_test_probe1_cnt++; } static int trace_selftest_test_probe2_cnt; static void trace_selftest_test_probe2_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op) { trace_selftest_test_probe2_cnt++; } static int trace_selftest_test_probe3_cnt; static void trace_selftest_test_probe3_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op) { trace_selftest_test_probe3_cnt++; } static int trace_selftest_test_global_cnt; static void trace_selftest_test_global_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op) { trace_selftest_test_global_cnt++; } static int trace_selftest_test_dyn_cnt; static void trace_selftest_test_dyn_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op) { trace_selftest_test_dyn_cnt++; } diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index d4545f49242e..e20006d5fb6a 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -111,7 +111,7 @@ static inline void check_stack(void) } static void -stack_trace_call(unsigned long ip, unsigned long parent_ip) +stack_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op) { int cpu; -- cgit v1.2.3 From ccf3672d530170c98c734dfc5db07d64bcbad2ad Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 5 Jun 2012 09:44:25 -0400 Subject: ftrace: Consolidate arch dependent functions with 'list' function As the function tracer starts to get more features, the support for theses features will spread out throughout the different architectures over time. These features boil down to what each arch does in the mcount trampoline (the ftrace_caller). Currently there's two features that are not the same throughout the archs. 1) Support to stop function tracing before the callback 2) passing of the ftrace ops Both of these require placing an indirect function to support the features if the mcount trampoline does not. On a side note, for all architectures, when more than one callback is registered to the function tracer, an intermediate 'list' function is called by the mcount trampoline to iterate through the callbacks that are registered. Instead of making a separate function for each of these features, and requiring several indirect calls, just use the single 'list' function as the intermediate, to handle all cases. If an arch does not support the 'stop function tracing' or the passing of ftrace ops, just force it to use the list function that will handle the features required. This makes the code cleaner and simpler and removes a lot of #ifdefs in the code. Link: http://lkml.kernel.org/r/20120612225424.495625483@goodmis.org Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 45 ++++----------------------------------------- 1 file changed, 4 insertions(+), 41 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4f2ab9352a68..4cbca2e6eb70 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -97,8 +97,6 @@ static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; -static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub; -ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; static struct ftrace_ops global_ops; static struct ftrace_ops control_ops; @@ -162,26 +160,9 @@ static void set_ftrace_pid_function(ftrace_func_t func) void clear_ftrace_function(void) { ftrace_trace_function = ftrace_stub; - __ftrace_trace_function = ftrace_stub; - __ftrace_trace_function_delay = ftrace_stub; ftrace_pid_function = ftrace_stub; } -#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST -/* - * For those archs that do not test ftrace_trace_stop in their - * mcount call site, we need to do it from C. - */ -static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) -{ - if (function_trace_stop) - return; - - __ftrace_trace_function(ip, parent_ip, op); -} -#endif - static void control_ops_disable_all(struct ftrace_ops *ops) { int cpu; @@ -246,7 +227,7 @@ static void update_ftrace_function(void) if (ftrace_ops_list == &ftrace_list_end || (ftrace_ops_list->next == &ftrace_list_end && !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && - ARCH_SUPPORTS_FTRACE_OPS)) { + !FTRACE_FORCE_LIST_FUNC)) { /* Set the ftrace_ops that the arch callback uses */ if (ftrace_ops_list == &global_ops) function_trace_op = ftrace_global_list; @@ -259,18 +240,7 @@ static void update_ftrace_function(void) func = ftrace_ops_list_func; } -#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST ftrace_trace_function = func; -#else -#ifdef CONFIG_DYNAMIC_FTRACE - /* do not update till all functions have been modified */ - __ftrace_trace_function_delay = func; -#else - __ftrace_trace_function = func; -#endif - ftrace_trace_function = - (func == ftrace_stub) ? func : ftrace_test_stop_func; -#endif } static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) @@ -1902,16 +1872,6 @@ static void ftrace_run_update_code(int command) */ arch_ftrace_update_code(command); -#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST - /* - * For archs that call ftrace_test_stop_func(), we must - * wait till after we update all the function callers - * before we update the callback. This keeps different - * ops that record different functions from corrupting - * each other. - */ - __ftrace_trace_function = __ftrace_trace_function_delay; -#endif function_trace_stop--; ret = ftrace_arch_code_modify_post_process(); @@ -3996,6 +3956,9 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, { struct ftrace_ops *op; + if (function_trace_stop) + return; + if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT))) return; -- cgit v1.2.3 From a1e2e31d175a1349274eba3465d17616c6725f8c Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 9 Aug 2011 12:50:46 -0400 Subject: ftrace: Return pt_regs to function trace callback Return as the 4th paramater to the function tracer callback the pt_regs. Later patches that implement regs passing for the architectures will require having the ftrace_ops set the SAVE_REGS flag, which will tell the arch to take the time to pass a full set of pt_regs to the ftrace_ops callback function. If the arch does not support it then it should pass NULL. If an arch can pass full regs, then it should define: ARCH_SUPPORTS_FTRACE_SAVE_REGS to 1 Link: http://lkml.kernel.org/r/20120702201821.019966811@goodmis.org Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 37 ++++++++++++++++++++++--------------- kernel/trace/trace_event_perf.c | 2 +- kernel/trace/trace_events.c | 2 +- kernel/trace/trace_functions.c | 7 ++++--- kernel/trace/trace_irqsoff.c | 2 +- kernel/trace/trace_sched_wakeup.c | 3 ++- kernel/trace/trace_selftest.c | 15 ++++++++++----- kernel/trace/trace_stack.c | 3 ++- 8 files changed, 43 insertions(+), 28 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4cbca2e6eb70..6ff07ad0ede3 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -103,7 +103,7 @@ static struct ftrace_ops control_ops; #if ARCH_SUPPORTS_FTRACE_OPS static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op); + struct ftrace_ops *op, struct pt_regs *regs); #else /* See comment below, where ftrace_ops_list_func is defined */ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); @@ -121,7 +121,7 @@ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); */ static void ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *regs) { if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT))) return; @@ -129,19 +129,19 @@ ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, trace_recursion_set(TRACE_GLOBAL_BIT); op = rcu_dereference_raw(ftrace_global_list); /*see above*/ while (op != &ftrace_list_end) { - op->func(ip, parent_ip, op); + op->func(ip, parent_ip, op, regs); op = rcu_dereference_raw(op->next); /*see above*/ }; trace_recursion_clear(TRACE_GLOBAL_BIT); } static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *regs) { if (!test_tsk_trace_trace(current)) return; - ftrace_pid_function(ip, parent_ip, op); + ftrace_pid_function(ip, parent_ip, op, regs); } static void set_ftrace_pid_function(ftrace_func_t func) @@ -763,7 +763,7 @@ ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) static void function_profile_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ops) + struct ftrace_ops *ops, struct pt_regs *regs) { struct ftrace_profile_stat *stat; struct ftrace_profile *rec; @@ -793,7 +793,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip, #ifdef CONFIG_FUNCTION_GRAPH_TRACER static int profile_graph_entry(struct ftrace_graph_ent *trace) { - function_profile_call(trace->func, 0, NULL); + function_profile_call(trace->func, 0, NULL, NULL); return 1; } @@ -2771,7 +2771,7 @@ static int __init ftrace_mod_cmd_init(void) device_initcall(ftrace_mod_cmd_init); static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *pt_regs) { struct ftrace_func_probe *entry; struct hlist_head *hhd; @@ -3923,7 +3923,7 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) static void ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *regs) { if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) return; @@ -3938,7 +3938,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, while (op != &ftrace_list_end) { if (!ftrace_function_local_disabled(op) && ftrace_ops_test(op, ip)) - op->func(ip, parent_ip, op); + op->func(ip, parent_ip, op, regs); op = rcu_dereference_raw(op->next); }; @@ -3952,7 +3952,7 @@ static struct ftrace_ops control_ops = { static inline void __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ignored) + struct ftrace_ops *ignored, struct pt_regs *regs) { struct ftrace_ops *op; @@ -3971,7 +3971,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, op = rcu_dereference_raw(ftrace_ops_list); while (op != &ftrace_list_end) { if (ftrace_ops_test(op, ip)) - op->func(ip, parent_ip, op); + op->func(ip, parent_ip, op, regs); op = rcu_dereference_raw(op->next); }; preempt_enable_notrace(); @@ -3983,17 +3983,24 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, * the list function ignores the op parameter, we do not want any * C side effects, where a function is called without the caller * sending a third parameter. + * Archs are to support both the regs and ftrace_ops at the same time. + * If they support ftrace_ops, it is assumed they support regs. + * If call backs want to use regs, they must either check for regs + * being NULL, or ARCH_SUPPORTS_FTRACE_SAVE_REGS. + * Note, ARCH_SUPPORT_SAVE_REGS expects a full regs to be saved. + * An architecture can pass partial regs with ftrace_ops and still + * set the ARCH_SUPPORT_FTARCE_OPS. */ #if ARCH_SUPPORTS_FTRACE_OPS static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *regs) { - __ftrace_ops_list_func(ip, parent_ip, NULL); + __ftrace_ops_list_func(ip, parent_ip, NULL, regs); } #else static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) { - __ftrace_ops_list_func(ip, parent_ip, NULL); + __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); } #endif diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index a872a9a298a0..9824419c8404 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -259,7 +259,7 @@ EXPORT_SYMBOL_GPL(perf_trace_buf_prepare); #ifdef CONFIG_FUNCTION_TRACER static void perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ops) + struct ftrace_ops *ops, struct pt_regs *pt_regs) { struct ftrace_entry *entry; struct hlist_head *head; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 88daa5177bf4..8c6696833686 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1682,7 +1682,7 @@ static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable); static void function_test_events_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *pt_regs) { struct ring_buffer_event *event; struct ring_buffer *buffer; diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index fceb7a9aa06d..5675ebd541f0 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -49,7 +49,7 @@ static void function_trace_start(struct trace_array *tr) static void function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *pt_regs) { struct trace_array *tr = func_trace; struct trace_array_cpu *data; @@ -77,7 +77,8 @@ function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip, static void function_trace_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *pt_regs) + { struct trace_array *tr = func_trace; struct trace_array_cpu *data; @@ -109,7 +110,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip, static void function_stack_trace_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *pt_regs) { struct trace_array *tr = func_trace; struct trace_array_cpu *data; diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 2862c77f95d9..c7a9ba936de6 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -137,7 +137,7 @@ static int func_prolog_dec(struct trace_array *tr, */ static void irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op) + struct ftrace_ops *op, struct pt_regs *pt_regs) { struct trace_array *tr = irqsoff_trace; struct trace_array_cpu *data; diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 0caf4f5da569..7547e36d483e 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -108,7 +108,8 @@ out_enable: * wakeup uses its own tracer function to keep the overhead down: */ static void -wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op) +wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct pt_regs *pt_regs) { struct trace_array *tr = wakeup_trace; struct trace_array_cpu *data; diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 9ae40c823af8..add37e019fd0 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -104,7 +104,8 @@ static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret) static int trace_selftest_test_probe1_cnt; static void trace_selftest_test_probe1_func(unsigned long ip, unsigned long pip, - struct ftrace_ops *op) + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_probe1_cnt++; } @@ -112,7 +113,8 @@ static void trace_selftest_test_probe1_func(unsigned long ip, static int trace_selftest_test_probe2_cnt; static void trace_selftest_test_probe2_func(unsigned long ip, unsigned long pip, - struct ftrace_ops *op) + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_probe2_cnt++; } @@ -120,7 +122,8 @@ static void trace_selftest_test_probe2_func(unsigned long ip, static int trace_selftest_test_probe3_cnt; static void trace_selftest_test_probe3_func(unsigned long ip, unsigned long pip, - struct ftrace_ops *op) + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_probe3_cnt++; } @@ -128,7 +131,8 @@ static void trace_selftest_test_probe3_func(unsigned long ip, static int trace_selftest_test_global_cnt; static void trace_selftest_test_global_func(unsigned long ip, unsigned long pip, - struct ftrace_ops *op) + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_global_cnt++; } @@ -136,7 +140,8 @@ static void trace_selftest_test_global_func(unsigned long ip, static int trace_selftest_test_dyn_cnt; static void trace_selftest_test_dyn_func(unsigned long ip, unsigned long pip, - struct ftrace_ops *op) + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_dyn_cnt++; } diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index e20006d5fb6a..2fa5328e8893 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -111,7 +111,8 @@ static inline void check_stack(void) } static void -stack_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op) +stack_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct pt_regs *pt_regs) { int cpu; -- cgit v1.2.3 From 08f6fba503111e0336f2b4d6915a4a18f9b60e51 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 30 Apr 2012 16:20:23 -0400 Subject: ftrace/x86: Add separate function to save regs Add a way to have different functions calling different trampolines. If a ftrace_ops wants regs saved on the return, then have only the functions with ops registered to save regs. Functions registered by other ops would not be affected, unless the functions overlap. If one ftrace_ops registered functions A, B and C and another ops registered fucntions to save regs on A, and D, then only functions A and D would be saving regs. Function B and C would work as normal. Although A is registered by both ops: normal and saves regs; this is fine as saving the regs is needed to satisfy one of the ops that calls it but the regs are ignored by the other ops function. x86_64 implements the full regs saving, and i386 just passes a NULL for regs to satisfy the ftrace_ops passing. Where an arch must supply both regs and ftrace_ops parameters, even if regs is just NULL. It is OK for an arch to pass NULL regs. All function trace users that require regs passing must add the flag FTRACE_OPS_FL_SAVE_REGS when registering the ftrace_ops. If the arch does not support saving regs then the ftrace_ops will fail to register. The flag FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED may be set that will prevent the ftrace_ops from failing to register. In this case, the handler may either check if regs is not NULL or check if ARCH_SUPPORTS_FTRACE_SAVE_REGS. If the arch supports passing regs it will set this macro and pass regs for ops that request them. All other archs will just pass NULL. Link: Link: http://lkml.kernel.org/r/20120711195745.107705970@goodmis.org Cc: Alexander van Heukelum Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 83 insertions(+), 8 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6ff07ad0ede3..c55f7e274613 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -314,6 +314,20 @@ static int __register_ftrace_function(struct ftrace_ops *ops) if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK) return -EINVAL; +#ifndef ARCH_SUPPORTS_FTRACE_SAVE_REGS + /* + * If the ftrace_ops specifies SAVE_REGS, then it only can be used + * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. + * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. + */ + if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && + !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) + return -EINVAL; + + if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) + ops->flags |= FTRACE_OPS_FL_SAVE_REGS; +#endif + if (!core_kernel_data((unsigned long)ops)) ops->flags |= FTRACE_OPS_FL_DYNAMIC; @@ -1515,6 +1529,12 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops, rec->flags++; if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) return; + /* + * If any ops wants regs saved for this function + * then all ops will get saved regs. + */ + if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) + rec->flags |= FTRACE_FL_REGS; } else { if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) return; @@ -1606,18 +1626,59 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) if (enable && (rec->flags & ~FTRACE_FL_MASK)) flag = FTRACE_FL_ENABLED; + /* + * If enabling and the REGS flag does not match the REGS_EN, then + * do not ignore this record. Set flags to fail the compare against + * ENABLED. + */ + if (flag && + (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN))) + flag |= FTRACE_FL_REGS; + /* If the state of this record hasn't changed, then do nothing */ if ((rec->flags & FTRACE_FL_ENABLED) == flag) return FTRACE_UPDATE_IGNORE; if (flag) { - if (update) + /* Save off if rec is being enabled (for return value) */ + flag ^= rec->flags & FTRACE_FL_ENABLED; + + if (update) { rec->flags |= FTRACE_FL_ENABLED; - return FTRACE_UPDATE_MAKE_CALL; + if (flag & FTRACE_FL_REGS) { + if (rec->flags & FTRACE_FL_REGS) + rec->flags |= FTRACE_FL_REGS_EN; + else + rec->flags &= ~FTRACE_FL_REGS_EN; + } + } + + /* + * If this record is being updated from a nop, then + * return UPDATE_MAKE_CALL. + * Otherwise, if the EN flag is set, then return + * UPDATE_MODIFY_CALL_REGS to tell the caller to convert + * from the non-save regs, to a save regs function. + * Otherwise, + * return UPDATE_MODIFY_CALL to tell the caller to convert + * from the save regs, to a non-save regs function. + */ + if (flag & FTRACE_FL_ENABLED) + return FTRACE_UPDATE_MAKE_CALL; + else if (rec->flags & FTRACE_FL_REGS_EN) + return FTRACE_UPDATE_MODIFY_CALL_REGS; + else + return FTRACE_UPDATE_MODIFY_CALL; } - if (update) - rec->flags &= ~FTRACE_FL_ENABLED; + if (update) { + /* If there's no more users, clear all flags */ + if (!(rec->flags & ~FTRACE_FL_MASK)) + rec->flags = 0; + else + /* Just disable the record (keep REGS state) */ + rec->flags &= ~FTRACE_FL_ENABLED; + } return FTRACE_UPDATE_MAKE_NOP; } @@ -1652,13 +1713,17 @@ int ftrace_test_record(struct dyn_ftrace *rec, int enable) static int __ftrace_replace_code(struct dyn_ftrace *rec, int enable) { + unsigned long ftrace_old_addr; unsigned long ftrace_addr; int ret; - ftrace_addr = (unsigned long)FTRACE_ADDR; - ret = ftrace_update_record(rec, enable); + if (rec->flags & FTRACE_FL_REGS) + ftrace_addr = (unsigned long)FTRACE_REGS_ADDR; + else + ftrace_addr = (unsigned long)FTRACE_ADDR; + switch (ret) { case FTRACE_UPDATE_IGNORE: return 0; @@ -1668,6 +1733,15 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable) case FTRACE_UPDATE_MAKE_NOP: return ftrace_make_nop(NULL, rec, ftrace_addr); + + case FTRACE_UPDATE_MODIFY_CALL_REGS: + case FTRACE_UPDATE_MODIFY_CALL: + if (rec->flags & FTRACE_FL_REGS) + ftrace_old_addr = (unsigned long)FTRACE_ADDR; + else + ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR; + + return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); } return -1; /* unknow ftrace bug */ @@ -2421,8 +2495,9 @@ static int t_show(struct seq_file *m, void *v) seq_printf(m, "%ps", (void *)rec->ip); if (iter->flags & FTRACE_ITER_ENABLED) - seq_printf(m, " (%ld)", - rec->flags & ~FTRACE_FL_MASK); + seq_printf(m, " (%ld)%s", + rec->flags & ~FTRACE_FL_MASK, + rec->flags & FTRACE_FL_REGS ? " R" : ""); seq_printf(m, "\n"); return 0; -- cgit v1.2.3 From 4740974a6844156c14d741b0080b59d275679a23 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 20 Jul 2012 11:04:44 -0400 Subject: ftrace: Add default recursion protection for function tracing As more users of the function tracer utility are being added, they do not always add the necessary recursion protection. To protect from function recursion due to tracing, if the callback ftrace_ops does not specifically specify that it protects against recursion (by setting the FTRACE_OPS_FL_RECURSION_SAFE flag), the list operation will be called by the mcount trampoline which adds recursion protection. If the flag is set, then the function will be called directly with no extra protection. Note, the list operation is called if more than one function callback is registered, or if the arch does not support all of the function tracer features. Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 10 ++++++++-- kernel/trace/trace_events.c | 1 + kernel/trace/trace_functions.c | 4 ++-- kernel/trace/trace_irqsoff.c | 2 +- kernel/trace/trace_sched_wakeup.c | 2 +- kernel/trace/trace_selftest.c | 7 +++++-- kernel/trace/trace_stack.c | 1 + 7 files changed, 19 insertions(+), 8 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index c55f7e274613..ad765b4ba426 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -66,6 +66,7 @@ static struct ftrace_ops ftrace_list_end __read_mostly = { .func = ftrace_stub, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; /* ftrace_enabled is a method to turn ftrace on or off */ @@ -221,12 +222,13 @@ static void update_ftrace_function(void) /* * If we are at the end of the list and this ops is - * not dynamic and the arch supports passing ops, then have the - * mcount trampoline call the function directly. + * recursion safe and not dynamic and the arch supports passing ops, + * then have the mcount trampoline call the function directly. */ if (ftrace_ops_list == &ftrace_list_end || (ftrace_ops_list->next == &ftrace_list_end && !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && + (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) && !FTRACE_FORCE_LIST_FUNC)) { /* Set the ftrace_ops that the arch callback uses */ if (ftrace_ops_list == &global_ops) @@ -867,6 +869,7 @@ static void unregister_ftrace_profiler(void) #else static struct ftrace_ops ftrace_profile_ops __read_mostly = { .func = function_profile_call, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static int register_ftrace_profiler(void) @@ -1049,6 +1052,7 @@ static struct ftrace_ops global_ops = { .func = ftrace_stub, .notrace_hash = EMPTY_HASH, .filter_hash = EMPTY_HASH, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static DEFINE_MUTEX(ftrace_regex_lock); @@ -3967,6 +3971,7 @@ void __init ftrace_init(void) static struct ftrace_ops global_ops = { .func = ftrace_stub, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static int __init ftrace_nodyn_init(void) @@ -4023,6 +4028,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, static struct ftrace_ops control_ops = { .func = ftrace_ops_control_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static inline void diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 8c6696833686..6825d833a257 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1721,6 +1721,7 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip, static struct ftrace_ops trace_ops __initdata = { .func = function_test_events_call, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static __init void event_trace_self_test_with_function(void) diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 5675ebd541f0..fdff65dff1bb 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -153,13 +153,13 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip, static struct ftrace_ops trace_ops __read_mostly = { .func = function_trace_call, - .flags = FTRACE_OPS_FL_GLOBAL, + .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, }; static struct ftrace_ops trace_stack_ops __read_mostly = { .func = function_stack_trace_call, - .flags = FTRACE_OPS_FL_GLOBAL, + .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, }; /* Our two options */ diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index c7a9ba936de6..d98ee8283b29 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -154,7 +154,7 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, static struct ftrace_ops trace_ops __read_mostly = { .func = irqsoff_tracer_call, - .flags = FTRACE_OPS_FL_GLOBAL, + .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, }; #endif /* CONFIG_FUNCTION_TRACER */ diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 7547e36d483e..02170c00c413 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -130,7 +130,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, static struct ftrace_ops trace_ops __read_mostly = { .func = wakeup_tracer_call, - .flags = FTRACE_OPS_FL_GLOBAL, + .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, }; #endif /* CONFIG_FUNCTION_TRACER */ diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index add37e019fd0..1fb6da85ff8b 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -148,19 +148,22 @@ static void trace_selftest_test_dyn_func(unsigned long ip, static struct ftrace_ops test_probe1 = { .func = trace_selftest_test_probe1_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static struct ftrace_ops test_probe2 = { .func = trace_selftest_test_probe2_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static struct ftrace_ops test_probe3 = { .func = trace_selftest_test_probe3_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static struct ftrace_ops test_global = { - .func = trace_selftest_test_global_func, - .flags = FTRACE_OPS_FL_GLOBAL, + .func = trace_selftest_test_global_func, + .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, }; static void print_counts(void) diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 2fa5328e8893..0c1b165778e5 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -137,6 +137,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip, static struct ftrace_ops trace_ops __read_mostly = { .func = stack_trace_call, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static ssize_t -- cgit v1.2.3 From 47239c4d8d6a24796039cada69d477a2b8cac9d6 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 20 Jul 2012 11:13:07 -0400 Subject: ftrace: Only compile ftrace selftest if selftests are enabled No need to compile in the ftrace selftest helper file if selftests are not being executed. Signed-off-by: Steven Rostedt --- kernel/trace/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index b831087c8200..837090808aac 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -5,10 +5,12 @@ ifdef CONFIG_FUNCTION_TRACER ORIG_CFLAGS := $(KBUILD_CFLAGS) KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS)) +ifdef CONFIG_FTRACE_SELFTEST # selftest needs instrumentation CFLAGS_trace_selftest_dynamic.o = -pg obj-y += trace_selftest_dynamic.o endif +endif # If unlikely tracing is enabled, do not trace these files ifdef CONFIG_TRACING_BRANCHES -- cgit v1.2.3 From ea701f11da44b44907af226fe5a5f57d2f26eeb2 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 20 Jul 2012 13:08:05 -0400 Subject: ftrace: Add selftest to test function trace recursion protection Add selftests to test the function tracing recursion protection actually does work. It also tests if a ftrace_ops states it will perform its own protection. Although, even if the ftrace_ops states it will protect itself, the ftrace infrastructure may still provide protection if the arch does not support all features or another ftrace_ops is registered. Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 21 +++++++ kernel/trace/trace_selftest.c | 136 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 157 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index ad765b4ba426..528d997c7f99 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -111,6 +111,27 @@ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) #endif +/** + * ftrace_nr_registered_ops - return number of ops registered + * + * Returns the number of ftrace_ops registered and tracing functions + */ +int ftrace_nr_registered_ops(void) +{ + struct ftrace_ops *ops; + int cnt = 0; + + mutex_lock(&ftrace_lock); + + for (ops = ftrace_ops_list; + ops != &ftrace_list_end; ops = ops->next) + cnt++; + + mutex_unlock(&ftrace_lock); + + return cnt; +} + /* * Traverse the ftrace_global_list, invoking all entries. The reason that we * can use rcu_dereference_raw() is that elements removed from this list diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 1fb6da85ff8b..86422f91dbe1 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -406,8 +406,141 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, return ret; } + +static int trace_selftest_recursion_cnt; +static void trace_selftest_test_recursion_func(unsigned long ip, + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) +{ + /* + * This function is registered without the recursion safe flag. + * The ftrace infrastructure should provide the recursion + * protection. If not, this will crash the kernel! + */ + trace_selftest_recursion_cnt++; + DYN_FTRACE_TEST_NAME(); +} + +static void trace_selftest_test_recursion_safe_func(unsigned long ip, + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) +{ + /* + * We said we would provide our own recursion. By calling + * this function again, we should recurse back into this function + * and count again. But this only happens if the arch supports + * all of ftrace features and nothing else is using the function + * tracing utility. + */ + if (trace_selftest_recursion_cnt++) + return; + DYN_FTRACE_TEST_NAME(); +} + +static struct ftrace_ops test_rec_probe = { + .func = trace_selftest_test_recursion_func, +}; + +static struct ftrace_ops test_recsafe_probe = { + .func = trace_selftest_test_recursion_safe_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, +}; + +static int +trace_selftest_function_recursion(void) +{ + int save_ftrace_enabled = ftrace_enabled; + int save_tracer_enabled = tracer_enabled; + char *func_name; + int len; + int ret; + int cnt; + + /* The previous test PASSED */ + pr_cont("PASSED\n"); + pr_info("Testing ftrace recursion: "); + + + /* enable tracing, and record the filter function */ + ftrace_enabled = 1; + tracer_enabled = 1; + + /* Handle PPC64 '.' name */ + func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); + len = strlen(func_name); + + ret = ftrace_set_filter(&test_rec_probe, func_name, len, 1); + if (ret) { + pr_cont("*Could not set filter* "); + goto out; + } + + ret = register_ftrace_function(&test_rec_probe); + if (ret) { + pr_cont("*could not register callback* "); + goto out; + } + + DYN_FTRACE_TEST_NAME(); + + unregister_ftrace_function(&test_rec_probe); + + ret = -1; + if (trace_selftest_recursion_cnt != 1) { + pr_cont("*callback not called once (%d)* ", + trace_selftest_recursion_cnt); + goto out; + } + + trace_selftest_recursion_cnt = 1; + + pr_cont("PASSED\n"); + pr_info("Testing ftrace recursion safe: "); + + ret = ftrace_set_filter(&test_recsafe_probe, func_name, len, 1); + if (ret) { + pr_cont("*Could not set filter* "); + goto out; + } + + ret = register_ftrace_function(&test_recsafe_probe); + if (ret) { + pr_cont("*could not register callback* "); + goto out; + } + + DYN_FTRACE_TEST_NAME(); + + unregister_ftrace_function(&test_recsafe_probe); + + /* + * If arch supports all ftrace features, and no other task + * was on the list, we should be fine. + */ + if (!ftrace_nr_registered_ops() && !FTRACE_FORCE_LIST_FUNC) + cnt = 2; /* Should have recursed */ + else + cnt = 1; + + ret = -1; + if (trace_selftest_recursion_cnt != cnt) { + pr_cont("*callback not called expected %d times (%d)* ", + cnt, trace_selftest_recursion_cnt); + goto out; + } + + ret = 0; +out: + ftrace_enabled = save_ftrace_enabled; + tracer_enabled = save_tracer_enabled; + + return ret; +} #else # define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; }) +# define trace_selftest_function_recursion() ({ 0; }) #endif /* CONFIG_DYNAMIC_FTRACE */ /* @@ -455,7 +588,10 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) ret = trace_selftest_startup_dynamic_tracing(trace, tr, DYN_FTRACE_TEST_NAME); + if (ret) + goto out; + ret = trace_selftest_function_recursion(); out: ftrace_enabled = save_ftrace_enabled; tracer_enabled = save_tracer_enabled; -- cgit v1.2.3 From ad97772ad82f57c83968079d0880c71ab126ab04 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 20 Jul 2012 13:45:59 -0400 Subject: ftrace: Add selftest to test function save-regs support Add selftests to test the save-regs functionality of ftrace. If the arch supports saving regs, then it will make sure that regs is at least not NULL in the callback. If the arch does not support saving regs, it makes sure that the registering of the ftrace_ops that requests saving regs fails. It then tests the registering of the ftrace_ops succeeds if the 'IF_SUPPORTED' flag is set. Then it makes sure that the regs passed to the function is NULL. Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 2 +- kernel/trace/trace_selftest.c | 114 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 115 insertions(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 55e1f7f0db12..593debefc4e9 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -472,11 +472,11 @@ extern void trace_find_cmdline(int pid, char comm[]); #ifdef CONFIG_DYNAMIC_FTRACE extern unsigned long ftrace_update_tot_cnt; +#endif #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func extern int DYN_FTRACE_TEST_NAME(void); #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2 extern int DYN_FTRACE_TEST_NAME2(void); -#endif extern int ring_buffer_expanded; extern bool tracing_selftest_disabled; diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 86422f91dbe1..1003a4d5eb25 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -543,6 +543,116 @@ out: # define trace_selftest_function_recursion() ({ 0; }) #endif /* CONFIG_DYNAMIC_FTRACE */ +static enum { + TRACE_SELFTEST_REGS_START, + TRACE_SELFTEST_REGS_FOUND, + TRACE_SELFTEST_REGS_NOT_FOUND, +} trace_selftest_regs_stat; + +static void trace_selftest_test_regs_func(unsigned long ip, + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) +{ + if (pt_regs) + trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND; + else + trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND; +} + +static struct ftrace_ops test_regs_probe = { + .func = trace_selftest_test_regs_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_SAVE_REGS, +}; + +static int +trace_selftest_function_regs(void) +{ + int save_ftrace_enabled = ftrace_enabled; + int save_tracer_enabled = tracer_enabled; + char *func_name; + int len; + int ret; + int supported = 0; + +#ifdef ARCH_SUPPORTS_FTRACE_SAVE_REGS + supported = 1; +#endif + + /* The previous test PASSED */ + pr_cont("PASSED\n"); + pr_info("Testing ftrace regs%s: ", + !supported ? "(no arch support)" : ""); + + /* enable tracing, and record the filter function */ + ftrace_enabled = 1; + tracer_enabled = 1; + + /* Handle PPC64 '.' name */ + func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); + len = strlen(func_name); + + ret = ftrace_set_filter(&test_regs_probe, func_name, len, 1); + /* + * If DYNAMIC_FTRACE is not set, then we just trace all functions. + * This test really doesn't care. + */ + if (ret && ret != -ENODEV) { + pr_cont("*Could not set filter* "); + goto out; + } + + ret = register_ftrace_function(&test_regs_probe); + /* + * Now if the arch does not support passing regs, then this should + * have failed. + */ + if (!supported) { + if (!ret) { + pr_cont("*registered save-regs without arch support* "); + goto out; + } + test_regs_probe.flags |= FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED; + ret = register_ftrace_function(&test_regs_probe); + } + if (ret) { + pr_cont("*could not register callback* "); + goto out; + } + + + DYN_FTRACE_TEST_NAME(); + + unregister_ftrace_function(&test_regs_probe); + + ret = -1; + + switch (trace_selftest_regs_stat) { + case TRACE_SELFTEST_REGS_START: + pr_cont("*callback never called* "); + goto out; + + case TRACE_SELFTEST_REGS_FOUND: + if (supported) + break; + pr_cont("*callback received regs without arch support* "); + goto out; + + case TRACE_SELFTEST_REGS_NOT_FOUND: + if (!supported) + break; + pr_cont("*callback received NULL regs* "); + goto out; + } + + ret = 0; +out: + ftrace_enabled = save_ftrace_enabled; + tracer_enabled = save_tracer_enabled; + + return ret; +} + /* * Simple verification test of ftrace function tracer. * Enable ftrace, sleep 1/10 second, and then read the trace @@ -592,6 +702,10 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) goto out; ret = trace_selftest_function_recursion(); + if (ret) + goto out; + + ret = trace_selftest_function_regs(); out: ftrace_enabled = save_ftrace_enabled; tracer_enabled = save_tracer_enabled; -- cgit v1.2.3 From 647664eaf4033501739ac1f42dd52ce8c9266ccc Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 5 Jun 2012 19:28:08 +0900 Subject: ftrace: add ftrace_set_filter_ip() for address based filter Add a new filter update interface ftrace_set_filter_ip() to set ftrace filter by ip address, not only glob pattern. Link: http://lkml.kernel.org/r/20120605102808.27845.67952.stgit@localhost.localdomain Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Ananth N Mavinakayanahalli Cc: "Frank Ch. Eigler" Cc: Andrew Morton Cc: Frederic Weisbecker Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 57 insertions(+), 2 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 528d997c7f99..9dcf15d38380 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3242,8 +3242,27 @@ ftrace_notrace_write(struct file *file, const char __user *ubuf, } static int -ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, - int reset, int enable) +ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) +{ + struct ftrace_func_entry *entry; + + if (!ftrace_location(ip)) + return -EINVAL; + + if (remove) { + entry = ftrace_lookup_ip(hash, ip); + if (!entry) + return -ENOENT; + free_hash_entry(hash, entry); + return 0; + } + + return add_hash_entry(hash, ip); +} + +static int +ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, + unsigned long ip, int remove, int reset, int enable) { struct ftrace_hash **orig_hash; struct ftrace_hash *hash; @@ -3272,6 +3291,11 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, ret = -EINVAL; goto out_regex_unlock; } + if (ip) { + ret = ftrace_match_addr(hash, ip, remove); + if (ret < 0) + goto out_regex_unlock; + } mutex_lock(&ftrace_lock); ret = ftrace_hash_move(ops, enable, orig_hash, hash); @@ -3288,6 +3312,37 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, return ret; } +static int +ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, + int reset, int enable) +{ + return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); +} + +/** + * ftrace_set_filter_ip - set a function to filter on in ftrace by address + * @ops - the ops to set the filter with + * @ip - the address to add to or remove from the filter. + * @remove - non zero to remove the ip from the filter + * @reset - non zero to reset all filters before applying this filter. + * + * Filters denote which functions should be enabled when tracing is enabled + * If @ip is NULL, it failes to update filter. + */ +int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, + int remove, int reset) +{ + return ftrace_set_addr(ops, ip, remove, reset, 1); +} +EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); + +static int +ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, + int reset, int enable) +{ + return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); +} + /** * ftrace_set_filter - set a function to filter on in ftrace * @ops - the ops to set the filter with -- cgit v1.2.3 From 3c18c10bde65b6dcaffab7a4d040285e4defa49b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 31 Jul 2012 10:23:37 -0400 Subject: tracing: Fix wakeup_rt self test on virtual machines The warkeup_rt self test used msleep() calls to wait for real time tasks to wake up and run. On bare-metal hardware, this was enough as the scheduler should let the RT task run way before the non-RT task wakes up from the msleep(). If it did not, then that would mean the scheduler was broken. But when dealing with virtual machines, this is a different story. If the RT task wakes up on a VCPU, it's up to the host to decide when that task gets to schedule, which can be far behind the time that the non-RT task wakes up. In this case, the test would fail incorrectly. As we are not testing the scheduler, but instead the wake up tracing, we can use completions to wait and not depend on scheduler timings to see if events happen on time. Link: http://lkml.kernel.org/r/1343663105.3847.7.camel@fedora Reported-by: Fengguang Wu Tested-by: Fengguang Wu Signed-off-by: Steven Rostedt --- kernel/trace/trace_selftest.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 1003a4d5eb25..2c00a691a540 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -1041,6 +1041,8 @@ static int trace_wakeup_test_thread(void *data) set_current_state(TASK_INTERRUPTIBLE); schedule(); + complete(x); + /* we are awake, now wait to disappear */ while (!kthread_should_stop()) { /* @@ -1084,24 +1086,21 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) /* reset the max latency */ tracing_max_latency = 0; - /* sleep to let the RT thread sleep too */ - msleep(100); + while (p->on_rq) { + /* + * Sleep to make sure the RT thread is asleep too. + * On virtual machines we can't rely on timings, + * but we want to make sure this test still works. + */ + msleep(100); + } - /* - * Yes this is slightly racy. It is possible that for some - * strange reason that the RT thread we created, did not - * call schedule for 100ms after doing the completion, - * and we do a wakeup on a task that already is awake. - * But that is extremely unlikely, and the worst thing that - * happens in such a case, is that we disable tracing. - * Honestly, if this race does happen something is horrible - * wrong with the system. - */ + init_completion(&isrt); wake_up_process(p); - /* give a little time to let the thread wake up */ - msleep(100); + /* Wait for the task to wake up */ + wait_for_completion(&isrt); /* stop the tracing. */ tracing_stop(); -- cgit v1.2.3 From 92d8d4a8b0f4c6eba70f6e62b48e38bd005a56e6 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Tue, 19 Jun 2012 17:47:52 +0200 Subject: tracing/filter: Add missing initialization Add missing initialization for ret variable. Its initialization is based on the re_cnt variable, which is being set deep down in the ftrace_function_filter_re function. I'm not sure compilers would be smart enough to see this in near future, so killing the warning this way. Link: http://lkml.kernel.org/r/1340120894-9465-2-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_filter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 431dba8b7542..c154797a7ff7 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -2002,7 +2002,7 @@ static int ftrace_function_set_regexp(struct ftrace_ops *ops, int filter, static int __ftrace_function_set_filter(int filter, char *buf, int len, struct function_filter_data *data) { - int i, re_cnt, ret; + int i, re_cnt, ret = -EINVAL; int *reset; char **re; -- cgit v1.2.3 From 87abb3b15c62033409f5bf2ffb5620c94f91cf2c Mon Sep 17 00:00:00 2001 From: Wang Tianhong Date: Thu, 2 Aug 2012 14:02:00 +0800 Subject: tracing/trivial: Fix some typos in kernel/trace Fix some typos in kernel/trace. Link: http://lkml.kernel.org/r/1343887320.2228.9.camel@louis-ThinkPad-T410 Signed-off-by: Wang Tianhong Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 4 ++-- kernel/trace/trace.c | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 49491fa7daa2..b32ed0e385a5 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2816,7 +2816,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_enable); * to the buffer after this will fail and return NULL. * * This is different than ring_buffer_record_disable() as - * it works like an on/off switch, where as the disable() verison + * it works like an on/off switch, where as the disable() version * must be paired with a enable(). */ void ring_buffer_record_off(struct ring_buffer *buffer) @@ -2839,7 +2839,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_off); * ring_buffer_record_off(). * * This is different than ring_buffer_record_enable() as - * it works like an on/off switch, where as the enable() verison + * it works like an on/off switch, where as the enable() version * must be paired with a disable(). */ void ring_buffer_record_on(struct ring_buffer *buffer) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a120f98c4112..d1a8d07ec866 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -426,15 +426,15 @@ __setup("trace_buf_size=", set_buf_size); static int __init set_tracing_thresh(char *str) { - unsigned long threshhold; + unsigned long threshold; int ret; if (!str) return 0; - ret = strict_strtoul(str, 0, &threshhold); + ret = strict_strtoul(str, 0, &threshold); if (ret < 0) return 0; - tracing_thresh = threshhold * 1000; + tracing_thresh = threshold * 1000; return 1; } __setup("tracing_thresh=", set_tracing_thresh); -- cgit v1.2.3 From a2546fae01124fb8063747439300fcf39bac033a Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 9 Feb 2011 13:15:59 -0500 Subject: ftrace: Add -mfentry to Makefile on function tracer Thanks to Andi Kleen, gcc 4.6.0 now supports -mfentry for x86 (and hopefully soon for other archs). What this does is to have the function profiler start at the beginning of the function instead of after the stack is set up. As plain -pg (mcount) is called after the stack is set up, and in some cases can have issues with the function graph tracer. It also requires frame pointers to be enabled. The -mfentry now calls __fentry__ at the beginning of the function. This allows for compiling without frame pointers and even has the ability to access parameters if needed. If the architecture and the compiler both support -mfentry then use that instead. Link: http://lkml.kernel.org/r/20120807194059.392617243@goodmis.org Acked-by: H. Peter Anvin Acked-by: Ingo Molnar Cc: Michal Marek Cc: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/Kconfig | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 8c4c07071cc5..9301a0e35e0c 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -49,6 +49,11 @@ config HAVE_SYSCALL_TRACEPOINTS help See Documentation/trace/ftrace-design.txt +config HAVE_FENTRY + bool + help + Arch supports the gcc options -pg with -mfentry + config HAVE_C_RECORDMCOUNT bool help -- cgit v1.2.3 From 781d06248234e221edb560a18461d65808a8a942 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 9 Feb 2011 13:27:22 -0500 Subject: ftrace: Do not test frame pointers if -mfentry is used The function graph has a test to check if the frame pointer is corrupted, which can happen with various options of gcc with mcount. But this is not an issue with -mfentry as -mfentry does not need nor use frame pointers for function graph tracing. Link: http://lkml.kernel.org/r/20120807194059.773895870@goodmis.org Acked-by: H. Peter Anvin Acked-by: Ingo Molnar Cc: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/trace_functions_graph.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index ce27c8ba8d31..99b4378393d5 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -143,7 +143,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, return; } -#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST +#if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY) /* * The arch may choose to record the frame pointer used * and check it here to make sure that it is what we expect it @@ -154,6 +154,9 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, * * Currently, x86_32 with optimize for size (-Os) makes the latest * gcc do the above. + * + * Note, -mfentry does not use frame pointers, and this test + * is not needed if CC_USING_FENTRY is set. */ if (unlikely(current->ret_stack[index].fp != frame_pointer)) { ftrace_graph_stop(); -- cgit v1.2.3 From 76bab1b78ab6f25d5f74165f94526c25fc93d984 Mon Sep 17 00:00:00 2001 From: Yuanhan Liu Date: Mon, 27 Aug 2012 15:13:45 +0800 Subject: tracing: Skip printing "OK" if failed to disable event No acutal case found. But logically, we should skip "OK" in case any error met. Link: http://lkml.kernel.org/r/1346051625-25231-1-git-send-email-yuanhan.liu@linux.intel.com Signed-off-by: Yuanhan Liu Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 6825d833a257..bbb0e63d78e9 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1646,9 +1646,11 @@ static __init void event_trace_self_tests(void) event_test_stuff(); ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0); - if (WARN_ON_ONCE(ret)) + if (WARN_ON_ONCE(ret)) { pr_warning("error disabling system %s\n", system->name); + continue; + } pr_cont("OK\n"); } -- cgit v1.2.3 From ea632e9f12033346cc68247faa3b924d54936b8b Mon Sep 17 00:00:00 2001 From: Josh Triplett Date: Sun, 2 Sep 2012 19:45:14 -0700 Subject: trace: Stop compiling in trace_clock unconditionally Commit 56449f437 "tracing: make the trace clocks available generally", in April 2009, made trace_clock available unconditionally, since CONFIG_X86_DS used it too. Commit faa4602e47 "x86, perf, bts, mm: Delete the never used BTS-ptrace code", in March 2010, removed CONFIG_X86_DS, and now only CONFIG_RING_BUFFER (split out from CONFIG_TRACING for general use) has a dependency on trace_clock. So, only compile in trace_clock with CONFIG_RING_BUFFER or CONFIG_TRACING enabled. Link: http://lkml.kernel.org/r/20120903024513.GA19583@leaf Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Andrew Morton Cc: "Eric W. Biederman" Cc: Al Viro Signed-off-by: Josh Triplett Signed-off-by: Steven Rostedt --- kernel/trace/Kconfig | 5 +++++ kernel/trace/Makefile | 6 +----- 2 files changed, 6 insertions(+), 5 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 9301a0e35e0c..4cea4f41c1d9 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -62,8 +62,12 @@ config HAVE_C_RECORDMCOUNT config TRACER_MAX_TRACE bool +config TRACE_CLOCK + bool + config RING_BUFFER bool + select TRACE_CLOCK config FTRACE_NMI_ENTER bool @@ -114,6 +118,7 @@ config TRACING select NOP_TRACER select BINARY_PRINTF select EVENT_TRACING + select TRACE_CLOCK config GENERIC_TRACER bool diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 837090808aac..d7e2068e4b71 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -19,11 +19,7 @@ endif CFLAGS_trace_events_filter.o := -I$(src) -# -# Make the trace clocks available generally: it's infrastructure -# relied on by ptrace for example: -# -obj-y += trace_clock.o +obj-$(CONFIG_TRACE_CLOCK) += trace_clock.o obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o obj-$(CONFIG_RING_BUFFER) += ring_buffer.o -- cgit v1.2.3 From 5224c3a31549f1c056039545b289e1b01ed02f12 Mon Sep 17 00:00:00 2001 From: Mandeep Singh Baines Date: Fri, 7 Sep 2012 18:12:19 -0700 Subject: tracing: Add an option for disabling markers In our application, we have trace markers spread through user-space. We have markers in GL, X, etc. These are super handy for Chrome's about:tracing feature (Chrome + system + kernel trace view), but can be very distracting when you're trying to debug a kernel issue. I normally, use "grep -v tracing_mark_write" but it would be nice if I could just temporarily disable markers all together. Link: http://lkml.kernel.org/r/1347066739-26285-1-git-send-email-msb@chromium.org CC: Frederic Weisbecker Signed-off-by: Mandeep Singh Baines Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 6 +++++- kernel/trace/trace.h | 1 + 2 files changed, 6 insertions(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 08acf42e325b..1ec5c1dab629 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -328,7 +328,7 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait); unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | - TRACE_ITER_IRQ_INFO; + TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS; static int trace_stop_count; static DEFINE_RAW_SPINLOCK(tracing_start_lock); @@ -470,6 +470,7 @@ static const char *trace_options[] = { "overwrite", "disable_on_free", "irq-info", + "markers", NULL }; @@ -3886,6 +3887,9 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, if (tracing_disabled) return -EINVAL; + if (!(trace_flags & TRACE_ITER_MARKERS)) + return -EINVAL; + if (cnt > TRACE_BUF_SIZE) cnt = TRACE_BUF_SIZE; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 593debefc4e9..63a2da0b9a6e 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -680,6 +680,7 @@ enum trace_iterator_flags { TRACE_ITER_OVERWRITE = 0x200000, TRACE_ITER_STOP_ON_FREE = 0x400000, TRACE_ITER_IRQ_INFO = 0x800000, + TRACE_ITER_MARKERS = 0x1000000, }; /* -- cgit v1.2.3 From 8781915ad2716adcd8cd5cc52cee791fc8b00fdf Mon Sep 17 00:00:00 2001 From: Ezequiel Garcia Date: Wed, 12 Sep 2012 11:47:57 -0300 Subject: trace: Move trace event enable from fs_initcall to core_initcall This patch splits trace event initialization in two stages: * ftrace enable * sysfs event entry creation This allows to capture trace events from an earlier point by using 'trace_event' kernel parameter and is important to trace boot-up allocations. Note that, in order to enable events at core_initcall, it's necessary to move init_ftrace_syscalls() from core_initcall to early_initcall. Link: http://lkml.kernel.org/r/1347461277-25302-1-git-send-email-elezegarcia@gmail.com Signed-off-by: Ezequiel Garcia Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 108 ++++++++++++++++++++++++++++-------------- kernel/trace/trace_syscalls.c | 2 +- 2 files changed, 73 insertions(+), 37 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index bbb0e63d78e9..d608d09d08c0 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1199,6 +1199,31 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events, return 0; } +static void event_remove(struct ftrace_event_call *call) +{ + ftrace_event_enable_disable(call, 0); + if (call->event.funcs) + __unregister_ftrace_event(&call->event); + list_del(&call->list); +} + +static int event_init(struct ftrace_event_call *call) +{ + int ret = 0; + + if (WARN_ON(!call->name)) + return -EINVAL; + + if (call->class->raw_init) { + ret = call->class->raw_init(call); + if (ret < 0 && ret != -ENOSYS) + pr_warn("Could not initialize trace events/%s\n", + call->name); + } + + return ret; +} + static int __trace_add_event_call(struct ftrace_event_call *call, struct module *mod, const struct file_operations *id, @@ -1209,19 +1234,9 @@ __trace_add_event_call(struct ftrace_event_call *call, struct module *mod, struct dentry *d_events; int ret; - /* The linker may leave blanks */ - if (!call->name) - return -EINVAL; - - if (call->class->raw_init) { - ret = call->class->raw_init(call); - if (ret < 0) { - if (ret != -ENOSYS) - pr_warning("Could not initialize trace events/%s\n", - call->name); - return ret; - } - } + ret = event_init(call); + if (ret < 0) + return ret; d_events = event_trace_events_dir(); if (!d_events) @@ -1272,13 +1287,10 @@ static void remove_subsystem_dir(const char *name) */ static void __trace_remove_event_call(struct ftrace_event_call *call) { - ftrace_event_enable_disable(call, 0); - if (call->event.funcs) - __unregister_ftrace_event(&call->event); - debugfs_remove_recursive(call->dir); - list_del(&call->list); + event_remove(call); trace_destroy_fields(call); destroy_preds(call); + debugfs_remove_recursive(call->dir); remove_subsystem_dir(call->class->system); } @@ -1450,15 +1462,43 @@ static __init int setup_trace_event(char *str) } __setup("trace_event=", setup_trace_event); +static __init int event_trace_enable(void) +{ + struct ftrace_event_call **iter, *call; + char *buf = bootup_event_buf; + char *token; + int ret; + + for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) { + + call = *iter; + ret = event_init(call); + if (!ret) + list_add(&call->list, &ftrace_events); + } + + while (true) { + token = strsep(&buf, ","); + + if (!token) + break; + if (!*token) + continue; + + ret = ftrace_set_clr_event(token, 1); + if (ret) + pr_warn("Failed to enable trace event: %s\n", token); + } + return 0; +} + static __init int event_trace_init(void) { - struct ftrace_event_call **call; + struct ftrace_event_call *call; struct dentry *d_tracer; struct dentry *entry; struct dentry *d_events; int ret; - char *buf = bootup_event_buf; - char *token; d_tracer = tracing_init_dentry(); if (!d_tracer) @@ -1497,24 +1537,19 @@ static __init int event_trace_init(void) if (trace_define_common_fields()) pr_warning("tracing: Failed to allocate common fields"); - for_each_event(call, __start_ftrace_events, __stop_ftrace_events) { - __trace_add_event_call(*call, NULL, &ftrace_event_id_fops, + /* + * Early initialization already enabled ftrace event. + * Now it's only necessary to create the event directory. + */ + list_for_each_entry(call, &ftrace_events, list) { + + ret = event_create_dir(call, d_events, + &ftrace_event_id_fops, &ftrace_enable_fops, &ftrace_event_filter_fops, &ftrace_event_format_fops); - } - - while (true) { - token = strsep(&buf, ","); - - if (!token) - break; - if (!*token) - continue; - - ret = ftrace_set_clr_event(token, 1); - if (ret) - pr_warning("Failed to enable trace event: %s\n", token); + if (ret < 0) + event_remove(call); } ret = register_module_notifier(&trace_module_nb); @@ -1523,6 +1558,7 @@ static __init int event_trace_init(void) return 0; } +core_initcall(event_trace_enable); fs_initcall(event_trace_init); #ifdef CONFIG_FTRACE_STARTUP_TEST diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 6b245f64c8dd..2485a7d09b11 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -487,7 +487,7 @@ int __init init_ftrace_syscalls(void) return 0; } -core_initcall(init_ftrace_syscalls); +early_initcall(init_ftrace_syscalls); #ifdef CONFIG_PERF_EVENTS -- cgit v1.2.3