diff options
| -rw-r--r-- | arch/x86/include/asm/trace/irq_vectors.h | 11 | ||||
| -rw-r--r-- | include/linux/ftrace_event.h | 16 | ||||
| -rw-r--r-- | include/linux/tracepoint.h | 4 | ||||
| -rw-r--r-- | include/trace/ftrace.h | 7 | ||||
| -rw-r--r-- | kernel/trace/trace_event_perf.c | 6 |
5 files changed, 44 insertions, 0 deletions
diff --git a/arch/x86/include/asm/trace/irq_vectors.h b/arch/x86/include/asm/trace/irq_vectors.h index 2874df2..4cab890 100644 --- a/arch/x86/include/asm/trace/irq_vectors.h +++ b/arch/x86/include/asm/trace/irq_vectors.h @@ -72,6 +72,17 @@ DEFINE_IRQ_VECTOR_EVENT(x86_platform_ipi); DEFINE_IRQ_VECTOR_EVENT(irq_work); /* + * We must dis-allow sampling irq_work_exit() because perf event sampling + * itself can cause irq_work, which would lead to an infinite loop; + * + * 1) irq_work_exit happens + * 2) generates perf sample + * 3) generates irq_work + * 4) goto 1 + */ +TRACE_EVENT_PERF_PERM(irq_work_exit, is_sampling_event(p_event) ? -EPERM : 0); + +/* * call_function - called when entering/exiting a call function interrupt * vector handler */ diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 9abbe63..8c9b7a1 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -248,6 +248,9 @@ struct ftrace_event_call { #ifdef CONFIG_PERF_EVENTS int perf_refcount; struct hlist_head __percpu *perf_events; + + int (*perf_perm)(struct ftrace_event_call *, + struct perf_event *); #endif }; @@ -317,6 +320,19 @@ struct ftrace_event_file { } \ early_initcall(trace_init_flags_##name); +#define __TRACE_EVENT_PERF_PERM(name, expr...) \ + static int perf_perm_##name(struct ftrace_event_call *tp_event, \ + struct perf_event *p_event) \ + { \ + return ({ expr; }); \ + } \ + static int __init trace_init_perf_perm_##name(void) \ + { \ + event_##name.perf_perm = &perf_perm_##name; \ + return 0; \ + } \ + early_initcall(trace_init_perf_perm_##name); + #define PERF_MAX_TRACE_SIZE 2048 #define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */ diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index ebeab36..f16dc0a4 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -267,6 +267,8 @@ static inline void tracepoint_synchronize_unregister(void) #define TRACE_EVENT_FLAGS(event, flag) +#define TRACE_EVENT_PERF_PERM(event, expr...) + #endif /* DECLARE_TRACE */ #ifndef TRACE_EVENT @@ -399,4 +401,6 @@ static inline void tracepoint_synchronize_unregister(void) #define TRACE_EVENT_FLAGS(event, flag) +#define TRACE_EVENT_PERF_PERM(event, expr...) + #endif /* ifdef TRACE_EVENT (see note above) */ diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index 52594b2..6b852f6 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -90,6 +90,10 @@ #define TRACE_EVENT_FLAGS(name, value) \ __TRACE_EVENT_FLAGS(name, value) +#undef TRACE_EVENT_PERF_PERM +#define TRACE_EVENT_PERF_PERM(name, expr...) \ + __TRACE_EVENT_PERF_PERM(name, expr) + #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) @@ -140,6 +144,9 @@ #undef TRACE_EVENT_FLAGS #define TRACE_EVENT_FLAGS(event, flag) +#undef TRACE_EVENT_PERF_PERM +#define TRACE_EVENT_PERF_PERM(event, expr...) + #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) /* diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 78e27e3..630889f 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -24,6 +24,12 @@ static int total_ref_count; static int perf_trace_event_perm(struct ftrace_event_call *tp_event, struct perf_event *p_event) { + if (tp_event->perf_perm) { + int ret = tp_event->perf_perm(tp_event, p_event); + if (ret) + return ret; + } + /* The ftrace function trace is allowed only for root. */ if (ftrace_event_is_function(tp_event) && perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN)) |
