diff options
| -rw-r--r-- | include/trace/perf.h | 42 | ||||
| -rw-r--r-- | kernel/trace/trace_syscalls.c | 12 |
2 files changed, 50 insertions, 4 deletions
diff --git a/include/trace/perf.h b/include/trace/perf.h index ded997af481e..15cde7eac8b4 100644 --- a/include/trace/perf.h +++ b/include/trace/perf.h @@ -12,10 +12,10 @@ #undef __perf_task #define __perf_task(t) (__task = (t)) -#undef DECLARE_EVENT_CLASS -#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ +#undef __DECLARE_EVENT_CLASS +#define __DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ static notrace void \ -perf_trace_##call(void *__data, proto) \ +do_perf_trace_##call(void *__data, proto) \ { \ struct trace_event_call *event_call = __data; \ struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\ @@ -55,8 +55,39 @@ perf_trace_##call(void *__data, proto) \ head, __task); \ } +/* + * Define unused __count and __task variables to use @args to pass + * arguments to do_perf_trace_##call. This is needed because the + * macros __perf_count and __perf_task introduce the side-effect to + * store copies into those local variables. + */ +#undef DECLARE_EVENT_CLASS +#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ +__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \ + PARAMS(assign), PARAMS(print)) \ +static notrace void \ +perf_trace_##call(void *__data, proto) \ +{ \ + u64 __count __attribute__((unused)); \ + struct task_struct *__task __attribute__((unused)); \ + \ + do_perf_trace_##call(__data, args); \ +} + #undef DECLARE_EVENT_SYSCALL_CLASS -#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS +#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \ +__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \ + PARAMS(assign), PARAMS(print)) \ +static notrace void \ +perf_trace_##call(void *__data, proto) \ +{ \ + u64 __count __attribute__((unused)); \ + struct task_struct *__task __attribute__((unused)); \ + \ + preempt_disable_notrace(); \ + do_perf_trace_##call(__data, args); \ + preempt_enable_notrace(); \ +} /* * This part is compiled out, it is only here as a build time check @@ -76,4 +107,7 @@ static inline void perf_test_probe_##call(void) \ DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args)) #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) + +#undef __DECLARE_EVENT_CLASS + #endif /* CONFIG_PERF_EVENTS */ diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index f9b21bac9d45..b1cc19806f3d 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -596,6 +596,12 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) int rctx; int size; + /* + * Syscall probe called with preemption enabled, but the ring + * buffer and per-cpu data require preemption to be disabled. + */ + guard(preempt_notrace)(); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0 || syscall_nr >= NR_syscalls) return; @@ -698,6 +704,12 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) int rctx; int size; + /* + * Syscall probe called with preemption enabled, but the ring + * buffer and per-cpu data require preemption to be disabled. + */ + guard(preempt_notrace)(); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0 || syscall_nr >= NR_syscalls) return; |