From ce71b9df8893ec954e56c5979df6da274f20f65e Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sun, 22 Nov 2009 05:26:55 +0100 Subject: tracing: Use the perf recursion protection from trace event When we commit a trace to perf, we first check if we are recursing in the same buffer so that we don't mess-up the buffer with a recursing trace. But later on, we do the same check from perf to avoid commit recursion. The recursion check is desired early before we touch the buffer but we want to do this check only once. Then export the recursion protection from perf and use it from the trace events before submitting a trace. v2: Put appropriate Reported-by tag Reported-by: Peter Zijlstra Signed-off-by: Frederic Weisbecker Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: Jason Baron LKML-Reference: <1258864015-10579-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_event_profile.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'kernel/trace/trace_event_profile.c') diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index e0d351b01f5a..d9c60f80aa0d 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -9,31 +9,33 @@ #include "trace.h" -struct perf_trace_buf *perf_trace_buf; +char *perf_trace_buf; EXPORT_SYMBOL_GPL(perf_trace_buf); -struct perf_trace_buf *perf_trace_buf_nmi; +char *perf_trace_buf_nmi; EXPORT_SYMBOL_GPL(perf_trace_buf_nmi); +typedef typeof(char [FTRACE_MAX_PROFILE_SIZE]) perf_trace_t ; + /* Count the events in use (per event id, not per instance) */ static int total_profile_count; static int ftrace_profile_enable_event(struct ftrace_event_call *event) { - struct perf_trace_buf *buf; + char *buf; int ret = -ENOMEM; if (atomic_inc_return(&event->profile_count)) return 0; if (!total_profile_count) { - buf = alloc_percpu(struct perf_trace_buf); + buf = (char *)alloc_percpu(perf_trace_t); if (!buf) goto fail_buf; rcu_assign_pointer(perf_trace_buf, buf); - buf = alloc_percpu(struct perf_trace_buf); + buf = (char *)alloc_percpu(perf_trace_t); if (!buf) goto fail_buf_nmi; @@ -79,7 +81,7 @@ int ftrace_profile_enable(int event_id) static void ftrace_profile_disable_event(struct ftrace_event_call *event) { - struct perf_trace_buf *buf, *nmi_buf; + char *buf, *nmi_buf; if (!atomic_add_negative(-1, &event->profile_count)) return; -- cgit v1.2.3