perf: Disable PERF_SAMPLE_BRANCH_* when not supported

PERF_SAMPLE_BRANCH_* is disabled for:

 - SW events (sw counters, tracepoints)
 - HW breakpoints
 - ALL but Intel x86 architecture
 - AMD64 processors

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1328826068-11713-10-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 30 insertions, 0 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 5820efdf47cd..242bb51c67f2 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5044,6 +5044,12 @@ static int perf_swevent_init(struct perf_event *event)
         if (event->attr.type != PERF_TYPE_SOFTWARE)
                 return -ENOENT;
 
+        /*
+         * no branch sampling for software events
+         */
+        if (has_branch_stack(event))
+                return -EOPNOTSUPP;
+
         switch (event_id) {
         case PERF_COUNT_SW_CPU_CLOCK:
         case PERF_COUNT_SW_TASK_CLOCK:
@@ -5154,6 +5160,12 @@ static int perf_tp_event_init(struct perf_event *event)
         if (event->attr.type != PERF_TYPE_TRACEPOINT)
                 return -ENOENT;
 
+        /*
+         * no branch sampling for tracepoint events
+         */
+        if (has_branch_stack(event))
+                return -EOPNOTSUPP;
+
         err = perf_trace_init(event);
         if (err)
                 return err;
@@ -5379,6 +5391,12 @@ static int cpu_clock_event_init(struct perf_event *event)
         if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
                 return -ENOENT;
 
+        /*
+         * no branch sampling for software events
+         */
+        if (has_branch_stack(event))
+                return -EOPNOTSUPP;
+
         perf_swevent_init_hrtimer(event);
 
         return 0;
@@ -5453,6 +5471,12 @@ static int task_clock_event_init(struct perf_event *event)
         if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
                 return -ENOENT;
 
+        /*
+         * no branch sampling for software events
+         */
+        if (has_branch_stack(event))
+                return -EOPNOTSUPP;
+
         perf_swevent_init_hrtimer(event);
 
         return 0;
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 3330022a7ac1..bb38c4d3ee12 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -581,6 +581,12 @@ static int hw_breakpoint_event_init(struct perf_event *bp)
         if (bp->attr.type != PERF_TYPE_BREAKPOINT)
                 return -ENOENT;
 
+        /*
+         * no branch sampling for breakpoint events
+         */
+        if (has_branch_stack(bp))
+                return -EOPNOTSUPP;
+
         err = register_perf_hw_breakpoint(bp);
         if (err)
                 return err;