[tip:perf/core] perf: Add kernel side syscall events support for breakpoints

From: tip-bot for Frederic Weisbecker
Date: Mon Nov 23 2009 - 12:44:35 EST


Commit-ID: f5ffe02e5046003ae7e2ce70d3d1c2a73331268b
Gitweb: http://git.kernel.org/tip/f5ffe02e5046003ae7e2ce70d3d1c2a73331268b
Author: Frederic Weisbecker <fweisbec@xxxxxxxxx>
AuthorDate: Mon, 23 Nov 2009 15:42:34 +0100
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Mon, 23 Nov 2009 18:18:31 +0100

perf: Add kernel side syscall events support for breakpoints

Add the remaining necessary bits to support breakpoints created
through perf syscall.

We don't use the software counter interface as:

- We don't need to check against recursion, this is already done
in hardware breakpoints arch level.

- We already know the perf event we are dealing with when the
event is to be committed.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Prasad <prasad@xxxxxxxxxxxxxxxxxx>
LKML-Reference: <1258987355-8751-3-git-send-email-fweisbec@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/perf_event.c | 34 +++++++++++++++++++++++++---------
1 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 0aafe85..9425c96 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -3831,6 +3831,20 @@ static int perf_swevent_is_counting(struct perf_event *event)
static int perf_tp_event_match(struct perf_event *event,
struct perf_sample_data *data);

+static int perf_exclude_event(struct perf_event *event,
+ struct pt_regs *regs)
+{
+ if (regs) {
+ if (event->attr.exclude_user && user_mode(regs))
+ return 1;
+
+ if (event->attr.exclude_kernel && !user_mode(regs))
+ return 1;
+ }
+
+ return 0;
+}
+
static int perf_swevent_match(struct perf_event *event,
enum perf_type_id type,
u32 event_id,
@@ -3842,16 +3856,12 @@ static int perf_swevent_match(struct perf_event *event,

if (event->attr.type != type)
return 0;
+
if (event->attr.config != event_id)
return 0;

- if (regs) {
- if (event->attr.exclude_user && user_mode(regs))
- return 0;
-
- if (event->attr.exclude_kernel && !user_mode(regs))
- return 0;
- }
+ if (perf_exclude_event(event, regs))
+ return 0;

if (event->attr.type == PERF_TYPE_TRACEPOINT &&
!perf_tp_event_match(event, data))
@@ -4282,9 +4292,15 @@ static const struct pmu *bp_perf_event_init(struct perf_event *bp)
return &perf_ops_bp;
}

-void perf_bp_event(struct perf_event *bp, void *regs)
+void perf_bp_event(struct perf_event *bp, void *data)
{
- /* TODO */
+ struct perf_sample_data sample;
+ struct pt_regs *regs = data;
+
+ sample.addr = bp->attr.bp_addr;
+
+ if (!perf_exclude_event(bp, regs))
+ perf_swevent_add(bp, 1, 1, &sample, regs);
}
#else
static void bp_perf_event_destroy(struct perf_event *event)
--
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