Commit-ID: bf06278c3fdf8909c3a9283e2c270b0fc170fa90
Gitweb: https://git.kernel.org/tip/bf06278c3fdf8909c3a9283e2c270b0fc170fa90
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Mon, 27 Aug 2018 11:12:28 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 30 Aug 2018 14:49:24 -0300
perf/hw_breakpoint: Simplify breakpoint enable in perf_event_modify_breakpoint
We can safely enable the breakpoint back for both the fail and success
paths by checking only the bp->attr.disabled, which either holds the new
'requested' disabled state or the original breakpoint state.
Committer testing:
At the end of the series, the 'perf test' entry introduced as the first
patch now runs to completion without finding the fixed issues:
# perf test "bp modify"
62: x86 bp modify : Ok
#
In verbose mode:
# perf test -v "bp modify"
62: x86 bp modify :
--- start ---
test child forked, pid 5161
rip 5950a0, bp_1 0x5950a0
in bp_1
rip 5950a0, bp_1 0x5950a0
in bp_1
test child finished with 0
---- end ----
x86 bp modify: Ok
Suggested-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Milind Chabbi <chabbi.milind@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20180827091228.2878-6-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
kernel/events/core.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index f6ea33a9f904..22ede28ec07d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2867,16 +2867,11 @@ static int perf_event_modify_breakpoint(struct perf_event *bp,
_perf_event_disable(bp);
err = modify_user_hw_breakpoint_check(bp, attr, true);
- if (err) {
- if (!bp->attr.disabled)
- _perf_event_enable(bp);
- return err;
- }
-
- if (!attr->disabled)
+ if (!bp->attr.disabled)
_perf_event_enable(bp);
- return 0;
+
+ return err;
}
static int perf_event_modify_attr(struct perf_event *event,
|