From bf06278c3fdf8909c3a9283e2c270b0fc170fa90 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 27 Aug 2018 11:12:28 +0200 Subject: [PATCH] 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 Acked-by: Oleg Nesterov Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: David Ahern Cc: Milind Chabbi Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20180827091228.2878-6-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- 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,