Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH 4/5] perf/hw_breakpoint: Enable breakpoint in modify_user_hw_breakpoint | Date | Fri, 10 Aug 2018 12:47:29 +0200 |
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Currently we enable the breakpoint back only if the breakpoint modification was successful. If it fails we can leave the breakpoint in disabled state with attr->disabled == 0.
We can safely enable the breakpoint back for both the fail and success paths by checking the bp->attr.disabled, which either holds the new 'requested' disabled state or the original breakpoint state.
Suggested-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/n/tip-79p9ttocwy2ju2s6qh25dvre@git.kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- kernel/events/hw_breakpoint.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index 3e560d7609fd..d6b56180827c 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -523,13 +523,11 @@ int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *att perf_event_disable(bp); err = modify_user_hw_breakpoint_check(bp, attr, false); - if (err) - return err; - if (!attr->disabled) + if (!bp->attr.disabled) perf_event_enable(bp); - return 0; + return err; } EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint); -- 2.17.1
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