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Subject[PATCH 4/5] perf/hw_breakpoint: Enable breakpoint in modify_user_hw_breakpoint
Date
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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