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SubjectRe: [PATCHv3 0/5] perf/hw_breakpoint: Fix breakpoint modify
On Fri, Aug 10, 2018 at 12:47:25PM +0200, Jiri Olsa wrote:
> hi,
> Milind reported that modify_user_hw_breakpoint wouldn't
> allow the breakpoint changing if the new attr had 'disabled'
> set to true.
>
> I found a case where it actualy prevents ptrace user interface
> to change the breakpoint. It's described in patch 1 as perf test,
> patch 2 is the breakpoint code fix.
>
> I ran strace tests, nothing (new) broken there..
>
> v3 changes:
> - added Oleg's ack for patch 3
> - new patches 4,5 based on Oleg's suggestions
> replacing the v2 fallback approach by enabling
> the event directly after failed modification

Ingo, Arnaldo,
would you please pick up those, or should I pushed them through somebody else?

thanks,
jirka

>
> v2 changes:
> - added Oleg's ack for patch 2
> - added new changes based on Oleg's questions
> plus new test code
>
> thanks,
> jirka
>
> ---
> Jiri Olsa (5):
> perf tests: Add breakpoint modify tests
> perf/hw_breakpoint: Modify breakpoint even if the new attr has disabled set
> perf/hw_breakpoint: Remove superfluous bp->attr.disabled = 0
> perf/hw_breakpoint: Enable breakpoint in modify_user_hw_breakpoint
> perf/hw_breakpoint: Simplify breakpoint enable in perf_event_modify_breakpoint
>
> kernel/events/core.c | 11 ++-----
> kernel/events/hw_breakpoint.c | 13 ++++----
> tools/perf/arch/x86/include/arch-tests.h | 1 +
> tools/perf/arch/x86/tests/Build | 1 +
> tools/perf/arch/x86/tests/arch-tests.c | 6 ++++
> tools/perf/arch/x86/tests/bp-modify.c | 213 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 6 files changed, 230 insertions(+), 15 deletions(-)
> create mode 100644 tools/perf/arch/x86/tests/bp-modify.c

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