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    Subject[PATCH -tip] x86: hw-breakpoints: Actually flush thread breakpoints in flush_thread().
    [ I noticed this whilst hacking up SH support, applies to the current
    tracing/hw-breakpoints topic branch. ]

    flush_thread() tries to do a TIF_DEBUG check before calling in to
    flush_thread_hw_breakpoint() (which subsequently clears the thread flag),
    but for some reason, the x86 code is manually clearing TIF_DEBUG
    immediately before the test, so this path will never be taken.

    This kills off the erroneous clear_tsk_thread_flag() and lets
    flush_thread_hw_breakpoint() actually get invoked.

    Presumably folks were getting lucky with testing and the
    free_thread_info() -> free_thread_xstate() path was taking care of the
    flush there.

    Signed-off-by: Paul Mundt <>


    arch/x86/kernel/process.c | 2 --
    1 file changed, 2 deletions(-)

    diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
    index 1092a1a..c62f647 100644
    --- a/arch/x86/kernel/process.c
    +++ b/arch/x86/kernel/process.c
    @@ -110,8 +110,6 @@ void flush_thread(void)

    - clear_tsk_thread_flag(tsk, TIF_DEBUG);
    if (unlikely(test_tsk_thread_flag(tsk, TIF_DEBUG)))
    memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));

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      Last update: 2009-10-05 12:31    [W:0.020 / U:4.128 seconds]
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