lkml.org 
[lkml]   [2009]   [Nov]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 2/6] x86/hw-breakpoints: Actually flush thread breakpoints in flush_thread().
    Date
    From: Paul Mundt <lethal@linux-sh.org>

    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 <lethal@linux-sh.org>
    Acked-by: "K.Prasad" <prasad@linux.vnet.ibm.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Alan Stern <stern@rowland.harvard.edu>
    LKML-Reference: <20091005102306.GA7889@linux-sh.org>
    Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
    ---
    arch/x86/kernel/process.c | 2 --
    1 files changed, 0 insertions(+), 2 deletions(-)

    diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
    index 2275ce5..cf8ee00 100644
    --- a/arch/x86/kernel/process.c
    +++ b/arch/x86/kernel/process.c
    @@ -107,8 +107,6 @@ void flush_thread(void)
    }
    #endif

    - clear_tsk_thread_flag(tsk, TIF_DEBUG);
    -
    if (unlikely(test_tsk_thread_flag(tsk, TIF_DEBUG)))
    flush_thread_hw_breakpoint(tsk);
    memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
    --
    1.6.2.3


    \
     
     \ /
      Last update: 2009-11-01 22:13    [W:2.967 / U:0.140 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site