lkml.org 
[lkml]   [2014]   [Jan]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.10 122/129] arm64: fix possible invalid FPSIMD initialization state
    Date
    3.10-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Jiang Liu <jiang.liu@huawei.com>

    commit 6db83cea1c975b9a102e17def7d2795814e1ae2b upstream.

    If context switching happens during executing fpsimd_flush_thread(),
    stale value in FPSIMD registers will be saved into current thread's
    fpsimd_state by fpsimd_thread_switch(). That may cause invalid
    initialization state for the new process, so disable preemption
    when executing fpsimd_flush_thread().

    Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
    Cc: Jiang Liu <liuj97@gmail.com>
    Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
    Cc: Mark Brown <broonie@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    arch/arm64/kernel/fpsimd.c | 2 ++
    1 file changed, 2 insertions(+)

    --- a/arch/arm64/kernel/fpsimd.c
    +++ b/arch/arm64/kernel/fpsimd.c
    @@ -79,8 +79,10 @@ void fpsimd_thread_switch(struct task_st

    void fpsimd_flush_thread(void)
    {
    + preempt_disable();
    memset(&current->thread.fpsimd_state, 0, sizeof(struct fpsimd_state));
    fpsimd_load_state(&current->thread.fpsimd_state);
    + preempt_enable();
    }

    /*



    \
     
     \ /
      Last update: 2014-01-07 03:41    [W:4.002 / U:0.168 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site