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    SubjectRe: [RFC PATCH 01/11] ARM: kprobes: directly modify code if kprobe is not initialized.
    On 01/07/2015 02:35 AM, Wang Nan wrote:
    > If kprobe is optimized before kprobe is initialized, there should
    > be only one core, the probed instruction is not armed with breakpoint,
    > so simply patch text is okay.
    >
    > Signed-off-by: Wang Nan <wangnan0@huawei.com>
    > ---
    > arch/arm/probes/kprobes/opt-arm.c | 11 ++++++++++-
    > 1 file changed, 10 insertions(+), 1 deletion(-)
    >
    > diff --git a/arch/arm/probes/kprobes/opt-arm.c b/arch/arm/probes/kprobes/opt-arm.c
    > index 15b37c0..a021474 100644
    > --- a/arch/arm/probes/kprobes/opt-arm.c
    > +++ b/arch/arm/probes/kprobes/opt-arm.c
    > @@ -325,8 +325,17 @@ void __kprobes arch_optimize_kprobes(struct list_head *oplist)
    > * Similar to __arch_disarm_kprobe, operations which
    > * removing breakpoints must be wrapped by stop_machine
    > * to avoid racing.
    > + *
    > + * If this function is called before kprobes initialized,
    > + * the kprobe should be an early kprobe, the instruction
    > + * is not armed with breakpoint. There should be only
    > + * one core now, so directly __patch_text is enough.
    > */
    > - kprobes_remove_breakpoint(op->kp.addr, insn);
    > + if (unlikely(!kprobes_initialized)) {
    > + BUG_ON(!(op->kp.flags & KPROBE_FLAG_EARLY));
    > + __patch_text(op->kp.addr, insn);
    > + } else
    > + kprobes_remove_breakpoint(op->kp.addr, insn);

    "...if only one branch of a conditional statement is a single statement ...
    use braces in both branches".

    https://www.kernel.org/doc/Documentation/CodingStyle

    >
    > list_del_init(&op->list);
    > }
    >

    Regards,
    Chris

    --
    Qualcomm Innovation Center, Inc.
    The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
    a Linux Foundation Collaborative Project


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