Re: [PATCH 1/2] uprobes/x86: Change __skip_sstep() to actuallyskip the whole insn

From: Srikar Dronamraju
Date: Thu Jan 03 2013 - 07:01:34 EST


* Oleg Nesterov <oleg@xxxxxxxxxx> [2012-12-30 16:47:19]:

> __skip_sstep() doesn't update regs->ip. Currently this is correct
> but only "by accident" and it doesn't skip the whole insn. Change
> it to advance ->ip by the length of the detected 0x66*0x90 sequence.
>
> Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>

Acked-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>

> ---
> arch/x86/kernel/uprobes.c | 5 ++++-
> 1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
> index c71025b..4e33a35 100644
> --- a/arch/x86/kernel/uprobes.c
> +++ b/arch/x86/kernel/uprobes.c
> @@ -680,8 +680,11 @@ static bool __skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
> if (auprobe->insn[i] == 0x66)
> continue;
>
> - if (auprobe->insn[i] == 0x90)
> + if (auprobe->insn[i] == 0x90) {
> + regs->ip = uprobe_get_swbp_addr(regs);
> + regs->ip += i + 1;
> return true;
> + }
>
> break;
> }
> --
> 1.5.5.1
>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/