(2014/04/01 4:44), Oleg Nesterov wrote:
> No functional changes. Preparation to simplify the review of the next
> change. Just reorder the code in arch_uprobe_pre/post_xol() functions
> so that UPROBE_FIX_{RIP_*,IP,CALL} logic goes to the end.
>
> Also change arch_uprobe_pre_xol() to use utask instead of autask, to
> make the code more symmetrical with arch_uprobe_post_xol().
>
> Signed-off-by: Oleg Nesterov <o...@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
Thank you!
> ---
> arch/x86/kernel/uprobes.c | 30 ++++++++++++++----------------
> 1 files changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
> index e8d7b38..7dd65dc 100644
> --- a/arch/x86/kernel/uprobes.c
> +++ b/arch/x86/kernel/uprobes.c
> @@ -472,19 +472,18 @@ int arch_uprobe_analyze_insn(struct arch_uprobe
> *auprobe, struct mm_struct *mm,
> */
> int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
> {
> - struct arch_uprobe_task *autask;
> + struct uprobe_task *utask = current->utask;
>
> - autask = ¤t->utask->autask;
> - autask->saved_trap_nr = current->thread.trap_nr;
> + regs->ip = utask->xol_vaddr;
> + utask->autask.saved_trap_nr = current->thread.trap_nr;
> current->thread.trap_nr = UPROBE_TRAP_NR;
> - regs->ip = current->utask->xol_vaddr;
> - pre_xol_rip_insn(auprobe, regs, autask);
>
> - autask->saved_tf = !!(regs->flags & X86_EFLAGS_TF);
> + utask->autask.saved_tf = !!(regs->flags & X86_EFLAGS_TF);
> regs->flags |= X86_EFLAGS_TF;
> if (test_tsk_thread_flag(current, TIF_BLOCKSTEP))
> set_task_blockstep(current, false);
>
> + pre_xol_rip_insn(auprobe, regs, &utask->autask);
> return 0;
> }
>
> @@ -558,22 +557,13 @@ bool arch_uprobe_xol_was_trapped(struct task_struct *t)
> */
> int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
> {
> - struct uprobe_task *utask;
> + struct uprobe_task *utask = current->utask;
> long correction;
> int result = 0;
>
> WARN_ON_ONCE(current->thread.trap_nr != UPROBE_TRAP_NR);
>
> - utask = current->utask;
> current->thread.trap_nr = utask->autask.saved_trap_nr;
> - correction = (long)(utask->vaddr - utask->xol_vaddr);
> - handle_riprel_post_xol(auprobe, regs, &correction);
> - if (auprobe->fixups & UPROBE_FIX_IP)
> - regs->ip += correction;
> -
> - if (auprobe->fixups & UPROBE_FIX_CALL)
> - result = adjust_ret_addr(regs->sp, correction);
> -
> /*
> * arch_uprobe_pre_xol() doesn't save the state of TIF_BLOCKSTEP
> * so we can get an extra SIGTRAP if we do not clear TF. We need
> @@ -584,6 +574,14 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe,
> struct pt_regs *regs)
> else if (!(auprobe->fixups & UPROBE_FIX_SETF))
> regs->flags &= ~X86_EFLAGS_TF;
>
> + correction = (long)(utask->vaddr - utask->xol_vaddr);
> + handle_riprel_post_xol(auprobe, regs, &correction);
> + if (auprobe->fixups & UPROBE_FIX_IP)
> + regs->ip += correction;
> +
> + if (auprobe->fixups & UPROBE_FIX_CALL)
> + result = adjust_ret_addr(regs->sp, correction);
> +
> return result;
> }
>
>
--
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu...@hitachi.com
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