Re: [PATCH x86/mm 6/6] x86-64 ia32 ptrace get/putreg32 current task

Chuck Ebbert
2007-11-29T17:35:13Z

On 11/28/2007 07:42 PM, Roland McGrath wrote:
> --- a/arch/x86/ia32/ptrace32.c
> +++ b/arch/x86/ia32/ptrace32.c
> @@ -48,19 +48,27 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 val)
> if (val && (val & 3) != 3)
> return -EIO;
> child->thread.fsindex = val & 0xffff;
> + if (child == current)
> + loadsegment(fs, child->thread.fsindex);
> break;
> case offsetof(struct user32, regs.gs):
> if (val && (val & 3) != 3)
> return -EIO;
> child->thread.gsindex = val & 0xffff;
> + if (child == current)
> + load_gs_index(child->thread.gsindex);
> break;
> case offsetof(struct user32, regs.ds):
> if (val && (val & 3) != 3)
> return -EIO;
> child->thread.ds = val & 0xffff;
> + if (child == current)
> + loadsegment(ds, child->thread.ds);
> break;
> case offsetof(struct user32, regs.es):
> child->thread.es = val & 0xffff;
> + if (child == current)
> + loadsegment(es, child->thread.ds);

child->thread.es ??

> @@ -129,15 +137,23 @@ static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
> switch (regno) {
> case offsetof(struct user32, regs.fs):
> *val = child->thread.fsindex;
> + if (child == current)
> + asm("movl %%fs,%0" : "=r" (*val));
> break;
> case offsetof(struct user32, regs.gs):
> *val = child->thread.gsindex;
> + if (child == current)
> + asm("movl %%gs,%0" : "=r" (*val));

Won't this return the kernel's GS instead of the user's?