Re: [PATCH] use ptrace_get_task_struct in various places

[Andrew Morton <akpm@osdl.org>]

Christoph Hellwig <hch@lst.de> wrote:
>
> > In arch/ia64/ia32/sys_ia32.c this patch will cause PTRACE_TRACEME requests
> > to be handled by ptrace_request()
> 
> you mean ptrace_get_task_struct?

No, I was referring to this code:

asmlinkage long
sys32_ptrace (int request, pid_t pid, unsigned int addr, unsigned int data)
{
	struct task_struct *child;
	unsigned int value, tmp;
	long i, ret;

	lock_kernel();
	if (request == PTRACE_TRACEME) {
		ret = sys_ptrace(request, pid, addr, data);
		goto out;
	}

Your patch removes the PTRACE_TRACEME special-case.  Consequently
sys32_ptrace() will fall all the way down to the default: case of the
switch statement and will use ptrace_request() instead.  And
ptrace_request() doesn't handle PTRACE_TRACEME, so I think it's busted.