Re: [PATCH] ptrace/x86: introduce TS_COMPAT_RESTART to fix get_nr_restart_syscall()

[Oleg Nesterov <oleg@redhat.com>]

On 11/26, Oleg Nesterov wrote:
>
> This patch adds the sticky TS_COMPAT_RESTART flag which survives after
> return to user mode, hopefully it allows us to kill TS_I386_REGS_POKED
> but this needs another patch.

Alternatively we could add ->compat_restart into struct restart_block,
logically this is the same thing.

Rather than changing syscall_return_slowpath() we could introduce a new
helper, say,

	void set_restart_block_fn(struct restart_block *restart, fn)
	{
		restart->fn = fn;

		set/clear TS_COMPAT_RESTART or restart->compat_restart
		depending on TS_COMPAT
	}

but this patch looks simpler to me.

Oleg.