On 04/23, Andrey Vagin wrote:
>
> @@ -841,6 +841,48 @@ int ptrace_request(struct task_struct *child, long
> request,
> ret = ptrace_setsiginfo(child, &siginfo);
> break;
>
> + case PTRACE_GETSIGMASK:
> + if (addr != sizeof(sigset_t)) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t)))
> + ret = -EFAULT;
Yes, we can do this lockless. Only the task itself (or the debugger with
this patch) can change ->blocked, and the tracee can't run.
> + case PTRACE_SETSIGMASK:
> + {
> + sigset_t new_set;
> +
> + if (addr != sizeof(sigset_t)) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
> + ret = -EFAULT;
> + break;
> + }
> +
> + sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
> +
> + /*
> + * Every thread does recalc_sigpending() after resume, so
> + * retarget_shared_pending() and recalc_sigpending() are not
> + * called here.
> + */
> + spin_lock_irq(&child->sighand->siglock);
> + child->blocked = new_set;
> + spin_unlock_irq(&child->sighand->siglock);
> +
> + ret = 0;
> + break;
> + }
And this looks fine too.
Personally I am not sure we need to check addr == sizeof(), debugger
should know what it does... But I won't argue.
Oleg.
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