----- On Apr 13, 2021, at 3:36 AM, Eric Dumazet eric.duma...@gmail.com wrote:
> From: Eric Dumazet <eduma...@google.com>
>
> After commit 8f2817701492 ("rseq: Use get_user/put_user rather
> than __get_user/__put_user") we no longer need
> an access_ok() call from __rseq_handle_notify_resume()
While we are doing that, should we also remove the access_ok() check in
rseq_syscall() ? It look like it can also be removed for the exact same
reason outlined here.
Thanks,
Mathieu
>
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Cc: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> Cc: Peter Zijlstra <pet...@infradead.org>
> Cc: "Paul E. McKenney" <paul...@kernel.org>
> Cc: Boqun Feng <boqun.f...@gmail.com>
> Cc: Arjun Roy <arjun...@google.com>
> Cc: Ingo Molnar <mi...@kernel.org>
> ---
> kernel/rseq.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/kernel/rseq.c b/kernel/rseq.c
> index
> d2689ccbb132c0fc8ec0924008771e5ee1ca855e..57344f9abb43905c7dd2b6081205ff508d963e1e
> 100644
> --- a/kernel/rseq.c
> +++ b/kernel/rseq.c
> @@ -273,8 +273,6 @@ void __rseq_handle_notify_resume(struct ksignal *ksig,
> struct pt_regs *regs)
>
> if (unlikely(t->flags & PF_EXITING))
> return;
> - if (unlikely(!access_ok(t->rseq, sizeof(*t->rseq))))
> - goto error;
> ret = rseq_ip_fixup(regs);
> if (unlikely(ret < 0))
> goto error;
> --
> 2.31.1.295.g9ea45b61b8-goog
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
