[PATCH v2 2/3] rseq: remove redundant access_ok()

[Eric Dumazet]

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()

Mathieu pointed out the same cleanup can be done
in rseq_syscall().

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 | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/rseq.c b/kernel/rseq.c
index 
f020f18f512a3f6241c3c9b104ce50e4d2c6188c..cfe01ab5253c1c424c0e8b25acbb6a8e1b41a5b6
 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;
@@ -301,8 +299,7 @@ void rseq_syscall(struct pt_regs *regs)
 
        if (!t->rseq)
                return;
-       if (!access_ok(t->rseq, sizeof(*t->rseq)) ||
-           rseq_get_rseq_cs(t, &rseq_cs) || in_rseq_cs(ip, &rseq_cs))
+       if (rseq_get_rseq_cs(t, &rseq_cs) || in_rseq_cs(ip, &rseq_cs))
                force_sig(SIGSEGV);
 }
 
-- 
2.31.1.295.g9ea45b61b8-goog