From: Eric Dumazet <eric.dumazet@gmail.com>
To: Ingo Molnar <mingo@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>,
Arjun Roy <arjunroy@google.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>
Subject: [PATCH v3 2/3] rseq: remove redundant access_ok()
Date: Tue, 13 Apr 2021 13:33:51 -0700 [thread overview]
Message-ID: <20210413203352.71350-3-eric.dumazet@gmail.com> (raw)
In-Reply-To: <20210413203352.71350-1-eric.dumazet@gmail.com>
From: Eric Dumazet <edumazet@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 <edumazet@google.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Ingo Molnar <mingo@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
next prev parent reply other threads:[~2021-04-13 20:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 20:33 [PATCH v3 0/3] rseq: minor optimizations Eric Dumazet
2021-04-13 20:33 ` [PATCH v3 1/3] rseq: optimize rseq_update_cpu_id() Eric Dumazet
2021-04-15 8:37 ` [tip: sched/core] rseq: Optimize rseq_update_cpu_id() tip-bot2 for Eric Dumazet
2021-04-13 20:33 ` Eric Dumazet [this message]
2021-04-15 8:37 ` [tip: sched/core] rseq: Remove redundant access_ok() tip-bot2 for Eric Dumazet
2021-04-13 20:33 ` [PATCH v3 3/3] rseq: optimise rseq_get_rseq_cs() and clear_rseq_cs() Eric Dumazet
2021-04-15 8:37 ` [tip: sched/core] rseq: Optimise " tip-bot2 for Eric Dumazet
2021-04-13 20:40 ` [PATCH v3 0/3] rseq: minor optimizations Mathieu Desnoyers
2021-04-14 7:51 ` Peter Zijlstra
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