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McKenney" , Boqun Feng , Arjun Roy , linux-kernel , Eric Dumazet , Eric Dumazet Subject: [PATCH v3 2/3] rseq: remove redundant access_ok() Date: Tue, 13 Apr 2021 13:33:51 -0700 Message-Id: <20210413203352.71350-3-eric.dumazet@gmail.com> X-Mailer: git-send-email 2.31.1.295.g9ea45b61b8-goog In-Reply-To: <20210413203352.71350-1-eric.dumazet@gmail.com> References: <20210413203352.71350-1-eric.dumazet@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet 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 Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Boqun Feng Cc: Arjun Roy Cc: Ingo Molnar --- 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