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From:   David Long <dave.long@linaro.org>
To:     stable@vger.kernel.org,
        Russell King - ARM Linux <linux@armlinux.org.uk>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Julien Thierry <julien.thierry@arm.com>,
        Tony Lindgren <tony@atomide.com>,
        Marc Zyngier <marc.zyngier@arm.com>,
        Greg KH <gregkh@linuxfoundation.org>,
        Mark Rutland <mark.rutland@arm.com>
Cc:     Will Deacon <will.deacon@arm.com>, Mark Brown <broonie@kernel.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH 4.9 03/16] ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user()
Date:   Thu, 14 Feb 2019 09:49:17 -0500
Message-Id: <20190214144930.27539-4-dave.long@linaro.org>
In-Reply-To: <20190214144930.27539-1-dave.long@linaro.org>
References: <20190214144930.27539-1-dave.long@linaro.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Julien Thierry <julien.thierry@arm.com>

Commit 319508902600c2688e057750148487996396e9ca upstream.

Copy events to user using __copy_to_user() rather than copy members of
individually with __put_user_error().
This has the benefit of disabling/enabling PAN once per event intead of
once per event member.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
---
 arch/arm/kernel/sys_oabi-compat.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index 640748e27035..d844c5c9364b 100644
--- a/arch/arm/kernel/sys_oabi-compat.c
+++ b/arch/arm/kernel/sys_oabi-compat.c
@@ -276,6 +276,7 @@ asmlinkage long sys_oabi_epoll_wait(int epfd,
 				    int maxevents, int timeout)
 {
 	struct epoll_event *kbuf;
+	struct oabi_epoll_event e;
 	mm_segment_t fs;
 	long ret, err, i;
 
@@ -294,8 +295,11 @@ asmlinkage long sys_oabi_epoll_wait(int epfd,
 	set_fs(fs);
 	err = 0;
 	for (i = 0; i < ret; i++) {
-		__put_user_error(kbuf[i].events, &events->events, err);
-		__put_user_error(kbuf[i].data,   &events->data,   err);
+		e.events = kbuf[i].events;
+		e.data = kbuf[i].data;
+		err = __copy_to_user(events, &e, sizeof(e));
+		if (err)
+			break;
 		events++;
 	}
 	kfree(kbuf);
-- 
2.17.1