[ARM32,v4.4,V2,30/47] ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user()

Message ID ea31022b55593a34417b2045fef8bf474fc80e16.1564646727.git.viresh.kumar@linaro.org
State New
Headers show
Series
  • V4.4 backport of arm32 Spectre patches
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Commit Message

Viresh Kumar Aug. 1, 2019, 8:16 a.m.
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: Viresh Kumar <viresh.kumar@linaro.org>

---
 arch/arm/kernel/sys_oabi-compat.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

-- 
2.21.0.rc0.269.g1a574e7a288b

Patch

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);