[PATCH 4.9 03/16] ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user()

David Long
2019-02-14T14:49:40Z

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