[v3,4/9] ARM: oabi-compat: copy oabi events using __copy_to_user()

Commit Message

Julien Thierry Sept. 10, 2018, 10:42 a.m. UTC

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 <[e-mail]>
---
 arch/arm/kernel/sys_oabi-compat.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Patch

diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index f0dd4b6..40da087 100644
--- a/arch/arm/kernel/sys_oabi-compat.c
+++ b/arch/arm/kernel/sys_oabi-compat.c
@@ -277,6 +277,7 @@  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;
 
@@ -295,8 +296,11 @@  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);