From: Julien Thierry <julien.thierry@arm.com>
Date: Tue, 11 Sep 2018 09:12:49 +0000 (+0100)
Subject: ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user()
X-Git-Tag: v4.20-rc1~154^2^3~5
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=319508902600c2688e057750148487996396e9ca;p=thirdparty%2Fkernel%2Flinux.git

ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user()

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>
---

diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index 4abe4909417fd..a87684532327b 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);