From: Antonino A. Daplas <adaplas@gmail.com>
Date: Tue, 8 May 2007 07:39:22 +0000 (-0700)
Subject: fbdev: save the activate field before calling fb_check_var()
X-Git-Tag: archive/raspbian/4.9.13-1+rpi1~10^2~37932
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=4941cb7a18fd84d4d8cd097d2beada3c79c8f781;p=linux-4.9.git

fbdev: save the activate field before calling fb_check_var()

Some drivers may reset the var->activate field on fb_check_var(). This can
lead to undefined behavior. For example, doing fbset -a <option> with vga16fb
will only modify the active console instead of modifying all.

Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index c4ce3e44327e..cd1407921af5 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -803,6 +803,8 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 
 	if ((var->activate & FB_ACTIVATE_FORCE) ||
 	    memcmp(&info->var, var, sizeof(struct fb_var_screeninfo))) {
+		u32 activate = var->activate;
+
 		if (!info->fbops->fb_check_var) {
 			*var = info->var;
 			return 0;
@@ -831,7 +833,7 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 
 			if (!err && (flags & FBINFO_MISC_USEREVENT)) {
 				struct fb_event event;
-				int evnt = (var->activate & FB_ACTIVATE_ALL) ?
+				int evnt = (activate & FB_ACTIVATE_ALL) ?
 					FB_EVENT_MODE_CHANGE_ALL :
 					FB_EVENT_MODE_CHANGE;