[PATCH] 2.5.24 matroxfb memory corruption

Petr Vandrovec (vandrove@vc.cvut.cz)
Sun, 30 Jun 2002 02:28:34 +0200


Hi,
Linus, please apply this. When James converted all drivers to unified
do_install_cmap(), he blindly changed also matroxfb, which happily
uses fbcon.currcon == -1. This caused memory corruption because of
memory before fb_display[] array was overwritten.
Default do_install_cmap() also installed invalid default color map
in some matroxfb resolutions. Not all world have >= 4bpp.
Thanks,
Petr Vandrovec
vandrove@vc.cvut.cz

diff -urdN linux/drivers/video/matrox/matroxfb_base.c linux/drivers/video/matrox/matroxfb_base.c
--- linux/drivers/video/matrox/matroxfb_base.c Fri Jun 21 00:53:55 2002
+++ linux/drivers/video/matrox/matroxfb_base.c Sun Jun 30 02:19:15 2002
@@ -141,6 +141,19 @@


/* --------------------------------------------------------------------- */
+static inline void my_install_cmap(WPMINFO2)
+{
+ /* Do not touch this code if you do not understand what it does! */
+ /* Never try to use do_install_cmap() instead. It is crap. */
+ struct fb_cmap* cmap = &ACCESS_FBINFO(currcon_display)->cmap;
+
+ if (cmap->len)
+ fb_set_cmap(cmap, 1, &ACCESS_FBINFO(fbcon));
+ else
+ fb_set_cmap(fb_default_cmap(ACCESS_FBINFO(curr.cmap_len)),
+ 1, &ACCESS_FBINFO(fbcon));
+}
+

static void matrox_pan_var(WPMINFO struct fb_var_screeninfo *var) {
unsigned int pos;
@@ -869,7 +882,7 @@
up_read(&ACCESS_FBINFO(altout.lock));
}
matrox_cfbX_init(PMINFO display);
- do_install_cmap(ACCESS_FBINFO(fbcon.currcon),&ACCESS_FBINFO(fbcon));
+ my_install_cmap(PMINFO2);
#if defined(CONFIG_FB_COMPAT_XPMAC)
if (console_fb_info == &ACCESS_FBINFO(fbcon)) {
int vmode, cmode;
diff -urdN linux/drivers/video/matrox/matroxfb_crtc2.c linux/drivers/video/matrox/matroxfb_crtc2.c
--- linux/drivers/video/matrox/matroxfb_crtc2.c Fri Jun 21 00:53:48 2002
+++ linux/drivers/video/matrox/matroxfb_crtc2.c Sun Jun 30 02:19:15 2002
@@ -84,6 +84,19 @@
#undef m2info
}

+static inline void my_install_cmap(struct matroxfb_dh_fb_info* m2info)
+{
+ /* Do not touch this code if you do not understand what it does! */
+ /* Never try to use do_install_cmap() instead. It is crap. */
+ struct fb_cmap* cmap = &m2info->currcon_display->cmap;
+
+ if (cmap->len)
+ fb_set_cmap(cmap, 1, &m2info->fbcon);
+ else
+ fb_set_cmap(fb_default_cmap(16), 1, &m2info->fbcon);
+}
+
+
static void matroxfb_dh_restore(struct matroxfb_dh_fb_info* m2info,
struct my_timming* mt,
struct display* p,
@@ -439,7 +452,7 @@
up_read(&ACCESS_FBINFO(altout.lock));
}
matroxfb_dh_cfbX_init(m2info, p);
- do_install_cmap(ACCESS_FBINFO(fbcon.currcon), &ACCESS_FBINFO(fbcon));
+ my_install_cmap(m2info);
}
return 0;
#undef m2info
-
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