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From: Michal Januszewski &lt;spock@gentoo.org&gt;

The fb_info struct, as defined in include/linux/fb.h, contains an element
that is supposed to hold the current color map:
  struct fb_cmap cmap;            /* Current cmap */

This cmap is currently never updated when either fb_set_cmap() or
fb_set_user_cmap() are called.  As a result, info-&gt;cmap contains the
default cmap that was set by a device driver/fbcon and a userspace
application using the FBIOGETCMAP ioctl will not always get the *currently*
used color map.

The patch fixes this by making sure the cmap is copied to info-&gt;cmap after
it is set correctly.  It moves most of the code that is responsible for
setting the cmap to fb_set_cmap() and out of fb_set_user_cmap() to avoid
code-duplication.

Signed-off-by: Michal Januszewski &lt;spock@gentoo.org&gt;
Cc: &lt;linux-fbdev-devel@lists.sourceforge.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
---

 drivers/video/fbcmap.c |   96 ++++++++++++++++++-------------------------------
 1 files changed, 36 insertions(+), 60 deletions(-)

diff -puN drivers/video/fbcmap.c~fbdev-update-info-cmap-when-setting-cmap-from-user-kernelspace drivers/video/fbcmap.c
--- devel/drivers/video/fbcmap.c~fbdev-update-info-cmap-when-setting-cmap-from-user-kernelspace	2005-07-25 19:47:37.000000000 -0700
+++ devel-akpm/drivers/video/fbcmap.c	2005-07-25 19:47:37.000000000 -0700
@@ -212,7 +212,7 @@ int fb_cmap_to_user(struct fb_cmap *from
 
 int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
 {
-	int i, start;
+	int i, start, rc = 0;
 	u16 *red, *green, *blue, *transp;
 	u_int hred, hgreen, hblue, htransp = 0xffff;
 
@@ -225,75 +225,51 @@ int fb_set_cmap(struct fb_cmap *cmap, st
 	if (start &lt; 0 || (!info-&gt;fbops-&gt;fb_setcolreg &amp;&amp;
 			  !info-&gt;fbops-&gt;fb_setcmap))
 		return -EINVAL;
-	if (info-&gt;fbops-&gt;fb_setcmap)
-		return info-&gt;fbops-&gt;fb_setcmap(cmap, info);
-	for (i = 0; i &lt; cmap-&gt;len; i++) {
-		hred = *red++;
-		hgreen = *green++;
-		hblue = *blue++;
-		if (transp)
-			htransp = *transp++;
-		if (info-&gt;fbops-&gt;fb_setcolreg(start++,
-					      hred, hgreen, hblue, htransp,
-					      info))
-			break;
+	if (info-&gt;fbops-&gt;fb_setcmap) {
+		rc = info-&gt;fbops-&gt;fb_setcmap(cmap, info);
+	} else {
+		for (i = 0; i &lt; cmap-&gt;len; i++) {
+			hred = *red++;
+			hgreen = *green++;
+			hblue = *blue++;
+			if (transp)
+				htransp = *transp++;
+			if (info-&gt;fbops-&gt;fb_setcolreg(start++,
+						      hred, hgreen, hblue,
+						      htransp, info))
+				break;
+		}
 	}
-	return 0;
+	if (rc == 0)
+		fb_copy_cmap(cmap, &amp;info-&gt;cmap);
+
+	return rc;
 }
 
 int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
 {
-	int i, start;
-	u16 __user *red, *green, *blue, *transp;
-	u_int hred, hgreen, hblue, htransp = 0xffff;
-
-	red = cmap-&gt;red;
-	green = cmap-&gt;green;
-	blue = cmap-&gt;blue;
-	transp = cmap-&gt;transp;
-	start = cmap-&gt;start;
+	int rc, size = cmap-&gt;len * sizeof(u16);
+	struct fb_cmap umap;
 
-	if (start &lt; 0 || (!info-&gt;fbops-&gt;fb_setcolreg &amp;&amp;
-			  !info-&gt;fbops-&gt;fb_setcmap))
+	if (cmap-&gt;start &lt; 0 || (!info-&gt;fbops-&gt;fb_setcolreg &amp;&amp;
+			        !info-&gt;fbops-&gt;fb_setcmap))
 		return -EINVAL;
 
-	/* If we can batch, do it */
-	if (info-&gt;fbops-&gt;fb_setcmap &amp;&amp; cmap-&gt;len &gt; 1) {
-		struct fb_cmap umap;
-		int size = cmap-&gt;len * sizeof(u16);
-		int rc;
-
-		memset(&amp;umap, 0, sizeof(struct fb_cmap));
-		rc = fb_alloc_cmap(&amp;umap, cmap-&gt;len, transp != NULL);
-		if (rc)
-			return rc;
-		if (copy_from_user(umap.red, red, size) ||
-		    copy_from_user(umap.green, green, size) ||
-		    copy_from_user(umap.blue, blue, size) ||
-		    (transp &amp;&amp; copy_from_user(umap.transp, transp, size))) {
-			rc = -EFAULT;
-		}
-		umap.start = start;
-		if (rc == 0)
-			rc = info-&gt;fbops-&gt;fb_setcmap(&amp;umap, info);
-		fb_dealloc_cmap(&amp;umap);
+	memset(&amp;umap, 0, sizeof(struct fb_cmap));
+	rc = fb_alloc_cmap(&amp;umap, cmap-&gt;len, cmap-&gt;transp != NULL);
+	if (rc)
 		return rc;
+	if (copy_from_user(umap.red, cmap-&gt;red, size) ||
+	    copy_from_user(umap.green, cmap-&gt;green, size) ||
+	    copy_from_user(umap.blue, cmap-&gt;blue, size) ||
+	    (cmap-&gt;transp &amp;&amp; copy_from_user(umap.transp, cmap-&gt;transp, size))) {
+		fb_dealloc_cmap(&amp;umap);
+		return -EFAULT;
 	}
-
-	for (i = 0; i &lt; cmap-&gt;len; i++, red++, blue++, green++) {
-		if (get_user(hred, red) ||
-		    get_user(hgreen, green) ||
-		    get_user(hblue, blue) ||
-		    (transp &amp;&amp; get_user(htransp, transp)))
-			return -EFAULT;
-		if (info-&gt;fbops-&gt;fb_setcolreg(start++,
-					      hred, hgreen, hblue, htransp,
-					      info))
-			return 0;
-		if (transp)
-			transp++;
-	}
-	return 0;
+	umap.start = cmap-&gt;start;
+	rc = fb_set_cmap(&amp;umap, info);
+	fb_dealloc_cmap(&amp;umap);
+	return rc;
 }
 
 /**
_
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