From: michael <trimarchi@gandalf.sssup.it>
Date: Sun, 2 Mar 2008 22:33:46 +0000 (+0100)
Subject: Fix checking fat32 cluster size.
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=8ce4e5c2c02cb7e8adddf7b651d3050d81ce4c1d;p=project%2Fbcm63xx%2Fu-boot.git

Fix checking fat32 cluster size.

This fixes the cluster size tests in the FAT32 file system.
The current implementation of VFAT support doesn't work if the
referred cluster has an offset > 16bit representation, causing
"fatload" and "fatls" commands etc. to fail.

Signed-off-by: michael trimarchi <trimarchi@gandalf.sssup.it>
---

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index c1e57412d7..49c78ed79a 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -352,7 +352,7 @@ get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
 			newclust = get_fatent(mydata, endclust);
 			if((newclust -1)!=endclust)
 				goto getit;
-			if (newclust <= 0x0001 || newclust >= 0xfff0) {
+			if (CHECK_CLUST(newclust, mydata->fatsize)) {
 				FAT_DPRINT("curclust: 0x%x\n", newclust);
 				FAT_DPRINT("Invalid FAT entry\n");
 				return gotsize;
@@ -387,7 +387,7 @@ getit:
 		filesize -= actsize;
 		buffer += actsize;
 		curclust = get_fatent(mydata, endclust);
-		if (curclust <= 0x0001 || curclust >= 0xfff0) {
+		if (CHECK_CLUST(curclust, mydata->fatsize)) {
 			FAT_DPRINT("curclust: 0x%x\n", curclust);
 			FAT_ERROR("Invalid FAT entry\n");
 			return gotsize;
@@ -459,7 +459,7 @@ get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
 
 		slotptr--;
 		curclust = get_fatent(mydata, curclust);
-		if (curclust <= 0x0001 || curclust >= 0xfff0) {
+		if (CHECK_CLUST(curclust, mydata->fatsize)) {
 			FAT_DPRINT("curclust: 0x%x\n", curclust);
 			FAT_ERROR("Invalid FAT entry\n");
 			return -1;
@@ -652,7 +652,7 @@ static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
 	    return retdent;
 	}
 	curclust = get_fatent (mydata, curclust);
-	if (curclust <= 0x0001 || curclust >= 0xfff0) {
+	if (CHECK_CLUST(curclust, mydata->fatsize)) {
 	    FAT_DPRINT ("curclust: 0x%x\n", curclust);
 	    FAT_ERROR ("Invalid FAT entry\n");
 	    return NULL;
diff --git a/include/fat.h b/include/fat.h
index 92638d535e..f993ccab1c 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -111,7 +111,8 @@
 #define START(dent)	(FAT2CPU16((dent)->start) \
 			+ (mydata->fatsize != 32 ? 0 : \
 			  (FAT2CPU16((dent)->starthi) << 16)))
-
+#define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
+				(x) >= ((fatsize) != 32 ? 0xfff0 : 0xffffff0))
 
 typedef struct boot_sector {
 	__u8	ignored[3];	/* Bootstrap code */