Commit ac8d35c5 authored by Andi Drebes's avatar Andi Drebes Committed by Linus Torvalds

cramfs: error message about endianess

The README file in the cramfs subdirectory says: "All data is currently in
host-endian format; neither mkcramfs nor the kernel ever do swabbing."

If somebody tries to mount a cramfs with the wrong endianess, cramfs only
complains about a wrong magic but doesn't inform the user that only the
endianess isn't right.

The following patch adds an error message to the cramfs sources.  If a user
tries to mount a cramfs with the wrong endianess using the patched sources,
cramfs will display the message "cramfs: wrong endianess".
Signed-off-by: default avatarAndi Drebes <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 7f44c362
......@@ -258,12 +258,21 @@ static int cramfs_fill_super(struct super_block *sb, void *data, int silent)
/* Do sanity checks on the superblock */
if (super.magic != CRAMFS_MAGIC) {
/* check for wrong endianess */
if (super.magic == CRAMFS_MAGIC_WEND) {
if (!silent)
printk(KERN_ERR "cramfs: wrong endianess\n");
goto out;
/* check at 512 byte offset */
memcpy(&super, cramfs_read(sb, 512, sizeof(super)), sizeof(super));
if (super.magic != CRAMFS_MAGIC) {
if (!silent)
if (super.magic == CRAMFS_MAGIC_WEND && !silent)
printk(KERN_ERR "cramfs: wrong endianess\n");
else if (!silent)
printk(KERN_ERR "cramfs: wrong magic\n");
goto out;
......@@ -4,6 +4,7 @@
#include <linux/types.h>
#define CRAMFS_MAGIC 0x28cd3d45 /* some random number */
#define CRAMFS_MAGIC_WEND 0x453dcd28 /* magic number with the wrong endianess */
#define CRAMFS_SIGNATURE "Compressed ROMFS"
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