From: Andi Drebes Date: Wed, 17 Oct 2007 06:27:12 +0000 (-0700) Subject: cramfs: error message about endianess X-Git-Tag: v2.6.24-rc1~688 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac8d35c5658377c280dc830352f66233e2f76f73;p=linux-2.6 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: Andi Drebes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c index 3d194a2be3..5c817bd083 100644 --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -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 */ mutex_lock(&read_mutex); memcpy(&super, cramfs_read(sb, 512, sizeof(super)), sizeof(super)); mutex_unlock(&read_mutex); 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; } diff --git a/include/linux/cramfs_fs.h b/include/linux/cramfs_fs.h index 1dba681e42..3be4e5a27d 100644 --- a/include/linux/cramfs_fs.h +++ b/include/linux/cramfs_fs.h @@ -4,6 +4,7 @@ #include #define CRAMFS_MAGIC 0x28cd3d45 /* some random number */ +#define CRAMFS_MAGIC_WEND 0x453dcd28 /* magic number with the wrong endianess */ #define CRAMFS_SIGNATURE "Compressed ROMFS" /*