From ac8d35c5658377c280dc830352f66233e2f76f73 Mon Sep 17 00:00:00 2001 From: Andi Drebes Date: Tue, 16 Oct 2007 23:27:12 -0700 Subject: [PATCH] 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 --- fs/cramfs/inode.c | 11 ++++++++++- include/linux/cramfs_fs.h | 1 + 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c index 3d194a2..5c817bd 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 1dba681..3be4e5a 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" /* -- 2.7.4