linux-hardened/lib/decompress.c
Aneesh Kumar K.V 5a09e6ce90 lib/decompress: set the compressor name to NULL on error
Without this we end up using the previous name of the compressor in the
loop in unpack_rootfs.  For example we get errors like "compression
method gzip not configured" even when we have CONFIG_DECOMPRESS_GZIP
enabled.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-17 16:39:54 -07:00

78 lines
1.7 KiB
C

/*
* decompress.c
*
* Detect the decompression method based on magic number
*/
#include <linux/decompress/generic.h>
#include <linux/decompress/bunzip2.h>
#include <linux/decompress/unlzma.h>
#include <linux/decompress/unxz.h>
#include <linux/decompress/inflate.h>
#include <linux/decompress/unlzo.h>
#include <linux/decompress/unlz4.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/printk.h>
#ifndef CONFIG_DECOMPRESS_GZIP
# define gunzip NULL
#endif
#ifndef CONFIG_DECOMPRESS_BZIP2
# define bunzip2 NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZMA
# define unlzma NULL
#endif
#ifndef CONFIG_DECOMPRESS_XZ
# define unxz NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZO
# define unlzo NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZ4
# define unlz4 NULL
#endif
struct compress_format {
unsigned char magic[2];
const char *name;
decompress_fn decompressor;
};
static const struct compress_format compressed_formats[] __initconst = {
{ {0x1f, 0x8b}, "gzip", gunzip },
{ {0x1f, 0x9e}, "gzip", gunzip },
{ {0x42, 0x5a}, "bzip2", bunzip2 },
{ {0x5d, 0x00}, "lzma", unlzma },
{ {0xfd, 0x37}, "xz", unxz },
{ {0x89, 0x4c}, "lzo", unlzo },
{ {0x02, 0x21}, "lz4", unlz4 },
{ {0, 0}, NULL, NULL }
};
decompress_fn __init decompress_method(const unsigned char *inbuf, long len,
const char **name)
{
const struct compress_format *cf;
if (len < 2) {
if (name)
*name = NULL;
return NULL; /* Need at least this much... */
}
pr_debug("Compressed data magic: %#.2x %#.2x\n", inbuf[0], inbuf[1]);
for (cf = compressed_formats; cf->name; cf++) {
if (!memcmp(inbuf, cf->magic, 2))
break;
}
if (name)
*name = cf->name;
return cf->decompressor;
}