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authorPhillip Lougher <phillip@lougher.demon.co.uk>2009-08-06 18:09:31 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-08-07 13:39:56 -0400
commitb1af4315d823a2b6659c5b14bc17f7bc61878ef4 (patch)
treed9a04709f52c27f59a93875fd705dbed2c581b09 /lib
parentdaeb6b6fbe27049f465c48a7d0ee5555c3b84064 (diff)
bzip2/lzma: remove nasty uncompressed size hack in pre-boot environment
decompress_bunzip2 and decompress_unlzma have a nasty hack that subtracts 4 from the input length if being called in the pre-boot environment. This is a nasty hack because it relies on the fact that flush = NULL only when called from the pre-boot environment (i.e. arch/x86/boot/compressed/misc.c). initramfs.c/do_mounts_rd.c pass in a flush buffer (flush != NULL). This hack prevents the decompressors from being used with flush = NULL by other callers unless knowledge of the hack is propagated to them. This patch removes the hack by making decompress (called only from the pre-boot environment) a wrapper function that subtracts 4 from the input length before calling the decompressor. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk> 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>
Diffstat (limited to 'lib')
-rw-r--r--lib/decompress_bunzip2.c22
-rw-r--r--lib/decompress_unlzma.c21
2 files changed, 32 insertions, 11 deletions
diff --git a/lib/decompress_bunzip2.c b/lib/decompress_bunzip2.c
index 708e2a86d87b..d3dc9f2beb27 100644
--- a/lib/decompress_bunzip2.c
+++ b/lib/decompress_bunzip2.c
@@ -45,9 +45,11 @@
45*/ 45*/
46 46
47 47
48#ifndef STATIC 48#ifdef STATIC
49#define PREBOOT
50#else
49#include <linux/decompress/bunzip2.h> 51#include <linux/decompress/bunzip2.h>
50#endif /* !STATIC */ 52#endif /* STATIC */
51 53
52#include <linux/decompress/mm.h> 54#include <linux/decompress/mm.h>
53#include <linux/slab.h> 55#include <linux/slab.h>
@@ -681,9 +683,7 @@ STATIC int INIT bunzip2(unsigned char *buf, int len,
681 set_error_fn(error_fn); 683 set_error_fn(error_fn);
682 if (flush) 684 if (flush)
683 outbuf = malloc(BZIP2_IOBUF_SIZE); 685 outbuf = malloc(BZIP2_IOBUF_SIZE);
684 else 686
685 len -= 4; /* Uncompressed size hack active in pre-boot
686 environment */
687 if (!outbuf) { 687 if (!outbuf) {
688 error("Could not allocate output bufer"); 688 error("Could not allocate output bufer");
689 return -1; 689 return -1;
@@ -733,4 +733,14 @@ exit_0:
733 return i; 733 return i;
734} 734}
735 735
736#define decompress bunzip2 736#ifdef PREBOOT
737STATIC int INIT decompress(unsigned char *buf, int len,
738 int(*fill)(void*, unsigned int),
739 int(*flush)(void*, unsigned int),
740 unsigned char *outbuf,
741 int *pos,
742 void(*error_fn)(char *x))
743{
744 return bunzip2(buf, len - 4, fill, flush, outbuf, pos, error_fn);
745}
746#endif
diff --git a/lib/decompress_unlzma.c b/lib/decompress_unlzma.c
index 32123a1340e6..d3f9468e49dc 100644
--- a/lib/decompress_unlzma.c
+++ b/lib/decompress_unlzma.c
@@ -29,7 +29,9 @@
29 *Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 29 *Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
30 */ 30 */
31 31
32#ifndef STATIC 32#ifdef STATIC
33#define PREBOOT
34#else
33#include <linux/decompress/unlzma.h> 35#include <linux/decompress/unlzma.h>
34#endif /* STATIC */ 36#endif /* STATIC */
35 37
@@ -543,9 +545,7 @@ STATIC inline int INIT unlzma(unsigned char *buf, int in_len,
543 int ret = -1; 545 int ret = -1;
544 546
545 set_error_fn(error_fn); 547 set_error_fn(error_fn);
546 if (!flush) 548
547 in_len -= 4; /* Uncompressed size hack active in pre-boot
548 environment */
549 if (buf) 549 if (buf)
550 inbuf = buf; 550 inbuf = buf;
551 else 551 else
@@ -645,4 +645,15 @@ exit_0:
645 return ret; 645 return ret;
646} 646}
647 647
648#define decompress unlzma 648#ifdef PREBOOT
649STATIC int INIT decompress(unsigned char *buf, int in_len,
650 int(*fill)(void*, unsigned int),
651 int(*flush)(void*, unsigned int),
652 unsigned char *output,
653 int *posp,
654 void(*error_fn)(char *x)
655 )
656{
657 return unlzma(buf, in_len - 4, fill, flush, output, posp, error_fn);
658}
659#endif