path: root/lib/decompress_bunzip2.c
diff options
authorPhillip Lougher <phillip@lougher.demon.co.uk>2009-08-06 15:09:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-08-07 10:39:56 -0700
commitb1af4315d823a2b6659c5b14bc17f7bc61878ef4 (patch)
treed9a04709f52c27f59a93875fd705dbed2c581b09 /lib/decompress_bunzip2.c
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/decompress_bunzip2.c')
1 files changed, 16 insertions, 6 deletions
diff --git a/lib/decompress_bunzip2.c b/lib/decompress_bunzip2.c
index 708e2a86d87..d3dc9f2beb2 100644
--- a/lib/decompress_bunzip2.c
+++ b/lib/decompress_bunzip2.c
@@ -45,9 +45,11 @@
-#ifndef STATIC
+#ifdef STATIC
+#define PREBOOT
#include <linux/decompress/bunzip2.h>
-#endif /* !STATIC */
+#endif /* STATIC */
#include <linux/decompress/mm.h>
#include <linux/slab.h>
@@ -681,9 +683,7 @@ STATIC int INIT bunzip2(unsigned char *buf, int len,
if (flush)
outbuf = malloc(BZIP2_IOBUF_SIZE);
- else
- len -= 4; /* Uncompressed size hack active in pre-boot
- environment */
if (!outbuf) {
error("Could not allocate output bufer");
return -1;
@@ -733,4 +733,14 @@ exit_0:
return i;
-#define decompress bunzip2
+#ifdef PREBOOT
+STATIC int INIT decompress(unsigned char *buf, int len,
+ int(*fill)(void*, unsigned int),
+ int(*flush)(void*, unsigned int),
+ unsigned char *outbuf,
+ int *pos,
+ void(*error_fn)(char *x))
+ return bunzip2(buf, len - 4, fill, flush, outbuf, pos, error_fn);