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| author | Phillip Lougher <phillip@lougher.demon.co.uk> | 2009-08-06 15:09:31 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-08-07 10:39:56 -0700 |
| commit | b1af4315d823a2b6659c5b14bc17f7bc61878ef4 (patch) | |
| tree | d9a04709f52c27f59a93875fd705dbed2c581b09 /lib/decompress_bunzip2.c | |
| parent | daeb6b6fbe27049f465c48a7d0ee5555c3b84064 (diff) | |
| download | lwn-b1af4315d823a2b6659c5b14bc17f7bc61878ef4.tar.gz lwn-b1af4315d823a2b6659c5b14bc17f7bc61878ef4.zip | |
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')
| -rw-r--r-- | lib/decompress_bunzip2.c | 22 |
1 files changed, 16 insertions, 6 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 @@ */ -#ifndef STATIC +#ifdef STATIC +#define PREBOOT +#else #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, set_error_fn(error_fn); 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); +} +#endif |