systemd/0001-journal-compress-return-early-in-uncompress_startswi.patch

187 lines
5.9 KiB
Diff

Based on 5e592c66bdf76dfc8445b332f7a5088ca504ee90 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Fri, 4 Jul 2014 19:53:58 -0400
Subject: [PATCH] journal/compress: return early in uncompress_startswith
uncompress_startswith would always decode the whole stream, even
if it did not start with the given prefix.
Reallocation policy was also strange.
---
src/journal/compress.c | 91 ++++++++++++++-----------------------------------
1 file changed, 27 insertions(+), 64 deletions(-)
Index: src/journal/compress.c
===================================================================
--- src/journal/compress.c.orig
+++ src/journal/compress.c
@@ -25,6 +25,7 @@
#include <lzma.h>
#include "macro.h"
+#include "util.h"
#include "compress.h"
bool compress_blob(const void *src, uint64_t src_size, void *dst, uint64_t *dst_size) {
@@ -69,10 +70,9 @@ fail:
bool uncompress_blob(const void *src, uint64_t src_size,
void **dst, uint64_t *dst_alloc_size, uint64_t* dst_size, uint64_t dst_max) {
- lzma_stream s = LZMA_STREAM_INIT;
+ _cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
lzma_ret ret;
uint64_t space;
- bool b = false;
assert(src);
assert(src_size > 0);
@@ -85,26 +85,18 @@ bool uncompress_blob(const void *src, ui
if (ret != LZMA_OK)
return false;
- if (*dst_alloc_size <= src_size) {
- void *p;
-
- p = realloc(*dst, src_size*2);
- if (!p)
- return false;
-
- *dst = p;
- *dst_alloc_size = src_size*2;
- }
+ space = MIN(src_size * 2, dst_max ?: (uint64_t) -1);
+ if (!greedy_realloc(dst, dst_alloc_size, space))
+ return false;
s.next_in = src;
s.avail_in = src_size;
s.next_out = *dst;
- space = dst_max > 0 ? MIN(*dst_alloc_size, dst_max) : *dst_alloc_size;
s.avail_out = space;
for (;;) {
- void *p;
+ uint64_t used;
ret = lzma_code(&s, LZMA_FINISH);
@@ -112,31 +104,25 @@ bool uncompress_blob(const void *src, ui
break;
if (ret != LZMA_OK)
- goto fail;
+ return false;
if (dst_max > 0 && (space - s.avail_out) >= dst_max)
break;
- p = realloc(*dst, space*2);
- if (!p)
- goto fail;
-
- s.next_out = (uint8_t*) p + ((uint8_t*) s.next_out - (uint8_t*) *dst);
- s.avail_out += space;
+ if (dst_max > 0 && space == dst_max)
+ return false;
- space *= 2;
+ used = space - s.avail_out;
+ space = MIN(2 * space, dst_max ?: (uint64_t) -1);
+ if (!greedy_realloc(dst, dst_alloc_size, space))
+ return false;
- *dst = p;
- *dst_alloc_size = space;
+ s.avail_out = space - used;
+ s.next_out = *dst + used;
}
*dst_size = space - s.avail_out;
- b = true;
-
-fail:
- lzma_end(&s);
-
- return b;
+ return true;
}
bool uncompress_startswith(const void *src, uint64_t src_size,
@@ -144,9 +130,8 @@ bool uncompress_startswith(const void *s
const void *prefix, uint64_t prefix_len,
uint8_t extra) {
- lzma_stream s = LZMA_STREAM_INIT;
+ _cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
lzma_ret ret;
- bool b = false;
/* Checks whether the uncompressed blob starts with the
* mentioned prefix. The byte extra needs to follow the
@@ -163,16 +148,8 @@ bool uncompress_startswith(const void *s
if (ret != LZMA_OK)
return false;
- if (*buffer_size <= prefix_len) {
- void *p;
-
- p = realloc(*buffer, prefix_len*2);
- if (!p)
- return false;
-
- *buffer = p;
- *buffer_size = prefix_len*2;
- }
+ if (!(greedy_realloc(buffer, buffer_size, prefix_len + 1)))
+ return false;
s.next_in = src;
s.avail_in = src_size;
@@ -181,36 +158,23 @@ bool uncompress_startswith(const void *s
s.avail_out = *buffer_size;
for (;;) {
- void *p;
-
ret = lzma_code(&s, LZMA_FINISH);
if (ret != LZMA_STREAM_END && ret != LZMA_OK)
- goto fail;
+ return false;
- if ((*buffer_size - s.avail_out > prefix_len) &&
- memcmp(*buffer, prefix, prefix_len) == 0 &&
- ((const uint8_t*) *buffer)[prefix_len] == extra)
- break;
+ if (*buffer_size - s.avail_out >= prefix_len + 1)
+ return memcmp(*buffer, prefix, prefix_len) == 0 &&
+ ((const uint8_t*) *buffer)[prefix_len] == extra;
if (ret == LZMA_STREAM_END)
- goto fail;
-
- p = realloc(*buffer, *buffer_size*2);
- if (!p)
- goto fail;
+ return false;
- s.next_out = (uint8_t*) p + ((uint8_t*) s.next_out - (uint8_t*) *buffer);
s.avail_out += *buffer_size;
- *buffer = p;
- *buffer_size *= 2;
- }
-
- b = true;
-
-fail:
- lzma_end(&s);
+ if (!(greedy_realloc(buffer, buffer_size, *buffer_size * 2)))
+ return false;
- return b;
+ s.next_out = *buffer + *buffer_size - s.avail_out;
+ }
}