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From 4b140cf65f44f5c7f1c069e7bfdab5ff751b2fdf Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Date: Mon, 31 Oct 2016 13:34:50 +0100
Subject: [PATCH 1/3] mmap() src file instead of malloc() + read() it
Bug: https://bugs.debian.org/632585
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
---
bsdiff.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/bsdiff.c b/bsdiff.c
index 150a7f79c488..f25304548101 100644
--- a/bsdiff.c
+++ b/bsdiff.c
@@ -37,6 +37,7 @@ __FBSDID("$FreeBSD: src/usr.bin/bsdiff/bsdiff/bsdiff.c,v 1.1 2005/08/06 01:59:05
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <sys/mman.h>
#define MIN(x,y) (((x)<(y)) ? (x) : (y))
@@ -215,14 +216,18 @@ int main(int argc,char *argv[])
if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]);
- /* Allocate oldsize+1 bytes instead of oldsize bytes to ensure
- that we never try to malloc(0) and get a NULL pointer */
- if(((fd=open(argv[1],O_RDONLY,0))<0) ||
- ((oldsize=lseek(fd,0,SEEK_END))==-1) ||
- ((old=malloc(oldsize+1))==NULL) ||
- (lseek(fd,0,SEEK_SET)!=0) ||
- (read(fd,old,oldsize)!=oldsize) ||
- (close(fd)==-1)) err(1,"%s",argv[1]);
+ fd = open(argv[1], O_RDONLY,0);
+ if (fd < 0)
+ err(1, "Open %s", argv[1]);
+
+ oldsize = lseek(fd, 0, SEEK_END);
+ if (oldsize < 0)
+ err(1, "seek %s", argv[1]);
+
+ old = mmap(NULL, oldsize, PROT_READ, MAP_SHARED | MAP_POPULATE, fd, 0);
+ if (old == MAP_FAILED)
+ err(1, "mmap() %s", argv[1]);
+ close(fd);
if(((I=malloc((oldsize+1)*sizeof(off_t)))==NULL) ||
((V=malloc((oldsize+1)*sizeof(off_t)))==NULL)) err(1,NULL);
@@ -397,7 +402,7 @@ int main(int argc,char *argv[])
free(db);
free(eb);
free(I);
- free(old);
+ munmap(old, oldsize);
free(new);
return 0;
--
2.9.3
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