tags 255457 + patch
thanks
Hi,
I couldn't sleep, so I found a bug tagged 'help' to do a patch for.
[EMAIL PROTECTED]:~/debian/nbd$ du -h reallargefile ; zum reallargefile ; du -h
reallargefile
4.1G reallargefile
reallargefile [33587168K] [1 link]
12K reallargefile
[EMAIL PROTECTED]:~/debian/nbd$
Whee. Real large file support.
While I was at it, I cleaned up the source a bit so that it doesn't
produce any warnings anymore.
I should note that the use of gets() in the source is worrisome; it
might be a good idea to contact people from the security (audit) team to
verify whether there's a threat here, because every use of gets() is a
potential buffer overflow (I don't think there is, but then I'm not that
experienced with security issues).
Anyway, here's the patch:
diff -ruN perforate-1.1/zum.c perforate-1.1.mine/zum.c
--- perforate-1.1/zum.c 1996-09-11 00:15:34.000000000 +0200
+++ perforate-1.1.mine/zum.c 2005-11-11 04:07:46.000000000 +0100
@@ -2,6 +2,8 @@
* zum 1.00 - free more disk space by making holes in files.
*
* Oleg Kibirev * April 1995 * [EMAIL PROTECTED]
+ * 2005-11-11: Wouter Verhelst <[EMAIL PROTECTED]>: clean up the code a bit (so
+ * that it no longer produces any warnings, add large file support.
*
* This code is covered by General Public License, version 2 or any later
* version of your choice. You should recieve file "COPYING" which contains
@@ -9,7 +11,11 @@
* have it, a copy is available from ftp.gnu.ai.mit.edu.
*/
+#define _FILE_OFFSET_BITS 64
+#define _LARGEFILE_SOURCE
+
#include <stdio.h>
+#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
@@ -25,10 +31,25 @@
static char suffix[] = "__zum__";
-static int zero_copy(int fds, int fdd, int size)
+static void* my_mmap(void *ptr, int fd, off_t size, off_t *pos)
+{
+ if(size-(*pos) > (off_t)1<<30) {
+ size=1<<30;
+ } else {
+ size=size-(*pos);
+ }
+ if(ptr)
+ munmap(ptr, 1<<30);
+ ptr=mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, (*pos));
+ (*pos)+=size;
+ return ptr;
+}
+
+static int zero_copy(int fds, int fdd, off_t size)
{
char *ms;
char *bp, *p, *ep;
+ off_t pos=0;
lseek(fdd, 0L, SEEK_SET);
if(ftruncate(fdd, 0) < 0) {
@@ -36,23 +57,31 @@
return -1;
}
- if((ms = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fds, 0)) == -1) {
+ if((ms = my_mmap(NULL, fds, size, &pos)) == MAP_FAILED) {
perror("mmap");
return -1;
}
- p = ms; ep = ms + size;
+ p = ms; ep = ms + (size - pos > 1<<30 ? 1<<30 : size - pos);
while(p < ep) {
for(bp = p; p < ep && *p; p++);
if(p != bp && write(fdd, bp, p-bp) != p-bp) {
perror("write");
- munmap(ms, size);
+ munmap(ms, (size - pos > 1<<30 ? 1<<30 : size - pos));
return -1;
}
for(bp = p; p < ep && !*p; p++);
if(p != bp)
lseek(fdd, p-bp, SEEK_CUR);
+ if((size > 1<<30) && (ep != (ms + size - pos))) {
+ if((ms = my_mmap(ms, fds, size, &pos)) == MAP_FAILED) {
+ perror("mmap");
+ return -1;
+ } else {
+ p = ms; ep = ms + (size - pos > 1<<30 ? 1<<30 : size - pos);
+ }
+ }
}
munmap(ms, size);
return ftruncate(fdd, size);
@@ -102,7 +131,7 @@
return;
}
- printf(" [%uK] ", (st.st_blocks-std.st_blocks)*st.st_blksize/1024);
+ printf(" [%uK] ", (unsigned
int)((st.st_blocks-std.st_blocks)*st.st_blksize/1024));
fflush(stdout);
if(st.st_nlink == 1) {
@@ -141,16 +170,16 @@
}
}
-main(int argc, char **argv)
+int main(int argc, char **argv)
{
char *p;
if(argc > 1)
- while(p = *(++argv))
+ while((p = *(++argv)))
zero_unmap(p);
else {
char buf[MAXPATHLEN];
- while(gets(buf))
+ while(fgets(buf, MAXPATHLEN, stdin))
zero_unmap(buf);
}
return 0;
--
.../ -/ ---/ .--./ / .--/ .-/ .../ -/ ../ -./ --./ / -.--/ ---/ ..-/ .-./ / -/
../ --/ ./ / .--/ ../ -/ ..../ / -../ ./ -.-./ ---/ -../ ../ -./ --./ / --/
-.--/ / .../ ../ --./ -./ .-/ -/ ..-/ .-./ ./ .-.-.-/ / --/ ---/ .-./ .../ ./ /
../ .../ / ---/ ..-/ -/ -../ .-/ -/ ./ -../ / -/ ./ -.-./ ..../ -./ ---/ .-../
---/ --./ -.--/ / .-/ -./ -.--/ .--/ .-/ -.--/ .-.-.-/ / ...-.-/
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