X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Fpartmap.c;h=d3892ff58ffd56816fd4a1ca40d17060e939306d;hb=e29c6b7097c92fb1ee0587d167e1c434db198056;hp=2947bedffa62ae1e10e3fbbc14cf60349648c503;hpb=bc6049e67fb8de5774b7f6d3160bc89f952f9428;p=libucw.git

diff --git a/lib/partmap.c b/lib/partmap.c
index 2947bedf..d3892ff5 100644
--- a/lib/partmap.c
+++ b/lib/partmap.c
@@ -2,6 +2,7 @@
  *	Sherlock Library -- Mapping of File Parts
  *
  *	(c) 2003 Martin Mares <mj@ucw.cz>
+ *	(c) 2003 Robert Spalek <robert@ucw.cz>
  *
  *	This software may be freely distributed and used according to the terms
  *	of the GNU Lesser General Public License.
@@ -16,6 +17,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/mman.h>
+#include <sys/user.h>
 
 struct partmap {
   int fd;
@@ -69,8 +71,12 @@ partmap_map(struct partmap *p, sh_off_t start, uns size)
 	munmap(p->start_map, p->end_off - p->start_off);
       uns win = PARTMAP_WINDOW;
       ASSERT(win >= size);
+      sh_off_t end = start + size;
+      start = start/PAGE_SIZE * PAGE_SIZE;
       if (start+win > p->file_size)
 	win = p->file_size - start;
+      if (start+win < end)
+	die("cannot mmap, the window is too small");
       p->start_map = sh_mmap(NULL, win, p->writeable ? (PROT_READ | PROT_WRITE) : PROT_READ, MAP_SHARED, p->fd, start);
       if (p->start_map == MAP_FAILED)
 	die("mmap failed at position %Ld: %m", (long long)start);