Fix rewriting of existing files.

diff --git a/libelf/ChangeLog b/libelf/ChangeLog
index 46083253cf74442022812a802380a37e71226483..d42bf18bf19256353771c767bdca7bf21dd3fcc4 100644 (file)
--- a/libelf/ChangeLog
+++ b/libelf/ChangeLog
@@ -1,3 +1,9 @@
+2006-05-28  Ulrich Drepper  <drepper@redhat.com>
+
+       * elf32_updatefile.c (updatemmap): Preserve section content if
+       copying would overwrite them.
+       Fix msync paramters.
+
 2006-04-04  Roland McGrath  <roland@redhat.com>
 
        * elf32_updatefile.c (updatemmap): Handle other-endian case.

diff --git a/libelf/elf32_updatefile.c b/libelf/elf32_updatefile.c
index 7561a685d3742f98ecdc98b12125a6393976ba9f..6eab3cf03f082f81b96d5b552752e13a7e19b397 100644 (file)
--- a/libelf/elf32_updatefile.c
+++ b/libelf/elf32_updatefile.c
@@ -239,6 +239,32 @@ __elfw2(LIBELFBITS,updatemmap) (Elf *elf, int change_bo, size_t shnum)
                = memcpy (p, scn->shdr.ELFW(e,LIBELFBITS),
                          sizeof (ElfW2(LIBELFBITS,Shdr)));
            }
+
+         /* If the file is mmaped and the original position of the
+            section in the file is lower than the new position we
+            need to save the section content since otherwise it is
+            overwritten before it can be copied.  If there are
+            multiple data segments in the list only the first can be
+            from the file.  */
+         if (((char *) elf->map_address + elf->start_offset
+              <= (char  *) scn->data_list.data.d.d_buf)
+             && ((char *) scn->data_list.data.d.d_buf
+                 < ((char *) elf->map_address + elf->start_offset
+                    + elf->maximum_size))
+             && (((char *) elf->map_address + elf->start_offset
+                  + scn->shdr.ELFW(e,LIBELFBITS)->sh_offset)
+                 > (char *) scn->data_list.data.d.d_buf))
+           {
+             void *p = malloc (scn->data_list.data.d.d_size);
+             if (p == NULL)
+               {
+                 __libelf_seterrno (ELF_E_NOMEM);
+                 return -1;
+               }
+             scn->data_list.data.d.d_buf = scn->data_base
+               = memcpy (p, scn->data_list.data.d.d_buf,
+                         scn->data_list.data.d.d_size);
+           }
        }
 
       /* Iterate over all the section in the order in which they
@@ -364,10 +390,10 @@ __elfw2(LIBELFBITS,updatemmap) (Elf *elf, int change_bo, size_t shnum)
 
   /* Make sure the content hits the disk.  */
   char *msync_start = ((char *) elf->map_address
-                      + elf->start_offset / sysconf (_SC_PAGESIZE));
+                      + (elf->start_offset & ~(sysconf (_SC_PAGESIZE) - 1)));
   char *msync_end = ((char *) elf->map_address
                     + elf->start_offset + ehdr->e_shoff
-                    * ehdr->e_shentsize * shnum);
+                    + ehdr->e_shentsize * shnum);
   (void) msync (msync_start, msync_end - msync_start, MS_SYNC);
 
   return 0;