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Tue Jan 9 16:10:26 1996 Roland McGrath <roland@churchy.gnu.ai.mit.edu>

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* elf/dl-load.c (_dl_map_object_from_fd): After mapping first
 	segment to find location, mprotect excess region to no access,
 	don't munmap it.

	* sysdeps/mach/hurd/dl-sysdep.c (mmap): If vm_map returns
	KERN_NO_SPACE for fixed location, deallocate it and try again.
This commit is contained in:
Roland McGrath
1996-01-10 10:00:22 +00:00
parent 7410183b8b
commit 22930c9bf2
3 changed files with 37 additions and 9 deletions
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19
elf/dl-load.c
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@ -355,20 +355,23 @@ _dl_map_object_from_fd (const char *name, int fd, char *realname)
kernel map it anywhere it likes, but we must have space for all
the segments in their specified positions relative to the first.
So we map the first segment without MAP_FIXED, but with its
extent increased to cover all the segments. Then we unmap the
excess portion, and there is known sufficient space there to map
the later segments. */
extent increased to cover all the segments. Then we remove
access from excess portion, and there is known sufficient space
there to remap from the later segments. */
caddr_t mapat;
mapat = map_segment (c->mapstart,
loadcmds[nloadcmds - 1].allocend - c->mapstart,
c->prot, 0, c->mapoff);
l->l_addr = (Elf32_Addr) mapat - c->mapstart;
/* Unmap the excess portion, and then jump into the normal
segment-mapping loop to handle the portion of the segment past
the end of the file mapping. */
munmap (mapat + c->mapend,
loadcmds[nloadcmds - 1].allocend - c->mapend);
/* Change protection on the excess portion to disallow all access;
the portions we do not remap later will be inaccessible as if
unallocated. Then jump into the normal segment-mapping loop to
handle the portion of the segment past the end of the file
mapping. */
mprotect (mapat + c->mapend,
loadcmds[nloadcmds - 1].allocend - c->mapend,
0);
goto postmap;
}