svn commit: r318312 - head/libexec/rtld-elf

[Konstantin Belousov]

Author: kib
Date: Mon May 15 18:47:25 2017
New Revision: 318312
URL: https://svnweb.freebsd.org/changeset/base/318312

Log:
  Fix the AT_EXECFD functionality.
  
  If the mapped object is linked at specific address, we must obey it.
  If AT_EXECFD is not used, only in-kernel ELF image activator needed to
  keep the mapping address, since only binaries are linked at the fixed
  address, and binaries are mapped by kernel in this case.
  
  Reviewed by:	emaste
  Sponsored by:	The FreeBSD Foundation
  MFC after:	2 weeks
  X-Differential revision:	https://reviews.freebsd.org/D10701

Modified:
  head/libexec/rtld-elf/map_object.c

Modified: head/libexec/rtld-elf/map_object.c
==============================================================================
--- head/libexec/rtld-elf/map_object.c	Mon May 15 18:41:12 2017	(r318311)
+++ head/libexec/rtld-elf/map_object.c	Mon May 15 18:47:25 2017	(r318312)
@@ -193,6 +193,8 @@ map_object(int fd, const char *path, con
     base_flags = MAP_PRIVATE | MAP_ANON | MAP_NOCORE;
     if (npagesizes > 1 && round_page(segs[0]->p_filesz) >= pagesizes[1])
 	base_flags |= MAP_ALIGNED_SUPER;
+    if (base_vaddr != 0)
+	base_flags |= MAP_FIXED | MAP_EXCL;
 
     mapbase = mmap(base_addr, mapsize, PROT_NONE, base_flags, -1, 0);
     if (mapbase == (caddr_t) -1) {