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authorRoland McGrath <roland@gnu.org>2003-09-23 12:06:48 +0000
committerRoland McGrath <roland@gnu.org>2003-09-23 12:06:48 +0000
commitecdeaac05f73c29eca92eecd55ad4fb8513c7771 (patch)
treee0cc585c839b68bc3e698f09d51c1f0b78c3cbef /elf/rtld.c
parent1deb5779e249255d4247529facd65025c1787cd1 (diff)
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2003-09-23 Roland McGrath <roland@redhat.com>
	* sysdeps/generic/ldsodefs.h (struct rtld_global): Add _dl_stack_flags
	and _dl_make_stack_executable_hook.  Declare _dl_make_stack_executable.
	* elf/rtld.c (_rtld_global): Add initializer for _dl_stack_flags.
	(dl_main): Reset _dl_stack_flags according to PT_GNU_STACK phdr.
	Initialize _dl_make_stack_executable_hook.
	* elf/dl-support.c: Define those new variables.
	(_dl_non_dynamic_init): Scan phdrs for PT_GNU_STACK.
	(_dl_phdr): Fix type.
	* elf/dl-load.c (_dl_map_object_from_fd): Grok PT_GNU_STACK phdr and
	enable execute permission for the stack if necessary.
	* sysdeps/generic/dl-execstack.c: New file.
	* elf/Makefile (dl-routines): Add it.
	* elf/Versions (ld: GLIBC_PRIVATE): Add _dl_make_stack_executable.
	* sysdeps/unix/sysv/linux/dl-execstack.c: New file.
Diffstat (limited to 'elf/rtld.c')
-rw-r--r--elf/rtld.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/elf/rtld.c b/elf/rtld.c
index 8f9fc7c063..c17f621cc9 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -98,6 +98,8 @@ struct rtld_global _rtld_global =
     ._dl_fpu_control = _FPU_DEFAULT,
     ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
     ._dl_hwcap_mask = HWCAP_IMPORTANT,
+    /* Default presumption without further information is executable stack.  */
+    ._dl_stack_flags = PF_R|PF_W|PF_X,
 #ifdef _LIBC_REENTRANT
     ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER
 #endif
@@ -249,7 +251,7 @@ _dl_start_final (void *arg, struct dl_start_final_info *info)
      file access.  It will call `dl_main' (below) to do all the real work
      of the dynamic linker, and then unwind our frame and run the user
      entry point on the same stack we entered on.  */
-  start_addr =  _dl_sysdep_start (arg, &dl_main);
+  start_addr = _dl_sysdep_start (arg, &dl_main);
 
 #ifndef HP_TIMING_NONAVAIL
   if (HP_TIMING_AVAIL)
@@ -903,6 +905,9 @@ of this helper program; chances are you did not intend to run this program.\n\
 	  }
 	break;
 #endif
+      case PT_GNU_STACK:
+	GL(dl_stack_flags) = ph->p_flags;
+	break;
       }
 #ifdef USE_TLS
     /* Adjust the address of the TLS initialization image in case
@@ -949,6 +954,10 @@ of this helper program; chances are you did not intend to run this program.\n\
       _exit (has_interp ? 0 : 2);
     }
 
+  /* The explicit initialization here is cheaper than processing the reloc
+     in the _rtld_local definition's initializer.  */
+  GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
+
   if (! rtld_is_main)
     /* Initialize the data structures for the search paths for shared
        objects.  */