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authorH.J. Lu <hjl.tools@gmail.com>2018-09-28 13:31:19 -0700
committerH.J. Lu <hjl.tools@gmail.com>2018-09-28 13:31:30 -0700
commit7b1f9406761331cf35fe521fbdb592beecf68a2c (patch)
tree33dd97f1e788774cc9ec32fe443b5046d80e8349 /sysdeps/i386/dl-machine.h
parent7a16bdbb9ff4122af0a28dc20996c95352011fdd (diff)
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i386: Use _dl_runtime_[resolve|profile]_shstk for SHSTK [BZ #23716]
When elf_machine_runtime_setup is called to set up resolver, it should
use _dl_runtime_resolve_shstk or _dl_runtime_profile_shstk if SHSTK is
enabled by kernel.

Tested on i686 with and without --enable-cet as well as on CET emulator
with --enable-cet.

	[BZ #23716]
	* sysdeps/i386/dl-cet.c: Removed.
	* sysdeps/i386/dl-machine.h (_dl_runtime_resolve_shstk): New
	prototype.
	(_dl_runtime_profile_shstk): Likewise.
	(elf_machine_runtime_setup): Use _dl_runtime_profile_shstk or
	_dl_runtime_resolve_shstk if SHSTK is enabled by kernel.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Diffstat (limited to 'sysdeps/i386/dl-machine.h')
-rw-r--r--sysdeps/i386/dl-machine.h13
1 files changed, 11 insertions, 2 deletions
diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index 1afdcbd9ea..f6cfb90e21 100644
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -67,6 +67,11 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
   Elf32_Addr *got;
   extern void _dl_runtime_resolve (Elf32_Word) attribute_hidden;
   extern void _dl_runtime_profile (Elf32_Word) attribute_hidden;
+  extern void _dl_runtime_resolve_shstk (Elf32_Word) attribute_hidden;
+  extern void _dl_runtime_profile_shstk (Elf32_Word) attribute_hidden;
+  /* Check if SHSTK is enabled by kernel.  */
+  bool shstk_enabled
+    = (GL(dl_x86_feature_1)[0] & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0;
 
   if (l->l_info[DT_JMPREL] && lazy)
     {
@@ -93,7 +98,9 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
 	 end in this function.  */
       if (__glibc_unlikely (profile))
 	{
-	  got[2] = (Elf32_Addr) &_dl_runtime_profile;
+	  got[2] = (shstk_enabled
+		    ? (Elf32_Addr) &_dl_runtime_profile_shstk
+		    : (Elf32_Addr) &_dl_runtime_profile);
 
 	  if (GLRO(dl_profile) != NULL
 	      && _dl_name_match_p (GLRO(dl_profile), l))
@@ -104,7 +111,9 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
       else
 	/* This function will get called to fix up the GOT entry indicated by
 	   the offset on the stack, and then jump to the resolved address.  */
-	got[2] = (Elf32_Addr) &_dl_runtime_resolve;
+	got[2] = (shstk_enabled
+		  ? (Elf32_Addr) &_dl_runtime_resolve_shstk
+		  : (Elf32_Addr) &_dl_runtime_resolve);
     }
 
   return lazy;