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authorIgor Zamyatin <igor.zamyatin@intel.com>2014-04-01 10:16:04 -0700
committerH.J. Lu <hjl.tools@gmail.com>2014-04-09 15:38:09 -0700
commita4c75cfd56e536c2b18556e8a482d88dffa0fffc (patch)
tree209bb53676f4cee8fde2a1f9d038829dd78fe28c /sysdeps/x86_64/configure.ac
parent27822ce67fbf7f2b204992a410e7da2e8c1e2607 (diff)
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Save/restore bound registers in _dl_runtime_resolve
This patch saves and restores bound registers in symbol lookup for x86-64:

1. Branches without BND prefix clear bound registers.
2. x86-64 pass bounds in bound registers as specified in MPX psABI
extension on hjl/mpx/master branch at

https://github.com/hjl-tools/x86-64-psABI
https://groups.google.com/forum/#!topic/x86-64-abi/KFsB0XTgWYc

Binutils has been updated to create an alternate PLT to add BND prefix
when branching to ld.so.

	* config.h.in (HAVE_MPX_SUPPORT): New #undef.
	* sysdeps/x86_64/configure.ac: Set HAVE_MPX_SUPPORT.
	* sysdeps/x86_64/configure: Regenerated.
	* sysdeps/x86_64/dl-trampoline.S (REGISTER_SAVE_AREA): New
	macro.
	(REGISTER_SAVE_RAX): Likewise.
	(REGISTER_SAVE_RCX): Likewise.
	(REGISTER_SAVE_RDX): Likewise.
	(REGISTER_SAVE_RSI): Likewise.
	(REGISTER_SAVE_RDI): Likewise.
	(REGISTER_SAVE_R8): Likewise.
	(REGISTER_SAVE_R9): Likewise.
	(REGISTER_SAVE_BND0): Likewise.
	(REGISTER_SAVE_BND1): Likewise.
	(REGISTER_SAVE_BND2): Likewise.
	(_dl_runtime_resolve): Use them.  Save and restore Intel MPX
	bound registers when calling _dl_fixup.
Diffstat (limited to 'sysdeps/x86_64/configure.ac')
-rw-r--r--sysdeps/x86_64/configure.ac15
1 files changed, 15 insertions, 0 deletions
diff --git a/sysdeps/x86_64/configure.ac b/sysdeps/x86_64/configure.ac
index d34f9a8eec..9138f63a3f 100644
--- a/sysdeps/x86_64/configure.ac
+++ b/sysdeps/x86_64/configure.ac
@@ -75,6 +75,21 @@ LIBC_TRY_CC_OPTION([-mno-vzeroupper],
 ])
 LIBC_CONFIG_VAR([config-cflags-novzeroupper], [$libc_cv_cc_novzeroupper])
 
+dnl Check whether asm supports Intel MPX
+AC_CACHE_CHECK(for Intel MPX support, libc_cv_asm_mpx, [dnl
+cat > conftest.s <<\EOF
+        bndmov %bnd0,(%rsp)
+EOF
+if AC_TRY_COMMAND(${CC-cc} -c $ASFLAGS conftest.s 1>&AS_MESSAGE_LOG_FD); then
+  libc_cv_asm_mpx=yes
+else
+  libc_cv_asm_mpx=no
+fi
+rm -f conftest*])
+if test $libc_cv_asm_mpx == yes; then
+  AC_DEFINE(HAVE_MPX_SUPPORT)
+fi
+
 dnl It is always possible to access static and hidden symbols in an
 dnl position independent way.
 AC_DEFINE(PI_STATIC_AND_HIDDEN)