i386: Add _CET_ENDBR to indirect jump targets in add_n.S/sub_n.S

i386 add_n.S and sub_n.S use a trick to implment jump tables with LEA.
We can't use conditional branches nor normal jump tables since jump
table entries use EFLAGS set by jump table index.  This patch adds
_CET_ENDBR to indirect jump targets and adjust destination for
_CET_ENDBR.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

	* sysdeps/i386/add_n.S: Include <sysdep.h>, instead of
	"sysdep.h".
	(__mpn_add_n): Save and restore %ebx if IBT is enabed.  Add
	_CET_ENDBR to indirect jump targets and adjust jump destination
	for _CET_ENDBR.
	* sysdeps/i386/i686/add_n.S: Include <sysdep.h>, instead of
	"sysdep.h".
	(__mpn_add_n): Save and restore %ebx if IBT is enabed.  Add
	_CET_ENDBR to indirect jump targets and adjust jump destination
	for _CET_ENDBR.
	* sysdeps/i386/sub_n.S: Include <sysdep.h>, instead of
	"sysdep.h".
	(__mpn_sub_n): Save and restore %ebx if IBT is enabed.  Add
	_CET_ENDBR to indirect jump targets and adjust jump destination
	for _CET_ENDBR.
This commit is contained in:
H.J. Lu 2018-07-17 16:11:13 -07:00
parent 5efc6777ad
commit be9ccd27c0
4 changed files with 95 additions and 3 deletions

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@ -1,3 +1,21 @@
2018-07-17 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/i386/add_n.S: Include <sysdep.h>, instead of
"sysdep.h".
(__mpn_add_n): Save and restore %ebx if IBT is enabed. Add
_CET_ENDBR to indirect jump targets and adjust jump destination
for _CET_ENDBR.
* sysdeps/i386/i686/add_n.S: Include <sysdep.h>, instead of
"sysdep.h".
(__mpn_add_n): Save and restore %ebx if IBT is enabed. Add
_CET_ENDBR to indirect jump targets and adjust jump destination
for _CET_ENDBR.
* sysdeps/i386/sub_n.S: Include <sysdep.h>, instead of
"sysdep.h".
(__mpn_sub_n): Save and restore %ebx if IBT is enabed. Add
_CET_ENDBR to indirect jump targets and adjust jump destination
for _CET_ENDBR.
2018-07-17 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/x86_64/multiarch/strcmp-sse42.S (STRCMP_SSE42): Add

View File

@ -17,7 +17,7 @@
along with the GNU MP Library; see the file COPYING.LIB. If not,
see <http://www.gnu.org/licenses/>. */
#include "sysdep.h"
#include <sysdep.h>
#include "asm-syntax.h"
#define PARMS 4+8 /* space for 2 saved regs */
@ -40,6 +40,13 @@ ENTRY (__mpn_add_n)
cfi_rel_offset (esi, 0)
movl S2(%esp),%edx
movl SIZE(%esp),%ecx
#if IBT_ENABLED
pushl %ebx
cfi_adjust_cfa_offset (4)
cfi_rel_offset (ebx, 0)
#endif
movl %ecx,%eax
shrl $3,%ecx /* compute count for unrolled loop */
negl %eax
@ -51,6 +58,9 @@ ENTRY (__mpn_add_n)
subl %eax,%esi /* ... by a constant when we ... */
subl %eax,%edx /* ... enter the loop */
shrl $2,%eax /* restore previous value */
#if IBT_ENABLED
leal -4(,%eax,4),%ebx /* Count for 4-byte endbr32 */
#endif
#ifdef PIC
/* Calculate start address in loop for PIC. Due to limitations in some
assemblers, Loop-L0-3 cannot be put into the leal */
@ -64,30 +74,40 @@ L(0): leal (%eax,%eax,8),%eax
#else
/* Calculate start address in loop for non-PIC. */
leal (L(oop) - 3)(%eax,%eax,8),%eax
#endif
#if IBT_ENABLED
addl %ebx,%eax /* Adjust for endbr32 */
#endif
jmp *%eax /* jump into loop */
ALIGN (3)
L(oop): movl (%esi),%eax
adcl (%edx),%eax
movl %eax,(%edi)
_CET_ENDBR
movl 4(%esi),%eax
adcl 4(%edx),%eax
movl %eax,4(%edi)
_CET_ENDBR
movl 8(%esi),%eax
adcl 8(%edx),%eax
movl %eax,8(%edi)
_CET_ENDBR
movl 12(%esi),%eax
adcl 12(%edx),%eax
movl %eax,12(%edi)
_CET_ENDBR
movl 16(%esi),%eax
adcl 16(%edx),%eax
movl %eax,16(%edi)
_CET_ENDBR
movl 20(%esi),%eax
adcl 20(%edx),%eax
movl %eax,20(%edi)
_CET_ENDBR
movl 24(%esi),%eax
adcl 24(%edx),%eax
movl %eax,24(%edi)
_CET_ENDBR
movl 28(%esi),%eax
adcl 28(%edx),%eax
movl %eax,28(%edi)
@ -100,6 +120,11 @@ L(oop): movl (%esi),%eax
sbbl %eax,%eax
negl %eax
#if IBT_ENABLED
popl %ebx
cfi_adjust_cfa_offset (-4)
cfi_restore (ebx)
#endif
popl %esi
cfi_adjust_cfa_offset (-4)
cfi_restore (esi)

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@ -17,7 +17,7 @@
along with the GNU MP Library; see the file COPYING.LIB. If not,
see <http://www.gnu.org/licenses/>. */
#include "sysdep.h"
#include <sysdep.h>
#include "asm-syntax.h"
#define PARMS 4+8 /* space for 2 saved regs */
@ -44,6 +44,13 @@ ENTRY (__mpn_add_n)
cfi_rel_offset (esi, 0)
movl S2(%esp),%edx
movl SIZE(%esp),%ecx
#if IBT_ENABLED
pushl %ebx
cfi_adjust_cfa_offset (4)
cfi_rel_offset (ebx, 0)
#endif
movl %ecx,%eax
shrl $3,%ecx /* compute count for unrolled loop */
negl %eax
@ -55,6 +62,9 @@ ENTRY (__mpn_add_n)
subl %eax,%esi /* ... by a constant when we ... */
subl %eax,%edx /* ... enter the loop */
shrl $2,%eax /* restore previous value */
#if IBT_ENABLED
leal -4(,%eax,4),%ebx /* Count for 4-byte endbr32 */
#endif
#ifdef PIC
/* Calculate start address in loop for PIC. */
leal (L(oop)-L(0)-3)(%eax,%eax,8),%eax
@ -63,30 +73,40 @@ L(0):
#else
/* Calculate start address in loop for non-PIC. */
leal (L(oop) - 3)(%eax,%eax,8),%eax
#endif
#if IBT_ENABLED
addl %ebx,%eax /* Adjust for endbr32 */
#endif
jmp *%eax /* jump into loop */
ALIGN (3)
L(oop): movl (%esi),%eax
adcl (%edx),%eax
movl %eax,(%edi)
_CET_ENDBR
movl 4(%esi),%eax
adcl 4(%edx),%eax
movl %eax,4(%edi)
_CET_ENDBR
movl 8(%esi),%eax
adcl 8(%edx),%eax
movl %eax,8(%edi)
_CET_ENDBR
movl 12(%esi),%eax
adcl 12(%edx),%eax
movl %eax,12(%edi)
_CET_ENDBR
movl 16(%esi),%eax
adcl 16(%edx),%eax
movl %eax,16(%edi)
_CET_ENDBR
movl 20(%esi),%eax
adcl 20(%edx),%eax
movl %eax,20(%edi)
_CET_ENDBR
movl 24(%esi),%eax
adcl 24(%edx),%eax
movl %eax,24(%edi)
_CET_ENDBR
movl 28(%esi),%eax
adcl 28(%edx),%eax
movl %eax,28(%edi)
@ -99,6 +119,11 @@ L(oop): movl (%esi),%eax
sbbl %eax,%eax
negl %eax
#if IBT_ENABLED
popl %ebx
cfi_adjust_cfa_offset (-4)
cfi_restore (ebx)
#endif
popl %esi
cfi_adjust_cfa_offset (-4)
cfi_restore (esi)

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@ -17,7 +17,7 @@
along with the GNU MP Library; see the file COPYING.LIB. If not,
see <http://www.gnu.org/licenses/>. */
#include "sysdep.h"
#include <sysdep.h>
#include "asm-syntax.h"
#define PARMS 4+8 /* space for 2 saved regs */
@ -40,6 +40,13 @@ ENTRY (__mpn_sub_n)
cfi_rel_offset (esi, 0)
movl S2(%esp),%edx
movl SIZE(%esp),%ecx
#if IBT_ENABLED
pushl %ebx
cfi_adjust_cfa_offset (4)
cfi_rel_offset (ebx, 0)
#endif
movl %ecx,%eax
shrl $3,%ecx /* compute count for unrolled loop */
negl %eax
@ -51,6 +58,9 @@ ENTRY (__mpn_sub_n)
subl %eax,%esi /* ... by a constant when we ... */
subl %eax,%edx /* ... enter the loop */
shrl $2,%eax /* restore previous value */
#if defined __CET__ && (__CET__ & 1) != 0
leal -4(,%eax,4),%ebx /* Count for 4-byte endbr32 */
#endif
#ifdef PIC
/* Calculate start address in loop for PIC. Due to limitations in some
assemblers, Loop-L0-3 cannot be put into the leal */
@ -64,30 +74,39 @@ L(0): leal (%eax,%eax,8),%eax
#else
/* Calculate start address in loop for non-PIC. */
leal (L(oop) - 3)(%eax,%eax,8),%eax
#endif
#if defined __CET__ && (__CET__ & 1) != 0
addl %ebx,%eax /* Adjust for endbr32 */
#endif
jmp *%eax /* jump into loop */
ALIGN (3)
L(oop): movl (%esi),%eax
sbbl (%edx),%eax
movl %eax,(%edi)
_CET_ENDBR
movl 4(%esi),%eax
sbbl 4(%edx),%eax
movl %eax,4(%edi)
_CET_ENDBR
movl 8(%esi),%eax
sbbl 8(%edx),%eax
movl %eax,8(%edi)
movl 12(%esi),%eax
sbbl 12(%edx),%eax
movl %eax,12(%edi)
_CET_ENDBR
movl 16(%esi),%eax
sbbl 16(%edx),%eax
movl %eax,16(%edi)
_CET_ENDBR
movl 20(%esi),%eax
sbbl 20(%edx),%eax
movl %eax,20(%edi)
_CET_ENDBR
movl 24(%esi),%eax
sbbl 24(%edx),%eax
movl %eax,24(%edi)
_CET_ENDBR
movl 28(%esi),%eax
sbbl 28(%edx),%eax
movl %eax,28(%edi)
@ -100,6 +119,11 @@ L(oop): movl (%esi),%eax
sbbl %eax,%eax
negl %eax
#if defined __CET__ && (__CET__ & 1) != 0
popl %ebx
cfi_adjust_cfa_offset (-4)
cfi_restore (ebx)
#endif
popl %esi
cfi_adjust_cfa_offset (-4)
cfi_restore (esi)