/* longjmp for i386.
- Copyright (C) 1995-1998,2000,2002,2005,2006,2009
- Free Software Foundation, Inc.
+ Copyright (C) 1995-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <jmpbuf-offsets.h>
+#include <jmp_buf-ssp.h>
#include <asm-syntax.h>
-#include <bp-sym.h>
-#include <bp-asm.h>
+#include <stap-probe.h>
-#define PARMS LINKAGE /* no space for saved regs */
-#define JBUF PARMS
-#define VAL JBUF+PTR_SIZE
-
-ENTRY (BP_SYM (__longjmp))
- ENTER
+/* Don't restore shadow stack register if
+ 1. Shadow stack isn't enabled. Or
+ 2. __longjmp is defined for __longjmp_cancel.
+ */
+#if !SHSTK_ENABLED || defined __longjmp
+# undef SHADOW_STACK_POINTER_OFFSET
+#endif
+ .text
+ENTRY (__longjmp)
#ifdef PTR_DEMANGLE
- movl JBUF(%esp), %eax /* User's jmp_buf in %eax. */
- CHECK_BOUNDS_BOTH_WIDE (%eax, JBUF(%esp), $JB_SIZE)
+ movl 4(%esp), %eax /* User's jmp_buf in %eax. */
+# ifdef SHADOW_STACK_POINTER_OFFSET
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+ /* Check if Shadow Stack is enabled. */
+ testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
+ jz L(skip_ssp)
+# else
+ xorl %edx, %edx
+# endif
+ /* Check and adjust the Shadow-Stack-Pointer. */
+ rdsspd %edx
+ /* And compare it with the saved ssp value. */
+ subl SHADOW_STACK_POINTER_OFFSET(%eax), %edx
+ je L(skip_ssp)
+ /* Count the number of frames to adjust and adjust it
+ with incssp instruction. The instruction can adjust
+ the ssp by [0..255] value only thus use a loop if
+ the number of frames is bigger than 255. */
+ negl %edx
+ shrl $2, %edx
+ /* NB: We saved Shadow-Stack-Pointer of setjmp. Since we are
+ restoring Shadow-Stack-Pointer of setjmp's caller, we
+ need to unwind shadow stack by one more frame. */
+ addl $1, %edx
+ movl $255, %ebx
+L(loop):
+ cmpl %ebx, %edx
+ cmovb %edx, %ebx
+ incsspd %ebx
+ subl %ebx, %edx
+ ja L(loop)
+L(skip_ssp):
+# endif
/* Save the return address now. */
movl (JB_PC*4)(%eax), %edx
/* Get the stack pointer. */
movl (JB_SP*4)(%eax), %ecx
PTR_DEMANGLE (%edx)
PTR_DEMANGLE (%ecx)
-# ifdef CHECK_ESP
- CHECK_ESP (%ecx)
-# endif
+ LIBC_PROBE (longjmp, 3, 4@%eax, -4@8(%esp), 4@%edx)
cfi_def_cfa(%eax, 0)
cfi_register(%eip, %edx)
cfi_register(%esp, %ecx)
cfi_offset(%esi, JB_SI*4)
cfi_offset(%edi, JB_DI*4)
cfi_offset(%ebp, JB_BP*4)
- /* Restore registers. */
+ /* Restore registers. */
movl (JB_BX*4)(%eax), %ebx
movl (JB_SI*4)(%eax), %esi
movl (JB_DI*4)(%eax), %edi
cfi_restore(%edi)
cfi_restore(%ebp)
- movl VAL(%esp), %eax /* Second argument is return value. */
+ LIBC_PROBE (longjmp_target, 3, 4@%eax, -4@8(%esp), 4@%edx)
+ movl 8(%esp), %eax /* Second argument is return value. */
movl %ecx, %esp
#else
- movl JBUF(%esp), %ecx /* User's jmp_buf in %ecx. */
- CHECK_BOUNDS_BOTH_WIDE (%ecx, JBUF(%esp), $JB_SIZE)
-
-# ifdef CHECK_ESP
- movl (JB_SP*4)(%ecx), %eax
- CHECK_ESP (%eax)
+ movl 4(%esp), %ecx /* User's jmp_buf in %ecx. */
+ movl 8(%esp), %eax /* Second argument is return value. */
+# ifdef SHADOW_STACK_POINTER_OFFSET
+# if IS_IN (libc) && defined SHARED
+ /* Check if Shadow Stack is enabled. */
+ testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
+ jz L(skip_ssp)
+# endif
+ /* Check and adjust the Shadow-Stack-Pointer. */
+ xorl %edx, %edx
+ /* Get the current ssp. */
+ rdsspd %edx
+ /* And compare it with the saved ssp value. */
+ subl SHADOW_STACK_POINTER_OFFSET(%ecx), %edx
+ je L(skip_ssp)
+ /* Count the number of frames to adjust and adjust it
+ with incssp instruction. The instruction can adjust
+ the ssp by [0..255] value only thus use a loop if
+ the number of frames is bigger than 255. */
+ negl %edx
+ shrl $2, %edx
+ /* NB: We saved Shadow-Stack-Pointer of setjmp. Since we are
+ restoring Shadow-Stack-Pointer of setjmp's caller, we
+ need to unwind shadow stack by one more frame. */
+ addl $1, %edx
+ movl $255, %ebx
+L(loop):
+ cmpl %ebx, %edx
+ cmovb %edx, %ebx
+ incsspd %ebx
+ subl %ebx, %edx
+ ja L(loop)
+L(skip_ssp):
# endif
-
- movl VAL(%esp), %eax /* Second argument is return value. */
/* Save the return address now. */
movl (JB_PC*4)(%ecx), %edx
- /* Restore registers. */
+ LIBC_PROBE (longjmp, 3, 4@%ecx, -4@%eax, 4@%edx)
+ /* Restore registers. */
movl (JB_BX*4)(%ecx), %ebx
movl (JB_SI*4)(%ecx), %esi
movl (JB_DI*4)(%ecx), %edi
movl (JB_BP*4)(%ecx), %ebp
movl (JB_SP*4)(%ecx), %esp
+ LIBC_PROBE (longjmp_target, 3, 4@%ecx, -4@%ecx, 4@%edx)
#endif
/* Jump to saved PC. */
- jmp *%edx
-END (BP_SYM (__longjmp))
+ jmp *%edx
+END (__longjmp)
projects / thirdparty / glibc.git / blobdiff