diff options
Diffstat (limited to 'sysdeps/i386/__longjmp.S')
| -rw-r--r-- | sysdeps/i386/__longjmp.S | 73 |
1 files changed, 0 insertions, 73 deletions
diff --git a/sysdeps/i386/__longjmp.S b/sysdeps/i386/__longjmp.S index 302c00a..bb83609 100644 --- a/sysdeps/i386/__longjmp.S +++ b/sysdeps/i386/__longjmp.S @@ -19,55 +19,14 @@ #include <sysdep.h> #include <pointer_guard.h> #include <jmpbuf-offsets.h> -#include <jmp_buf-ssp.h> #include <asm-syntax.h> #include <stap-probe.h> -/* 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 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. */ @@ -98,38 +57,6 @@ L(skip_ssp): #else 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 /* Save the return address now. */ movl (JB_PC*4)(%ecx), %edx LIBC_PROBE (longjmp, 3, 4@%ecx, -4@%eax, 4@%edx) |