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- //===-- hwasan_setjmp_x86_64.S --------------------------------------------===//
- //
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
- // See https://llvm.org/LICENSE.txt for license information.
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
- //
- //===----------------------------------------------------------------------===//
- //
- // setjmp interceptor for x86_64.
- //
- //===----------------------------------------------------------------------===//
- #include "sanitizer_common/sanitizer_asm.h"
- #if HWASAN_WITH_INTERCEPTORS && defined(__x86_64__)
- #include "sanitizer_common/sanitizer_platform.h"
- // We want to save the context of the calling function.
- // That requires
- // 1) No modification of the return address by this function.
- // 2) No modification of the stack pointer by this function.
- // 3) (no modification of any other saved register, but that's not really going
- // to occur, and hence isn't as much of a worry).
- //
- // There's essentially no way to ensure that the compiler will not modify the
- // stack pointer when compiling a C function.
- // Hence we have to write this function in assembly.
- //
- // TODO: Handle Intel CET.
- .section .text
- .file "hwasan_setjmp_x86_64.S"
- .global __interceptor_setjmp
- ASM_TYPE_FUNCTION(__interceptor_setjmp)
- __interceptor_setjmp:
- CFI_STARTPROC
- _CET_ENDBR
- xorl %esi, %esi
- jmp __interceptor_sigsetjmp
- CFI_ENDPROC
- ASM_SIZE(__interceptor_setjmp)
- .global __interceptor_sigsetjmp
- ASM_TYPE_FUNCTION(__interceptor_sigsetjmp)
- __interceptor_sigsetjmp:
- CFI_STARTPROC
- _CET_ENDBR
- // Save callee save registers.
- mov %rbx, (0*8)(%rdi)
- mov %rbp, (1*8)(%rdi)
- mov %r12, (2*8)(%rdi)
- mov %r13, (3*8)(%rdi)
- mov %r14, (4*8)(%rdi)
- mov %r15, (5*8)(%rdi)
- // Save SP as it was in caller's frame.
- lea 8(%rsp), %rdx
- mov %rdx, (6*8)(%rdi)
- // Save return address.
- mov (%rsp), %rax
- mov %rax, (7*8)(%rdi)
- jmp __sigjmp_save
- CFI_ENDPROC
- ASM_SIZE(__interceptor_sigsetjmp)
- .macro WEAK_ALIAS first second
- .weak \second
- .equ \second\(), \first
- .endm
- WEAK_ALIAS __interceptor_sigsetjmp, __sigsetjmp
- WEAK_ALIAS __interceptor_setjmp, _setjmp
- #endif
- // We do not need executable stack.
- NO_EXEC_STACK_DIRECTIVE
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