| 1 | //===-- Implementation of longjmp -----------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "src/setjmp/longjmp.h" |
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| 10 | #include "src/__support/common.h" |
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| 11 | |
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| 12 | #if !defined(LIBC_TARGET_ARCH_IS_X86_64) |
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| 13 | #error "Invalid file include" |
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| 14 | #endif |
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| 15 | |
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| 16 | namespace LIBC_NAMESPACE { |
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| 17 | |
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| 18 | LLVM_LIBC_FUNCTION(void, longjmp, (__jmp_buf * buf, int val)) { |
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| 19 | register __UINT64_TYPE__ rbx __asm__("rbx" ); |
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| 20 | register __UINT64_TYPE__ rbp __asm__("rbp" ); |
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| 21 | register __UINT64_TYPE__ r12 __asm__("r12" ); |
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| 22 | register __UINT64_TYPE__ r13 __asm__("r13" ); |
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| 23 | register __UINT64_TYPE__ r14 __asm__("r14" ); |
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| 24 | register __UINT64_TYPE__ r15 __asm__("r15" ); |
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| 25 | register __UINT64_TYPE__ rsp __asm__("rsp" ); |
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| 26 | register __UINT64_TYPE__ rax __asm__("rax" ); |
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| 27 | |
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| 28 | // ABI requires that the return value should be stored in rax. So, we store |
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| 29 | // |val| in rax. Note that this has to happen before we restore the registers |
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| 30 | // from values in |buf|. Otherwise, once rsp and rbp are updated, we cannot |
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| 31 | // read |val|. |
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| 32 | val = val == 0 ? 1 : val; |
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| 33 | LIBC_INLINE_ASM("mov %1, %0\n\t" : "=r" (rax) : "m" (val) :); |
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| 34 | LIBC_INLINE_ASM("mov %1, %0\n\t" : "=r" (rbx) : "m" (buf->rbx) :); |
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| 35 | LIBC_INLINE_ASM("mov %1, %0\n\t" : "=r" (rbp) : "m" (buf->rbp) :); |
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| 36 | LIBC_INLINE_ASM("mov %1, %0\n\t" : "=r" (r12) : "m" (buf->r12) :); |
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| 37 | LIBC_INLINE_ASM("mov %1, %0\n\t" : "=r" (r13) : "m" (buf->r13) :); |
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| 38 | LIBC_INLINE_ASM("mov %1, %0\n\t" : "=r" (r14) : "m" (buf->r14) :); |
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| 39 | LIBC_INLINE_ASM("mov %1, %0\n\t" : "=r" (r15) : "m" (buf->r15) :); |
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| 40 | LIBC_INLINE_ASM("mov %1, %0\n\t" : "=r" (rsp) : "m" (buf->rsp) :); |
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| 41 | LIBC_INLINE_ASM("jmp *%0\n\t" : : "m" (buf->rip)); |
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| 42 | } |
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| 43 | |
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| 44 | } // namespace LIBC_NAMESPACE |
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| 45 | |
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