Edit File: jump_x86_64_sysv_elf_gas.S
/* Copyright Oliver Kowalke 2009. Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) */ /**************************************************************************************** * * * ---------------------------------------------------------------------------------- * * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | * * ---------------------------------------------------------------------------------- * * | 0x0 | 0x4 | 0x8 | 0xc | 0x10 | 0x14 | 0x18 | 0x1c | * * ---------------------------------------------------------------------------------- * * | fc_mxcsr|fc_x87_cw| guard | R12 | R13 | * * ---------------------------------------------------------------------------------- * * ---------------------------------------------------------------------------------- * * | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | * * ---------------------------------------------------------------------------------- * * | 0x20 | 0x24 | 0x28 | 0x2c | 0x30 | 0x34 | 0x38 | 0x3c | * * ---------------------------------------------------------------------------------- * * | R14 | R15 | RBX | RBP | * * ---------------------------------------------------------------------------------- * * ---------------------------------------------------------------------------------- * * | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | * * ---------------------------------------------------------------------------------- * * | 0x40 | 0x44 | | * * ---------------------------------------------------------------------------------- * * | RIP | | * * ---------------------------------------------------------------------------------- * * * ****************************************************************************************/ # if defined __CET__ # include <cet.h> # define SHSTK_ENABLED (__CET__ & 0x2) # define BOOST_CONTEXT_SHADOW_STACK (SHSTK_ENABLED && SHADOW_STACK_SYSCALL) # else # define _CET_ENDBR # endif .file "jump_x86_64_sysv_elf_gas.S" .text .globl jump_fcontext .type jump_fcontext,@function .align 16 jump_fcontext: _CET_ENDBR leaq -0x40(%rsp), %rsp /* prepare stack */ #if !defined(BOOST_USE_TSX) stmxcsr (%rsp) /* save MMX control- and status-word */ fnstcw 0x4(%rsp) /* save x87 control-word */ #endif #if defined(BOOST_CONTEXT_TLS_STACK_PROTECTOR) movq %fs:0x28, %rcx /* read stack guard from TLS record */ movq %rcx, 0x8(%rsp) /* save stack guard */ #endif movq %r12, 0x10(%rsp) /* save R12 */ movq %r13, 0x18(%rsp) /* save R13 */ movq %r14, 0x20(%rsp) /* save R14 */ movq %r15, 0x28(%rsp) /* save R15 */ movq %rbx, 0x30(%rsp) /* save RBX */ movq %rbp, 0x38(%rsp) /* save RBP */ #if BOOST_CONTEXT_SHADOW_STACK /* grow the stack to reserve space for shadow stack pointer(SSP) */ leaq -0x8(%rsp), %rsp /* read the current SSP and store it */ rdsspq %rcx movq %rcx, (%rsp) #endif /* store RSP (pointing to context-data) in RAX */ movq %rsp, %rax /* restore RSP (pointing to context-data) from RDI */ movq %rdi, %rsp #if BOOST_CONTEXT_SHADOW_STACK /* first 8 bytes are SSP */ movq (%rsp), %rcx leaq 0x8(%rsp), %rsp /* Restore target(new) shadow stack */ rstorssp -8(%rcx) /* restore token for previous shadow stack is pushed */ /* on previous shadow stack after saveprevssp */ saveprevssp /* when return, jump_fcontext jump to restored return address */ /* (r8) instead of RET. This miss of RET implies us to unwind */ /* shadow stack accordingly. Otherwise mismatch occur */ movq $1, %rcx incsspq %rcx #endif movq 0x40(%rsp), %r8 /* restore return-address */ #if !defined(BOOST_USE_TSX) ldmxcsr (%rsp) /* restore MMX control- and status-word */ fldcw 0x4(%rsp) /* restore x87 control-word */ #endif #if defined(BOOST_CONTEXT_TLS_STACK_PROTECTOR) movq 0x8(%rsp), %rdx /* load stack guard */ movq %rdx, %fs:0x28 /* restore stack guard to TLS record */ #endif movq 0x10(%rsp), %r12 /* restore R12 */ movq 0x18(%rsp), %r13 /* restore R13 */ movq 0x20(%rsp), %r14 /* restore R14 */ movq 0x28(%rsp), %r15 /* restore R15 */ movq 0x30(%rsp), %rbx /* restore RBX */ movq 0x38(%rsp), %rbp /* restore RBP */ leaq 0x48(%rsp), %rsp /* prepare stack */ /* return transfer_t from jump */ #if !defined(_ILP32) /* RAX == fctx, RDX == data */ movq %rsi, %rdx #else /* RAX == data:fctx */ salq $32, %rsi orq %rsi, %rax #endif /* pass transfer_t as first arg in context function */ #if !defined(_ILP32) /* RDI == fctx, RSI == data */ #else /* RDI == data:fctx */ #endif movq %rax, %rdi /* indirect jump to context */ jmp *%r8 .size jump_fcontext,.-jump_fcontext /* Mark that we don't need executable stack. */ .section .note.GNU-stack,"",%progbits