1/* libunwind - a platform-independent unwind library 2 Copyright (C) 2008 Google, Inc 3 Contributed by Paul Pluzhnikov <ppluzhnikov@google.com> 4 Copyright (C) 2010 Konstantin Belousov <kib@freebsd.org> 5 6This file is part of libunwind. 7 8Permission is hereby granted, free of charge, to any person obtaining 9a copy of this software and associated documentation files (the 10"Software"), to deal in the Software without restriction, including 11without limitation the rights to use, copy, modify, merge, publish, 12distribute, sublicense, and/or sell copies of the Software, and to 13permit persons to whom the Software is furnished to do so, subject to 14the following conditions: 15 16The above copyright notice and this permission notice shall be 17included in all copies or substantial portions of the Software. 18 19THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 20EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 21MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 22NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 23LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 24OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 25WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ 26 27#include "ucontext_i.h" 28 29/* int _Ux86_64_getcontext (ucontext_t *ucp) 30 31 Saves the machine context in UCP necessary for libunwind. 32 Unlike the libc implementation, we don't save the signal mask 33 and hence avoid the cost of a system call per unwind. 34 35*/ 36 37 .global _Ux86_64_getcontext 38 .type _Ux86_64_getcontext, @function 39_Ux86_64_getcontext: 40 .cfi_startproc 41 42 /* Callee saved: RBX, RBP, R12-R15 */ 43 movq %r12, UC_MCONTEXT_GREGS_R12(%rdi) 44 movq %r13, UC_MCONTEXT_GREGS_R13(%rdi) 45 movq %r14, UC_MCONTEXT_GREGS_R14(%rdi) 46 movq %r15, UC_MCONTEXT_GREGS_R15(%rdi) 47 movq %rbp, UC_MCONTEXT_GREGS_RBP(%rdi) 48 movq %rbx, UC_MCONTEXT_GREGS_RBX(%rdi) 49 50 /* Save argument registers (not strictly needed, but setcontext 51 restores them, so don't restore garbage). */ 52 movq %r8, UC_MCONTEXT_GREGS_R8(%rdi) 53 movq %r9, UC_MCONTEXT_GREGS_R9(%rdi) 54 movq %rdi, UC_MCONTEXT_GREGS_RDI(%rdi) 55 movq %rsi, UC_MCONTEXT_GREGS_RSI(%rdi) 56 movq %rdx, UC_MCONTEXT_GREGS_RDX(%rdi) 57 movq %rax, UC_MCONTEXT_GREGS_RAX(%rdi) 58 movq %rcx, UC_MCONTEXT_GREGS_RCX(%rdi) 59 60#if defined __linux__ || defined __sun 61 /* Save fp state (not needed, except for setcontext not 62 restoring garbage). */ 63 leaq UC_MCONTEXT_FPREGS_MEM(%rdi),%r8 64#ifdef UC_MCONTEXT_FPREGS_PTR 65 movq %r8, UC_MCONTEXT_FPREGS_PTR(%rdi) 66#endif // UC_MCONTEXT_FPREGS_PTR 67 fnstenv (%r8) 68 stmxcsr FPREGS_OFFSET_MXCSR(%r8) 69#elif defined __FreeBSD__ 70 fxsave UC_MCONTEXT_FPSTATE(%rdi) 71 movq $UC_MCONTEXT_FPOWNED_FPU,UC_MCONTEXT_OWNEDFP(%rdi) 72 movq $UC_MCONTEXT_FPFMT_XMM,UC_MCONTEXT_FPFORMAT(%rdi) 73 /* Save rflags and segment registers, so that sigreturn(2) 74 does not complain. */ 75 pushfq 76 .cfi_adjust_cfa_offset 8 77 popq UC_MCONTEXT_RFLAGS(%rdi) 78 .cfi_adjust_cfa_offset -8 79 movl $0, UC_MCONTEXT_FLAGS(%rdi) 80 movw %cs, UC_MCONTEXT_CS(%rdi) 81 movw %ss, UC_MCONTEXT_SS(%rdi) 82#if 0 83 /* Setting the flags to 0 above disables restore of segment 84 registers from the context */ 85 movw %ds, UC_MCONTEXT_DS(%rdi) 86 movw %es, UC_MCONTEXT_ES(%rdi) 87 movw %fs, UC_MCONTEXT_FS(%rdi) 88 movw %gs, UC_MCONTEXT_GS(%rdi) 89#endif 90 movq $UC_MCONTEXT_MC_LEN_VAL, UC_MCONTEXT_MC_LEN(%rdi) 91#else 92#error Port me 93#endif 94 95 leaq 8(%rsp), %rax /* exclude this call. */ 96 movq %rax, UC_MCONTEXT_GREGS_RSP(%rdi) 97 98 movq 0(%rsp), %rax 99 movq %rax, UC_MCONTEXT_GREGS_RIP(%rdi) 100 101 xorq %rax, %rax 102 retq 103 .cfi_endproc 104 .size _Ux86_64_getcontext, . - _Ux86_64_getcontext 105 106/* int _Ux86_64_getcontext_trace (ucontext_t *ucp) 107 108 Saves limited machine context in UCP necessary for libunwind. 109 Unlike _Ux86_64_getcontext, saves only the parts needed for 110 fast trace. If fast trace fails, caller will have to get the 111 full context. 112*/ 113 114 .global _Ux86_64_getcontext_trace 115 .hidden _Ux86_64_getcontext_trace 116 .type _Ux86_64_getcontext_trace, @function 117_Ux86_64_getcontext_trace: 118 .cfi_startproc 119 120 /* Save only RBP, RBX, RSP, RIP - exclude this call. */ 121 movq %rbp, UC_MCONTEXT_GREGS_RBP(%rdi) 122 movq %rbx, UC_MCONTEXT_GREGS_RBX(%rdi) 123 124 leaq 8(%rsp), %rax 125 movq %rax, UC_MCONTEXT_GREGS_RSP(%rdi) 126 127 movq 0(%rsp), %rax 128 movq %rax, UC_MCONTEXT_GREGS_RIP(%rdi) 129 130 xorq %rax, %rax 131 retq 132 .cfi_endproc 133 .size _Ux86_64_getcontext_trace, . - _Ux86_64_getcontext_trace 134 135 /* We do not need executable stack. */ 136 .section .note.GNU-stack,"",@progbits 137