diff options
Diffstat (limited to 'src/third_party/unwind/dist/src/x86_64/getcontext.S')
| -rw-r--r-- | src/third_party/unwind/dist/src/x86_64/getcontext.S | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/src/third_party/unwind/dist/src/x86_64/getcontext.S b/src/third_party/unwind/dist/src/x86_64/getcontext.S new file mode 100644 index 00000000000..7a8b5664bda --- /dev/null +++ b/src/third_party/unwind/dist/src/x86_64/getcontext.S @@ -0,0 +1,134 @@ +/* libunwind - a platform-independent unwind library + Copyright (C) 2008 Google, Inc + Contributed by Paul Pluzhnikov <ppluzhnikov@google.com> + Copyright (C) 2010 Konstantin Belousov <kib@freebsd.org> + +This file is part of libunwind. + +Permission is hereby granted, free of charge, to any person obtaining +a copy of this software and associated documentation files (the +"Software"), to deal in the Software without restriction, including +without limitation the rights to use, copy, modify, merge, publish, +distribute, sublicense, and/or sell copies of the Software, and to +permit persons to whom the Software is furnished to do so, subject to +the following conditions: + +The above copyright notice and this permission notice shall be +included in all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE +LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ + +#include "ucontext_i.h" + +/* int _Ux86_64_getcontext (ucontext_t *ucp) + + Saves the machine context in UCP necessary for libunwind. + Unlike the libc implementation, we don't save the signal mask + and hence avoid the cost of a system call per unwind. + +*/ + + .global _Ux86_64_getcontext + .type _Ux86_64_getcontext, @function +_Ux86_64_getcontext: + .cfi_startproc + + /* Callee saved: RBX, RBP, R12-R15 */ + movq %r12, UC_MCONTEXT_GREGS_R12(%rdi) + movq %r13, UC_MCONTEXT_GREGS_R13(%rdi) + movq %r14, UC_MCONTEXT_GREGS_R14(%rdi) + movq %r15, UC_MCONTEXT_GREGS_R15(%rdi) + movq %rbp, UC_MCONTEXT_GREGS_RBP(%rdi) + movq %rbx, UC_MCONTEXT_GREGS_RBX(%rdi) + + /* Save argument registers (not strictly needed, but setcontext + restores them, so don't restore garbage). */ + movq %r8, UC_MCONTEXT_GREGS_R8(%rdi) + movq %r9, UC_MCONTEXT_GREGS_R9(%rdi) + movq %rdi, UC_MCONTEXT_GREGS_RDI(%rdi) + movq %rsi, UC_MCONTEXT_GREGS_RSI(%rdi) + movq %rdx, UC_MCONTEXT_GREGS_RDX(%rdi) + movq %rax, UC_MCONTEXT_GREGS_RAX(%rdi) + movq %rcx, UC_MCONTEXT_GREGS_RCX(%rdi) + +#if defined __linux__ + /* Save fp state (not needed, except for setcontext not + restoring garbage). */ + leaq UC_MCONTEXT_FPREGS_MEM(%rdi),%r8 + movq %r8, UC_MCONTEXT_FPREGS_PTR(%rdi) + fnstenv (%r8) + stmxcsr FPREGS_OFFSET_MXCSR(%r8) +#elif defined __FreeBSD__ + fxsave UC_MCONTEXT_FPSTATE(%rdi) + movq $UC_MCONTEXT_FPOWNED_FPU,UC_MCONTEXT_OWNEDFP(%rdi) + movq $UC_MCONTEXT_FPFMT_XMM,UC_MCONTEXT_FPFORMAT(%rdi) + /* Save rflags and segment registers, so that sigreturn(2) + does not complain. */ + pushfq + .cfi_adjust_cfa_offset 8 + popq UC_MCONTEXT_RFLAGS(%rdi) + .cfi_adjust_cfa_offset -8 + movl $0, UC_MCONTEXT_FLAGS(%rdi) + movw %cs, UC_MCONTEXT_CS(%rdi) + movw %ss, UC_MCONTEXT_SS(%rdi) +#if 0 + /* Setting the flags to 0 above disables restore of segment + registers from the context */ + movw %ds, UC_MCONTEXT_DS(%rdi) + movw %es, UC_MCONTEXT_ES(%rdi) + movw %fs, UC_MCONTEXT_FS(%rdi) + movw %gs, UC_MCONTEXT_GS(%rdi) +#endif + movq $UC_MCONTEXT_MC_LEN_VAL, UC_MCONTEXT_MC_LEN(%rdi) +#else +#error Port me +#endif + + leaq 8(%rsp), %rax /* exclude this call. */ + movq %rax, UC_MCONTEXT_GREGS_RSP(%rdi) + + movq 0(%rsp), %rax + movq %rax, UC_MCONTEXT_GREGS_RIP(%rdi) + + xorq %rax, %rax + retq + .cfi_endproc + .size _Ux86_64_getcontext, . - _Ux86_64_getcontext + +/* int _Ux86_64_getcontext_trace (ucontext_t *ucp) + + Saves limited machine context in UCP necessary for libunwind. + Unlike _Ux86_64_getcontext, saves only the parts needed for + fast trace. If fast trace fails, caller will have to get the + full context. +*/ + + .global _Ux86_64_getcontext_trace + .hidden _Ux86_64_getcontext_trace + .type _Ux86_64_getcontext_trace, @function +_Ux86_64_getcontext_trace: + .cfi_startproc + + /* Save only RBP, RBX, RSP, RIP - exclude this call. */ + movq %rbp, UC_MCONTEXT_GREGS_RBP(%rdi) + movq %rbx, UC_MCONTEXT_GREGS_RBX(%rdi) + + leaq 8(%rsp), %rax + movq %rax, UC_MCONTEXT_GREGS_RSP(%rdi) + + movq 0(%rsp), %rax + movq %rax, UC_MCONTEXT_GREGS_RIP(%rdi) + + xorq %rax, %rax + retq + .cfi_endproc + .size _Ux86_64_getcontext_trace, . - _Ux86_64_getcontext_trace + + /* We do not need executable stack. */ + .section .note.GNU-stack,"",@progbits |