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1/* libunwind - a platform-independent unwind library
2   Copyright (C) 2007 Google, Inc
3	Contributed by Arun Sharma <arun.sharma@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_setcontext (const ucontext_t *ucp)
30
31  Restores the machine context provided.
32  Unlike the libc implementation, doesn't clobber %rax
33
34*/
35	.global _Ux86_64_setcontext
36	.type _Ux86_64_setcontext, @function
37
38_Ux86_64_setcontext:
39
40#if defined __linux__ || defined __sun
41        /* restore fp state */
42#ifdef UC_MCONTEXT_FPREGS_PTR
43	mov    UC_MCONTEXT_FPREGS_PTR(%rdi),%r8
44#else // UC_MCONTEXT_FPREGS_PTR
45	leaq UC_MCONTEXT_FPREGS_MEM(%rdi),%r8
46#endif // UC_MCONTEXT_FPREGS_PTR
47	fldenv (%r8)
48	ldmxcsr FPREGS_OFFSET_MXCSR(%r8)
49#elif defined __FreeBSD__
50	/* restore fp state */
51	cmpq $UC_MCONTEXT_FPOWNED_FPU,UC_MCONTEXT_OWNEDFP(%rdi)
52	jne 1f
53	cmpq $UC_MCONTEXT_FPFMT_XMM,UC_MCONTEXT_FPFORMAT(%rdi)
54	jne 1f
55	fxrstor UC_MCONTEXT_FPSTATE(%rdi)
561:
57#else
58#error Port me
59#endif
60
61	/* restore the rest of the state */
62	mov    UC_MCONTEXT_GREGS_R8(%rdi),%r8
63	mov    UC_MCONTEXT_GREGS_R9(%rdi),%r9
64	mov    UC_MCONTEXT_GREGS_RBX(%rdi),%rbx
65	mov    UC_MCONTEXT_GREGS_RBP(%rdi),%rbp
66	mov    UC_MCONTEXT_GREGS_R12(%rdi),%r12
67	mov    UC_MCONTEXT_GREGS_R13(%rdi),%r13
68	mov    UC_MCONTEXT_GREGS_R14(%rdi),%r14
69	mov    UC_MCONTEXT_GREGS_R15(%rdi),%r15
70	mov    UC_MCONTEXT_GREGS_RSI(%rdi),%rsi
71	mov    UC_MCONTEXT_GREGS_RDX(%rdi),%rdx
72	mov    UC_MCONTEXT_GREGS_RAX(%rdi),%rax
73	mov    UC_MCONTEXT_GREGS_RCX(%rdi),%rcx
74	mov    UC_MCONTEXT_GREGS_RSP(%rdi),%rsp
75
76        /* push the return address on the stack */
77	mov    UC_MCONTEXT_GREGS_RIP(%rdi),%rcx
78	push   %rcx
79
80	mov    UC_MCONTEXT_GREGS_RCX(%rdi),%rcx
81	mov    UC_MCONTEXT_GREGS_RDI(%rdi),%rdi
82	retq
83
84	.size _Ux86_64_setcontext, . - _Ux86_64_setcontext
85
86      /* We do not need executable stack.  */
87      .section        .note.GNU-stack,"",@progbits
88