1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
/* Save current context.
Copyright (C) 2002-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Andreas Jaeger <aj@suse.de>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include "ucontext_i.h"
/* int __getcontext (ucontext_t *ucp)
Saves the machine context in UCP such that when it is activated,
it appears as if __getcontext() returned again.
This implementation is intended to be used for *synchronous* context
switches only. Therefore, it does not have to save anything
other than the PRESERVED state. */
ENTRY(__getcontext)
/* Save the preserved registers, the registers used for passing
args, and the return address. */
movq %rbx, oRBX(%rdi)
movq %rbp, oRBP(%rdi)
movq %r12, oR12(%rdi)
movq %r13, oR13(%rdi)
movq %r14, oR14(%rdi)
movq %r15, oR15(%rdi)
movq %rdi, oRDI(%rdi)
movq %rsi, oRSI(%rdi)
movq %rdx, oRDX(%rdi)
movq %rcx, oRCX(%rdi)
movq %r8, oR8(%rdi)
movq %r9, oR9(%rdi)
movq (%rsp), %rcx
movq %rcx, oRIP(%rdi)
leaq 8(%rsp), %rcx /* Exclude the return address. */
movq %rcx, oRSP(%rdi)
/* We have separate floating-point register content memory on the
stack. We use the __fpregs_mem block in the context. Set the
links up correctly. */
leaq oFPREGSMEM(%rdi), %rcx
movq %rcx, oFPREGS(%rdi)
/* Save the floating-point environment. */
fnstenv (%rcx)
fldenv (%rcx)
stmxcsr oMXCSR(%rdi)
/* Save the current signal mask with
rt_sigprocmask (SIG_BLOCK, NULL, set,_NSIG/8). */
leaq oSIGMASK(%rdi), %rdx
xorl %esi,%esi
#if SIG_BLOCK == 0
xorl %edi, %edi
#else
movl $SIG_BLOCK, %edi
#endif
movl $_NSIG8,%r10d
movl $__NR_rt_sigprocmask, %eax
syscall
cmpq $-4095, %rax /* Check %rax for error. */
jae SYSCALL_ERROR_LABEL /* Jump to error handler if error. */
/* All done, return 0 for success. */
xorl %eax, %eax
ret
PSEUDO_END(__getcontext)
weak_alias (__getcontext, getcontext)
|
