1 | /* Save current context. |
2 | Copyright (C) 2002-2016 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | Contributed by Andreas Jaeger <aj@suse.de>, 2002. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <sysdep.h> |
21 | |
22 | #include "ucontext_i.h" |
23 | |
24 | /* int __getcontext (ucontext_t *ucp) |
25 | |
26 | Saves the machine context in UCP such that when it is activated, |
27 | it appears as if __getcontext() returned again. |
28 | |
29 | This implementation is intended to be used for *synchronous* context |
30 | switches only. Therefore, it does not have to save anything |
31 | other than the PRESERVED state. */ |
32 | |
33 | |
34 | ENTRY(__getcontext) |
35 | /* Save the preserved registers, the registers used for passing |
36 | args, and the return address. */ |
37 | movq %rbx, oRBX(%rdi) |
38 | movq %rbp, oRBP(%rdi) |
39 | movq %r12, oR12(%rdi) |
40 | movq %r13, oR13(%rdi) |
41 | movq %r14, oR14(%rdi) |
42 | movq %r15, oR15(%rdi) |
43 | |
44 | movq %rdi, oRDI(%rdi) |
45 | movq %rsi, oRSI(%rdi) |
46 | movq %rdx, oRDX(%rdi) |
47 | movq %rcx, oRCX(%rdi) |
48 | movq %r8, oR8(%rdi) |
49 | movq %r9, oR9(%rdi) |
50 | |
51 | movq (%rsp), %rcx |
52 | movq %rcx, oRIP(%rdi) |
53 | leaq 8(%rsp), %rcx /* Exclude the return address. */ |
54 | movq %rcx, oRSP(%rdi) |
55 | |
56 | /* We have separate floating-point register content memory on the |
57 | stack. We use the __fpregs_mem block in the context. Set the |
58 | links up correctly. */ |
59 | |
60 | leaq oFPREGSMEM(%rdi), %rcx |
61 | movq %rcx, oFPREGS(%rdi) |
62 | /* Save the floating-point environment. */ |
63 | fnstenv (%rcx) |
64 | fldenv (%rcx) |
65 | stmxcsr oMXCSR(%rdi) |
66 | |
67 | /* Save the current signal mask with |
68 | rt_sigprocmask (SIG_BLOCK, NULL, set,_NSIG/8). */ |
69 | leaq oSIGMASK(%rdi), %rdx |
70 | xorl %esi,%esi |
71 | #if SIG_BLOCK == 0 |
72 | xorl %edi, %edi |
73 | #else |
74 | movl $SIG_BLOCK, %edi |
75 | #endif |
76 | movl $_NSIG8,%r10d |
77 | movl $__NR_rt_sigprocmask, %eax |
78 | syscall |
79 | cmpq $-4095, %rax /* Check %rax for error. */ |
80 | jae SYSCALL_ERROR_LABEL /* Jump to error handler if error. */ |
81 | |
82 | /* All done, return 0 for success. */ |
83 | xorl %eax, %eax |
84 | ret |
85 | PSEUDO_END(__getcontext) |
86 | |
87 | weak_alias (__getcontext, getcontext) |
88 | |