1 | /* Save current context. |
2 | Copyright (C) 2001-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <sysdep.h> |
20 | |
21 | #include "ucontext_i.h" |
22 | |
23 | |
24 | ENTRY(__getcontext) |
25 | /* Load address of the context data structure. */ |
26 | movl 4(%esp), %eax |
27 | |
28 | /* Return value of getcontext. EAX is the only register whose |
29 | value is not preserved. */ |
30 | movl $0, oEAX(%eax) |
31 | |
32 | /* Save the 32-bit register values and the return address. */ |
33 | movl %ecx, oECX(%eax) |
34 | movl %edx, oEDX(%eax) |
35 | movl %edi, oEDI(%eax) |
36 | movl %esi, oESI(%eax) |
37 | movl %ebp, oEBP(%eax) |
38 | movl (%esp), %ecx |
39 | movl %ecx, oEIP(%eax) |
40 | leal 4(%esp), %ecx /* Exclude the return address. */ |
41 | movl %ecx, oESP(%eax) |
42 | movl %ebx, oEBX(%eax) |
43 | |
44 | /* Save the FS segment register. We don't touch the GS register |
45 | since it is used for threads. */ |
46 | xorl %edx, %edx |
47 | movw %fs, %dx |
48 | movl %edx, oFS(%eax) |
49 | |
50 | leal oFPREGS(%eax), %ecx |
51 | /* Save the floating-point context. */ |
52 | fnstenv (%ecx) |
53 | /* And load it right back since the processor changes the mask. |
54 | Intel thought this opcode to be used in interrupt handlers which |
55 | would block all exceptions. */ |
56 | fldenv (%ecx) |
57 | |
58 | /* Save the current signal mask. */ |
59 | subl $12, %esp |
60 | cfi_adjust_cfa_offset (12) |
61 | leal oSIGMASK(%eax), %eax |
62 | movl %eax, 8(%esp) |
63 | movl $0, 4(%esp) |
64 | movl $SIG_BLOCK, (%esp) |
65 | call HIDDEN_JUMPTARGET (__sigprocmask) |
66 | addl $12, %esp |
67 | cfi_adjust_cfa_offset (-12) |
68 | /* Propagate %eax (and errno, in case). */ |
69 | |
70 | ret |
71 | PSEUDO_END(__getcontext) |
72 | |
73 | weak_alias (__getcontext, getcontext) |
74 | |