1 | /* Install given 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(__setcontext) |
25 | /* Load address of the context data structure. */ |
26 | movl 4(%esp), %eax |
27 | |
28 | /* Get the current signal mask. */ |
29 | subl $12, %esp |
30 | cfi_adjust_cfa_offset (12) |
31 | movl $0, 8(%esp) |
32 | leal oSIGMASK(%eax), %eax |
33 | movl %eax, 4(%esp) |
34 | movl $SIG_SETMASK, (%esp) |
35 | call HIDDEN_JUMPTARGET (__sigprocmask) |
36 | addl $12, %esp |
37 | cfi_adjust_cfa_offset (-12) |
38 | testl %eax, %eax |
39 | jne L(pseudo_end) |
40 | |
41 | /* EAX was modified, reload it. */ |
42 | movl 4(%esp), %eax |
43 | |
44 | /* Restore the floating-point context. Not the registers, only the |
45 | rest. */ |
46 | leal oFPREGS(%eax), %ecx |
47 | fldenv (%ecx) |
48 | |
49 | /* Restore the FS segment register. We don't touch the GS register |
50 | since it is used for threads. */ |
51 | movl oFS(%eax), %ecx |
52 | movw %cx, %fs |
53 | |
54 | /* Fetch the address to return to. */ |
55 | movl oEIP(%eax), %ecx |
56 | |
57 | /* Load the new stack pointer. */ |
58 | cfi_def_cfa (eax, 0) |
59 | cfi_offset (edi, oEDI) |
60 | cfi_offset (esi, oESI) |
61 | cfi_offset (ebp, oEBP) |
62 | cfi_offset (ebx, oEBX) |
63 | cfi_offset (edx, oEDX) |
64 | cfi_offset (ecx, oECX) |
65 | movl oESP(%eax), %esp |
66 | |
67 | /* Push the return address on the new stack so we can return there. */ |
68 | pushl %ecx |
69 | |
70 | /* Load the values of all the 32-bit registers (except ESP). |
71 | Since we are loading from EAX, it must be last. */ |
72 | movl oEDI(%eax), %edi |
73 | movl oESI(%eax), %esi |
74 | movl oEBP(%eax), %ebp |
75 | movl oEBX(%eax), %ebx |
76 | movl oEDX(%eax), %edx |
77 | movl oECX(%eax), %ecx |
78 | movl oEAX(%eax), %eax |
79 | |
80 | /* End FDE here, we fall into another context. */ |
81 | cfi_endproc |
82 | cfi_startproc |
83 | |
84 | /* The following 'ret' will pop the address of the code and jump |
85 | to it. */ |
86 | |
87 | L(pseudo_end): |
88 | ret |
89 | PSEUDO_END(__setcontext) |
90 | libc_hidden_def (__setcontext) |
91 | |
92 | weak_alias (__setcontext, setcontext) |
93 | |