]>
Commit | Line | Data |
---|---|---|
5bccf609 | 1 | /* Create new context. |
b168057a | 2 | Copyright (C) 2008-2015 Free Software Foundation, Inc. |
5bccf609 CD |
3 | This file is part of the GNU C Library. |
4 | Contributed by Helge Deller <deller@gmx.de>, 2008. | |
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 | |
ab84e3ff PE |
17 | License along with the GNU C Library. If not, see |
18 | <http://www.gnu.org/licenses/>. */ | |
5bccf609 CD |
19 | |
20 | #include <libintl.h> | |
21 | #include <stdarg.h> | |
22 | #include <stdio.h> | |
23 | #include <stdlib.h> | |
24 | #include <sysdep.h> | |
25 | #include <ucontext.h> | |
26 | ||
40215fde | 27 | /* POSIX only supports integer arguments. */ |
131fafa7 CD |
28 | |
29 | /* Stack must be 64-byte aligned at all times. */ | |
40215fde | 30 | #define STACK_ALIGN 64 |
131fafa7 | 31 | /* Size of frame marker in unsigned long words. */ |
5556231d | 32 | #define FRAME_SIZE_UL 8 |
131fafa7 | 33 | /* Size of frame marker in bytes. */ |
5556231d | 34 | #define FRAME_SIZE_BYTES (8 * sizeof(unsigned long)) |
131fafa7 CD |
35 | /* Size of X arguments in bytes. */ |
36 | #define ARGS(x) (x * sizeof(unsigned long)) | |
5bccf609 CD |
37 | |
38 | void | |
39 | __makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) | |
40 | { | |
131fafa7 | 41 | unsigned long *sp, *osp; |
5bccf609 CD |
42 | va_list ap; |
43 | int i; | |
44 | ||
5556231d | 45 | /* Create a 64-byte aligned frame to store args. Use ss_sp if |
131fafa7 CD |
46 | it is available, otherwise be robust and use the currently |
47 | saved stack pointer. */ | |
48 | if (ucp->uc_stack.ss_sp && ucp->uc_stack.ss_size) | |
49 | osp = (unsigned long *)ucp->uc_stack.ss_sp; | |
50 | else | |
51 | osp = (unsigned long *)ucp->uc_mcontext.sc_gr[30]; | |
52 | ||
5556231d JM |
53 | sp = (unsigned long *)((((unsigned long) osp) |
54 | + FRAME_SIZE_BYTES + ARGS(argc) + STACK_ALIGN) | |
131fafa7 CD |
55 | & ~(STACK_ALIGN - 1)); |
56 | ||
57 | /* Use new frame. */ | |
58 | ucp->uc_mcontext.sc_gr[30] = ((unsigned long) sp); | |
59 | ||
60 | /* Finish frame setup. */ | |
61 | if (ucp->uc_link) | |
62 | { | |
63 | /* Returning to the next context and next frame. */ | |
64 | sp[-4/sizeof(unsigned long)] = ucp->uc_link->uc_mcontext.sc_gr[30]; | |
65 | sp[-20/sizeof(unsigned long)] = ucp->uc_link->uc_mcontext.sc_gr[2]; | |
66 | } | |
67 | else | |
68 | { | |
69 | /* This is the main context. No frame marker, and no return address. */ | |
70 | sp[-4/sizeof(unsigned long)] = 0x0; | |
71 | sp[-20/sizeof(unsigned long)] = 0x0; | |
72 | } | |
5bccf609 CD |
73 | |
74 | /* Store address to jump to. */ | |
75 | ucp->uc_mcontext.sc_gr[2] = (unsigned long) func; | |
76 | ||
131fafa7 | 77 | /* Process arguments. */ |
5bccf609 | 78 | va_start (ap, argc); |
5bccf609 | 79 | for (i = 0; i < argc; ++i) |
40215fde CD |
80 | { |
81 | if (i < 4) | |
82 | { | |
83 | ucp->uc_mcontext.sc_gr[26-i] = va_arg (ap, int); | |
84 | continue; | |
5bccf609 | 85 | } |
5bccf609 | 86 | |
40215fde CD |
87 | if ((i < 8) && (sizeof(unsigned long) == 8)) |
88 | { | |
89 | /* 64bit: r19-r22 are arg7-arg4. */ | |
90 | ucp->uc_mcontext.sc_gr[22+4-i] = va_arg (ap, int); | |
91 | continue; | |
5556231d | 92 | } |
40215fde CD |
93 | |
94 | /* All other arguments go on the stack. */ | |
131fafa7 | 95 | sp[-1 * (FRAME_SIZE_UL + 1 + i)] = va_arg (ap, int); |
40215fde | 96 | } |
5556231d | 97 | va_end (ap); |
5bccf609 | 98 | } |
5bccf609 | 99 | weak_alias(__makecontext, makecontext) |