xref: /freebsd/lib/libc/aarch64/gen/getcontextx.c (revision 5202ca77aaf552310bcbaccba750ee9f0888d0d8)
1 /*
2  * Copyright (c) 2011 Konstantin Belousov <kib@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/ucontext.h>
29 #include <errno.h>
30 #include <stdlib.h>
31 
32 int
__getcontextx_size(void)33 __getcontextx_size(void)
34 {
35 	size_t size;
36 
37 	size = sizeof(ucontext_t);
38 	size += sizeof(struct arm64_reg_context); /* Space for ARM64_CTX_END */
39 
40 	return (size);
41 }
42 
43 int
__fillcontextx2(char * ctx)44 __fillcontextx2(char *ctx)
45 {
46 	struct arm64_reg_context *reg_ctx;
47 	ucontext_t *ucp;
48 
49 	ucp = (ucontext_t *)ctx;
50 	ucp->uc_mcontext.mc_ptr = (uint64_t)(ucp + 1);
51 
52 	reg_ctx = (struct arm64_reg_context *)ucp->uc_mcontext.mc_ptr;
53 	reg_ctx->ctx_id = ARM64_CTX_END;
54 	reg_ctx->ctx_size = sizeof(struct arm64_reg_context);
55 
56 	return (0);
57 }
58 
59 int
__fillcontextx(char * ctx)60 __fillcontextx(char *ctx)
61 {
62 	ucontext_t *ucp;
63 
64 	ucp = (ucontext_t *)ctx;
65 	if (getcontext(ucp) == -1)
66 		return (-1);
67 	__fillcontextx2(ctx);
68 	return (0);
69 }
70 
71 __weak_reference(__getcontextx, getcontextx);
72 
73 ucontext_t *
__getcontextx(void)74 __getcontextx(void)
75 {
76 	char *ctx;
77 	int error;
78 
79 	ctx = malloc(__getcontextx_size());
80 	if (ctx == NULL)
81 		return (NULL);
82 	if (__fillcontextx(ctx) == -1) {
83 		error = errno;
84 		free(ctx);
85 		errno = error;
86 		return (NULL);
87 	}
88 	return ((ucontext_t *)ctx);
89 }
90