1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2015-2019 ARM Limited.
4 * Original author: Dave Martin <Dave.Martin@arm.com>
5 */
6 #define _GNU_SOURCE
7 #include <assert.h>
8 #include <errno.h>
9 #include <limits.h>
10 #include <stddef.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <getopt.h>
15 #include <unistd.h>
16 #include <sys/auxv.h>
17 #include <sys/prctl.h>
18 #include <asm/hwcap.h>
19 #include <asm/sigcontext.h>
20
21 static int inherit = 0;
22 static int no_inherit = 0;
23 static int force = 0;
24 static unsigned long vl;
25 static int set_ctl = PR_SVE_SET_VL;
26 static int get_ctl = PR_SVE_GET_VL;
27
28 static const struct option options[] = {
29 { "force", no_argument, NULL, 'f' },
30 { "inherit", no_argument, NULL, 'i' },
31 { "max", no_argument, NULL, 'M' },
32 { "no-inherit", no_argument, &no_inherit, 1 },
33 { "sme", no_argument, NULL, 's' },
34 { "help", no_argument, NULL, '?' },
35 {}
36 };
37
38 static char const *program_name;
39
parse_options(int argc,char ** argv)40 static int parse_options(int argc, char **argv)
41 {
42 int c;
43 char *rest;
44
45 program_name = strrchr(argv[0], '/');
46 if (program_name)
47 ++program_name;
48 else
49 program_name = argv[0];
50
51 while ((c = getopt_long(argc, argv, "Mfhi", options, NULL)) != -1)
52 switch (c) {
53 case 'M': vl = SVE_VL_MAX; break;
54 case 'f': force = 1; break;
55 case 'i': inherit = 1; break;
56 case 's': set_ctl = PR_SME_SET_VL;
57 get_ctl = PR_SME_GET_VL;
58 break;
59 case 0: break;
60 default: goto error;
61 }
62
63 if (inherit && no_inherit)
64 goto error;
65
66 if (!vl) {
67 /* vector length */
68 if (optind >= argc)
69 goto error;
70
71 errno = 0;
72 vl = strtoul(argv[optind], &rest, 0);
73 if (*rest) {
74 vl = ULONG_MAX;
75 errno = EINVAL;
76 }
77 if (vl == ULONG_MAX && errno) {
78 fprintf(stderr, "%s: %s: %s\n",
79 program_name, argv[optind], strerror(errno));
80 goto error;
81 }
82
83 ++optind;
84 }
85
86 /* command */
87 if (optind >= argc)
88 goto error;
89
90 return 0;
91
92 error:
93 fprintf(stderr,
94 "Usage: %s [-f | --force] "
95 "[-i | --inherit | --no-inherit] "
96 "{-M | --max | <vector length>} "
97 "<command> [<arguments> ...]\n",
98 program_name);
99 return -1;
100 }
101
main(int argc,char ** argv)102 int main(int argc, char **argv)
103 {
104 int ret = 126; /* same as sh(1) command-not-executable error */
105 long flags;
106 char *path;
107 int t, e;
108
109 if (parse_options(argc, argv))
110 return 2; /* same as sh(1) builtin incorrect-usage */
111
112 if (vl & ~(vl & PR_SVE_VL_LEN_MASK)) {
113 fprintf(stderr, "%s: Invalid vector length %lu\n",
114 program_name, vl);
115 return 2; /* same as sh(1) builtin incorrect-usage */
116 }
117
118 if (!(getauxval(AT_HWCAP) & HWCAP_SVE)) {
119 fprintf(stderr, "%s: Scalable Vector Extension not present\n",
120 program_name);
121
122 if (!force)
123 goto error;
124
125 fputs("Going ahead anyway (--force): "
126 "This is a debug option. Don't rely on it.\n",
127 stderr);
128 }
129
130 flags = PR_SVE_SET_VL_ONEXEC;
131 if (inherit)
132 flags |= PR_SVE_VL_INHERIT;
133
134 t = prctl(set_ctl, vl | flags);
135 if (t < 0) {
136 fprintf(stderr, "%s: PR_SVE_SET_VL: %s\n",
137 program_name, strerror(errno));
138 goto error;
139 }
140
141 t = prctl(get_ctl);
142 if (t == -1) {
143 fprintf(stderr, "%s: PR_SVE_GET_VL: %s\n",
144 program_name, strerror(errno));
145 goto error;
146 }
147 flags = PR_SVE_VL_LEN_MASK;
148 flags = t & ~flags;
149
150 assert(optind < argc);
151 path = argv[optind];
152
153 execvp(path, &argv[optind]);
154 e = errno;
155 if (errno == ENOENT)
156 ret = 127; /* same as sh(1) not-found error */
157 fprintf(stderr, "%s: %s: %s\n", program_name, path, strerror(e));
158
159 error:
160 return ret; /* same as sh(1) not-executable error */
161 }
162