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 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 } 101 102 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