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 26 static const struct option options[] = { 27 { "force", no_argument, NULL, 'f' }, 28 { "inherit", no_argument, NULL, 'i' }, 29 { "max", no_argument, NULL, 'M' }, 30 { "no-inherit", no_argument, &no_inherit, 1 }, 31 { "help", no_argument, NULL, '?' }, 32 {} 33 }; 34 35 static char const *program_name; 36 37 static int parse_options(int argc, char **argv) 38 { 39 int c; 40 char *rest; 41 42 program_name = strrchr(argv[0], '/'); 43 if (program_name) 44 ++program_name; 45 else 46 program_name = argv[0]; 47 48 while ((c = getopt_long(argc, argv, "Mfhi", options, NULL)) != -1) 49 switch (c) { 50 case 'M': vl = SVE_VL_MAX; break; 51 case 'f': force = 1; break; 52 case 'i': inherit = 1; break; 53 case 0: break; 54 default: goto error; 55 } 56 57 if (inherit && no_inherit) 58 goto error; 59 60 if (!vl) { 61 /* vector length */ 62 if (optind >= argc) 63 goto error; 64 65 errno = 0; 66 vl = strtoul(argv[optind], &rest, 0); 67 if (*rest) { 68 vl = ULONG_MAX; 69 errno = EINVAL; 70 } 71 if (vl == ULONG_MAX && errno) { 72 fprintf(stderr, "%s: %s: %s\n", 73 program_name, argv[optind], strerror(errno)); 74 goto error; 75 } 76 77 ++optind; 78 } 79 80 /* command */ 81 if (optind >= argc) 82 goto error; 83 84 return 0; 85 86 error: 87 fprintf(stderr, 88 "Usage: %s [-f | --force] " 89 "[-i | --inherit | --no-inherit] " 90 "{-M | --max | <vector length>} " 91 "<command> [<arguments> ...]\n", 92 program_name); 93 return -1; 94 } 95 96 int main(int argc, char **argv) 97 { 98 int ret = 126; /* same as sh(1) command-not-executable error */ 99 long flags; 100 char *path; 101 int t, e; 102 103 if (parse_options(argc, argv)) 104 return 2; /* same as sh(1) builtin incorrect-usage */ 105 106 if (vl & ~(vl & PR_SVE_VL_LEN_MASK)) { 107 fprintf(stderr, "%s: Invalid vector length %lu\n", 108 program_name, vl); 109 return 2; /* same as sh(1) builtin incorrect-usage */ 110 } 111 112 if (!(getauxval(AT_HWCAP) & HWCAP_SVE)) { 113 fprintf(stderr, "%s: Scalable Vector Extension not present\n", 114 program_name); 115 116 if (!force) 117 goto error; 118 119 fputs("Going ahead anyway (--force): " 120 "This is a debug option. Don't rely on it.\n", 121 stderr); 122 } 123 124 flags = PR_SVE_SET_VL_ONEXEC; 125 if (inherit) 126 flags |= PR_SVE_VL_INHERIT; 127 128 t = prctl(PR_SVE_SET_VL, vl | flags); 129 if (t < 0) { 130 fprintf(stderr, "%s: PR_SVE_SET_VL: %s\n", 131 program_name, strerror(errno)); 132 goto error; 133 } 134 135 t = prctl(PR_SVE_GET_VL); 136 if (t == -1) { 137 fprintf(stderr, "%s: PR_SVE_GET_VL: %s\n", 138 program_name, strerror(errno)); 139 goto error; 140 } 141 flags = PR_SVE_VL_LEN_MASK; 142 flags = t & ~flags; 143 144 assert(optind < argc); 145 path = argv[optind]; 146 147 execvp(path, &argv[optind]); 148 e = errno; 149 if (errno == ENOENT) 150 ret = 127; /* same as sh(1) not-found error */ 151 fprintf(stderr, "%s: %s: %s\n", program_name, path, strerror(e)); 152 153 error: 154 return ret; /* same as sh(1) not-executable error */ 155 } 156