162 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2015-2019 ARM Limited.4 * Original author: Dave Martin <Dave.Martin@arm.com>5 */6#define _GNU_SOURCE7#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 21static int inherit = 0;22static int no_inherit = 0;23static int force = 0;24static unsigned long vl;25static int set_ctl = PR_SVE_SET_VL;26static int get_ctl = PR_SVE_GET_VL;27 28static 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 38static char const *program_name;39 40static 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 else49 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 92error: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 102int 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 159error:160 return ret; /* same as sh(1) not-executable error */161}162