1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Helper functions for handling target threads/cpus 4 * 5 * Copyright (C) 2012, LG Electronics, Namhyung Kim <namhyung.kim@lge.com> 6 */ 7 8 #include "target.h" 9 10 #include <pwd.h> 11 #include <stdio.h> 12 #include <stdlib.h> 13 #include <string.h> 14 #include <linux/kernel.h> 15 #include <linux/string.h> 16 17 enum target_errno target__validate(struct target *target) 18 { 19 enum target_errno ret = TARGET_ERRNO__SUCCESS; 20 21 if (target->pid) 22 target->tid = target->pid; 23 24 /* CPU and PID are mutually exclusive */ 25 if (target->tid && target->cpu_list) { 26 target->cpu_list = NULL; 27 if (ret == TARGET_ERRNO__SUCCESS) 28 ret = TARGET_ERRNO__PID_OVERRIDE_CPU; 29 } 30 31 /* UID and PID are mutually exclusive */ 32 if (target->tid && target->uid_str) { 33 target->uid_str = NULL; 34 if (ret == TARGET_ERRNO__SUCCESS) 35 ret = TARGET_ERRNO__PID_OVERRIDE_UID; 36 } 37 38 /* UID and CPU are mutually exclusive */ 39 if (target->uid_str && target->cpu_list) { 40 target->cpu_list = NULL; 41 if (ret == TARGET_ERRNO__SUCCESS) 42 ret = TARGET_ERRNO__UID_OVERRIDE_CPU; 43 } 44 45 /* PID and SYSTEM are mutually exclusive */ 46 if (target->tid && target->system_wide) { 47 target->system_wide = false; 48 if (ret == TARGET_ERRNO__SUCCESS) 49 ret = TARGET_ERRNO__PID_OVERRIDE_SYSTEM; 50 } 51 52 /* UID and SYSTEM are mutually exclusive */ 53 if (target->uid_str && target->system_wide) { 54 target->system_wide = false; 55 if (ret == TARGET_ERRNO__SUCCESS) 56 ret = TARGET_ERRNO__UID_OVERRIDE_SYSTEM; 57 } 58 59 /* BPF and CPU are mutually exclusive */ 60 if (target->bpf_str && target->cpu_list) { 61 target->cpu_list = NULL; 62 if (ret == TARGET_ERRNO__SUCCESS) 63 ret = TARGET_ERRNO__BPF_OVERRIDE_CPU; 64 } 65 66 /* BPF and PID/TID are mutually exclusive */ 67 if (target->bpf_str && target->tid) { 68 target->tid = NULL; 69 if (ret == TARGET_ERRNO__SUCCESS) 70 ret = TARGET_ERRNO__BPF_OVERRIDE_PID; 71 } 72 73 /* BPF and UID are mutually exclusive */ 74 if (target->bpf_str && target->uid_str) { 75 target->uid_str = NULL; 76 if (ret == TARGET_ERRNO__SUCCESS) 77 ret = TARGET_ERRNO__BPF_OVERRIDE_UID; 78 } 79 80 /* BPF and THREADS are mutually exclusive */ 81 if (target->bpf_str && target->per_thread) { 82 target->per_thread = false; 83 if (ret == TARGET_ERRNO__SUCCESS) 84 ret = TARGET_ERRNO__BPF_OVERRIDE_THREAD; 85 } 86 87 /* THREAD and SYSTEM/CPU are mutually exclusive */ 88 if (target->per_thread && (target->system_wide || target->cpu_list)) { 89 target->per_thread = false; 90 if (ret == TARGET_ERRNO__SUCCESS) 91 ret = TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD; 92 } 93 94 return ret; 95 } 96 97 enum target_errno target__parse_uid(struct target *target) 98 { 99 struct passwd pwd, *result; 100 char buf[1024]; 101 const char *str = target->uid_str; 102 103 target->uid = UINT_MAX; 104 if (str == NULL) 105 return TARGET_ERRNO__SUCCESS; 106 107 /* Try user name first */ 108 getpwnam_r(str, &pwd, buf, sizeof(buf), &result); 109 110 if (result == NULL) { 111 /* 112 * The user name not found. Maybe it's a UID number. 113 */ 114 char *endptr; 115 int uid = strtol(str, &endptr, 10); 116 117 if (*endptr != '\0') 118 return TARGET_ERRNO__INVALID_UID; 119 120 getpwuid_r(uid, &pwd, buf, sizeof(buf), &result); 121 122 if (result == NULL) 123 return TARGET_ERRNO__USER_NOT_FOUND; 124 } 125 126 target->uid = result->pw_uid; 127 return TARGET_ERRNO__SUCCESS; 128 } 129 130 /* 131 * This must have a same ordering as the enum target_errno. 132 */ 133 static const char *target__error_str[] = { 134 "PID/TID switch overriding CPU", 135 "PID/TID switch overriding UID", 136 "UID switch overriding CPU", 137 "PID/TID switch overriding SYSTEM", 138 "UID switch overriding SYSTEM", 139 "SYSTEM/CPU switch overriding PER-THREAD", 140 "BPF switch overriding CPU", 141 "BPF switch overriding PID/TID", 142 "BPF switch overriding UID", 143 "BPF switch overriding THREAD", 144 "Invalid User: %s", 145 "Problems obtaining information for user %s", 146 }; 147 148 int target__strerror(struct target *target, int errnum, 149 char *buf, size_t buflen) 150 { 151 int idx; 152 const char *msg; 153 154 BUG_ON(buflen == 0); 155 156 if (errnum >= 0) { 157 str_error_r(errnum, buf, buflen); 158 return 0; 159 } 160 161 if (errnum < __TARGET_ERRNO__START || errnum >= __TARGET_ERRNO__END) 162 return -1; 163 164 idx = errnum - __TARGET_ERRNO__START; 165 msg = target__error_str[idx]; 166 167 switch (errnum) { 168 case TARGET_ERRNO__PID_OVERRIDE_CPU ... 169 TARGET_ERRNO__BPF_OVERRIDE_THREAD: 170 snprintf(buf, buflen, "%s", msg); 171 break; 172 173 case TARGET_ERRNO__INVALID_UID: 174 case TARGET_ERRNO__USER_NOT_FOUND: 175 snprintf(buf, buflen, msg, target->uid_str); 176 break; 177 178 default: 179 /* cannot reach here */ 180 break; 181 } 182 183 return 0; 184 } 185