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
target__validate(struct target * target)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 /* THREAD and SYSTEM/CPU are mutually exclusive */
60 if (target->per_thread && (target->system_wide || target->cpu_list)) {
61 target->per_thread = false;
62 if (ret == TARGET_ERRNO__SUCCESS)
63 ret = TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD;
64 }
65
66 return ret;
67 }
68
target__parse_uid(struct target * target)69 enum target_errno target__parse_uid(struct target *target)
70 {
71 struct passwd pwd, *result;
72 char buf[1024];
73 const char *str = target->uid_str;
74
75 target->uid = UINT_MAX;
76 if (str == NULL)
77 return TARGET_ERRNO__SUCCESS;
78
79 /* Try user name first */
80 getpwnam_r(str, &pwd, buf, sizeof(buf), &result);
81
82 if (result == NULL) {
83 /*
84 * The user name not found. Maybe it's a UID number.
85 */
86 char *endptr;
87 int uid = strtol(str, &endptr, 10);
88
89 if (*endptr != '\0')
90 return TARGET_ERRNO__INVALID_UID;
91
92 getpwuid_r(uid, &pwd, buf, sizeof(buf), &result);
93
94 if (result == NULL)
95 return TARGET_ERRNO__USER_NOT_FOUND;
96 }
97
98 target->uid = result->pw_uid;
99 return TARGET_ERRNO__SUCCESS;
100 }
101
102 /*
103 * This must have a same ordering as the enum target_errno.
104 */
105 static const char *target__error_str[] = {
106 "PID/TID switch overriding CPU",
107 "PID/TID switch overriding UID",
108 "UID switch overriding CPU",
109 "PID/TID switch overriding SYSTEM",
110 "UID switch overriding SYSTEM",
111 "SYSTEM/CPU switch overriding PER-THREAD",
112 "Invalid User: %s",
113 "Problems obtaining information for user %s",
114 };
115
target__strerror(struct target * target,int errnum,char * buf,size_t buflen)116 int target__strerror(struct target *target, int errnum,
117 char *buf, size_t buflen)
118 {
119 int idx;
120 const char *msg;
121
122 BUG_ON(buflen == 0);
123
124 if (errnum >= 0) {
125 str_error_r(errnum, buf, buflen);
126 return 0;
127 }
128
129 if (errnum < __TARGET_ERRNO__START || errnum >= __TARGET_ERRNO__END)
130 return -1;
131
132 idx = errnum - __TARGET_ERRNO__START;
133 msg = target__error_str[idx];
134
135 switch (errnum) {
136 case TARGET_ERRNO__PID_OVERRIDE_CPU ...
137 TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD:
138 snprintf(buf, buflen, "%s", msg);
139 break;
140
141 case TARGET_ERRNO__INVALID_UID:
142 case TARGET_ERRNO__USER_NOT_FOUND:
143 snprintf(buf, buflen, msg, target->uid_str);
144 break;
145
146 default:
147 /* cannot reach here */
148 break;
149 }
150
151 return 0;
152 }
153