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142 lines · 3.1 KiB

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 <[email protected]>
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
17enum 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 /* PID and SYSTEM are mutually exclusive */
32 if (target->tid && target->system_wide) {
33 target->system_wide = false;
34 if (ret == TARGET_ERRNO__SUCCESS)
35 ret = TARGET_ERRNO__PID_OVERRIDE_SYSTEM;
36 }
37
38 /* BPF and CPU are mutually exclusive */
39 if (target->bpf_str && target->cpu_list) {
40 target->cpu_list = NULL;
41 if (ret == TARGET_ERRNO__SUCCESS)
42 ret = TARGET_ERRNO__BPF_OVERRIDE_CPU;
43 }
44
45 /* BPF and PID/TID are mutually exclusive */
46 if (target->bpf_str && target->tid) {
47 target->tid = NULL;
48 if (ret == TARGET_ERRNO__SUCCESS)
49 ret = TARGET_ERRNO__BPF_OVERRIDE_PID;
50 }
51
52 /* BPF and THREADS are mutually exclusive */
53 if (target->bpf_str && target->per_thread) {
54 target->per_thread = false;
55 if (ret == TARGET_ERRNO__SUCCESS)
56 ret = TARGET_ERRNO__BPF_OVERRIDE_THREAD;
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
69uid_t parse_uid(const char *str)
70{
71 struct passwd pwd, *result;
72 char buf[1024];
73
74 if (str == NULL)
75 return UINT_MAX;
76
77 /* Try user name first */
78 getpwnam_r(str, &pwd, buf, sizeof(buf), &result);
79
80 if (result == NULL) {
81 /*
82 * The user name not found. Maybe it's a UID number.
83 */
84 char *endptr;
85 int uid = strtol(str, &endptr, 10);
86
87 if (*endptr != '\0')
88 return UINT_MAX;
89
90 getpwuid_r(uid, &pwd, buf, sizeof(buf), &result);
91
92 if (result == NULL)
93 return UINT_MAX;
94 }
95
96 return result->pw_uid;
97}
98
99/*
100 * This must have a same ordering as the enum target_errno.
101 */
102static const char *target__error_str[] = {
103 "PID/TID switch overriding CPU",
104 "PID/TID switch overriding SYSTEM",
105 "SYSTEM/CPU switch overriding PER-THREAD",
106 "BPF switch overriding CPU",
107 "BPF switch overriding PID/TID",
108 "BPF switch overriding THREAD",
109};
110
111int target__strerror(struct target *target __maybe_unused, int errnum,
112 char *buf, size_t buflen)
113{
114 int idx;
115 const char *msg;
116
117 BUG_ON(buflen == 0);
118
119 if (errnum >= 0) {
120 str_error_r(errnum, buf, buflen);
121 return 0;
122 }
123
124 if (errnum < __TARGET_ERRNO__START || errnum >= __TARGET_ERRNO__END)
125 return -1;
126
127 idx = errnum - __TARGET_ERRNO__START;
128 msg = target__error_str[idx];
129
130 switch (errnum) {
131 case TARGET_ERRNO__PID_OVERRIDE_CPU ...
132 TARGET_ERRNO__BPF_OVERRIDE_THREAD:
133 snprintf(buf, buflen, "%s", msg);
134 break;
135
136 default:
137 /* cannot reach here */
138 break;
139 }
140
141 return 0;
142}