xref: /kernel/linux/linux-5.10/tools/perf/util/target.c (revision 8c2ecf20)
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
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	/* 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
69enum 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 */
105static 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
116int 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