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1 /*
2  * Helper functions for handling target threads/cpus
3  *
4  * Copyright (C) 2012, LG Electronics, Namhyung Kim <namhyung.kim@lge.com>
5  *
6  * Released under the GPL v2.
7  */
8 
9 #include "target.h"
10 #include "debug.h"
11 
12 #include <pwd.h>
13 #include <string.h>
14 
15 
perf_target__validate(struct perf_target * target)16 enum perf_target_errno perf_target__validate(struct perf_target *target)
17 {
18 	enum perf_target_errno ret = PERF_ERRNO_TARGET__SUCCESS;
19 
20 	if (target->pid)
21 		target->tid = target->pid;
22 
23 	/* CPU and PID are mutually exclusive */
24 	if (target->tid && target->cpu_list) {
25 		target->cpu_list = NULL;
26 		if (ret == PERF_ERRNO_TARGET__SUCCESS)
27 			ret = PERF_ERRNO_TARGET__PID_OVERRIDE_CPU;
28 	}
29 
30 	/* UID and PID are mutually exclusive */
31 	if (target->tid && target->uid_str) {
32 		target->uid_str = NULL;
33 		if (ret == PERF_ERRNO_TARGET__SUCCESS)
34 			ret = PERF_ERRNO_TARGET__PID_OVERRIDE_UID;
35 	}
36 
37 	/* UID and CPU are mutually exclusive */
38 	if (target->uid_str && target->cpu_list) {
39 		target->cpu_list = NULL;
40 		if (ret == PERF_ERRNO_TARGET__SUCCESS)
41 			ret = PERF_ERRNO_TARGET__UID_OVERRIDE_CPU;
42 	}
43 
44 	/* PID and SYSTEM are mutually exclusive */
45 	if (target->tid && target->system_wide) {
46 		target->system_wide = false;
47 		if (ret == PERF_ERRNO_TARGET__SUCCESS)
48 			ret = PERF_ERRNO_TARGET__PID_OVERRIDE_SYSTEM;
49 	}
50 
51 	/* UID and SYSTEM are mutually exclusive */
52 	if (target->uid_str && target->system_wide) {
53 		target->system_wide = false;
54 		if (ret == PERF_ERRNO_TARGET__SUCCESS)
55 			ret = PERF_ERRNO_TARGET__UID_OVERRIDE_SYSTEM;
56 	}
57 
58 	return ret;
59 }
60 
perf_target__parse_uid(struct perf_target * target)61 enum perf_target_errno perf_target__parse_uid(struct perf_target *target)
62 {
63 	struct passwd pwd, *result;
64 	char buf[1024];
65 	const char *str = target->uid_str;
66 
67 	target->uid = UINT_MAX;
68 	if (str == NULL)
69 		return PERF_ERRNO_TARGET__SUCCESS;
70 
71 	/* Try user name first */
72 	getpwnam_r(str, &pwd, buf, sizeof(buf), &result);
73 
74 	if (result == NULL) {
75 		/*
76 		 * The user name not found. Maybe it's a UID number.
77 		 */
78 		char *endptr;
79 		int uid = strtol(str, &endptr, 10);
80 
81 		if (*endptr != '\0')
82 			return PERF_ERRNO_TARGET__INVALID_UID;
83 
84 		getpwuid_r(uid, &pwd, buf, sizeof(buf), &result);
85 
86 		if (result == NULL)
87 			return PERF_ERRNO_TARGET__USER_NOT_FOUND;
88 	}
89 
90 	target->uid = result->pw_uid;
91 	return PERF_ERRNO_TARGET__SUCCESS;
92 }
93 
94 /*
95  * This must have a same ordering as the enum perf_target_errno.
96  */
97 static const char *perf_target__error_str[] = {
98 	"PID/TID switch overriding CPU",
99 	"PID/TID switch overriding UID",
100 	"UID switch overriding CPU",
101 	"PID/TID switch overriding SYSTEM",
102 	"UID switch overriding SYSTEM",
103 	"Invalid User: %s",
104 	"Problems obtaining information for user %s",
105 };
106 
perf_target__strerror(struct perf_target * target,int errnum,char * buf,size_t buflen)107 int perf_target__strerror(struct perf_target *target, int errnum,
108 			  char *buf, size_t buflen)
109 {
110 	int idx;
111 	const char *msg;
112 
113 	BUG_ON(buflen == 0);
114 
115 	if (errnum >= 0) {
116 		const char *err = strerror_r(errnum, buf, buflen);
117 
118 		if (err != buf) {
119 			size_t len = strlen(err);
120 			memcpy(buf, err, min(buflen - 1, len));
121 			*(buf + min(buflen - 1, len)) = '\0';
122 		}
123 
124 		return 0;
125 	}
126 
127 	if (errnum <  __PERF_ERRNO_TARGET__START ||
128 	    errnum >= __PERF_ERRNO_TARGET__END)
129 		return -1;
130 
131 	idx = errnum - __PERF_ERRNO_TARGET__START;
132 	msg = perf_target__error_str[idx];
133 
134 	switch (errnum) {
135 	case PERF_ERRNO_TARGET__PID_OVERRIDE_CPU
136 	 ... PERF_ERRNO_TARGET__UID_OVERRIDE_SYSTEM:
137 		snprintf(buf, buflen, "%s", msg);
138 		break;
139 
140 	case PERF_ERRNO_TARGET__INVALID_UID:
141 	case PERF_ERRNO_TARGET__USER_NOT_FOUND:
142 		snprintf(buf, buflen, msg, target->uid_str);
143 		break;
144 
145 	default:
146 		/* cannot reach here */
147 		break;
148 	}
149 
150 	return 0;
151 }
152