Rename lttng_event_rule_userspace_probe to lttng_event_rule_kernel_uprobe
[lttng-tools.git] / src / common / defaults.c
1 /*
2 * Copyright (C) 2012 Simon Marchi <simon.marchi@polymtl.ca>
3 *
4 * SPDX-License-Identifier: GPL-2.0-only
5 *
6 */
7
8 #define _LGPL_SOURCE
9 #include <stddef.h>
10 #include <unistd.h>
11 #include <stdbool.h>
12 #include <sys/resource.h>
13 #include <pthread.h>
14
15 #include "defaults.h"
16 #include "macros.h"
17 #include "align.h"
18 #include "error.h"
19
20 static int pthread_attr_init_done;
21 static pthread_attr_t tattr;
22
23 LTTNG_HIDDEN
24 size_t default_get_channel_subbuf_size(void)
25 {
26 return max(_DEFAULT_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
27 }
28
29 LTTNG_HIDDEN
30 size_t default_get_metadata_subbuf_size(void)
31 {
32 return max(DEFAULT_METADATA_SUBBUF_SIZE, PAGE_SIZE);
33 }
34
35 LTTNG_HIDDEN
36 size_t default_get_kernel_channel_subbuf_size(void)
37 {
38 return max(DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
39 }
40
41 LTTNG_HIDDEN
42 size_t default_get_ust_pid_channel_subbuf_size(void)
43 {
44 return max(DEFAULT_UST_PID_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
45 }
46
47 LTTNG_HIDDEN
48 size_t default_get_ust_uid_channel_subbuf_size(void)
49 {
50 return max(DEFAULT_UST_UID_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
51 }
52
53 LTTNG_HIDDEN
54 pthread_attr_t *default_pthread_attr(void)
55 {
56 if (pthread_attr_init_done) {
57 return &tattr;
58 }
59
60 WARN("Uninitialized pthread attributes, using libc defaults.");
61 return NULL;
62 }
63
64 static void __attribute__((constructor)) init_default_pthread_attr(void)
65 {
66 int ret;
67 struct rlimit rlim;
68 size_t pthread_ss, system_ss, selected_ss;
69
70 ret = pthread_attr_init(&tattr);
71 if (ret) {
72 errno = ret;
73 PERROR("pthread_attr_init");
74 goto error;
75 }
76
77 /* Get system stack size limits. */
78 ret = getrlimit(RLIMIT_STACK, &rlim);
79 if (ret < 0) {
80 PERROR("getrlimit");
81 goto error_destroy;
82 }
83 DBG("Stack size limits: soft %lld, hard %lld bytes",
84 (long long) rlim.rlim_cur,
85 (long long) rlim.rlim_max);
86
87 /*
88 * getrlimit() may return a stack size of "-1", meaning "unlimited".
89 * In this case, we impose a known-good default minimum value which will
90 * override the libc's default stack size if it is smaller.
91 */
92 system_ss = rlim.rlim_cur != -1 ? rlim.rlim_cur :
93 DEFAULT_LTTNG_THREAD_STACK_SIZE;
94
95 /* Get pthread default thread stack size. */
96 ret = pthread_attr_getstacksize(&tattr, &pthread_ss);
97 if (ret < 0) {
98 PERROR("pthread_attr_getstacksize");
99 goto error_destroy;
100 }
101 DBG("Default pthread stack size is %zu bytes", pthread_ss);
102
103 selected_ss = max_t(size_t, pthread_ss, system_ss);
104 if (selected_ss < DEFAULT_LTTNG_THREAD_STACK_SIZE) {
105 DBG("Default stack size is too small, setting it to %zu bytes",
106 (size_t) DEFAULT_LTTNG_THREAD_STACK_SIZE);
107 selected_ss = DEFAULT_LTTNG_THREAD_STACK_SIZE;
108 }
109
110 if (rlim.rlim_max > 0 && selected_ss > rlim.rlim_max) {
111 WARN("Your system's stack size restrictions (%zu bytes) may be too low for the LTTng daemons to function properly, please set the stack size limit to at least %zu bytes to ensure reliable operation",
112 (size_t) rlim.rlim_max, (size_t) DEFAULT_LTTNG_THREAD_STACK_SIZE);
113 selected_ss = (size_t) rlim.rlim_max;
114 }
115
116 ret = pthread_attr_setstacksize(&tattr, selected_ss);
117 if (ret < 0) {
118 PERROR("pthread_attr_setstacksize");
119 goto error_destroy;
120 }
121 pthread_attr_init_done = 1;
122 error:
123 return;
124 error_destroy:
125 ret = pthread_attr_destroy(&tattr);
126 if (ret) {
127 errno = ret;
128 PERROR("pthread_attr_destroy");
129 }
130 }
131
132 static void __attribute__((destructor)) fini_default_pthread_attr(void)
133 {
134 int ret;
135
136 if (!pthread_attr_init_done) {
137 return;
138 }
139
140 ret = pthread_attr_destroy(&tattr);
141 if (ret) {
142 errno = ret;
143 PERROR("pthread_attr_destroy");
144 }
145 }
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