Add mkdirat utils and runas wrappers

[lttng-tools.git] / src / common / defaults.c

diff --git a/src/common/defaults.c b/src/common/defaults.c
index e670eeb0ffbb1b74819916dd7e58ad8cb3001e61..874578183ede2f9ad73c89627c7591f78fb3eba8 100644 (file)
--- a/src/common/defaults.c
+++ b/src/common/defaults.c
@@ -18,36 +18,138 @@
 #define _LGPL_SOURCE
 #include <stddef.h>
 #include <unistd.h>
+#include <stdbool.h>
+#include <sys/resource.h>
+#include <pthread.h>
 
 #include "defaults.h"
 #include "macros.h"
+#include "align.h"
+#include "error.h"
 
-size_t default_channel_subbuf_size;
-size_t default_metadata_subbuf_size;
-size_t default_kernel_channel_subbuf_size;
-size_t default_ust_pid_channel_subbuf_size;
-size_t default_ust_uid_channel_subbuf_size;
+static int pthread_attr_init_done;
+static pthread_attr_t tattr;
 
-static void __attribute__((constructor)) init_defaults(void)
+LTTNG_HIDDEN
+size_t default_get_channel_subbuf_size(void)
 {
+       return max(_DEFAULT_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+size_t default_get_metadata_subbuf_size(void)
+{
+       return max(DEFAULT_METADATA_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+size_t default_get_kernel_channel_subbuf_size(void)
+{
+       return max(DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+size_t default_get_ust_pid_channel_subbuf_size(void)
+{
+       return max(DEFAULT_UST_PID_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+size_t default_get_ust_uid_channel_subbuf_size(void)
+{
+       return max(DEFAULT_UST_UID_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+pthread_attr_t *default_pthread_attr(void)
+{
+       if (pthread_attr_init_done) {
+               return &tattr;
+       }
+
+       WARN("Uninitialized pthread attributes, using libc defaults.");
+       return NULL;
+}
+
+static void __attribute__((constructor)) init_default_pthread_attr(void)
+{
+       int ret;
+       struct rlimit rlim;
+       size_t pthread_ss, system_ss, selected_ss;
+
+       ret = pthread_attr_init(&tattr);
+       if (ret) {
+               errno = ret;
+               PERROR("pthread_attr_init");
+               goto error;
+       }
+
+       /* Get system stack size limits. */
+       ret = getrlimit(RLIMIT_STACK, &rlim);
+       if (ret < 0) {
+               PERROR("getrlimit");
+               goto error_destroy;
+       }
+       DBG("Stack size limits: soft %lld, hard %lld bytes",
+                       (long long) rlim.rlim_cur,
+                       (long long) rlim.rlim_max);
+
        /*
-        * The libringbuffer won't accept subbuf sizes smaller than the page size.
-        * If the default subbuf size is smaller, replace it by the page size.
+        * getrlimit() may return a stack size of "-1", meaning "unlimited".
+        * In this case, we impose a known-good default minimum value which will
+        * override the libc's default stack size if it is smaller.
         */
-       long page_size = sysconf(_SC_PAGESIZE);
-
-       if (page_size < 0) {
-               page_size = 0;
-       }
-
-       default_channel_subbuf_size =
-               max(_DEFAULT_CHANNEL_SUBBUF_SIZE, page_size);
-       default_metadata_subbuf_size =
-               max(DEFAULT_METADATA_SUBBUF_SIZE, page_size);
-       default_kernel_channel_subbuf_size =
-               max(DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE, page_size);
-       default_ust_pid_channel_subbuf_size =
-               max(DEFAULT_UST_PID_CHANNEL_SUBBUF_SIZE, page_size);
-       default_ust_uid_channel_subbuf_size =
-               max(DEFAULT_UST_UID_CHANNEL_SUBBUF_SIZE, page_size);
+       system_ss = rlim.rlim_cur != -1 ? rlim.rlim_cur :
+                       DEFAULT_LTTNG_THREAD_STACK_SIZE;
+
+       /* Get pthread default thread stack size. */
+       ret = pthread_attr_getstacksize(&tattr, &pthread_ss);
+       if (ret < 0) {
+               PERROR("pthread_attr_getstacksize");
+               goto error_destroy;
+       }
+       DBG("Default pthread stack size is %zu bytes", pthread_ss);
+
+       selected_ss = max_t(size_t, pthread_ss, system_ss);
+       if (selected_ss < DEFAULT_LTTNG_THREAD_STACK_SIZE) {
+               DBG("Default stack size is too small, setting it to %zu bytes",
+                       (size_t) DEFAULT_LTTNG_THREAD_STACK_SIZE);
+               selected_ss = DEFAULT_LTTNG_THREAD_STACK_SIZE;
+       }
+
+       if (rlim.rlim_max > 0 && selected_ss > rlim.rlim_max) {
+               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",
+                       (size_t) rlim.rlim_max, (size_t) DEFAULT_LTTNG_THREAD_STACK_SIZE);
+               selected_ss = (size_t) rlim.rlim_max;
+       }
+
+       ret = pthread_attr_setstacksize(&tattr, selected_ss);
+       if (ret < 0) {
+               PERROR("pthread_attr_setstacksize");
+               goto error_destroy;
+       }
+       pthread_attr_init_done = 1;
+error:
+       return;
+error_destroy:
+       ret = pthread_attr_destroy(&tattr);
+       if (ret) {
+               errno = ret;
+               PERROR("pthread_attr_destroy");
+       }
+}
+
+static void __attribute__((destructor)) fini_default_pthread_attr(void)
+{
+       int ret;
+
+       if (!pthread_attr_init_done) {
+               return;
+       }
+
+       ret = pthread_attr_destroy(&tattr);
+       if (ret) {
+               errno = ret;
+               PERROR("pthread_attr_destroy");
+       }
 }