Move to kernel style SPDX license identifiers

[lttng-ust.git] / liblttng-ust / compat.h

diff --git a/liblttng-ust/compat.h b/liblttng-ust/compat.h
index 7d1ee590326fd1b9616569420b32846d4e458f7f..200d9771f85462b91ceabb7b5404254787e25fb9 100644 (file)
--- a/liblttng-ust/compat.h
+++ b/liblttng-ust/compat.h
@@ -1,31 +1,19 @@
-#ifndef _UST_COMPAT_H
-#define _UST_COMPAT_H
-
 /*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  * Copyright (C) 2016 Raphaël Beamonte <raphael.beamonte@gmail.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * Copyright (C) 2020 Michael Jeanson <mjeanson@efficios.com>
  */
 
+#ifndef _UST_COMPAT_H
+#define _UST_COMPAT_H
+
 #include <pthread.h>
+#include <errno.h>
+#include <string.h>
 
-/*
- * Limit imposed by Linux UST-sessiond ABI.
- */
-#define LTTNG_UST_PROCNAME_LEN 17
+#include <lttng/ust-abi.h>
 
 #define LTTNG_UST_PROCNAME_SUFFIX "-ust"
 
@@ -34,57 +22,99 @@
 static inline
 int lttng_pthread_setname_np(const char *name)
 {
-        return pthread_setname_np(pthread_self(), name);
+       /*
+        * Some implementations don't error out, replicate this behavior for
+        * consistency.
+        */
+       if (strnlen(name, LTTNG_UST_ABI_PROCNAME_LEN) >= LTTNG_UST_ABI_PROCNAME_LEN) {
+               return ERANGE;
+       }
+
+       return pthread_setname_np(pthread_self(), name);
 }
 
 static inline
 int lttng_pthread_getname_np(char *name, size_t len)
 {
-        return pthread_getname_np(pthread_self(), name, len);
+       return pthread_getname_np(pthread_self(), name, len);
 }
 #elif defined(HAVE_PTHREAD_SETNAME_NP_WITHOUT_TID)
 static inline
 int lttng_pthread_setname_np(const char *name)
 {
-        return pthread_setname_np(name);
+       return pthread_setname_np(name);
 }
 
 static inline
 int lttng_pthread_getname_np(char *name, size_t len)
 {
-        return pthread_getname_np(name, len);
+       return pthread_getname_np(name, len);
 }
-#else
-/*
- * For platforms without thread name support, do nothing.
- */
+#elif defined(HAVE_PTHREAD_SET_NAME_NP_WITH_TID)
+
+#include <pthread_np.h>
 static inline
 int lttng_pthread_setname_np(const char *name)
 {
-        return -ENOSYS;
+       /* Replicate pthread_setname_np's behavior */
+       if (strnlen(name, LTTNG_UST_ABI_PROCNAME_LEN) >= LTTNG_UST_ABI_PROCNAME_LEN) {
+               return ERANGE;
+       }
+
+       pthread_set_name_np(pthread_self(), name);
+       return 0;
 }
 
 static inline
 int lttng_pthread_getname_np(char *name, size_t len)
 {
-        return -ENOSYS;
+       pthread_get_name_np(pthread_self(), name, len);
+       return 0;
 }
-#endif
+#elif defined(__linux__)
+
+/* Fallback on prtctl on Linux */
+#include <sys/prctl.h>
 
 static inline
-void lttng_ust_getprocname(char *name)
+int lttng_pthread_setname_np(const char *name)
 {
-       lttng_pthread_getname_np(name, LTTNG_UST_PROCNAME_LEN);
+       /* Replicate pthread_setname_np's behavior */
+       if (strnlen(name, LTTNG_UST_ABI_PROCNAME_LEN) >= LTTNG_UST_ABI_PROCNAME_LEN) {
+               return ERANGE;
+       }
+       return prctl(PR_SET_NAME, name, 0, 0, 0);
 }
 
+static inline
+int lttng_pthread_getname_np(char *name, size_t len)
+{
+       return prctl(PR_GET_NAME, name, 0, 0, 0);
+}
+
+#else
+#error "Please add pthread name support for your OS."
+#endif
+
+/*
+ * If a pthread setname/set_name function is available, declare
+ * the setustprocname() function that will add '-ust' to the end
+ * of the current process name, while truncating it if needed.
+ */
 static inline
 int lttng_ust_setustprocname(void)
 {
        int ret = 0, len;
-       char name[LTTNG_UST_PROCNAME_LEN];
-       int limit = LTTNG_UST_PROCNAME_LEN - strlen(LTTNG_UST_PROCNAME_SUFFIX) - 1;
-
-       lttng_pthread_getname_np(name, LTTNG_UST_PROCNAME_LEN);
+       char name[LTTNG_UST_ABI_PROCNAME_LEN];
+       int limit = LTTNG_UST_ABI_PROCNAME_LEN - strlen(LTTNG_UST_PROCNAME_SUFFIX) - 1;
+
+       /*
+        * Get the current thread name.
+        */
+       ret = lttng_pthread_getname_np(name, LTTNG_UST_ABI_PROCNAME_LEN);
+       if (ret) {
+               goto error;
+       }
 
        len = strlen(name);
        if (len > limit) {
@@ -102,7 +132,6 @@ error:
        return ret;
 }
 
-
 #include <errno.h>
 
 #ifndef ENODATA