Fix: memory corruption in compat.h

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

diff --git a/liblttng-ust/compat.h b/liblttng-ust/compat.h
index 19d4da828b67cc793b056a46933d3b332c74b870..cd83b46ba8e4000dc901f2e5adddca8debf59977 100644 (file)
--- a/liblttng-ust/compat.h
+++ b/liblttng-ust/compat.h
@@ -3,6 +3,7 @@
 
 /*
  * 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
@@ -19,17 +20,117 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include <sys/syscall.h>
+/*
+ * lttng_ust_getprocname.
+ */
+#ifdef __linux__
+
+#include <sys/prctl.h>
+
+#define LTTNG_UST_PROCNAME_LEN 17
+
+static inline
+void lttng_ust_getprocname(char *name)
+{
+       (void) prctl(PR_GET_NAME, (unsigned long) name, 0, 0, 0);
+}
+
+/*
+ * If pthread_setname_np is available.
+ */
+#ifdef HAVE_PTHREAD_SETNAME_NP
+static inline
+int lttng_pthread_setname_np(pthread_t thread, const char *name)
+{
+       return pthread_setname_np(thread, name);
+}
+#endif
+
+#elif defined(__FreeBSD__)
+
+#include <stdlib.h>
+#include <string.h>
+
+/*
+ * Limit imposed by Linux UST-sessiond ABI.
+ */
+#define LTTNG_UST_PROCNAME_LEN 17
 
-#ifdef __UCLIBC__
-#define __getcpu(cpu, node, cache)     syscall(__NR_getcpu, cpu, node, cache)
+/*
+ * Acts like linux prctl, the string is not necessarily 0-terminated if
+ * 16-byte long.
+ */
 static inline
-int sched_getcpu(void)
+void lttng_ust_getprocname(char *name)
 {
-       int c, s;
+       const char *bsd_name;
 
-       s = __getcpu(&c, NULL, NULL);
-       return (s == -1) ? s : c;
+       bsd_name = getprogname();
+       if (!bsd_name)
+               name[0] = '\0';
+       else
+               strncpy(name, bsd_name, LTTNG_UST_PROCNAME_LEN - 1);
 }
-#endif /* __UCLIBC__ */
+
+/*
+ * If pthread_set_name_np is available.
+ */
+#ifdef HAVE_PTHREAD_SET_NAME_NP
+static inline
+int lttng_pthread_setname_np(pthread_t thread, const char *name)
+{
+       return pthread_set_name_np(thread, name);
+}
+#endif
+
+#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.
+ */
+#if defined(HAVE_PTHREAD_SETNAME_NP) || defined(HAVE_PTHREAD_SETNAME_NP)
+#define LTTNG_UST_PROCNAME_SUFFIX "-ust"
+
+#include <pthread.h>
+
+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_ust_getprocname(name);
+
+       len = strlen(name);
+       if (len > limit) {
+               len = limit;
+       }
+
+       ret = sprintf(name + len, LTTNG_UST_PROCNAME_SUFFIX);
+       if (ret) {
+               goto error;
+       }
+
+       ret = lttng_pthread_setname_np(pthread_self(), name);
+
+error:
+       return ret;
+}
+#else
+static inline
+int lttng_ust_setustprocname(void)
+{
+       return 0;
+}
+#endif
+
+#include <errno.h>
+
+#ifndef ENODATA
+#define ENODATA        ENOMSG
+#endif
+
 #endif /* _UST_COMPAT_H */