configure: check whether gettid() is declared

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/configure.ac b/configure.ac
index cd424c450590d927b970e9663edcf6a2353241f3..2b284cdea39a939f358d3d87bd86740c82f22a6e 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -628,7 +628,7 @@ AC_CHECK_DECLS([PR_GET_NO_NEW_PRIVS], [], [], [#include <sys/prctl.h>])
 AC_CHECK_HEADERS([sys/signalfd.h pty.h ifaddrs.h sys/capability.h sys/personality.h utmpx.h sys/timerfd.h])
 
 # Check for some syscalls functions
-AC_CHECK_FUNCS([setns pivot_root sethostname unshare rand_r confstr faccessat])
+AC_CHECK_FUNCS([setns pivot_root sethostname unshare rand_r confstr faccessat gettid])
 
 # Check for some functions
 AC_CHECK_LIB(pthread, main)

diff --git a/src/lxc/log.c b/src/lxc/log.c
index a08cc2637e61a0b55822ce46f03a976df71913ee..7b89aada9490404e945d4e3ce3e880ae9e215cf3 100644 (file)
--- a/src/lxc/log.c
+++ b/src/lxc/log.c
@@ -45,6 +45,20 @@
 
 #define LXC_LOG_DATEFOMAT_SIZE  15
 
+#ifndef HAVE_GETTID
+static inline pid_t gettid(void)
+{
+#ifdef __NR_gettid
+       return (pid_t)syscall(SYS_gettid);
+#else
+       errno = ENOSYS;
+       return -1;
+#endif
+}
+#else
+extern pid_t gettid(void);
+#endif
+
 int lxc_log_fd = -1;
 static int syslog_enable = 0;
 int lxc_quiet_specified;