diff --git a/build-aux/build-cc.sh b/build-aux/build-cc.sh
index 3c4efd59..723d7dbe 100755
--- a/build-aux/build-cc.sh
+++ b/build-aux/build-cc.sh
@@ -53,11 +53,11 @@ ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/linux/x86_64-mes-gcc/c
 # ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/linux/x86_64/crtn
 ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/libc-mini
 ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/libc
-# ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/libc+gnu
-# ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/libg
 ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/libgetopt
 ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/libc+tcc
 ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/libtcc1
+ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/libc+gnu
+ARCHDIR=1 NOLINK=1 sh ${srcdest}build-aux/cc64-mes.sh lib/libg
 
 sh ${srcdest}build-aux/cc64-mes.sh scaffold/main
 sh ${srcdest}build-aux/cc64-mes.sh scaffold/hello
diff --git a/include/linux/x86/syscall.h b/include/linux/x86/syscall.h
index aa8bca28..1b5639a4 100644
--- a/include/linux/x86/syscall.h
+++ b/include/linux/x86/syscall.h
@@ -45,4 +45,26 @@
 #define SYS_stat   0x6a
 #define SYS_getcwd 0xb7
 
+// libc+gnu
+#define SYS_link      0x09
+#define SYS_getpid    0x14
+#define SYS_getuid    0x18
+#define SYS_kill      0x25
+#define SYS_rename    0x26
+#define SYS_mkdir     0x27
+#define SYS_dup       0x29
+#define SYS_pipe      0x2a
+#define SYS_getgid    0x2f
+#define SYS_signal    0x30
+#define SYS_sigaction 0x43
+#define SYS_rt_sigaction 0xae
+#define SYS_signal    0x30
+#define SYS_fcntl     0x37
+#define SYS_dup2      0x3f
+#define SYS_getrusage 0x4d
+#define SYS_lstat     0x6b
+#define SYS_setitimer 0x68
+#define SYS_fstat     0x6c
+#define SYS_nanosleep 0xa2
+
 #endif // __MES_LINUX_X86_SYSCALL_H
diff --git a/include/linux/x86_64/syscall.h b/include/linux/x86_64/syscall.h
index c8846d73..c5b33c33 100644
--- a/include/linux/x86_64/syscall.h
+++ b/include/linux/x86_64/syscall.h
@@ -45,4 +45,23 @@
 #define SYS_stat   0x04
 #define SYS_getcwd 0x4f
 
+// libc+gnu
+#define SYS_link      0x56
+#define SYS_getpid    0x27
+#define SYS_getuid    0x66
+#define SYS_kill      0x3e
+#define SYS_rename    0x52
+#define SYS_mkdir     0x53
+#define SYS_dup       0x20
+#define SYS_pipe      0x16
+#define SYS_getgid    0x68
+#define SYS_rt_sigaction 0x0d
+#define SYS_fcntl     0x48
+#define SYS_dup2      0x21
+#define SYS_getrusage 0x62
+#define SYS_lstat     0x06
+#define SYS_setitimer 0x26
+#define SYS_fstat     0x05
+#define SYS_nanosleep 0x33
+
 #endif // __MES_LINUX_X86_64_SYSCALL_H
diff --git a/lib/linux/gnu.c b/lib/linux/gnu.c
index 582c18bc..e756b060 100644
--- a/lib/linux/gnu.c
+++ b/lib/linux/gnu.c
@@ -18,24 +18,6 @@
  * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#define SYS_link      0x09
-#define SYS_getpid    0x14
-#define SYS_getuid    0x18
-#define SYS_kill      0x25
-#define SYS_rename    0x26
-#define SYS_mkdir     0x27
-#define SYS_dup       0x29
-#define SYS_pipe      0x2a
-#define SYS_getgid    0x2f
-#define SYS_signal    0x30
-#define SYS_fcntl     0x37
-#define SYS_dup2      0x3f
-#define SYS_getrusage 0x4d
-#define SYS_lstat     0x6b
-#define SYS_setitimer 0x68
-#define SYS_fstat     0x6c
-#define SYS_nanosleep 0xa2
-
 #include <sys/resource.h>
 
 int
@@ -86,6 +68,7 @@ getgid ()
   return _sys_call (SYS_getgid);
 }
 
+#if __i386__
 #if __MESC__
 void *
 signal (int signum, void * action)
@@ -96,6 +79,17 @@ signal (int signum, sighandler_t action)
 {
   return _sys_call2 (SYS_signal, signum, action);
 }
+#elif __x86_64__
+sighandler_t
+signal (int signum, sighandler_t action)
+{
+  sighandler_t old;
+  _sys_call3 (SYS_rt_sigaction, signum, action, &old);
+  return old;
+}
+#else
+#error arch not supported
+#endif
 
 int
 fcntl (int filedes, int command, ...)
diff --git a/lib/stdlib/abort.c b/lib/stdlib/abort.c
index 6f6be919..bc93a329 100644
--- a/lib/stdlib/abort.c
+++ b/lib/stdlib/abort.c
@@ -21,9 +21,5 @@
 void
 abort (void)
 {
-#if __i386__
   asm ("hlt");
-#else
-  asm ("break  0");
-#endif
 }