Index: linux-2.4.24-2/arch/um/os-Linux/process.c
--- linux-2.4.24-2/arch/um/os-Linux/process.c	19 Jan 2004 21:02:20 -0000	1.8
+++ linux-2.4.24-2/arch/um/os-Linux/process.c	17 May 2004 18:35:49 -0000
@@ -7,6 +7,7 @@
 #include <stdio.h>
 #include <errno.h>
 #include <signal.h>
+#include <linux/unistd.h>
 #include <sys/mman.h>
 #include <sys/wait.h>
 #include "os.h"
@@ -92,7 +93,8 @@
 
 void os_usr1_process(int pid)
 {
-	kill(pid, SIGUSR1);
+	if (syscall(__NR_tkill, pid, SIGUSR1) < 0)
+	    kill(pid, SIGUSR1);
 }
 
 int os_getpid(void)