diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 735d035a7f33..5178eba9afa5 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -73,6 +73,34 @@ static int ptrace_child(void *arg)
 	_exit(ret);
 }
 
+static void fatal_perror(char *str)
+{
+	perror(str);
+	exit(1);
+}
+
+static void fatal(char *fmt, ...)
+{
+	va_list list;
+
+	va_start(list, fmt);
+	vprintf(fmt, list);
+	va_end(list);
+	fflush(stdout);
+
+	exit(1);
+}
+
+static void non_fatal(char *fmt, ...)
+{
+	va_list list;
+
+	va_start(list, fmt);
+	vprintf(fmt, list);
+	va_end(list);
+	fflush(stdout);
+}
+
 static int start_ptraced_child(void **stack_out)
 {
 	void *stack;
@@ -82,16 +110,16 @@ static int start_ptraced_child(void **stack_out)
 	stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if(stack == MAP_FAILED)
-		panic("check_ptrace : mmap failed, errno = %d", errno);
+		fatal_perror("check_ptrace : mmap failed");
 	sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
 	pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
 	if(pid < 0)
-		panic("start_ptraced_child : clone failed, errno = %d", errno);
+		fatal_perror("start_ptraced_child : clone failed");
 	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if(n < 0)
-		panic("check_ptrace : clone failed, errno = %d", errno);
+		fatal_perror("check_ptrace : clone failed");
 	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
-		panic("check_ptrace : expected SIGSTOP, got status = %d",
+		fatal("check_ptrace : expected SIGSTOP, got status = %d",
 		      status);
 
 	*stack_out = stack;
@@ -105,31 +133,30 @@ static int start_ptraced_child(void **stack_out)
  * must work anyway!
  */
 static int stop_ptraced_child(int pid, void *stack, int exitcode,
-			      int mustpanic)
+			      int mustexit)
 {
 	int status, n, ret = 0;
 
 	if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-		panic("check_ptrace : ptrace failed, errno = %d", errno);
+		fatal_perror("stop_ptraced_child : ptrace failed");
 	CATCH_EINTR(n = waitpid(pid, &status, 0));
 	if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
 		int exit_with = WEXITSTATUS(status);
 		if (exit_with == 2)
-			printf("check_ptrace : child exited with status 2. "
-			       "Serious trouble happening! Try updating your "
-			       "host skas patch!\nDisabling SYSEMU support.");
-		printf("check_ptrace : child exited with exitcode %d, while "
-		      "expecting %d; status 0x%x", exit_with,
-		      exitcode, status);
-		if (mustpanic)
-			panic("\n");
-		else
-			printf("\n");
+			non_fatal("check_ptrace : child exited with status 2. "
+				  "Serious trouble happening! Try updating "
+				  "your host skas patch!\nDisabling SYSEMU "
+				  "support.");
+		non_fatal("check_ptrace : child exited with exitcode %d, while "
+			  "expecting %d; status 0x%x\n", exit_with,
+			  exitcode, status);
+		if (mustexit)
+			exit(1);
 		ret = -1;
 	}
 
 	if(munmap(stack, PAGE_SIZE) < 0)
-		panic("check_ptrace : munmap failed, errno = %d", errno);
+		fatal_perror("check_ptrace : munmap failed");
 	return ret;
 }
 
@@ -184,7 +211,7 @@ static void __init check_sysemu(void)
 	void *stack;
 	int pid, n, status, count=0;
 
-	printf("Checking syscall emulation patch for ptrace...");
+	non_fatal("Checking syscall emulation patch for ptrace...");
 	sysemu_supported = 0;
 	pid = start_ptraced_child(&stack);
 
@@ -193,31 +220,30 @@ static void __init check_sysemu(void)
 
 	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if (n < 0)
-		panic("check_sysemu : wait failed, errno = %d", errno);
+		fatal_perror("check_sysemu : wait failed");
 	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-		panic("check_sysemu : expected SIGTRAP, "
-		      "got status = %d", status);
+		fatal("check_sysemu : expected SIGTRAP, got status = %d",
+		      status);
 
 	n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
 		   os_getpid());
 	if(n < 0)
-		panic("check_sysemu : failed to modify system "
-		      "call return, errno = %d", errno);
+		fatal_perror("check_sysemu : failed to modify system call "
+			     "return");
 
 	if (stop_ptraced_child(pid, stack, 0, 0) < 0)
 		goto fail_stopped;
 
 	sysemu_supported = 1;
-	printf("OK\n");
+	non_fatal("OK\n");
 	set_using_sysemu(!force_sysemu_disabled);
 
-	printf("Checking advanced syscall emulation patch for ptrace...");
+	non_fatal("Checking advanced syscall emulation patch for ptrace...");
 	pid = start_ptraced_child(&stack);
 
-	if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
-		  (void *) PTRACE_O_TRACESYSGOOD) < 0)
-		panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d",
-		      errno);
+	if((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
+		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
+		fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed");
 
 	while(1){
 		count++;
@@ -225,29 +251,30 @@ static void __init check_sysemu(void)
 			goto fail;
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 		if(n < 0)
-			panic("check_ptrace : wait failed, errno = %d", errno);
+			fatal_perror("check_ptrace : wait failed");
+
 		if(WIFSTOPPED(status) && (WSTOPSIG(status) == (SIGTRAP|0x80))){
 			if (!count)
-				panic("check_ptrace : SYSEMU_SINGLESTEP "
+				fatal("check_ptrace : SYSEMU_SINGLESTEP "
 				      "doesn't singlestep");
 			n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
 				   os_getpid());
 			if(n < 0)
-				panic("check_sysemu : failed to modify system "
-				      "call return, errno = %d", errno);
+				fatal_perror("check_sysemu : failed to modify "
+					     "system call return");
 			break;
 		}
 		else if(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
 			count++;
 		else
-			panic("check_ptrace : expected SIGTRAP or "
-			      "(SIGTRAP|0x80), got status = %d", status);
+			fatal("check_ptrace : expected SIGTRAP or "
+			      "(SIGTRAP | 0x80), got status = %d", status);
 	}
 	if (stop_ptraced_child(pid, stack, 0, 0) < 0)
 		goto fail_stopped;
 
 	sysemu_supported = 2;
-	printf("OK\n");
+	non_fatal("OK\n");
 
 	if ( !force_sysemu_disabled )
 		set_using_sysemu(sysemu_supported);
@@ -256,7 +283,7 @@ static void __init check_sysemu(void)
 fail:
 	stop_ptraced_child(pid, stack, 1, 0);
 fail_stopped:
-	printf("missing\n");
+	non_fatal("missing\n");
 }
 
 static void __init check_ptrace(void)
@@ -264,22 +291,25 @@ static void __init check_ptrace(void)
 	void *stack;
 	int pid, syscall, n, status;
 
-	printf("Checking that ptrace can change system call numbers...");
+	non_fatal("Checking that ptrace can change system call numbers...");
 	pid = start_ptraced_child(&stack);
 
-	if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
-		panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", errno);
+	if((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
+		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
+		fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed");
 
 	while(1){
 		if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
-			panic("check_ptrace : ptrace failed, errno = %d",
-			      errno);
+			fatal_perror("check_ptrace : ptrace failed");
+
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 		if(n < 0)
-			panic("check_ptrace : wait failed, errno = %d", errno);
-		if(!WIFSTOPPED(status) || (WSTOPSIG(status) != (SIGTRAP|0x80)))
-			panic("check_ptrace : expected (SIGTRAP|0x80), "
-			      "got status = %d", status);
+			fatal_perror("check_ptrace : wait failed");
+
+		if(!WIFSTOPPED(status) ||
+		   (WSTOPSIG(status) != (SIGTRAP | 0x80)))
+			fatal("check_ptrace : expected (SIGTRAP|0x80), "
+			       "got status = %d", status);
 
 		syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
 				 0);
@@ -287,13 +317,13 @@ static void __init check_ptrace(void)
 			n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
 				   __NR_getppid);
 			if(n < 0)
-				panic("check_ptrace : failed to modify system "
-				      "call, errno = %d", errno);
+				fatal_perror("check_ptrace : failed to modify "
+					     "system call");
 			break;
 		}
 	}
 	stop_ptraced_child(pid, stack, 0, 1);
-	printf("OK\n");
+	non_fatal("OK\n");
 	check_sysemu();
 }
 
@@ -352,22 +382,22 @@ static inline void check_skas3_ptrace_faultinfo(void)
 	void *stack;
 	int pid, n;
 
-	printf("  - PTRACE_FAULTINFO...");
+	non_fatal("  - PTRACE_FAULTINFO...");
 	pid = start_ptraced_child(&stack);
 
 	n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
 	if (n < 0) {
 		ptrace_faultinfo = 0;
 		if(errno == EIO)
-			printf("not found\n");
+			non_fatal("not found\n");
 		else
 			perror("not found");
 	}
 	else {
 		if (!ptrace_faultinfo)
-			printf("found but disabled on command line\n");
+			non_fatal("found but disabled on command line\n");
 		else
-			printf("found\n");
+			non_fatal("found\n");
 	}
 
 	init_registers(pid);
@@ -385,13 +415,13 @@ static inline void check_skas3_ptrace_ldt(void)
 		.ptr = ldtbuf,
 		.bytecount = sizeof(ldtbuf)};
 
-	printf("  - PTRACE_LDT...");
+	non_fatal("  - PTRACE_LDT...");
 	pid = start_ptraced_child(&stack);
 
 	n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
 	if (n < 0) {
 		if(errno == EIO)
-			printf("not found\n");
+			non_fatal("not found\n");
 		else {
 			perror("not found");
 		}
@@ -399,9 +429,9 @@ static inline void check_skas3_ptrace_ldt(void)
 	}
 	else {
 		if(ptrace_ldt)
-			printf("found\n");
+			non_fatal("found\n");
 		else
-			printf("found, but use is disabled\n");
+			non_fatal("found, but use is disabled\n");
 	}
 
 	stop_ptraced_child(pid, stack, 1, 1);
@@ -416,22 +446,22 @@ static inline void check_skas3_ptrace_ldt(void)
 
 static inline void check_skas3_proc_mm(void)
 {
-	printf("  - /proc/mm...");
+	non_fatal("  - /proc/mm...");
 	if (access("/proc/mm", W_OK) < 0) {
 		proc_mm = 0;
-		printf("not found\n");
+		perror("not found");
 	}
 	else {
 		if (!proc_mm)
-			printf("found but disabled on command line\n");
+			non_fatal("found but disabled on command line\n");
 		else
-			printf("found\n");
+			non_fatal("found\n");
 	}
 }
 
 int can_do_skas(void)
 {
-	printf("Checking for the skas3 patch in the host:\n");
+	non_fatal("Checking for the skas3 patch in the host:\n");
 
 	check_skas3_proc_mm();
 	check_skas3_ptrace_faultinfo();