[PATCH] uml: Handles correctly errno == EINTR in lots of places.

On various places (mostly waitpid() calls) this patch makes sure that if errno
== EINTR on return, then the syscall is endlessly retried.  It also defines a
simple generic way to do this.

Signed-off-by: <blaisorblade_spam@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/drivers/net_user.c

@@ -175,7 +175,8 @@ static int change_tramp(char **argv, char *output, int output_len)
 
 	os_close_file(fds[1]);
 	read_output(fds[0], output, output_len);
-	waitpid(pid, NULL, 0);	
+
+	CATCH_EINTR(err = waitpid(pid, NULL, 0));
 	return(pid);
 }
 

arch/um/drivers/slip_user.c

@@ -4,7 +4,7 @@
 #include <stddef.h>
 #include <sched.h>
 #include <string.h>
-#include <sys/errno.h>
+#include <errno.h>
 #include <sys/termios.h>
 #include <sys/wait.h>
 #include <sys/signal.h>
@@ -100,7 +100,9 @@ static int slip_tramp(char **argv, int fd)
 			printk("%s", output);
 			kfree(output);
 		}
-		if(waitpid(pid, &status, 0) < 0) err = errno;
+		CATCH_EINTR(err = waitpid(pid, &status, 0));
+		if(err < 0)
+			err = errno;
 		else if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0)){
 			printk("'%s' didn't exit with status 0\n", argv[0]);
 			err = -EINVAL;

arch/um/drivers/slirp_user.c

@@ -4,7 +4,7 @@
 #include <stddef.h>
 #include <sched.h>
 #include <string.h>
-#include <sys/errno.h>
+#include <errno.h>
 #include <sys/wait.h>
 #include <sys/signal.h>
 #include "user_util.h"
@@ -113,13 +113,13 @@ static void slirp_close(int fd, void *data)
 	}
 #endif
 
-	err = waitpid(pri->pid, &status, WNOHANG);
-	if(err<0) {
+	CATCH_EINTR(err = waitpid(pri->pid, &status, WNOHANG));
+	if(err < 0) {
 		printk("slirp_close: waitpid returned %d\n", errno);
 		return;
 	}
 
-	if(err==0) {
+	if(err == 0) {
 		printk("slirp_close: process %d has not exited\n");
 		return;
 	}

arch/um/include/user_util.h

@@ -92,6 +92,7 @@ extern void arch_init_thread(void);
 extern int __raw(int fd, int complain, int now);
 #define raw(fd, complain) __raw((fd), (complain), 1)
 
+#define CATCH_EINTR(expr) while ( ((expr) < 0) && errno == EINTR)
 #endif
 
 /*

arch/um/kernel/frame.c

@@ -21,6 +21,7 @@
 #include "sysdep/sigcontext.h"
 #include "frame_user.h"
 #include "kern_util.h"
+#include "user_util.h"
 #include "ptrace_user.h"
 #include "os.h"
 
@@ -40,7 +41,7 @@ static int capture_stack(int (*child)(void *arg), void *arg, void *sp,
 	/* Wait for it to stop itself and continue it with a SIGUSR1 to force 
 	 * it into the signal handler.
 	 */
-	n = waitpid(pid, &status, WUNTRACED);
+	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if(n < 0){
 		printf("capture_stack : waitpid failed - errno = %d\n", errno);
 		exit(1);
@@ -60,7 +61,7 @@ static int capture_stack(int (*child)(void *arg), void *arg, void *sp,
 	 * At this point, the handler has stuffed the addresses of
 	 * sig, sc, and SA_RESTORER in raw.
 	 */
-	n = waitpid(pid, &status, WUNTRACED);
+	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if(n < 0){
 		printf("capture_stack : waitpid failed - errno = %d\n", errno);
 		exit(1);
@@ -82,7 +83,8 @@ static int capture_stack(int (*child)(void *arg), void *arg, void *sp,
 		       errno);
 		exit(1);
 	}
-	if(waitpid(pid, &status, 0) < 0){
+	CATCH_EINTR(n = waitpid(pid, &status, 0));
+	if(n < 0){
 		printf("capture_stack : waitpid failed - errno = %d\n", errno);
 		exit(1);
 	}

arch/um/kernel/helper.c

@@ -12,6 +12,7 @@
 #include <sys/wait.h>
 #include "user.h"
 #include "kern_util.h"
+#include "user_util.h"
 #include "os.h"
 
 struct helper_data {
@@ -96,7 +97,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
 		goto out_kill;
 	}
 	else if(n != 0){
-		waitpid(pid, NULL, 0);
+		CATCH_EINTR(n = waitpid(pid, NULL, 0));
 		pid = -errno;
 	}
 

arch/um/kernel/process.c

@@ -125,7 +125,7 @@ int start_fork_tramp(void *thread_arg, unsigned long temp_stack,
 	/* Start the process and wait for it to kill itself */
 	new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg);
 	if(new_pid < 0) return(-errno);
-	while(((err = waitpid(new_pid, &status, 0)) < 0) && (errno == EINTR)) ;
+	CATCH_EINTR(err = waitpid(new_pid, &status, 0));
 	if(err < 0) panic("Waiting for outer trampoline failed - errno = %d", 
 			  errno);
 	if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL))
@@ -171,7 +171,7 @@ static int start_ptraced_child(void **stack_out)
 	pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
 	if(pid < 0)
 		panic("check_ptrace : clone failed, errno = %d", errno);
-	n = waitpid(pid, &status, WUNTRACED);
+	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if(n < 0)
 		panic("check_ptrace : wait failed, errno = %d", errno);
 	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
@@ -188,7 +188,7 @@ static void stop_ptraced_child(int pid, void *stack, int exitcode)
 
 	if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
 		panic("check_ptrace : ptrace failed, errno = %d", errno);
-	n = waitpid(pid, &status, 0);
+	CATCH_EINTR(n = waitpid(pid, &status, 0));
 	if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode))
 		panic("check_ptrace : child exited with status 0x%x", status);
 
@@ -226,7 +226,8 @@ static void __init check_sysemu(void)
 	if(ptrace(PTRACE_SYSEMU, pid, 0, 0) >= 0) {
 		struct user_regs_struct regs;
 
-		if (waitpid(pid, &status, WUNTRACED) < 0)
+		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
+		if (n < 0)
 			panic("check_ptrace : wait failed, errno = %d", errno);
 		if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
 			panic("check_ptrace : expected SIGTRAP, "
@@ -267,7 +268,7 @@ void __init check_ptrace(void)
 		if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
 			panic("check_ptrace : ptrace failed, errno = %d", 
 			      errno);
-		n = waitpid(pid, &status, WUNTRACED);
+		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 		if(n < 0)
 			panic("check_ptrace : wait failed, errno = %d", errno);
 		if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))

arch/um/kernel/skas/exec_user.c

@@ -11,6 +11,7 @@
 #include <sys/ptrace.h>
 #include "user.h"
 #include "kern_util.h"
+#include "user_util.h"
 #include "os.h"
 #include "time_user.h"
 
@@ -26,7 +27,7 @@ static int user_thread_tramp(void *arg)
 
 int user_thread(unsigned long stack, int flags)
 {
-	int pid, status;
+	int pid, status, err;
 
 	pid = clone(user_thread_tramp, (void *) stack_sp(stack), 
 		    flags | CLONE_FILES | SIGCHLD, NULL);
@@ -35,7 +36,8 @@ int user_thread(unsigned long stack, int flags)
 		return(pid);
 	}
 
-	if(waitpid(pid, &status, WUNTRACED) < 0){
+	CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
+	if(err < 0){
 		printk("user_thread - waitpid failed, errno = %d\n", errno);
 		return(-errno);
 	}

arch/um/kernel/skas/process.c

@@ -81,7 +81,7 @@ static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu
 			panic("handle_trap - continuing to end of syscall failed, "
 			      "errno = %d\n", errno);
 
-		err = waitpid(pid, &status, WUNTRACED);
+		CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
 		if((err < 0) || !WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
 			panic("handle_trap - failed to wait at end of syscall, "
 			      "errno = %d, status = %d\n", errno, status);
@@ -121,7 +121,7 @@ void start_userspace(int cpu)
 		panic("start_userspace : clone failed, errno = %d", errno);
 
 	do {
-		n = waitpid(pid, &status, WUNTRACED);
+		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 		if(n < 0)
 			panic("start_userspace : wait failed, errno = %d", 
 			      errno);
@@ -154,7 +154,7 @@ void userspace(union uml_pt_regs *regs)
 		panic("userspace - PTRACE_%s failed, errno = %d\n",
 		       local_using_sysemu ? "SYSEMU" : "SYSCALL", errno);
 	while(1){
-		err = waitpid(pid, &status, WUNTRACED);
+		CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
 		if(err < 0)
 			panic("userspace - waitpid failed, errno = %d\n", 
 			      errno);

arch/um/kernel/trap_user.c

@@ -32,7 +32,14 @@ void kill_child_dead(int pid)
 {
 	kill(pid, SIGKILL);
 	kill(pid, SIGCONT);
-	while(waitpid(pid, NULL, 0) > 0) kill(pid, SIGCONT);
+	do {
+		int n;
+		CATCH_EINTR(n = waitpid(pid, NULL, 0));
+		if (n > 0)
+			kill(pid, SIGCONT);
+		else
+			break;
+	} while(1);
 }
 
 /* Unlocked - don't care if this is a bit off */

arch/um/kernel/tt/exec_user.c

@@ -19,13 +19,18 @@
 void do_exec(int old_pid, int new_pid)
 {
 	unsigned long regs[FRAME_SIZE];
+	int err;
 
 	if((ptrace(PTRACE_ATTACH, new_pid, 0, 0) < 0) ||
-	   (ptrace(PTRACE_CONT, new_pid, 0, 0) < 0) ||
-	   (waitpid(new_pid, 0, WUNTRACED) < 0))
+	   (ptrace(PTRACE_CONT, new_pid, 0, 0) < 0))
 		tracer_panic("do_exec failed to attach proc - errno = %d",
 			     errno);
 
+	CATCH_EINTR(err = waitpid(new_pid, 0, WUNTRACED));
+	if (err < 0)
+		tracer_panic("do_exec failed to attach proc in waitpid - errno = %d",
+			     errno);
+
 	if(ptrace_getregs(old_pid, regs) < 0)
 		tracer_panic("do_exec failed to get registers - errno = %d",
 			     errno);

arch/um/kernel/tt/ptproxy/proxy.c

@@ -272,7 +272,7 @@ void fake_child_exit(void)
 
 	child_proxy(1, W_EXITCODE(0, 0));
 	while(debugger.waiting == 1){
-		pid = waitpid(debugger.pid, &status, WUNTRACED);
+		CATCH_EINTR(pid = waitpid(debugger.pid, &status, WUNTRACED));
 		if(pid != debugger.pid){
 			printk("fake_child_exit - waitpid failed, "
 			       "errno = %d\n", errno);
@@ -280,7 +280,7 @@ void fake_child_exit(void)
 		}
 		debugger_proxy(status, debugger.pid);
 	}
-	pid = waitpid(debugger.pid, &status, WUNTRACED);
+	CATCH_EINTR(pid = waitpid(debugger.pid, &status, WUNTRACED));
 	if(pid != debugger.pid){
 		printk("fake_child_exit - waitpid failed, "
 		       "errno = %d\n", errno);

arch/um/kernel/tt/tracer.c

@@ -192,7 +192,7 @@ int tracer(int (*init_proc)(void *), void *sp)
 	printf("tracing thread pid = %d\n", tracing_pid);
 
 	pid = clone(signal_tramp, sp, CLONE_FILES | SIGCHLD, init_proc);
-	n = waitpid(pid, &status, WUNTRACED);
+	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if(n < 0){
 		printf("waitpid on idle thread failed, errno = %d\n", errno);
 		exit(1);
@@ -233,7 +233,7 @@ int tracer(int (*init_proc)(void *), void *sp)
 	}
 	set_cmdline("(tracing thread)");
 	while(1){
-		pid = waitpid(-1, &status, WUNTRACED);
+		CATCH_EINTR(pid = waitpid(-1, &status, WUNTRACED));
 		if(pid <= 0){
 			if(errno != ECHILD){
 				printf("wait failed - errno = %d\n", errno);

arch/um/kernel/user_util.c

@@ -80,11 +80,10 @@ int wait_for_stop(int pid, int sig, int cont_type, void *relay)
 	int status, ret;
 
 	while(1){
-		ret = waitpid(pid, &status, WUNTRACED);
+		CATCH_EINTR(ret = waitpid(pid, &status, WUNTRACED));
 		if((ret < 0) ||
 		   !WIFSTOPPED(status) || (WSTOPSIG(status) != sig)){
 			if(ret < 0){
-				if(errno == EINTR) continue;
 				printk("wait failed, errno = %d\n",
 				       errno);
 			}
@@ -124,8 +123,7 @@ int __raw(int fd, int complain, int now)
 	int err;
 	int when;
 
-	while (((err = tcgetattr(fd, &tt)) < 0) && errno == EINTR)
-		;
+	CATCH_EINTR(err = tcgetattr(fd, &tt));
 
 	if (err < 0) {
 		if (complain)
@@ -140,8 +138,8 @@ int __raw(int fd, int complain, int now)
 	else
 		when = TCSADRAIN;
 
-	while (((err = tcsetattr(fd, when, &tt)) < 0) && errno == EINTR)
-		;
+	CATCH_EINTR(err = tcsetattr(fd, when, &tt));
+
 	if (err < 0) {
 		if (complain)
 			printk("tcsetattr failed, errno = %d\n", errno);

arch/um/os-Linux/drivers/ethertap_user.c

@@ -16,6 +16,7 @@
 #include <net/if.h>
 #include "user.h"
 #include "kern_util.h"
+#include "user_util.h"
 #include "net_user.h"
 #include "etap.h"
 #include "helper.h"
@@ -125,7 +126,8 @@ static int etap_tramp(char *dev, char *gate, int control_me,
 	if(c != 1){
 		printk("etap_tramp : uml_net failed\n");
 		err = -EINVAL;
-		if(waitpid(pid, &status, 0) < 0)
+		CATCH_EINTR(n = waitpid(pid, &status, 0));
+		if(n < 0)
 			err = -errno;
 		else if(!WIFEXITED(status) || (WEXITSTATUS(status) != 1))
 			printk("uml_net didn't exit with status 1\n");

arch/um/os-Linux/drivers/tuntap_user.c

@@ -18,6 +18,7 @@
 #include "net_user.h"
 #include "tuntap.h"
 #include "kern_util.h"
+#include "user_util.h"
 #include "user.h"
 #include "helper.h"
 #include "os.h"
@@ -108,7 +109,7 @@ static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
 		       errno);
 		return(-errno);
 	}
-	waitpid(pid, NULL, 0);
+	CATCH_EINTR(waitpid(pid, NULL, 0));
 
 	cmsg = CMSG_FIRSTHDR(&msg);
 	if(cmsg == NULL){

arch/um/os-Linux/process.c

@@ -12,6 +12,7 @@
 #include <sys/wait.h>
 #include "os.h"
 #include "user.h"
+#include "user_util.h"
 
 #define ARBITRARY_ADDR -1
 #define FAILURE_PID    -1
@@ -87,7 +88,7 @@ void os_kill_process(int pid, int reap_child)
 {
 	kill(pid, SIGKILL);
 	if(reap_child)
-		waitpid(pid, NULL, 0);
+		CATCH_EINTR(waitpid(pid, NULL, 0));
 		
 }