1 files changed, 90 insertions, 91 deletions

diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index 36cc8475bcd..e3ee4a51ef6 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -1,165 +1,164 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>
 #include <sched.h>
-#include <sys/signal.h>
+#include <linux/limits.h>
+#include <sys/socket.h>
 #include <sys/wait.h>
-#include "user.h"
-#include "kern_util.h"
-#include "user_util.h"
-#include "os.h"
+#include <kern_util.h>
+#include <os.h>
+#include <um_malloc.h>
 
 struct helper_data {
 	void (*pre_exec)(void*);
 	void *pre_data;
 	char **argv;
 	int fd;
+	char *buf;
 };
 
-/* Debugging aid, changed only from gdb */
-int helper_pause = 0;
-
-static void helper_hup(int sig)
-{
-}
-
 static int helper_child(void *arg)
 {
 	struct helper_data *data = arg;
 	char **argv = data->argv;
-	int errval;
+	int err, ret;
 
-	if(helper_pause){
-		signal(SIGHUP, helper_hup);
-		pause();
-	}
-	if(data->pre_exec != NULL)
+	if (data->pre_exec != NULL)
 		(*data->pre_exec)(data->pre_data);
-	execvp(argv[0], argv);
-	errval = errno;
-	printk("execvp of '%s' failed - errno = %d\n", argv[0], errno);
-	os_write_file(data->fd, &errval, sizeof(errval));
-	kill(os_getpid(), SIGKILL);
-	return(0);
+	err = execvp_noalloc(data->buf, argv[0], argv);
+
+	/* If the exec succeeds, we don't get here */
+	CATCH_EINTR(ret = write(data->fd, &err, sizeof(err)));
+
+	return 0;
 }
 
-/* Returns either the pid of the child process we run or -E* on failure.
- * XXX The alloc_stack here breaks if this is called in the tracing thread */
-int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
-	       unsigned long *stack_out)
+/* Returns either the pid of the child process we run or -E* on failure. */
+int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
 {
 	struct helper_data data;
 	unsigned long stack, sp;
 	int pid, fds[2], ret, n;
 
-	if((stack_out != NULL) && (*stack_out != 0))
-		stack = *stack_out;
-	else stack = alloc_stack(0, um_in_interrupt());
-	if(stack == 0)
-		return(-ENOMEM);
+	stack = alloc_stack(0, __cant_sleep());
+	if (stack == 0)
+		return -ENOMEM;
 
-	ret = os_pipe(fds, 1, 0);
-	if(ret < 0){
-		printk("run_helper : pipe failed, ret = %d\n", -ret);
+	ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
+	if (ret < 0) {
+		ret = -errno;
+		printk(UM_KERN_ERR "run_helper : pipe failed, errno = %d\n",
+		       errno);
 		goto out_free;
 	}
 
-	ret = os_set_exec_close(fds[1], 1);
-	if(ret < 0){
-		printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n",
-		       -ret);
+	ret = os_set_exec_close(fds[1]);
+	if (ret < 0) {
+		printk(UM_KERN_ERR "run_helper : setting FD_CLOEXEC failed, "
+		       "ret = %d\n", -ret);
 		goto out_close;
 	}
 
-	sp = stack + page_size() - sizeof(void *);
+	sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *);
 	data.pre_exec = pre_exec;
 	data.pre_data = pre_data;
 	data.argv = argv;
 	data.fd = fds[1];
-	pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data);
-	if(pid < 0){
+	data.buf = __cant_sleep() ? uml_kmalloc(PATH_MAX, UM_GFP_ATOMIC) :
+					uml_kmalloc(PATH_MAX, UM_GFP_KERNEL);
+	pid = clone(helper_child, (void *) sp, CLONE_VM, &data);
+	if (pid < 0) {
 		ret = -errno;
-		printk("run_helper : clone failed, errno = %d\n", errno);
-		goto out_close;
+		printk(UM_KERN_ERR "run_helper : clone failed, errno = %d\n",
+		       errno);
+		goto out_free2;
 	}
 
 	close(fds[1]);
 	fds[1] = -1;
 
-	/*Read the errno value from the child.*/
-	n = os_read_file(fds[0], &ret, sizeof(ret));
-	if(n < 0){
-		printk("run_helper : read on pipe failed, ret = %d\n", -n);
-		ret = n;
-		kill(pid, SIGKILL);
-		CATCH_EINTR(waitpid(pid, NULL, 0));
-	}
-	else if(n != 0){
-		CATCH_EINTR(n = waitpid(pid, NULL, 0));
-		ret = -errno;
-	} else {
+	/*
+	 * Read the errno value from the child, if the exec failed, or get 0 if
+	 * the exec succeeded because the pipe fd was set as close-on-exec.
+	 */
+	n = read(fds[0], &ret, sizeof(ret));
+	if (n == 0) {
 		ret = pid;
+	} else {
+		if (n < 0) {
+			n = -errno;
+			printk(UM_KERN_ERR "run_helper : read on pipe failed, "
+			       "ret = %d\n", -n);
+			ret = n;
+		}
+		CATCH_EINTR(waitpid(pid, NULL, __WCLONE));
 	}
 
+out_free2:
+	kfree(data.buf);
 out_close:
 	if (fds[1] != -1)
 		close(fds[1]);
 	close(fds[0]);
 out_free:
-	if(stack_out == NULL)
-		free_stack(stack, 0);
-	else *stack_out = stack;
-	return(ret);
+	free_stack(stack, 0);
+	return ret;
 }
 
 int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
-		      unsigned long *stack_out, int stack_order)
+		      unsigned long *stack_out)
 {
 	unsigned long stack, sp;
 	int pid, status, err;
 
-	stack = alloc_stack(stack_order, um_in_interrupt());
-	if(stack == 0) return(-ENOMEM);
+	stack = alloc_stack(0, __cant_sleep());
+	if (stack == 0)
+		return -ENOMEM;
 
-	sp = stack + (page_size() << stack_order) - sizeof(void *);
-	pid = clone(proc, (void *) sp, flags | SIGCHLD, arg);
-	if(pid < 0){
+	sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *);
+	pid = clone(proc, (void *) sp, flags, arg);
+	if (pid < 0) {
 		err = -errno;
-		printk("run_helper_thread : clone failed, errno = %d\n",
-		       errno);
+		printk(UM_KERN_ERR "run_helper_thread : clone failed, "
+		       "errno = %d\n", errno);
 		return err;
 	}
-	if(stack_out == NULL){
-		CATCH_EINTR(pid = waitpid(pid, &status, 0));
-		if(pid < 0){
+	if (stack_out == NULL) {
+		CATCH_EINTR(pid = waitpid(pid, &status, __WCLONE));
+		if (pid < 0) {
 			err = -errno;
-			printk("run_helper_thread - wait failed, errno = %d\n",
-			       errno);
+			printk(UM_KERN_ERR "run_helper_thread - wait failed, "
+			       "errno = %d\n", errno);
 			pid = err;
 		}
-		if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
-			printk("run_helper_thread - thread returned status "
-			       "0x%x\n", status);
-		free_stack(stack, stack_order);
-	}
-	else *stack_out = stack;
-	return(pid);
+		if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
+			printk(UM_KERN_ERR "run_helper_thread - thread "
+			       "returned status 0x%x\n", status);
+		free_stack(stack, 0);
+	} else
+		*stack_out = stack;
+	return pid;
 }
 
 int helper_wait(int pid)
 {
-	int ret;
-
-	CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG));
-	if(ret < 0){
-		ret = -errno;
-		printk("helper_wait : waitpid failed, errno = %d\n", errno);
-	}
-	return(ret);
+	int ret, status;
+	int wflags = __WCLONE;
+
+	CATCH_EINTR(ret = waitpid(pid, &status, wflags));
+	if (ret < 0) {
+		printk(UM_KERN_ERR "helper_wait : waitpid process %d failed, "
+		       "errno = %d\n", pid, errno);
+		return -errno;
+	} else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+		printk(UM_KERN_ERR "helper_wait : process %d exited with "
+		       "status 0x%x\n", pid, status);
+		return -ECHILD;
+	} else
+		return 0;
 }