3 files changed, 11 insertions, 40 deletions

diff --git a/arch/um/drivers/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c
index f6b911cc3923..3a4b58730f5f 100644
--- a/arch/um/drivers/hostaudio_kern.c
+++ b/arch/um/drivers/hostaudio_kern.c
@@ -105,13 +105,9 @@ static ssize_t hostaudio_write(struct file *file, const char __user *buffer,
 	printk(KERN_DEBUG "hostaudio: write called, count = %d\n", count);
 #endif
 
-	kbuf = kmalloc(count, GFP_KERNEL);
-	if (kbuf == NULL)
-		return -ENOMEM;
-
-	err = -EFAULT;
-	if (copy_from_user(kbuf, buffer, count))
-		goto out;
+	kbuf = memdup_user(buffer, count);
+	if (IS_ERR(kbuf))
+		return PTR_ERR(kbuf);
 
 	err = os_write_file(state->fd, kbuf, count);
 	if (err < 0)
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 29880c9b324e..b821b13d343a 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -748,19 +748,11 @@ static ssize_t mconsole_proc_write(struct file *file,
 {
 	char *buf;
 
-	buf = kmalloc(count + 1, GFP_KERNEL);
-	if (buf == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(buf, buffer, count)) {
-		count = -EFAULT;
-		goto out;
-	}
-
-	buf[count] = '\0';
+	buf = memdup_user_nul(buffer, count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
 
 	mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
- out:
 	kfree(buf);
 	return count;
 }
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index e8ab93c3e638..39ba20755e03 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -535,11 +535,7 @@ static int read_cow_bitmap(int fd, void *buf, int offset, int len)
 {
 	int err;
 
-	err = os_seek_file(fd, offset);
-	if (err < 0)
-		return err;
-
-	err = os_read_file(fd, buf, len);
+	err = os_pread_file(fd, buf, len, offset);
 	if (err < 0)
 		return err;
 
@@ -1377,14 +1373,8 @@ static int update_bitmap(struct io_thread_req *req)
 	if(req->cow_offset == -1)
 		return 0;
 
-	n = os_seek_file(req->fds[1], req->cow_offset);
-	if(n < 0){
-		printk("do_io - bitmap lseek failed : err = %d\n", -n);
-		return 1;
-	}
-
-	n = os_write_file(req->fds[1], &req->bitmap_words,
-			  sizeof(req->bitmap_words));
+	n = os_pwrite_file(req->fds[1], &req->bitmap_words,
+			  sizeof(req->bitmap_words), req->cow_offset);
 	if(n != sizeof(req->bitmap_words)){
 		printk("do_io - bitmap update failed, err = %d fd = %d\n", -n,
 		       req->fds[1]);
@@ -1399,7 +1389,6 @@ static void do_io(struct io_thread_req *req)
 	char *buf;
 	unsigned long len;
 	int n, nsectors, start, end, bit;
-	int err;
 	__u64 off;
 
 	if (req->op == UBD_FLUSH) {
@@ -1428,18 +1417,12 @@ static void do_io(struct io_thread_req *req)
 		len = (end - start) * req->sectorsize;
 		buf = &req->buffer[start * req->sectorsize];
 
-		err = os_seek_file(req->fds[bit], off);
-		if(err < 0){
-			printk("do_io - lseek failed : err = %d\n", -err);
-			req->error = 1;
-			return;
-		}
 		if(req->op == UBD_READ){
 			n = 0;
 			do {
 				buf = &buf[n];
 				len -= n;
-				n = os_read_file(req->fds[bit], buf, len);
+				n = os_pread_file(req->fds[bit], buf, len, off);
 				if (n < 0) {
 					printk("do_io - read failed, err = %d "
 					       "fd = %d\n", -n, req->fds[bit]);
@@ -1449,7 +1432,7 @@ static void do_io(struct io_thread_req *req)
 			} while((n < len) && (n != 0));
 			if (n < len) memset(&buf[n], 0, len - n);
 		} else {
-			n = os_write_file(req->fds[bit], buf, len);
+			n = os_pwrite_file(req->fds[bit], buf, len, off);
 			if(n != len){
 				printk("do_io - write failed err = %d "
 				       "fd = %d\n", -n, req->fds[bit]);