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Commit 85f1cb60 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86: msr: correct return value on partial operations 



Return the correct return value when the MSR driver partially
completes a request (we should return the number of bytes actually
read or written, instead of the error code.)

Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 4b46ca70

arch/x86/kernel/msr.c

+18 −10
Original line number Diff line number Diff line
@@ -72,7 +72,8 @@ static ssize_t msr_read(struct file *file, char __user *buf, 
	u32 data[2];

	u32 reg = *ppos;

	int cpu = iminor(file->f_path.dentry->d_inode);

	int err;

	int err = 0;

	ssize_t bytes = 0;



	if (count % 8)

		return -EINVAL;	/* Invalid chunk size */
@@ -82,14 +83,17 @@ static ssize_t msr_read(struct file *file, char __user *buf, 
		if (err) {

			if (err == -EFAULT) /* Fix idiotic error code */

				err = -EIO;

			return err;

			break;

		}

		if (copy_to_user(tmp, &data, 8)) {

			err = -EFAULT;

			break;

		}

		if (copy_to_user(tmp, &data, 8))

			return -EFAULT;

		tmp += 2;

		bytes += 8;

	}



	return ((char __user *)tmp) - buf;

	return bytes ? bytes : err;

}



static ssize_t msr_write(struct file *file, const char __user *buf,
@@ -99,24 +103,28 @@ static ssize_t msr_write(struct file *file, const char __user *buf, 
	u32 data[2];

	u32 reg = *ppos;

	int cpu = iminor(file->f_path.dentry->d_inode);

	int err;

	int err = 0;

	ssize_t bytes = 0;



	if (count % 8)

		return -EINVAL;	/* Invalid chunk size */



	for (; count; count -= 8) {

		if (copy_from_user(&data, tmp, 8))

			return -EFAULT;

		if (copy_from_user(&data, tmp, 8)) {

			err = -EFAULT;

			break;

		}

		err = wrmsr_safe_on_cpu(cpu, reg, data[0], data[1]);

		if (err) {

			if (err == -EFAULT) /* Fix idiotic error code */

				err = -EIO;

			return err;

			break;

		}

		tmp += 2;

		bytes += 8;

	}



	return ((char __user *)tmp) - buf;

	return bytes ? bytes : err;

}



static int msr_open(struct inode *inode, struct file *file)