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| author | H. Peter Anvin <hpa@zytor.com> | 2008-08-25 17:34:27 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2008-08-25 17:46:12 -0700 |
| commit | 85f1cb60157e06d9e8996b02fad9ba6964523d75 (patch) | |
| tree | f4e5ebe8284718a50a67351d4d63b701b1a1e605 /arch/x86/kernel | |
| parent | 4b46ca701bdcdc19fcf32823f9fcabf8236e4e78 (diff) | |
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: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/msr.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index 9c34a1005db..2e2af5d1819 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -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) |