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authorH. Peter Anvin <hpa@zytor.com>2008-08-25 17:35:25 -0700
committerH. Peter Anvin <hpa@zytor.com>2008-08-25 17:46:12 -0700
commit9ea2b82ed6265a31f9a84886d74d8a2ef01b27c8 (patch)
treec42e3515b37c0e16e03e230d8cf28d07b240d9b2 /arch/x86/kernel/cpuid.c
parent85f1cb60157e06d9e8996b02fad9ba6964523d75 (diff)
x86: cpuid: correct return value on partial operations
Return the correct return value when the CPUID 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/cpuid.c')
-rw-r--r--arch/x86/kernel/cpuid.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index 23e8316c835..8e9cd6a8ec1 100644
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -89,7 +89,8 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
struct cpuid_regs cmd;
int cpu = iminor(file->f_path.dentry->d_inode);
u64 pos = *ppos;
- int err;
+ ssize_t bytes = 0;
+ int err = 0;
if (count % 16)
return -EINVAL; /* Invalid chunk size */
@@ -99,14 +100,17 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
cmd.ecx = pos >> 32;
err = smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
if (err)
- return err;
- if (copy_to_user(tmp, &cmd, 16))
- return -EFAULT;
+ break;
+ if (copy_to_user(tmp, &cmd, 16)) {
+ err = -EFAULT;
+ break;
+ }
tmp += 16;
+ bytes += 16;
*ppos = ++pos;
}
- return tmp - buf;
+ return bytes ? bytes : err;
}
static int cpuid_open(struct inode *inode, struct file *file)