Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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>
+9
-5
arch/x86/kernel/cpuid.c
+9
-5
arch/x86/kernel/cpuid.c
···
89
struct cpuid_regs cmd;
90
int cpu = iminor(file->f_path.dentry->d_inode);
91
u64 pos = *ppos;
92
-
int err;
93
94
if (count % 16)
95
return -EINVAL; /* Invalid chunk size */
···
100
cmd.ecx = pos >> 32;
101
err = smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
102
if (err)
103
-
return err;
104
-
if (copy_to_user(tmp, &cmd, 16))
105
-
return -EFAULT;
106
tmp += 16;
107
*ppos = ++pos;
108
}
109
110
-
return tmp - buf;
111
}
112
113
static int cpuid_open(struct inode *inode, struct file *file)
···
89
struct cpuid_regs cmd;
90
int cpu = iminor(file->f_path.dentry->d_inode);
91
u64 pos = *ppos;
92
+
ssize_t bytes = 0;
93
+
int err = 0;
94
95
if (count % 16)
96
return -EINVAL; /* Invalid chunk size */
···
99
cmd.ecx = pos >> 32;
100
err = smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
101
if (err)
102
+
break;
103
+
if (copy_to_user(tmp, &cmd, 16)) {
104
+
err = -EFAULT;
105
+
break;
106
+
}
107
tmp += 16;
108
+
bytes += 16;
109
*ppos = ++pos;
110
}
111
112
+
return bytes ? bytes : err;
113
}
114
115
static int cpuid_open(struct inode *inode, struct file *file)