From 9ea2b82ed6265a31f9a84886d74d8a2ef01b27c8 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 25 Aug 2008 17:35:25 -0700 Subject: [PATCH] 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 --- arch/x86/kernel/cpuid.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c index 23e8316c83..8e9cd6a8ec 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) -- 2.39.5