From: H. Peter Anvin <hpa@zytor.com>
Date: Tue, 26 Aug 2008 00:28:20 +0000 (-0700)
Subject: x86: cpuid: propagate error from smp_call_function_single()
X-Git-Tag: v2.6.27-rc5~5^2~4
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4b46ca701bdcdc19fcf32823f9fcabf8236e4e78;p=linux-2.6

x86: cpuid: propagate error from smp_call_function_single()

Propagate error (-ENXIO) from smp_call_function_single() in the CPUID
driver.  This can happen when a CPU is unplugged while the CPUID
driver is open.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---

diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index 14b11b3be3..23e8316c83 100644
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -89,6 +89,7 @@ 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;
 
 	if (count % 16)
 		return -EINVAL;	/* Invalid chunk size */
@@ -96,7 +97,9 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
 	for (; count; count -= 16) {
 		cmd.eax = pos;
 		cmd.ecx = pos >> 32;
-		smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
+		err = smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
+		if (err)
+			return err;
 		if (copy_to_user(tmp, &cmd, 16))
 			return -EFAULT;
 		tmp += 16;