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Commit 4b46ca70 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

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: default avatarH. Peter Anvin <hpa@zytor.com>
parent c6f31932

arch/x86/kernel/cpuid.c

+4 −1
Original line number Original line Diff line number Diff line
@@ -89,6 +89,7 @@ static ssize_t cpuid_read(struct file *file, char __user *buf, 
	struct cpuid_regs cmd;

	struct cpuid_regs cmd;

	int cpu = iminor(file->f_path.dentry->d_inode);

	int cpu = iminor(file->f_path.dentry->d_inode);

	u64 pos = *ppos;

	u64 pos = *ppos;

	int err;





	if (count % 16)

	if (count % 16)

		return -EINVAL;	/* Invalid chunk size */

		return -EINVAL;	/* Invalid chunk size */
@@ -96,7 +97,9 @@ static ssize_t cpuid_read(struct file *file, char __user *buf, 
	for (; count; count -= 16) {

	for (; count; count -= 16) {

		cmd.eax = pos;

		cmd.eax = pos;

		cmd.ecx = pos >> 32;

		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))

		if (copy_to_user(tmp, &cmd, 16))

			return -EFAULT;

			return -EFAULT;

		tmp += 16;

		tmp += 16;