x86, msr/cpuid: Register enough minors for the MSR and CPUID drivers

register_chrdev() hardcodes registering 256 minors, presumably to
avoid breaking old drivers.  However, we need to register enough
minors so that we have all possible CPUs.

checkpatch warns on this patch, but the patch is correct: NR_CPUS here
is a static *upper bound* on the *maximum CPU index* (not *number of
CPUs!*) and that is what we want.

Reported-and-tested-by: Russ Anderson <rja@sgi.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <tip-*@git.kernel.org>

diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index 7ef24a796992b6b39ccbb7894b72301ecd80645a..cb27fd6136c9bec099b0a944ee59a8425d39d09c 100644 (file)
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -187,7 +187,8 @@ static int __init cpuid_init(void)
        int i, err = 0;
        i = 0;
 
-       if (register_chrdev(CPUID_MAJOR, "cpu/cpuid", &cpuid_fops)) {
+       if (__register_chrdev(CPUID_MAJOR, 0, NR_CPUS,
+                             "cpu/cpuid", &cpuid_fops)) {
                printk(KERN_ERR "cpuid: unable to get major %d for cpuid\n",
                       CPUID_MAJOR);
                err = -EBUSY;
@@ -216,7 +217,7 @@ out_class:
        }
        class_destroy(cpuid_class);
 out_chrdev:
-       unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
+       __unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
 out:
        return err;
 }

diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index 572b07eee3f421570047343bae9fb42a4a93dc7b..4bd93c9b2b2716d86367c41631ffa1a0c4625a83 100644 (file)
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -246,7 +246,7 @@ static int __init msr_init(void)
        int i, err = 0;
        i = 0;
 
-       if (register_chrdev(MSR_MAJOR, "cpu/msr", &msr_fops)) {
+       if (__register_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr", &msr_fops)) {
                printk(KERN_ERR "msr: unable to get major %d for msr\n",
                       MSR_MAJOR);
                err = -EBUSY;
@@ -274,7 +274,7 @@ out_class:
                msr_device_destroy(i);
        class_destroy(msr_class);
 out_chrdev:
-       unregister_chrdev(MSR_MAJOR, "cpu/msr");
+       __unregister_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr");
 out:
        return err;
 }