x86: Remove "x86 CPU features in debugfs" (CONFIG_X86_CPU_DEBUG)

CONFIG_X86_CPU_DEBUG, which provides some parsed versions of the x86
CPU configuration via debugfs, has caused boot failures on real
hardware.  The value of this feature has been marginal at best, as all
this information is already available to userspace via generic
interfaces.

Causes crashes that have not been fixed + minimal utility -> remove.

See the referenced LKML thread for more information.
Reported-by: Ozan Çağlayan <ozan@pardus.org.tr>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <alpine.LFD.2.00.1001221755320.13231@localhost.localdomain>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: <stable@kernel.org>

arch/x86/Kconfig

@@ -989,12 +989,6 @@ config X86_CPUID
 	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
 	  /dev/cpu/31/cpuid.
 
-config X86_CPU_DEBUG
-	tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
-	---help---
-	  If you select this option, this will provide various x86 CPUs
-	  information through debugfs.
-
 choice
 	prompt "High Memory Support"
 	default HIGHMEM4G if !X86_NUMAQ

arch/x86/include/asm/cpu_debug.h

-#ifndef _ASM_X86_CPU_DEBUG_H
-#define _ASM_X86_CPU_DEBUG_H
-
-/*
- * CPU x86 architecture debug
- *
- * Copyright(C) 2009 Jaswinder Singh Rajput
- */
-
-/* Register flags */
-enum cpu_debug_bit {
-/* Model Specific Registers (MSRs)					*/
-	CPU_MC_BIT,				/* Machine Check	*/
-	CPU_MONITOR_BIT,			/* Monitor		*/
-	CPU_TIME_BIT,				/* Time			*/
-	CPU_PMC_BIT,				/* Performance Monitor	*/
-	CPU_PLATFORM_BIT,			/* Platform		*/
-	CPU_APIC_BIT,				/* APIC			*/
-	CPU_POWERON_BIT,			/* Power-on		*/
-	CPU_CONTROL_BIT,			/* Control		*/
-	CPU_FEATURES_BIT,			/* Features control	*/
-	CPU_LBRANCH_BIT,			/* Last Branch		*/
-	CPU_BIOS_BIT,				/* BIOS			*/
-	CPU_FREQ_BIT,				/* Frequency		*/
-	CPU_MTTR_BIT,				/* MTRR			*/
-	CPU_PERF_BIT,				/* Performance		*/
-	CPU_CACHE_BIT,				/* Cache		*/
-	CPU_SYSENTER_BIT,			/* Sysenter		*/
-	CPU_THERM_BIT,				/* Thermal		*/
-	CPU_MISC_BIT,				/* Miscellaneous	*/
-	CPU_DEBUG_BIT,				/* Debug		*/
-	CPU_PAT_BIT,				/* PAT			*/
-	CPU_VMX_BIT,				/* VMX			*/
-	CPU_CALL_BIT,				/* System Call		*/
-	CPU_BASE_BIT,				/* BASE Address		*/
-	CPU_VER_BIT,				/* Version ID		*/
-	CPU_CONF_BIT,				/* Configuration	*/
-	CPU_SMM_BIT,				/* System mgmt mode	*/
-	CPU_SVM_BIT,				/*Secure Virtual Machine*/
-	CPU_OSVM_BIT,				/* OS-Visible Workaround*/
-/* Standard Registers							*/
-	CPU_TSS_BIT,				/* Task Stack Segment	*/
-	CPU_CR_BIT,				/* Control Registers	*/
-	CPU_DT_BIT,				/* Descriptor Table	*/
-/* End of Registers flags						*/
-	CPU_REG_ALL_BIT,			/* Select all Registers	*/
-};
-
-#define	CPU_REG_ALL		(~0)		/* Select all Registers	*/
-
-#define	CPU_MC			(1 << CPU_MC_BIT)
-#define	CPU_MONITOR		(1 << CPU_MONITOR_BIT)
-#define	CPU_TIME		(1 << CPU_TIME_BIT)
-#define	CPU_PMC			(1 << CPU_PMC_BIT)
-#define	CPU_PLATFORM		(1 << CPU_PLATFORM_BIT)
-#define	CPU_APIC		(1 << CPU_APIC_BIT)
-#define	CPU_POWERON		(1 << CPU_POWERON_BIT)
-#define	CPU_CONTROL		(1 << CPU_CONTROL_BIT)
-#define	CPU_FEATURES		(1 << CPU_FEATURES_BIT)
-#define	CPU_LBRANCH		(1 << CPU_LBRANCH_BIT)
-#define	CPU_BIOS		(1 << CPU_BIOS_BIT)
-#define	CPU_FREQ		(1 << CPU_FREQ_BIT)
-#define	CPU_MTRR		(1 << CPU_MTTR_BIT)
-#define	CPU_PERF		(1 << CPU_PERF_BIT)
-#define	CPU_CACHE		(1 << CPU_CACHE_BIT)
-#define	CPU_SYSENTER		(1 << CPU_SYSENTER_BIT)
-#define	CPU_THERM		(1 << CPU_THERM_BIT)
-#define	CPU_MISC		(1 << CPU_MISC_BIT)
-#define	CPU_DEBUG		(1 << CPU_DEBUG_BIT)
-#define	CPU_PAT			(1 << CPU_PAT_BIT)
-#define	CPU_VMX			(1 << CPU_VMX_BIT)
-#define	CPU_CALL		(1 << CPU_CALL_BIT)
-#define	CPU_BASE		(1 << CPU_BASE_BIT)
-#define	CPU_VER			(1 << CPU_VER_BIT)
-#define	CPU_CONF		(1 << CPU_CONF_BIT)
-#define	CPU_SMM			(1 << CPU_SMM_BIT)
-#define	CPU_SVM			(1 << CPU_SVM_BIT)
-#define	CPU_OSVM		(1 << CPU_OSVM_BIT)
-#define	CPU_TSS			(1 << CPU_TSS_BIT)
-#define	CPU_CR			(1 << CPU_CR_BIT)
-#define	CPU_DT			(1 << CPU_DT_BIT)
-
-/* Register file flags */
-enum cpu_file_bit {
-	CPU_INDEX_BIT,				/* index		*/
-	CPU_VALUE_BIT,				/* value		*/
-};
-
-#define	CPU_FILE_VALUE		(1 << CPU_VALUE_BIT)
-
-#define MAX_CPU_FILES		512
-
-struct cpu_private {
-	unsigned		cpu;
-	unsigned		type;
-	unsigned		reg;
-	unsigned		file;
-};
-
-struct cpu_debug_base {
-	char			*name;		/* Register name	*/
-	unsigned		flag;		/* Register flag	*/
-	unsigned		write;		/* Register write flag	*/
-};
-
-/*
- * Currently it looks similar to cpu_debug_base but once we add more files
- * cpu_file_base will go in different direction
- */
-struct cpu_file_base {
-	char			*name;		/* Register file name	*/
-	unsigned		flag;		/* Register file flag	*/
-	unsigned		write;		/* Register write flag	*/
-};
-
-struct cpu_cpuX_base {
-	struct dentry		*dentry;	/* Register dentry	*/
-	int			init;		/* Register index file	*/
-};
-
-struct cpu_debug_range {
-	unsigned		min;		/* Register range min	*/
-	unsigned		max;		/* Register range max	*/
-	unsigned		flag;		/* Supported flags	*/
-};
-
-#endif /* _ASM_X86_CPU_DEBUG_H */

arch/x86/kernel/cpu/Makefile

@@ -19,8 +19,6 @@ obj-y			+= vmware.o hypervisor.o sched.o
 obj-$(CONFIG_X86_32)	+= bugs.o cmpxchg.o
 obj-$(CONFIG_X86_64)	+= bugs_64.o
 
-obj-$(CONFIG_X86_CPU_DEBUG)		+= cpu_debug.o
-
 obj-$(CONFIG_CPU_SUP_INTEL)		+= intel.o
 obj-$(CONFIG_CPU_SUP_AMD)		+= amd.o
 obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o