Revert "x86/cpuid: Provide get_scattered_cpuid_leaf()"

CVE-2017-5753 (revert embargoed)
CVE-2017-5715 (revert embargoed)

This reverts commit 36c867e8.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/x86/include/asm/processor.h

@@ -180,9 +180,6 @@ extern void identify_secondary_cpu(struct cpuinfo_x86 *);
 extern void print_cpu_info(struct cpuinfo_x86 *);
 void print_cpu_msr(struct cpuinfo_x86 *);
 extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
-extern u32 get_scattered_cpuid_leaf(unsigned int level,
-				    unsigned int sub_leaf,
-				    u8 reg);
 extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
 extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
 

arch/x86/kernel/cpu/scattered.c

@@ -24,13 +24,16 @@ enum cpuid_regs {
 	CR_EBX
 };
 
-/* Please keep the leaf sorted by cpuid_bit.level for faster search. */
-static const struct cpuid_bit cpuid_bits[] = {
+void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
+{
+	u32 max_level;
+	u32 regs[4];
+	const struct cpuid_bit *cb;
+
+	static const struct cpuid_bit cpuid_bits[] = {
 		{ X86_FEATURE_DTHERM,		CR_EAX, 0, 0x00000006, 0 },
-	{ X86_FEATURE_APERFMPERF,	CR_ECX, 0, 0x00000006, 0 },
 		{ X86_FEATURE_IDA,		CR_EAX, 1, 0x00000006, 0 },
 		{ X86_FEATURE_ARAT,		CR_EAX, 2, 0x00000006, 0 },
-	{ X86_FEATURE_EPB,		CR_ECX, 3, 0x00000006, 0 },
 		{ X86_FEATURE_PLN,		CR_EAX, 4, 0x00000006, 0 },
 		{ X86_FEATURE_PTS,		CR_EAX, 6, 0x00000006, 0 },
 		{ X86_FEATURE_HWP,		CR_EAX, 7, 0x00000006, 0 },
@@ -40,6 +43,8 @@ static const struct cpuid_bit cpuid_bits[] = {
 		{ X86_FEATURE_HWP_PKG_REQ,	CR_EAX,11, 0x00000006, 0 },
 		{ X86_FEATURE_INTEL_PT,		CR_EBX,25, 0x00000007, 0 },
 		{ X86_FEATURE_SPEC_CTRL,	CR_EDX,26, 0x00000007, 0 },
+		{ X86_FEATURE_APERFMPERF,	CR_ECX, 0, 0x00000006, 0 },
+		{ X86_FEATURE_EPB,		CR_ECX, 3, 0x00000006, 0 },
 		{ X86_FEATURE_HW_PSTATE,	CR_EDX, 7, 0x80000007, 0 },
 		{ X86_FEATURE_CPB,		CR_EDX, 9, 0x80000007, 0 },
 		{ X86_FEATURE_PROC_FEEDBACK,	CR_EDX,11, 0x80000007, 0 },
@@ -54,13 +59,7 @@ static const struct cpuid_bit cpuid_bits[] = {
 		{ X86_FEATURE_PAUSEFILTER,	CR_EDX,10, 0x8000000a, 0 },
 		{ X86_FEATURE_PFTHRESHOLD,	CR_EDX,12, 0x8000000a, 0 },
 		{ 0, 0, 0, 0, 0 }
-};
-
-void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
-{
-	u32 max_level;
-	u32 regs[4];
-	const struct cpuid_bit *cb;
+	};
 
 	for (cb = cpuid_bits; cb->feature; cb++) {
 
@@ -77,26 +76,3 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
 			set_cpu_cap(c, cb->feature);
 	}
 }
-
-u32 get_scattered_cpuid_leaf(unsigned int level, unsigned int sub_leaf, u8 reg)
-{
-	const struct cpuid_bit *cb;
-	u32 cpuid_val = 0;
-
-	for (cb = cpuid_bits; cb->feature; cb++) {
-
-		if (level > cb->level)
-			continue;
-
-		if (level < cb->level)
-			break;
-
-		if (reg == cb->reg && sub_leaf == cb->sub_leaf) {
-			if (cpu_has(&boot_cpu_data, cb->feature))
-				cpuid_val |= BIT(cb->bit);
-		}
-	}
-
-	return cpuid_val;
-}
-EXPORT_SYMBOL_GPL(get_scattered_cpuid_leaf);