x86/cpufeatures: Add X86_BUG_SPECTRE_V[12]

Add the bug bits for spectre v1/2 and force them unconditionally for all
cpus.

Signed-off-by: David Woodhouse <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: Rik van Riel <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

arch/x86/include/asm/cpufeatures.h

@@ -342,5 +342,7 @@
 #define X86_BUG_MONITOR			X86_BUG(12) /* IPI required to wake up remote CPU */
 #define X86_BUG_AMD_E400		X86_BUG(13) /* CPU is among the affected by Erratum 400 */
 #define X86_BUG_CPU_MELTDOWN		X86_BUG(14) /* CPU is affected by meltdown attack and needs kernel page table isolation */
+#define X86_BUG_SPECTRE_V1		X86_BUG(15) /* CPU is affected by Spectre variant 1 attack with conditional branches */
+#define X86_BUG_SPECTRE_V2		X86_BUG(16) /* CPU is affected by Spectre variant 2 attack with indirect branches */
 
 #endif /* _ASM_X86_CPUFEATURES_H */

arch/x86/kernel/cpu/common.c

@@ -902,6 +902,9 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 	if (c->x86_vendor != X86_VENDOR_AMD)
 		setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
 
+	setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
+	setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+
 	fpu__init_system(c);
 
 #ifdef CONFIG_X86_32