x86/cpufeatures: Add X86_BUG_SPECTRE_V[12]

commit 99c6fa2511d8a683e61468be91b83f85452115fa upstream.

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

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515239374-23361-2-git-send-email-dwmw@amazon.co.uk
[bwh: Backported to 3.2: assign the first available bug numbers]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 87d11d1..a6afd47 100644 (file)
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -215,6 +215,8 @@
 #define X86_BUG(x)             (NCAPINTS*32 + (x))
 
 #define X86_BUG_CPU_MELTDOWN   X86_BUG(0) /* CPU is affected by meltdown attack and needs kernel page table isolation */
+#define X86_BUG_SPECTRE_V1     X86_BUG(1) /* CPU is affected by Spectre variant 1 attack with conditional branches */
+#define X86_BUG_SPECTRE_V2     X86_BUG(2) /* CPU is affected by Spectre variant 2 attack with indirect branches */
 
 #if defined(__KERNEL__) && !defined(__ASSEMBLY__)
 

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8da173c..458c595 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -770,6 +770,9 @@ 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);
 }
 
 void __init early_cpu_init(void)