Linux Patch #1

PATCH In review [email protected] 1 participant 1 message Apr 27, 2018 x86

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2018-04-27 00:01 UTC #0 lore raw

PATCH v6 1/10 Linux Patch #1

Combine the various logic which goes through all those x86_cpu_id matching structures in one function.

xReviewed-by Borislav Petkov <[email protected]>

Signed-off-by Konrad Rzeszutek Wilk <[email protected]>

---
v2: New patch
v3: Added Reviewed-by
v4: Changed title of the patch

---
 arch/x86/kernel/cpu/common.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

arch/x86/kernel/cpu/common.c +11 ~~-10~~

index 8a5b185735e1..b70cd22a9528 100644
@@ -923,21 +923,27 @@ static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
 	{}
 };
 
-static bool __init cpu_vulnerable_to_meltdown(struct cpuinfo_x86 *c)
+static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 {
 	u64 ia32_cap = 0;
 
+	if (x86_match_cpu(cpu_no_speculation))
+		return;
+
+	setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
+	setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+
 	if (x86_match_cpu(cpu_no_meltdown))
-		return false;
+		return;
 
 	if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
 		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
 
 	/* Rogue Data Cache Load? No! */
 	if (ia32_cap & ARCH_CAP_RDCL_NO)
-		return false;
+		return;
 
-	return true;
+	setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
 }
 
 /*

@@ -988,12 +994,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 
 	setup_force_cpu_cap(X86_FEATURE_ALWAYS);
 
-	if (!x86_match_cpu(cpu_no_speculation)) {
-		if (cpu_vulnerable_to_meltdown(c))
-			setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
-		setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
-		setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
-	}
+	cpu_set_bug_bits(c);
 
 	fpu__init_system(c);

Signature · 1 line

2.14.3