[PATCH 3.16 62/86] x86/speculation: Consolidate CPU whitelists

Ben Hutchings
2019-05-16T16:03:35Z

From: Thomas Gleixner <tglx@linutronix.de>

commit 36ad35131adacc29b328b9c8b6277a8bf0d6fd5d upstream.

The CPU vulnerability whitelists have some overlap and there are more
whitelists coming along.

Use the driver_data field in the x86_cpu_id struct to denote the
whitelisted vulnerabilities and combine all whitelists into one.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/kernel/cpu/common.c | 105 +++++++++++++++++++----------------
1 file changed, 56 insertions(+), 49 deletions(-)

--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -807,60 +807,68 @@ static void identify_cpu_without_cpuid(s
#endif
}

-static const __initconst struct x86_cpu_id cpu_no_speculation[] = {
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SALTWELL, X86_FEATURE_ANY },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SALTWELL_TABLET, X86_FEATURE_ANY },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_BONNELL_MID, X86_FEATURE_ANY },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SALTWELL_MID, X86_FEATURE_ANY },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_BONNELL, X86_FEATURE_ANY },
- { X86_VENDOR_CENTAUR, 5 },
- { X86_VENDOR_INTEL, 5 },
- { X86_VENDOR_NSC, 5 },
- { X86_VENDOR_ANY, 4 },
- {}
-};
+#define NO_SPECULATION BIT(0)
+#define NO_MELTDOWN BIT(1)
+#define NO_SSB BIT(2)
+#define NO_L1TF BIT(3)
+
+#define VULNWL(_vendor, _family, _model, _whitelist) \
+ { X86_VENDOR_##_vendor, _family, _model, X86_FEATURE_ANY, _whitelist }
+
+#define VULNWL_INTEL(model, whitelist) \
+ VULNWL(INTEL, 6, INTEL_FAM6_##model, whitelist)
+
+#define VULNWL_AMD(family, whitelist) \
+ VULNWL(AMD, family, X86_MODEL_ANY, whitelist)
+
+static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
+ VULNWL(ANY, 4, X86_MODEL_ANY, NO_SPECULATION),
+ VULNWL(CENTAUR, 5, X86_MODEL_ANY, NO_SPECULATION),
+ VULNWL(INTEL, 5, X86_MODEL_ANY, NO_SPECULATION),
+ VULNWL(NSC, 5, X86_MODEL_ANY, NO_SPECULATION),
+
+ VULNWL_INTEL(ATOM_SALTWELL, NO_SPECULATION),
+ VULNWL_INTEL(ATOM_SALTWELL_TABLET, NO_SPECULATION),
+ VULNWL_INTEL(ATOM_SALTWELL_MID, NO_SPECULATION),
+ VULNWL_INTEL(ATOM_BONNELL, NO_SPECULATION),
+ VULNWL_INTEL(ATOM_BONNELL_MID, NO_SPECULATION),
+
+ VULNWL_INTEL(ATOM_SILVERMONT, NO_SSB | NO_L1TF),
+ VULNWL_INTEL(ATOM_SILVERMONT_X, NO_SSB | NO_L1TF),
+ VULNWL_INTEL(ATOM_SILVERMONT_MID, NO_SSB | NO_L1TF),
+ VULNWL_INTEL(ATOM_AIRMONT, NO_SSB | NO_L1TF),
+ VULNWL_INTEL(XEON_PHI_KNL, NO_SSB | NO_L1TF),
+ VULNWL_INTEL(XEON_PHI_KNM, NO_SSB | NO_L1TF),
+
+ VULNWL_INTEL(CORE_YONAH, NO_SSB),
+
+ VULNWL_INTEL(ATOM_AIRMONT_MID, NO_L1TF),
+ VULNWL_INTEL(ATOM_GOLDMONT, NO_L1TF),
+ VULNWL_INTEL(ATOM_GOLDMONT_X, NO_L1TF),
+ VULNWL_INTEL(ATOM_GOLDMONT_PLUS, NO_L1TF),
+
+ VULNWL_AMD(0x0f, NO_MELTDOWN | NO_SSB | NO_L1TF),
+ VULNWL_AMD(0x10, NO_MELTDOWN | NO_SSB | NO_L1TF),
+ VULNWL_AMD(0x11, NO_MELTDOWN | NO_SSB | NO_L1TF),
+ VULNWL_AMD(0x12, NO_MELTDOWN | NO_SSB | NO_L1TF),

-static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
- { X86_VENDOR_AMD },
+ /* FAMILY_ANY must be last, otherwise 0x0f - 0x12 matches won't work */
+ VULNWL_AMD(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF),
{}
};

-/* Only list CPUs which speculate but are non susceptible to SSB */
-static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT_X },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT_MID },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_CORE_YONAH },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNL },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNM },
- { X86_VENDOR_AMD, 0x12, },
- { X86_VENDOR_AMD, 0x11, },
- { X86_VENDOR_AMD, 0x10, },
- { X86_VENDOR_AMD, 0xf, },
- {}
-};
+static bool __init cpu_matches(unsigned long which)
+{
+ const struct x86_cpu_id *m = x86_match_cpu(cpu_vuln_whitelist);

-static const __initconst struct x86_cpu_id cpu_no_l1tf[] = {
- /* in addition to cpu_no_speculation */
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT_X },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT_MID },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT_MID },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_GOLDMONT },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_GOLDMONT_X },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_GOLDMONT_PLUS },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNL },
- { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNM },
- {}
-};
+ return m && !!(m->driver_data & which);
+}

static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
{
u64 ia32_cap = 0;

- if (x86_match_cpu(cpu_no_speculation))
+ if (cpu_matches(NO_SPECULATION))
return;

setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
@@ -869,15 +877,14 @@ static void __init cpu_set_bug_bits(stru
if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);

- if (!x86_match_cpu(cpu_no_spec_store_bypass) &&
- !(ia32_cap & ARCH_CAP_SSB_NO) &&
+ if (!cpu_matches(NO_SSB) && !(ia32_cap & ARCH_CAP_SSB_NO) &&
!cpu_has(c, X86_FEATURE_AMD_SSB_NO))
setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);

if (ia32_cap & ARCH_CAP_IBRS_ALL)
setup_force_cpu_cap(X86_FEATURE_IBRS_ENHANCED);

- if (x86_match_cpu(cpu_no_meltdown))
+ if (cpu_matches(NO_MELTDOWN))
return;

/* Rogue Data Cache Load? No! */
@@ -886,7 +893,7 @@ static void __init cpu_set_bug_bits(stru

setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);

- if (x86_match_cpu(cpu_no_l1tf))
+ if (cpu_matches(NO_L1TF))
return;

setup_force_cpu_bug(X86_BUG_L1TF);