x86, microcode, AMD: Make cpu_has_amd_erratum() use the correct struct cpuinfo_x86 (8c6b79bb) · Commits · 戴 / test

cpu_has_amd_erratum() is buggy, because it uses the per-cpu cpu_info before it is filled by smp_store_boot_cpu_info() / smp_store_cpu_info(). If early microcode loading is enabled its collect_cpu_info_amd_early() will fill ->x86 and so the fallback to boot_cpu_data is not used. But ->x86_vendor was not filled and is still X86_VENDOR_INTEL resulting in no errata fixes getting applied and my system hangs on boot. Using cpu_info in cpu_has_amd_erratum() is wrong anyway: its only caller init_amd() will have a struct cpuinfo_x86 as parameter and the set_cpu_bug() that is controlled by cpu_has_amd_erratum() also only uses that struct. So pass the struct cpuinfo_x86 from init_amd() to cpu_has_amd_erratum() and the broken fallback can be dropped. [ Boris: Drop WARN_ON() since we're called only from init_amd() ] Signed-off-by:

Torsten Kaiser <just.for.lkml@googlemail.com> Signed-off-by:

Borislav Petkov <bp@suse.de>

arch/x86/kernel/cpu/amd.c

+5 −15

Original line number	Diff line number	Diff line
		@@ -512,7 +512,7 @@ static void early_init_amd(struct cpuinfo_x86 *c)

		static const int amd_erratum_383[];
		static const int amd_erratum_400[];
		static bool cpu_has_amd_erratum(const int *erratum);
		static bool cpu_has_amd_erratum(struct cpuinfo_x86 cpu, const int erratum);

		static void init_amd(struct cpuinfo_x86 *c)
		{
		@@ -729,11 +729,11 @@ static void init_amd(struct cpuinfo_x86 *c)
		value &= ~(1ULL << 24);
		wrmsrl_safe(MSR_AMD64_BU_CFG2, value);

		if (cpu_has_amd_erratum(amd_erratum_383))
		if (cpu_has_amd_erratum(c, amd_erratum_383))
		set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);
		}

		if (cpu_has_amd_erratum(amd_erratum_400))
		if (cpu_has_amd_erratum(c, amd_erratum_400))
		set_cpu_bug(c, X86_BUG_AMD_APIC_C1E);

		rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);
		@@ -878,23 +878,13 @@ static const int amd_erratum_400[] =
		static const int amd_erratum_383[] =
		AMD_OSVW_ERRATUM(3, AMD_MODEL_RANGE(0x10, 0, 0, 0xff, 0xf));

		static bool cpu_has_amd_erratum(const int *erratum)

		static bool cpu_has_amd_erratum(struct cpuinfo_x86 cpu, const int erratum)
		{
		struct cpuinfo_x86 *cpu = __this_cpu_ptr(&cpu_info);
		int osvw_id = *erratum++;
		u32 range;
		u32 ms;

		/*
		* If called early enough that current_cpu_data hasn't been initialized
		* yet, fall back to boot_cpu_data.
		*/
		if (cpu->x86 == 0)
		cpu = &boot_cpu_data;

		if (cpu->x86_vendor != X86_VENDOR_AMD)
		return false;

		if (osvw_id >= 0 && osvw_id < 65536 &&
		cpu_has(cpu, X86_FEATURE_OSVW)) {
		u64 osvw_len;

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