From 2760f452a71899af860355abe818a8b2bd32b2cb Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Thu, 12 Oct 2017 13:23:16 +0200 Subject: x86/microcode: Do the family check first commit 1f161f67a272cc4f29f27934dd3f74cb657eb5c4 upstream with adjustments. On CPUs like AMD's Geode, for example, we shouldn't even try to load microcode because they do not support the modern microcode loading interface. However, we do the family check *after* the other checks whether the loader has been disabled on the command line or whether we're running in a guest. So move the family checks first in order to exit early if we're being loaded on an unsupported family. Reported-and-tested-by: Sven Glodowski Signed-off-by: Borislav Petkov Cc: # 4.11.. Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://bugzilla.suse.com/show_bug.cgi?id=1061396 Link: http://lkml.kernel.org/r/20171012112316.977-1-bp@alien8.de Signed-off-by: Ingo Molnar Signed-off-by: Rolf Neugebauer Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/microcode/core.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index dc0b9f8763ad..0afaf00b029b 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -86,9 +86,6 @@ static bool __init check_loader_disabled_bsp(void) bool *res = &dis_ucode_ldr; #endif - if (!have_cpuid_p()) - return *res; - a = 1; c = 0; native_cpuid(&a, &b, &c, &d); @@ -130,8 +127,9 @@ void __init load_ucode_bsp(void) { int vendor; unsigned int family; + bool intel = true; - if (check_loader_disabled_bsp()) + if (!have_cpuid_p()) return; vendor = x86_cpuid_vendor(); @@ -139,16 +137,27 @@ void __init load_ucode_bsp(void) switch (vendor) { case X86_VENDOR_INTEL: - if (family >= 6) - load_ucode_intel_bsp(); + if (family < 6) + return; break; + case X86_VENDOR_AMD: - if (family >= 0x10) - load_ucode_amd_bsp(family); + if (family < 0x10) + return; + intel = false; break; + default: - break; + return; } + + if (check_loader_disabled_bsp()) + return; + + if (intel) + load_ucode_intel_bsp(); + else + load_ucode_amd_bsp(family); } static bool check_loader_disabled_ap(void) -- cgit v1.2.3