From 02ecc41abcea4ff9291d548f6f846b29b354ddd2 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Sun, 30 Nov 2014 14:26:39 +0100 Subject: [PATCH] x86, microcode: Limit the microcode reloading to 64-bit for now Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit First, there was this: https://bugzilla.kernel.org/show_bug.cgi?id=88001 The problem there was that microcode patches are not being reapplied after suspend-to-ram. It was important to reapply them, though, because of for example Haswell's TSX erratum which disabled TSX instructions with a microcode patch. A simple fix was fb86b97300d9 ("x86, microcode: Update BSPs microcode on resume") but, as it is often the case, simple fixes are too simple. This one causes 32-bit resume to fail: https://bugzilla.kernel.org/show_bug.cgi?id=88391 Properly fixing this would require more involved changes for which it is too late now, right before the merge window. Thus, limit this to 64-bit only temporarily. Signed-off-by: Borislav Petkov Link: http://lkml.kernel.org/r/1417353999-32236-1-git-send-email-bp@alien8.de Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/microcode/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index 2ce9051..08fe6e8 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -465,6 +465,7 @@ static void mc_bp_resume(void) if (uci->valid && uci->mc) microcode_ops->apply_microcode(cpu); +#ifdef CONFIG_X86_64 else if (!uci->mc) /* * We might resume and not have applied late microcode but still @@ -473,6 +474,7 @@ static void mc_bp_resume(void) * applying patches early on the APs. */ load_ucode_ap(); +#endif } static struct syscore_ops mc_syscore_ops = { -- 2.1.3