From b8da0b33d3899e5911aaf0220a317545fe2e3b37 Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Mon, 29 Jul 2024 09:40:50 -0700 Subject: [PATCH] x86/bugs: Add a separate config for TAA Currently, the CONFIG_SPECULATION_MITIGATIONS is halfway populated, where some mitigations have entries in Kconfig, and they could be modified, while others mitigations do not have Kconfig entries, and could not be controlled at build time. Create an entry for the TAA CPU mitigation under CONFIG_SPECULATION_MITIGATIONS. This allow users to enable or disable it at compilation time. Signed-off-by: Breno Leitao Signed-off-by: Borislav Petkov (AMD) Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20240729164105.554296-3-leitao@debian.org --- arch/x86/Kconfig | 11 +++++++++++ arch/x86/kernel/cpu/bugs.c | 3 ++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 36e871ab1ef9..712a4f8cb7dd 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2659,6 +2659,17 @@ config MITIGATION_MDS a hardware vulnerability which allows unprivileged speculative access to data which is available in various CPU internal buffers. See also + +config MITIGATION_TAA + bool "Mitigate TSX Asynchronous Abort (TAA) hardware bug" + depends on CPU_SUP_INTEL + default y + help + Enable mitigation for TSX Asynchronous Abort (TAA). TAA is a hardware + vulnerability that allows unprivileged speculative access to data + which is available in various CPU internal buffers by using + asynchronous aborts within an Intel TSX transactional region. + See also endif config ARCH_HAS_ADD_PAGES diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index dbfc7d5c5f48..ab306986762d 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -294,7 +294,8 @@ enum taa_mitigations { }; /* Default mitigation for TAA-affected CPUs */ -static enum taa_mitigations taa_mitigation __ro_after_init = TAA_MITIGATION_VERW; +static enum taa_mitigations taa_mitigation __ro_after_init = + IS_ENABLED(CONFIG_MITIGATION_TAA) ? TAA_MITIGATION_VERW : TAA_MITIGATION_OFF; static bool taa_nosmt __ro_after_init; static const char * const taa_strings[] = {