Commit b8da0b33 authored by Breno Leitao's avatar Breno Leitao Committed by Borislav Petkov (AMD)
Browse files

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: default avatarBreno Leitao <leitao@debian.org>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20240729164105.554296-3-leitao@debian.org
parent 94045568

arch/x86/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -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 <file:Documentation/admin-guide/hw-vuln/mds.rst>



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 <file:Documentation/admin-guide/hw-vuln/tsx_async_abort.rst>

endif



config ARCH_HAS_ADD_PAGES

arch/x86/kernel/cpu/bugs.c

+2 −1
Original line number Diff line number Diff line
@@ -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[] = {