The following commit has been merged into the x86/urgent branch of tip: Commit-ID: e8f2ec1cc10e86adfc2089fb93a1158e69989bbd Gitweb: https://git.kernel.org/tip/e8f2ec1cc10e86adfc2089fb93a1158e69989bbd Author: Sean Christopherson <seanjc@xxxxxxxxxx> AuthorDate: Tue, 09 Apr 2024 10:51:06 -07:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Wed, 10 Apr 2024 16:22:56 +02:00 x86/cpu: Disable BHI mitigation by default when SPECULATION_MITIGATIONS=n Rework the initialization of bhi_mitigation to use positive CONFIG tests for the ON/AUTO cases so that lack of *any* CONFIG_SPECTRE_BHI_* #define, i.e. when the kernel is built with CONFIG_SPECULATION_MITIGATIONS=n, results in the mitigation being OFF by default, not AUTO. Per the help text for SPECULATION_MITIGATIONS, the intent is that 'N' disables all mitigations. Fixes: ec9404e40e8f ("x86/bhi: Add BHI mitigation knob") Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Reviewed-by: Daniel Sneddon <daniel.sneddon@xxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240409175108.1512861-3-seanjc@xxxxxxxxxx --- arch/x86/kernel/cpu/bugs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 27f5004..7e4a706 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1630,9 +1630,9 @@ enum bhi_mitigations { }; static enum bhi_mitigations bhi_mitigation __ro_after_init = - IS_ENABLED(CONFIG_SPECTRE_BHI_ON) ? BHI_MITIGATION_ON : - IS_ENABLED(CONFIG_SPECTRE_BHI_OFF) ? BHI_MITIGATION_OFF : - BHI_MITIGATION_AUTO; + IS_ENABLED(CONFIG_SPECTRE_BHI_ON) ? BHI_MITIGATION_ON : + IS_ENABLED(CONFIG_SPECTRE_BHI_AUTO) ? BHI_MITIGATION_AUTO : + BHI_MITIGATION_OFF; static int __init spectre_bhi_parse_cmdline(char *str) {
