SPECULATION_MITIGATIONS is currently defined only for x86. As a result, IS_ENABLED(CONFIG_SPECULATION_MITIGATIONS) is always false for other archs. f337a6a21e2f effectively set "mitigations=off" by default on non-x86 archs, which is not desired behavior. Jakub observed this change when running bpf selftests on s390 and arm64.

Fix this by moving SPECULATION_MITIGATIONS to arch/Kconfig so that it is available in all archs and thus can be used safely in kernel/cpu.c

Fixes: f337a6a21e2f ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n") Cc: stable@vger.kernel.org Cc: Sean Christopherson seanjc@google.com Cc: Ingo Molnar mingo@kernel.org Cc: Daniel Sneddon daniel.sneddon@linux.intel.com Cc: Jakub Kicinski kuba@kernel.org Signed-off-by: Song Liu song@kernel.org --- arch/Kconfig | 10 ++++++++++ arch/x86/Kconfig | 10 ---------- 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig index 9f066785bb71..8f4af75005f8 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1609,4 +1609,14 @@ config CC_HAS_SANE_FUNCTION_ALIGNMENT # strict alignment always, even with -falign-functions. def_bool CC_HAS_MIN_FUNCTION_ALIGNMENT || CC_IS_CLANG

+menuconfig SPECULATION_MITIGATIONS + bool "Mitigations for speculative execution vulnerabilities" + default y + help + Say Y here to enable options which enable mitigations for + speculative execution hardware vulnerabilities. + + If you say N, all mitigations will be disabled. You really + should know what you are doing to say so. + endmenu diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 39886bab943a..50c890fce5e0 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2486,16 +2486,6 @@ config PREFIX_SYMBOLS def_bool y depends on CALL_PADDING && !CFI_CLANG

-menuconfig SPECULATION_MITIGATIONS - bool "Mitigations for speculative execution vulnerabilities" - default y - help - Say Y here to enable options which enable mitigations for - speculative execution hardware vulnerabilities. - - If you say N, all mitigations will be disabled. You really - should know what you are doing to say so. - if SPECULATION_MITIGATIONS

config MITIGATION_PAGE_TABLE_ISOLATION