diff options
Diffstat (limited to 'arch/s390/Kconfig')
| -rw-r--r-- | arch/s390/Kconfig | 46 |
1 files changed, 45 insertions, 1 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 0105ce28e246..eaee7087886f 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -112,7 +112,6 @@ config S390 select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF select ARCH_WANTS_DYNAMIC_TASK_STRUCT - select ARCH_WANTS_PROT_NUMA_PROT_NONE select ARCH_WANTS_UBSAN_NO_NULL select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT @@ -540,6 +539,51 @@ config ARCH_RANDOM If unsure, say Y. +config KERNEL_NOBP + def_bool n + prompt "Enable modified branch prediction for the kernel by default" + help + If this option is selected the kernel will switch to a modified + branch prediction mode if the firmware interface is available. + The modified branch prediction mode improves the behaviour in + regard to speculative execution. + + With the option enabled the kernel parameter "nobp=0" or "nospec" + can be used to run the kernel in the normal branch prediction mode. + + With the option disabled the modified branch prediction mode is + enabled with the "nobp=1" kernel parameter. + + If unsure, say N. + +config EXPOLINE + def_bool n + prompt "Avoid speculative indirect branches in the kernel" + help + Compile the kernel with the expoline compiler options to guard + against kernel-to-user data leaks by avoiding speculative indirect + branches. + Requires a compiler with -mindirect-branch=thunk support for full + protection. The kernel may run slower. + + If unsure, say N. + +choice + prompt "Expoline default" + depends on EXPOLINE + default EXPOLINE_FULL + +config EXPOLINE_OFF + bool "spectre_v2=off" + +config EXPOLINE_MEDIUM + bool "spectre_v2=auto" + +config EXPOLINE_FULL + bool "spectre_v2=on" + +endchoice + endmenu menu "Memory setup" |