In check_cpu_pa_features() we check a number of bits in the ibm,pa-features array and set and clear CPU features based on what we find. One of these bits is CPU_FTR_TM, the transactional memory feature bit.
If this does disable TM at runtime, then we need to tell userspace about it by clearing the user CPU feature bits. Without this patch userspace processes will think they can execute TM instructions and get killed when they try. Signed-off-by: Anton Blanchard <an...@samba.org> Cc: sta...@vger.kernel.org --- Michael I've added stable here because I'm seeing this on a number of distros and would like to get it backported, but I'll leave it up to you if it should go there. diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index f98be83..98c6c86 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -822,4 +822,18 @@ static int __init disable_hardlockup_detector(void) return 0; } early_initcall(disable_hardlockup_detector); + +static int __init update_cpu_user_features(void) +{ + /* + * Firmware might have disabled TM by clearing the relevant + * bit in the ibm,pa-features array. In this case we need to + * tell userspace. + */ + if (!cpu_has_feature(CPU_FTR_TM)) + cur_cpu_spec->cpu_user_features2 &= ~(PPC_FEATURE2_HTM|PPC_FEATURE2_HTM_NOSC); + + return 0; +} +early_initcall(update_cpu_user_features); #endif _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev