From b0f16b46988fde02a1e32078f66a3059d7e53bfc Mon Sep 17 00:00:00 2001 From: Cyril Bur Date: Fri, 23 Sep 2016 16:18:09 +1000 Subject: [PATCH] powerpc: Add check_if_tm_restore_required() to giveup_all() giveup_all() causes FPU/VMX/VSX facilities to be disabled in a threads MSR. If the thread performing the giveup was transactional, the kernel must record which facilities were in use before the giveup as the thread must have these facilities re-enabled on return to userspace. >From process.c: /* * This is called if we are on the way out to userspace and the * TIF_RESTORE_TM flag is set. It checks if we need to reload * FP and/or vector state and does so if necessary. * If userspace is inside a transaction (whether active or * suspended) and FP/VMX/VSX instructions have ever been enabled * inside that transaction, then we have to keep them enabled * and keep the FP/VMX/VSX state loaded while ever the transaction * continues. The reason is that if we didn't, and subsequently * got a FP/VMX/VSX unavailable interrupt inside a transaction, * we don't know whether it's the same transaction, and thus we * don't know which of the checkpointed state and the transactional * state to use. */ Calling check_if_tm_restore_required() will set TIF_RESTORE_TM and save the MSR if needed. Fixes: c208505 ("powerpc: create giveup_all()") Signed-off-by: Cyril Bur Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/process.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 3846fab5d1ce..50295670c617 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -446,6 +446,7 @@ void giveup_all(struct task_struct *tsk) return; msr_check_and_set(msr_all_available); + check_if_tm_restore_required(tsk); #ifdef CONFIG_PPC_FPU if (usermsr & MSR_FP) -- 2.20.1