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authorCyril Bur <cyrilbur@gmail.com>2016-09-23 16:18:09 +1000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-10-31 05:02:14 -0600
commitd4d5154f8aa5fbd2862990a1e81e73cf3a56f4fe (patch)
parent613036d9e91990f2043130ff8f78fd770432b3de (diff)
powerpc: Add check_if_tm_restore_required() to giveup_all()
commit b0f16b46988fde02a1e32078f66a3059d7e53bfc upstream. 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 <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 59ef4417545f..ad37aa175f59 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -445,6 +445,7 @@ void giveup_all(struct task_struct *tsk)
+ check_if_tm_restore_required(tsk);
if (usermsr & MSR_FP)