diff options
| author | Cyril Bur <cyrilbur@gmail.com> | 2016-09-23 16:18:09 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-10-31 05:02:14 -0600 |
| commit | d4d5154f8aa5fbd2862990a1e81e73cf3a56f4fe (patch) | |
| tree | 6bcdf82718407428d0f3a51a1ec2b297bba00725 /arch | |
| parent | 613036d9e91990f2043130ff8f78fd770432b3de (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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 1 |
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) return; msr_check_and_set(msr_all_available); + check_if_tm_restore_required(tsk); #ifdef CONFIG_PPC_FPU if (usermsr & MSR_FP) |