Am Freitag, 26 August 2016, 11:50:10 schrieb Rui Teng:
> The same logic appears twice and should probably be pulled out into a
> function.
>
> Suggested-by: Michael Ellerman <m...@ellerman.id.au>
> Signed-off-by: Rui Teng <rui.t...@linux.vnet.ibm.com>
> ---
> arch/powerpc/mm/hash_utils_64.c | 45
> +++++++++++++++++------------------------ 1 file changed, 19
> insertions(+), 26 deletions(-)
>
> diff --git a/arch/powerpc/mm/hash_utils_64.c
> b/arch/powerpc/mm/hash_utils_64.c index 0821556..69ef702 100644
> --- a/arch/powerpc/mm/hash_utils_64.c
> +++ b/arch/powerpc/mm/hash_utils_64.c
> @@ -1460,6 +1460,23 @@ out_exit:
> local_irq_restore(flags);
> }
>
> +/*
> + * Transactions are not aborted by tlbiel, only tlbie.
> + * Without, syncing a page back to a block device w/ PIO could pick up
> + * transactional data (bad!) so we force an abort here. Before the
> + * sync the page will be made read-only, which will flush_hash_page.
> + * BIG ISSUE here: if the kernel uses a page from userspace without
> + * unmapping it first, it may see the speculated version.
> + */
> +void local_tm_abort(int local)
> +{
> + if (local && cpu_has_feature(CPU_FTR_TM) && current->thread.regs &&
> + MSR_TM_ACTIVE(current->thread.regs->msr)) {
> + tm_enable();
> + tm_abort(TM_CAUSE_TLBI);
> + }
> +}
> +
Since local_tm_abort is only used in this file, it should be static.
Also, since both places calling it are guarded by
CONFIG_PPC_TRANSACTIONAL_MEM, wouldn't it be cleaner if the #ifdef was here
instead and the #else block defined an empty static inline function? Then
the call sites wouldn't need to be guarded.
--
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center
