Subject: Re: [PATCH] powerpc/kernel: Initialize load_tm on task creation

From: Daniel Axtens <[email-masked]>
Date: Tue, 06 Jun 2017 08:52:28 +1000

Hi Breno,

Looks good to me.

> Currently tsk->thread.load_tm is not initialized in the task creation
> and can contain garbage on a new task.
>
> This is an undesired behaviour, since it affects the timing to enable
> and disable the transactional memory laziness (disabling and enabling
> the MSR TM bit, which affects TM reclaim and recheckpoint in the
> scheduling process).

Is there any chance this uninitialised memory will leak something
interesting/sensitive? (Therefore, should this go to stable?)

Regards,
Daniel

> CC: Anton Blanchard <[email-masked]>
> Fixes: 5d176f751ee3c6eededd984ad409bff201f436a7
> Signed-off-by: Breno Leitao <[email-masked]>
> ---
>  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 a9435397eab8..2ad725ef4368 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -1687,6 +1687,7 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
>  	current->thread.tm_tfhar = 0;
>  	current->thread.tm_texasr = 0;
>  	current->thread.tm_tfiar = 0;
> +	current->thread.load_tm = 0;
>  #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
>  }
>  EXPORT_SYMBOL(start_thread);
> -- 
> 2.11.0