On Fri, Mar 07, 2014 at 05:07:21PM -0800, Greg Kroah-Hartman wrote:
> 3.4-stable review patch.  If anyone has any objections, please let me know.
> 

As per Tony request, I've dropped this patch from the 3.5 kernel.  Looks
like it is applicable to kernels >= 3.10, so I guess you can drop it from
3.4 as well.

Cheers,
--
Luís

> ------------------
> 
> From: Tony Breeds <t...@bakeyournoodle.com>
> 
> commit 41dd03a94c7d408d2ef32530545097f7d1befe5c upstream.
> 
> Currently we're storing a host endian RTAS token in
> rtas_stop_self_args.token.  We then pass that directly to rtas.  This is
> fine on big endian however on little endian the token is not what we
> expect.
> 
> This will typically result in hitting:
>       panic("Alas, I survived.\n");
> 
> To fix this we always use the stop-self token in host order and always
> convert it to be32 before passing this to rtas.
> 
> Signed-off-by: Tony Breeds <t...@bakeyournoodle.com>
> Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
> 
> ---
>  arch/powerpc/platforms/pseries/hotplug-cpu.c |   22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> @@ -34,12 +34,7 @@
>  #include "offline_states.h"
>  
>  /* This version can't take the spinlock, because it never returns */
> -static struct rtas_args rtas_stop_self_args = {
> -     .token = RTAS_UNKNOWN_SERVICE,
> -     .nargs = 0,
> -     .nret = 1,
> -     .rets = &rtas_stop_self_args.args[0],
> -};
> +static int rtas_stop_self_token = RTAS_UNKNOWN_SERVICE;
>  
>  static DEFINE_PER_CPU(enum cpu_state_vals, preferred_offline_state) =
>                                                       CPU_STATE_OFFLINE;
> @@ -92,15 +87,20 @@ void set_default_offline_state(int cpu)
>  
>  static void rtas_stop_self(void)
>  {
> -     struct rtas_args *args = &rtas_stop_self_args;
> +     struct rtas_args args = {
> +             .token = cpu_to_be32(rtas_stop_self_token),
> +             .nargs = 0,
> +             .nret = 1,
> +             .rets = &args.args[0],
> +     };
>  
>       local_irq_disable();
>  
> -     BUG_ON(args->token == RTAS_UNKNOWN_SERVICE);
> +     BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE);
>  
>       printk("cpu %u (hwid %u) Ready to die...\n",
>              smp_processor_id(), hard_smp_processor_id());
> -     enter_rtas(__pa(args));
> +     enter_rtas(__pa(&args));
>  
>       panic("Alas, I survived.\n");
>  }
> @@ -383,10 +383,10 @@ static int __init pseries_cpu_hotplug_in
>               }
>       }
>  
> -     rtas_stop_self_args.token = rtas_token("stop-self");
> +     rtas_stop_self_token = rtas_token("stop-self");
>       qcss_tok = rtas_token("query-cpu-stopped-state");
>  
> -     if (rtas_stop_self_args.token == RTAS_UNKNOWN_SERVICE ||
> +     if (rtas_stop_self_token == RTAS_UNKNOWN_SERVICE ||
>                       qcss_tok == RTAS_UNKNOWN_SERVICE) {
>               printk(KERN_INFO "CPU Hotplug not supported by firmware "
>                               "- disabling.\n");
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe stable" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to