[Cbe-oss-dev] [PATCH 2/2] libspe2 : Add emulated isolation support RESEND

[Kazunori Asayama]

kannas at ofb.net (Kanna Shimizu) wrote:
> libspe2: Add emulated isolated mode support
> 
> Using a userspace loader, we can add an 'emulated' isolated mode, which
> provides a facility to run contexts with an isolated-mode environment,
> but without restricted access to SPE hardware. Contexts can be created
> in emulated isolated mode by providing the SPE_ISOLATE_EMULATE flag to
> spe_context_create.
> 
> This functionality depends on an emulated loader - a SPE program to
> load the "emulated isolated" SPE application, using the same ABI as the
> real isolated mode loader. We check for this in the file:
> 
>   $libdir/spe/emulated-loader.bin
> 
> - if this isn't present (or isn't a valid SPE binary) then we refuse to
> create emulated-isolated contexts.

(snip)

> Index: libspe2/spebase/run.c
> ===================================================================
> --- libspe2.orig/spebase/run.c
> +++ libspe2/spebase/run.c
> @@ -102,7 +102,7 @@ int _base_spe_context_run(spe_context_pt
>  		spe_stop_info_t *stopinfo)
>  {
>  	int retval = 0, run_rc;
> -	unsigned int run_status;
> +	unsigned int run_status, tmp_entry;
>  	spe_stop_info_t	stopinfo_buf;
>  	struct spe_context_info this_context_info __attribute__((cleanup(cleanupspeinfo)));
>  
> @@ -111,13 +111,20 @@ int _base_spe_context_run(spe_context_pt
>  	if (!stopinfo)
>  		stopinfo = &stopinfo_buf;
>  
> -	if (*entry == SPE_DEFAULT_ENTRY)
> -		*entry = spe->base_private->entry;
> +
> +	/* In emulated isolated mode, the npc will always return as zero.
> +	 * use our private entry point instead */
> +	if (spe->base_private->flags & SPE_ISOLATE_EMULATE)
> +		tmp_entry = spe->base_private->emulated_entry;
> +
> +	else if (*entry == SPE_DEFAULT_ENTRY)
> +		tmp_entry = spe->base_private->entry;

The tmp_entry is never initialized in other cases. It must be
initialized as:
--
	else
		tmp_entry = *entry;
--

The other parts look good.

--
(ASAYAMA Kazunori
  (asayama at sm.sony.co.jp))
t