Re: [PATCH 17/26] intel_telemetry_debugfs: constify local structures

[Darren Hart <dvhart@infradead.org>]

On Sun, Sep 11, 2016 at 03:05:59PM +0200, Julia Lawall wrote:

Hi Julia,

> For structure types defined in the same file or local header files, find
> top-level static structure declarations that have the following
> properties:
> 1. Never reassigned.
> 2. Address never taken

Hrm. telem_apl_debugfs_conf is passed to the TELEM_DEBUGFS_CPU macro as the
second argument "data":

#define TELEM_DEBUGFS_CPU(model, data) \
	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&data}

And the address is taken, and later assigned to the debugfs_conf pointer.

The usage still seems OK, but did I misunderstand the conditions?


> 3. Not passed to a top-level macro call
> 4. No pointer or array-typed field passed to a function or stored in a
> variable.
> Declare structures having all of these properties as const.
> 
> Done using Coccinelle.
> Based on a suggestion by Joe Perches <joe@perches.com>.

> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
> 
> ---
> The semantic patch seems too long for a commit log, but is in the cover
> letter.
> 
>  drivers/platform/x86/intel_telemetry_debugfs.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/intel_telemetry_debugfs.c b/drivers/platform/x86/intel_telemetry_debugfs.c
> index ef29f18..d0761f3 100644
> --- a/drivers/platform/x86/intel_telemetry_debugfs.c
> +++ b/drivers/platform/x86/intel_telemetry_debugfs.c
> @@ -297,7 +297,7 @@ struct telemetry_debugfs_conf {
>  
>  static struct telemetry_debugfs_conf *debugfs_conf;
>  
> -static struct telemetry_debugfs_conf telem_apl_debugfs_conf = {
> +static const struct telemetry_debugfs_conf telem_apl_debugfs_conf = {
>  	.pss_idle_data = telem_apl_pss_idle_data,
>  	.pcs_idle_blkd_data = telem_apl_pcs_idle_blkd_data,
>  	.pcs_s0ix_blkd_data = telem_apl_pcs_s0ix_blkd_data,
> 
> 

-- 
Darren Hart
Intel Open Source Technology Center