Re: [PATCH v2 3/4] RAS/AMD/FMPM: Make max_nr_entries read-only

[Yazen Ghannam <yazen.ghannam@amd.com>]

On Wed, Aug 26, 2026 at 11:53:13AM +0800, Rui Qi wrote:
> max_nr_entries is used during module init to calculate max_rec_len.
> That length determines the size of each allocated FRU record and is not
> resized after init.
> 
> Leaving the parameter writable lets a later sysfs write raise the runtime
> limit used by update_fru_record(), allowing entries beyond the allocated
> flexible array to be written.
> 
> Expose the parameter as read-only so it can still be set at module load
> time, but cannot diverge from the allocation size afterwards.
> 
> Fixes: 6f15e617cc99 ("RAS: Introduce a FRU memory poison manager")
> Signed-off-by: Rui Qi <qirui.001@bytedance.com>
> ---
>  drivers/ras/amd/fmpm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/ras/amd/fmpm.c b/drivers/ras/amd/fmpm.c
> index e3f7bd053479..c13db1f743e5 100644
> --- a/drivers/ras/amd/fmpm.c
> +++ b/drivers/ras/amd/fmpm.c
> @@ -138,7 +138,7 @@ static struct dentry *fmpm_dfs_entries;
>   * No input or '0' will default to FMPM_DEFAULT_MAX_NR_ENTRIES.
>   */
>  static u8 max_nr_entries;
> -module_param(max_nr_entries, byte, 0644);
> +module_param(max_nr_entries, byte, 0444);
>  MODULE_PARM_DESC(max_nr_entries,
>  		 "Maximum number of memory poison descriptor entries per FRU");
>  
> -- 

Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>

Thanks,
Yazen