Re: [PATCH v5 7/9] ACPI: APEI: EINJ: Add debugfs files for EINJv2 support

[Ira Weiny <ira.weiny@intel.com>]

Zaid Alali wrote:
> Create a debugfs blob file to be used for reading the user
> input for the component array. EINJv2 enables users to inject
> errors to multiple components/devices at the same time using
> component array.
> 
> Signed-off-by: Zaid Alali <zaidal@os.amperecomputing.com>

[snip]

> @@ -890,6 +893,17 @@ static int __init einj_probe(struct platform_device *pdev)
>  				   &error_param4);
>  		debugfs_create_x32("notrigger", S_IRUSR | S_IWUSR,
>  				   einj_debug_dir, &notrigger);
> +		if (available_error_type & ACPI65_EINJV2_SUPP) {
> +			user_input = kzalloc(COMP_ARR_SIZE, GFP_KERNEL);
> +			if (!user_input) {
> +				rc = -ENOMEM;
> +				goto err_alloc;
> +			}
> +			einjv2_component_arr.data = user_input;
> +			einjv2_component_arr.size = COMP_ARR_SIZE;
> +			debugfs_create_blob("einjv2_component_array", S_IRUSR | S_IWUSR,
> +					einj_debug_dir, &einjv2_component_arr);
> +		}
>  	}
>  
>  	if (vendor_dev[0]) {
> @@ -909,6 +923,8 @@ static int __init einj_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> +err_alloc:
> +	apei_exec_post_unmap_gars(&ctx);

The addition of an unmap call without a corresponding map call threw me.
I see that this is needed in this flow.

Why not attempt the kzalloc() right off in the function?  This avoids the extra
goto and all the unwind path.

Like:

diff --git a/drivers/acpi/apei/einj-core.c b/drivers/acpi/apei/einj-core.c
index 04731a5b01fa..2993e0eb4f81 100644
--- a/drivers/acpi/apei/einj-core.c
+++ b/drivers/acpi/apei/einj-core.c
@@ -771,6 +771,10 @@ static int __init einj_probe(struct platform_device *pdev)
                return -EINVAL;
        }
 
+       user_input = kzalloc(COMP_ARR_SIZE, GFP_KERNEL);
+       if (!user_input)
+               return -ENOMEM;
+
        rc = einj_check_table(einj_tab);
        if (rc) {
                pr_warn(FW_BUG "Invalid EINJ table.\n");


Or, perhaps better, just disable einjv2 if the alloc fails and not fail the probe?

Ira

[snip]