Re: [PATCH v3 2/2] drm/xe/devcoredump: Remove IS_ERR_OR_NULL check for kzalloc

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

On 20.02.2025 01:17, Shuicheng Lin wrote:
> kzalloc returns a valid pointer or NULL if the allocation fails.
> It never returns an error pointer. It is better to check for NULL directly.
> 
> Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
> Cc: John Harrison <John.C.Harrison@Intel.com>
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_devcoredump.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_devcoredump.c b/drivers/gpu/drm/xe/xe_devcoredump.c
> index 60d15e455017..81b9d9bb3f57 100644
> --- a/drivers/gpu/drm/xe/xe_devcoredump.c
> +++ b/drivers/gpu/drm/xe/xe_devcoredump.c
> @@ -426,8 +426,8 @@ void xe_print_blob_ascii85(struct drm_printer *p, const char *prefix, char suffi
>  		drm_printf(p, "Offset not word aligned: %zu", offset);
>  
>  	line_buff = kzalloc(DMESG_MAX_LINE_LEN, GFP_KERNEL);
> -	if (IS_ERR_OR_NULL(line_buff)) {
> -		drm_printf(p, "Failed to allocate line buffer: %pe", line_buff);
> +	if (!line_buff) {
> +		drm_printf(p, "Failed to allocate line buffer\n");

btw, since this line will be included in the output, where one could
expect ascii85 data, shouldn't we print that diagnostic message with
some special prefix to make it clear there is nothing to parse? like

	"# Failed to allocate internal data\n"

also since caller may have already provided a prefix, shouldn't we also
include it in this diagnostic message?

	"%s%s# Failed to allocate internal data\n",
	prefix ?: "",
	prefix ? ": " : ""

>  		return;
>  	}
>