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

[Lucas De Marchi]

On Thu, Feb 20, 2025 at 05:29:56PM +0100, Michal Wajdeczko wrote:
>
>
>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 at intel.com>
>> Cc: John Harrison <John.C.Harrison at Intel.com>
>> Cc: Lucas De Marchi <lucas.demarchi at 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 ? ": " : ""

or stop printing and return an error. we are missing the `.error: ...`
already that is used in other places.

$ git grep '\.error: ' -- drivers/gpu/drm/xe
drivers/gpu/drm/xe/xe_vm.c:             drm_printf(p, "[0].error: %li\n", PTR_ERR(snap));
drivers/gpu/drm/xe/xe_vm.c:                     drm_printf(p, "[%llx].error: %li\n", snap->snap[i].ofs,

Lucas De Marchi




>
>>  		return;
>>  	}
>>
>