EDAC/skx_common: Fix allocation check when adxl_component_count is 0

[PATCH] EDAC/skx_common: Fix allocation check when adxl_component_count is 0

Posted by Rui Qi 1 week, 6 days ago

From: Rui Qi <qirui.001@bytedance.com>

Use ZERO_OR_NULL_PTR instead of simple NULL check to properly handle
the case where adxl_component_count is 0, which would result in
kcalloc returning ZERO_SIZE_PTR rather than NULL.

This ensures correct error handling when no ADXL components are
present and prevents potential issues with zero-sized allocations.

Signed-off-by: Rui Qi <qirui.001@bytedance.com>
---
 drivers/edac/skx_common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/edac/skx_common.c b/drivers/edac/skx_common.c
index 39c733dbc5b9..768d787813ec 100644
--- a/drivers/edac/skx_common.c
+++ b/drivers/edac/skx_common.c
@@ -90,7 +90,7 @@ int skx_adxl_get(void)
 
 	adxl_values = kcalloc(adxl_component_count, sizeof(*adxl_values),
 			      GFP_KERNEL);
-	if (!adxl_values) {
+	if (ZERO_OR_NULL_PTR(adxl_values)) {
 		adxl_component_count = 0;
 		return -ENOMEM;
 	}
-- 
2.20.1

RE: [PATCH] EDAC/skx_common: Fix allocation check when adxl_component_count is 0

Posted by Zhuo, Qiuxu 1 week, 5 days ago

Hi Rui Qi,

Thanks for looking at the code.

> From: Rui Qi <qirui.001@bytedance.com>
> [...]
> Subject: [PATCH] EDAC/skx_common: Fix allocation check when
> adxl_component_count is 0
> 
> From: Rui Qi <qirui.001@bytedance.com>
> 
> Use ZERO_OR_NULL_PTR instead of simple NULL check to properly handle the
> case where adxl_component_count is 0, which would result in kcalloc
> returning ZERO_SIZE_PTR rather than NULL.
> 
> This ensures correct error handling when no ADXL components are present
> and prevents potential issues with zero-sized allocations.

If the ADXL component names are empty, skx_adxl_get() will immediately jump to error handling.
So, the adxl_component_count value is guaranteed to be non-zero when passed to kcalloc(). 

> 
> Signed-off-by: Rui Qi <qirui.001@bytedance.com>
> [...]

Re: [External] RE: [PATCH] EDAC/skx_common: Fix allocation check when adxl_component_count is 0

Posted by Rui Qi 1 week, 3 days ago

On 9/19/25 8:56 PM, Zhuo, Qiuxu wrote:
> Hi Rui Qi,
>
> Thanks for looking at the code.
>
>> From: Rui Qi <qirui.001@bytedance.com>
>> [...]
>> Subject: [PATCH] EDAC/skx_common: Fix allocation check when
>> adxl_component_count is 0
>>
>> From: Rui Qi <qirui.001@bytedance.com>
>>
>> Use ZERO_OR_NULL_PTR instead of simple NULL check to properly handle the
>> case where adxl_component_count is 0, which would result in kcalloc
>> returning ZERO_SIZE_PTR rather than NULL.
>>
>> This ensures correct error handling when no ADXL components are present
>> and prevents potential issues with zero-sized allocations.
>
> If the ADXL component names are empty, skx_adxl_get() will immediately jump to error handling.
> So, the adxl_component_count value is guaranteed to be non-zero when passed to kcalloc().
>

Well, I've rechecked the code, and your statement is correct. So my
modification is indeed unnecessary.

>>
>> Signed-off-by: Rui Qi <qirui.001@bytedance.com>
>> [...]