Re: [PATCH -next] mm: kence: add __kmem_cache_free to function skip list

[Hyeonggon Yoo <42.hyeyoo@gmail.com>]

On Wed, Aug 31, 2022 at 03:30:51PM +0800, Feng Tang wrote:
> When testing the linux-next kernel, kfence's kunit test reported some
> errors:
> 
>   [   12.812412]     not ok 7 - test_double_free
>   [   13.011968]     not ok 9 - test_invalid_addr_free
>   [   13.438947]     not ok 11 - test_corruption
>   [   18.635647]     not ok 18 - test_kmalloc_aligned_oob_write
> 
> Further check shows there is the "common kmalloc" patchset from
> Hyeonggon Yoo, which cleanup the kmalloc code and make a better
> sharing of slab/slub. There is some function name change around it,
> which was not recognized by current kfence function name handling
> code, and interpreted as error.
> 
> Add new function name "__kmem_cache_free" to make it known to kfence.
> 
> Signed-off-by: Feng Tang <feng.tang@intel.com>
> ---
>  mm/kfence/report.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/mm/kfence/report.c b/mm/kfence/report.c
> index f5a6d8ba3e21..7e496856c2eb 100644
> --- a/mm/kfence/report.c
> +++ b/mm/kfence/report.c
> @@ -86,6 +86,7 @@ static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries
>  		/* Also the *_bulk() variants by only checking prefixes. */
>  		if (str_has_prefix(buf, ARCH_FUNC_PREFIX "kfree") ||
>  		    str_has_prefix(buf, ARCH_FUNC_PREFIX "kmem_cache_free") ||
> +		    str_has_prefix(buf, ARCH_FUNC_PREFIX "__kmem_cache_free") ||
>  		    str_has_prefix(buf, ARCH_FUNC_PREFIX "__kmalloc") ||
>  		    str_has_prefix(buf, ARCH_FUNC_PREFIX "kmem_cache_alloc"))
>  			goto found;
> -- 
> 2.27.0
> 

Thank you for catching this!

Unfortunately not reproducible on my environment with linux-next (IDK why).

Maybe you can include those functions too?

- __kmem_cache_alloc_node
- kmalloc_[node_]trace, kmalloc_large[_node]

-- 
Thanks,
Hyeonggon