Re: WARNING in memory_failure() at include/linux/huge_mm.h:635 triggered

["David Hildenbrand (arm)" <david@kernel.org>]

On 2/4/26 22:08, Zi Yan wrote:
> On 4 Feb 2026, at 14:18, David Hildenbrand (arm) wrote:
> 
>> On 2/4/26 18:41, Zi Yan wrote:
>>>
>>>
>>> More details:
>>> later at sg_vma_fault(), the driver just handles a page fault by supplying
>>> a subpage from a pre-allocated compound page[3]. We then get a large folio
>>> without !CONFIG_TRANSPARENT_HUGEPAGE.
>>
>> We can identify such non-folio (but compound) things by looking at PG_large_rmappable IIRC.
> 
> OK, back to the issue. The patch below should fix the issue?
> 
> Hi 是参差,
> 
> Can you test it?
> 
>  From fa4a900e027a0c7365a9f786840943990d5da971 Mon Sep 17 00:00:00 2001
> From: Zi Yan <ziy@nvidia.com>
> Date: Wed, 4 Feb 2026 16:04:19 -0500
> Subject: [PATCH] mm/memory_failure: reject unsupported non-folio compound page
> 
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> ---
>   mm/memory-failure.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 825c706ac576..4ed903de9a0e 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2440,9 +2440,12 @@ int memory_failure(unsigned long pfn, int flags)
> 
>   	folio = page_folio(p);
> 
> -	/* filter pages that are protected from hwpoison test by users */
> +	/*
> +	 * filter pages that are protected from hwpoison test by users
> +	 * or unsupported non folio compound pages
> +	 */
>   	folio_lock(folio);
> -	if (hwpoison_filter(p)) {
> +	if (hwpoison_filter(p) || !folio_test_large_rmappable(folio)) {

I think you have to test for folio_test_large() before testing 
folio_test_large_rmappable().

-- 
Cheers,

David