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Date:   Fri, 20 Oct 2023 09:34:07 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Dan Carpenter <dan.carpenter@linaro.org>
Cc:     Zach O'Keefe <zokeefe@google.com>, Yang Shi <shy828301@gmail.com>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        kernel-janitors@vger.kernel.org, Zach O'Keefe <zokeefe@google.com>
Subject: Re: [PATCH 1/2] mm/khugepaged: Fix an uninitialized variable bug
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On Fri, 20 Oct 2023 17:13:32 +0300 Dan Carpenter <dan.carpenter@linaro.org> wrote:

> Smatch complains that "hpage" can be used uninitialized:
> 
>     mm/khugepaged.c:1234 collapse_huge_page()
>     error: uninitialized symbol 'hpage'.
> 
> Initialized it on this path.
> 
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -1062,8 +1062,10 @@ static int alloc_charge_hpage(struct page **hpage, struct mm_struct *mm,
>  	int node = hpage_collapse_find_target_node(cc);
>  	struct folio *folio;
>  
> -	if (!hpage_collapse_alloc_folio(&folio, gfp, node, &cc->alloc_nmask))
> +	if (!hpage_collapse_alloc_folio(&folio, gfp, node, &cc->alloc_nmask)) {
> +		*hpage = NULL;
>  		return SCAN_ALLOC_HUGE_PAGE_FAIL;
> +	}
>  
>  	if (unlikely(mem_cgroup_charge(folio, mm, gfp))) {
>  		folio_put(folio);

Thanks.   Seems this was accidentally fixed by 

Author:     Peter Xu <peterx@redhat.com>
AuthorDate: Wed Feb 22 14:52:47 2023 -0500
Commit:     Andrew Morton <akpm@linux-foundation.org>
CommitDate: Tue Mar 28 16:20:06 2023 -0700

    mm/khugepaged: alloc_charge_hpage() take care of mem charge errors


Which was quite a long time ago.  Are you scanning old kernel versions?