From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 90DE62D9EFB; Mon, 1 Jun 2026 18:06:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780337169; cv=none; b=u6VompFcegsDQBNTfAPZ8w3AgBOIj5Sw6jWh5dLwgQocfBhYCccugl/Z2L/CoxHmv3sEtAENhWPbR3WvARzo+DyRYjrjSfJTAOHzyiVCiAiP+FHnQtukyPpzFLZ0R627RPo+uP7TjkdR1qgPzBYvkt53vuzierakUrvrdCl4d0o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780337169; c=relaxed/simple; bh=y8b8cdu75Vz6SQYYvSK1vHmq/Yl9xle2fQvD2+pPBqA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pQMjYmlK0VC0RrvPX7Z60vvrdyvFh01GOOXy+2EPOJJCnMtjHIIaoOJ+0oDqrp4l9/BEiv+ee3a6Dx8JXFdxJcRdtPgOH7rFdlpyA/S5lVeZMgPuy6bKvtt9LeM8fsWRsD57YnUUusR62GowKTmNbdirSsiZCeCsn6mzQlDDBX0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GZpNh+px; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GZpNh+px" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48B1F1F00898; Mon, 1 Jun 2026 18:06:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780337168; bh=MPIfI9k2oAu7CLM7hdDN2drmWMIEsFegPNxwh6nEkHY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=GZpNh+pxAYEE2fyC60cEj1j/k/7WKOtv6elnviyPut51Cp3Bwg83O+8rFr+aw9//L NUHhdBp+BdH0mdlnvLB3IXWW/SAasUb2Iz+wEjh+MA2eQbSqqwQ6qIVMFjzyzVAwGi PtdtKFQaS6HeqTCYPfjQo3NlXgFy7YTAuWzQbVxPiY81kZRB9ue35+nKj2rNQxSeFJ Eux/po7Go3RMxO2L8q38ORR/f3OzfWHqdETnIoOrZT0ssYSDchjxlUOpqRRgxo7mbL SPWstnIweCSymw20ncdWUtJY9Vov2pU3k8KWH2TAqYnsRNhuL+fWIncxX3D77zDEQ/ /WOzowHtk1QXg== Date: Mon, 1 Jun 2026 19:06:02 +0100 From: Lorenzo Stoakes To: "Kiryl Shutsemau (Meta)" Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mike Rapoport , David Hildenbrand , stable@vger.kernel.org, Sashiko AI review , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= , Muhammad Usama Anjum , Arnd Bergmann , Andrei Vagin , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 2/6] fs/proc/task_mmu: use huge_page_size() in pagemap_scan_hugetlb_entry() Message-ID: References: <20260529172331.356655-1-kas@kernel.org> <20260529172331.356655-3-kas@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260529172331.356655-3-kas@kernel.org> On Fri, May 29, 2026 at 06:23:26PM +0100, Kiryl Shutsemau (Meta) wrote: > The partial-page check compares against HPAGE_SIZE (PMD_SIZE), which > is wrong for gigantic hugetlb hstates (e.g. 1G). The walker hands the > callback a huge_page_size()-sized range, never start + HPAGE_SIZE, so > the comparison always declares it partial and aborts the WP. Compare > against the actual hstate's page size. > > Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") > Cc: stable@vger.kernel.org > Reported-by: Sashiko AI review > Signed-off-by: Kiryl Shutsemau LGTM, so: Reviewed-by: Lorenzo Stoakes > --- > fs/proc/task_mmu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index e21a38ac745b..1489c67e88f7 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -2960,7 +2960,7 @@ static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask, > if (~categories & PAGE_IS_WRITTEN) > goto out_unlock; > > - if (end != start + HPAGE_SIZE) { > + if (end != start + huge_page_size(hstate_vma(vma))) { > /* Partial HugeTLB page WP isn't possible. */ > pagemap_scan_backout_range(p, start, end); > p->arg.walk_end = start; > -- > 2.54.0 >