From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (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 9F1502594BD for ; Wed, 24 Jun 2026 10:26:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782296805; cv=none; b=Ll6PCY7rUqR1XW8H/UM9Jw8QWioyeArTIMZmEC07PCmmQRZWnCnva+MPEQnwdtA44fOiXPuBN500fYmm6CZAXJRo4kXGcA4U3EbM6Gengd0awtSHzAxxz66xiE4Xusu1QMdsUy2m2I2MfM99RjSnhXBFMV1jlkqh6SzcCGiLjT8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782296805; c=relaxed/simple; bh=vB/+pduY8W2aSe2B53EzG0p/Gq5D5OvsdlA7KCSPxrY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=f4o9UmtzC1+l8ZQA7M3icnUzZ0WYsXg+y+AFPOPHLHMUY365ZxyxGX+ppMBbzxRAQe8PGgaE+LLoH1OXqAPPm3G/zsBRZ1mU4ZPOOSI8ySd3wD9zc9YlF7X71y2zCLzgyrOl1iPen9NIJ2KEyJsr4I/DAu/Bjf/ryAArXq0B8Vo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=apSiimHy; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="apSiimHy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1782296801; bh=vB/+pduY8W2aSe2B53EzG0p/Gq5D5OvsdlA7KCSPxrY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=apSiimHyCPKHyW4pfJO5br+B6Opds6HPMpLL+tFOWsb1ErJZ9mAtByaqMcxn43hmZ 9TGU1QHMHZu3mnzl5Y/tJlu2+xPFnzm7U5l74+v8aqu/eBxOT++/KMY3qetujTdZ3l a7MJVOAzcmHpzuavGQDusF2bMcR45lzQpS3h9whUfx1KWXn1WXaDwyrT4n06FCzfuG J78OqTscGXA2qszTbI7Om8LvDmdqavwliiyDafrJl8kLo1Mgs5Xve79MfEvNWE292X H6elRWWnmzQeZakuIdEiLifBnz7CdWnm5oTnyu0mUB4oDPRwBGRzXaGfPT5j+N9ZhR N/67ntEsQXVcA== Received: from fedora-2.home (unknown [100.64.0.11]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 1BB2C17E0C91; Wed, 24 Jun 2026 12:26:41 +0200 (CEST) Date: Wed, 24 Jun 2026 12:26:36 +0200 From: Boris Brezillon To: "Christian A. Ehrhardt" Cc: dri-devel@lists.freedesktop.org, Steven Price , Liviu Dudau , Andrew Morton , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/panthor: Check VMA boundaries for PMD mappings Message-ID: <20260624122636.22d34274@fedora-2.home> In-Reply-To: <20260623181942.1536598-1-lk@c--e.de> References: <20260623181942.1536598-1-lk@c--e.de> Organization: Collabora X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 23 Jun 2026 20:19:42 +0200 "Christian A. Ehrhardt" wrote: > When checking a different patch[1] sashiko AI pointed out that > panthor needs the same fix[2]: > > In the ->huge_fault handler do not install a PMD huge page > mapping if the huge page exceeds the boundaries of the VMA. > > [1] https://lore.kernel.org/lkml/20260622215718.1532689-1-lk@c--e.de/ > [2] https://sashiko.dev/#/patchset/20260622215718.1532689-1-lk%40c--e.de > > Cc: Boris Brezillon > Cc: Steven Price > Cc: Liviu Dudau > Fixes: 68cbf96b1e9b ("drm/panthor: Part ways with drm_gem_shmem_object") > Signed-off-by: Christian A. Ehrhardt I know the discussion is ongoing to decide what we should do about these huge_fault() handlers, but I think it's worth getting this fix in in the meantime. Reviewed-by: Boris Brezillon > --- > drivers/gpu/drm/panthor/panthor_gem.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > NOTE: > The panthor version is only compile tested because I don't > have the hardware. However, the code is identical to that > fixed in [1] and I have a reproducer for that. > > No need for for stable backports. The code is new in 7.1. > > diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/panthor/panthor_gem.c > index a1e2eb1ca7bb..54535bae2b0c 100644 > --- a/drivers/gpu/drm/panthor/panthor_gem.c > +++ b/drivers/gpu/drm/panthor/panthor_gem.c > @@ -802,9 +802,13 @@ static vm_fault_t insert_page(struct vm_fault *vmf, unsigned int order, struct p > } else if (order == PMD_ORDER) { > unsigned long pfn = page_to_pfn(page); > unsigned long paddr = pfn << PAGE_SHIFT; > + struct vm_area_struct *vma = vmf->vma; > + unsigned long start = ALIGN_DOWN(vmf->address, PMD_SIZE); > + unsigned long end = start + PMD_SIZE; > + bool in_range = vma->vm_start <= start && end <= vma->vm_end; > bool aligned = (vmf->address & ~PMD_MASK) == (paddr & ~PMD_MASK); > > - if (aligned && > + if (aligned && in_range && > folio_test_pmd_mappable(page_folio(page))) { > pfn &= PMD_MASK >> PAGE_SHIFT; > return vmf_insert_pfn_pmd(vmf, pfn, vmf->flags & FAULT_FLAG_WRITE);