linux-kernel - Re: [PATCH 3/5] mm: Rename __thp_get_unmapped_area to mm_get_unmapped_area

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250613141745.GJ1174925@nvidia.com>
Date: Fri, 13 Jun 2025 11:17:45 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: Peter Xu <peterx@...hat.com>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org, kvm@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Alex Williamson <alex.williamson@...hat.com>,
	Zi Yan <ziy@...dia.com>, Alex Mastro <amastro@...com>,
	David Hildenbrand <david@...hat.com>,
	Nico Pache <npache@...hat.com>,
	Baolin Wang <baolin.wang@...ux.alibaba.com>,
	Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
	"Liam R. Howlett" <Liam.Howlett@...cle.com>,
	Ryan Roberts <ryan.roberts@....com>, Dev Jain <dev.jain@....com>,
	Barry Song <baohua@...nel.org>
Subject: Re: [PATCH 3/5] mm: Rename __thp_get_unmapped_area to
 mm_get_unmapped_area_aligned

On Fri, Jun 13, 2025 at 09:41:09AM -0400, Peter Xu wrote:
> @@ -1088,7 +1088,7 @@ static inline bool is_transparent_hugepage(const struct folio *folio)
>  		folio_test_large_rmappable(folio);
>  }
>  
> -static unsigned long __thp_get_unmapped_area(struct file *filp,
> +unsigned long mm_get_unmapped_area_aligned(struct file *filp,
>  		unsigned long addr, unsigned long len,
>  		loff_t off, unsigned long flags, unsigned long size,
>  		vm_flags_t vm_flags)

Please add a kdoc for this since it is going to be exported..

I didn't intuitively guess how it works or why there are two
length/size arguments. It seems to have an exciting return code as
well.

I suppose size is the alignment target? Maybe rename the parameter too?

For the purposes of VFIO do we need to be careful about math overflow here:

	loff_t off_end = off + len;
	loff_t off_align = round_up(off, size);

?

Jason