linux-kernel - Re: [PATCH 4/4] arm64: tlb: set huge page size to stride for hugepage

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: <ZMeW5jcsYgisxsoJ@arm.com>
Date:   Mon, 31 Jul 2023 12:11:34 +0100
From:   Catalin Marinas <catalin.marinas@....com>
To:     Kefeng Wang <wangkefeng.wang@...wei.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Will Deacon <will@...nel.org>,
        Mike Kravetz <mike.kravetz@...cle.com>,
        Muchun Song <muchun.song@...ux.dev>,
        Mina Almasry <almasrymina@...gle.com>, kirill@...temov.name,
        joel@...lfernandes.org, william.kucharski@...cle.com,
        kaleshsingh@...gle.com, linux-mm@...ck.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/4] arm64: tlb: set huge page size to stride for hugepage

On Mon, Jul 31, 2023 at 03:48:29PM +0800, Kefeng Wang wrote:
> +/*
> + * We cannot use leaf-only invalidation here, since we may be invalidating
> + * table entries as part of collapsing hugepages or moving page tables.
> + * Set the tlb_level to 0 because we can not get enough information here.
> + */
> +#define flush_tlb_range(vma, start, end)				\
> +	__flush_tlb_range(vma, start, end,				\
> +				((vma)->vm_flags & VM_HUGETLB)		\
> +				? huge_page_size(hstate_vma(vma))	\
> +				: PAGE_SIZE, false, 0)

This won't work if we use the contiguous PTE to get 64K hugetlb pages on
a 4K base page configuration. The 16 base pages in the range would have
to be invalidated individually (the contig PTE bit is just a hint, the
hardware may or may not take it into account).

-- 
Catalin