linux-kernel - Re: [PATCH] mm: Track page table modifications in __apply_to_page

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: <159800481672.29194.17217138842959831589@build.alporthouse.com>
Date:   Fri, 21 Aug 2020 11:13:36 +0100
From:   Chris Wilson <chris@...is-wilson.co.uk>
To:     Joerg Roedel <jroedel@...e.de>
Cc:     linux-kernel@...r.kernel.org, intel-gfx@...ts.freedesktop.org,
        linux-mm@...ck.org, Pavel Machek <pavel@....cz>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Dave Airlie <airlied@...hat.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        David Vrabel <david.vrabel@...rix.com>, stable@...r.kernel.org
Subject: Re: [PATCH] mm: Track page table modifications in __apply_to_page_range() construction

Quoting Joerg Roedel (2020-08-21 11:09:02)
> @@ -2333,6 +2339,7 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
>         pgd_t *pgd;
>         unsigned long next;
>         unsigned long end = addr + size;
> +       pgtbl_mod_mask mask = 0;
>         int err = 0;
>  
>         if (WARN_ON(addr >= end))
> @@ -2343,11 +2350,14 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
>                 next = pgd_addr_end(addr, end);
>                 if (!create && pgd_none_or_clear_bad(pgd))
>                         continue;
> -               err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, create);
> +               err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, create, &mask);
>                 if (err)
>                         break;
>         } while (pgd++, addr = next, addr != end);
>  
> +       if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
> +               arch_sync_kernel_mappings(addr, addr + size);

We need to store the initial addr, as here addr == end [or earlier on
earlier], so range is (start, addr).
-Chris