linux-kernel - Re: [PATCH 4/7] mm: Introduce verify_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: <YHQQMPvsO5LtuI+/@hirez.programming.kicks-ass.net>
Date:   Mon, 12 Apr 2021 11:17:36 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Christoph Hellwig <hch@....de>
Cc:     akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
        boris.ostrovsky@...cle.com, jgross@...e.com,
        sstabellini@...nel.org, x86@...nel.org,
        jani.nikula@...ux.intel.com, joonas.lahtinen@...ux.intel.com,
        rodrigo.vivi@...el.com, chris@...is-wilson.co.uk,
        intel-gfx@...ts.freedesktop.org, linux-mm@...ck.org,
        keescook@...omium.org
Subject: Re: [PATCH 4/7] mm: Introduce verify_page_range()

On Mon, Apr 12, 2021 at 10:28:05AM +0200, Christoph Hellwig wrote:
> On Mon, Apr 12, 2021 at 10:00:16AM +0200, Peter Zijlstra wrote:
> > +extern int verify_page_range(struct mm_struct *mm,
> 
> No need for the extern here.

It's consistent with the rest of the functions there. Also, I personally
like that extern.

> > +int verify_page_range(struct mm_struct *mm,
> > +		      unsigned long addr, unsigned long size,
> > +		      int (*fn)(pte_t pte, unsigned long addr, void *data),
> > +		      void *data)
> 
> A kerneldoc comment would be nice for this function.
> 
> Otherwise this looks fine.

Something like so?

/**
 * verify_page_range() - Scan (and fill) a range of virtual memory and validate PTEs
 * @mm: mm identifying the virtual memory map
 * @addr: starting virtual address of the range
 * @size: size of the range
 * @fn: function that verifies the PTEs
 * @data: opaque data passed to @fn
 *
 * Scan a region of virtual memory, filling in page tables as necessary and
 * calling a provided function on each leaf, providing a copy of the
 * page-table-entry.
 *
 * Similar apply_to_page_range(), but does not provide direct access to the
 * page-tables.
 *
 * NOTE! this function does not work correctly vs large pages.
 *
 * Return: the first !0 return of the provided function, or 0 on completion.
 */
int verify_page_range(struct mm_struct *mm,
		      unsigned long addr, unsigned long size,
		      int (*fn)(pte_t pte, unsigned long addr, void *data),
		      void *data)