linux-kernel - Re: [PATCH 13/13] maps#2: Add /proc/kpagemap interface

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: <1177009598.12599.152.camel@localhost.localdomain>
Date:	Thu, 19 Apr 2007 12:06:38 -0700
From:	Dave Hansen <hansendc@...ibm.com>
To:	Matt Mackall <mpm@...enic.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 13/13] maps#2: Add /proc/kpagemap interface

On Fri, 2007-04-06 at 17:03 -0500, Matt Mackall wrote:
> 
> +static ssize_t kpagemap_read(struct file *file, char __user *buf,
> +                            size_t count, loff_t *ppos)
> +{
...
> +               for (; i < 2 * chunk / KPMSIZE; i += 2, pfn++) {
> +                       ppage = pfn_to_page(pfn);
> +                       if (!ppage) {
> +                               page[i] = 0;
> +                               page[i + 1] = 0;
> +                       } else {
> +                               page[i] = ppage->flags;
> +                               page[i + 1] = atomic_read(&ppage->_count);
> +                       }
> +               } 

I think this needs a pfn_valid() check for sparse/discontig systems.  I
think we'll oops if we have holes because we don't check pfn_valid()
inside of pfn_to_page().

-- Dave

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/