linux-kernel - Re: [RFC v10 PATCH 1/3] mm: mmap: zap pages with read mmap

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20180915092101.GA31572@bombadil.infradead.org>
Date:   Sat, 15 Sep 2018 02:21:01 -0700
From:   Matthew Wilcox <willy@...radead.org>
To:     Yang Shi <yang.shi@...ux.alibaba.com>
Cc:     mhocko@...nel.org, ldufour@...ux.vnet.ibm.com, vbabka@...e.cz,
        kirill@...temov.name, akpm@...ux-foundation.org,
        dave.hansen@...el.com, oleg@...hat.com, srikar@...ux.vnet.ibm.com,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [RFC v10 PATCH 1/3] mm: mmap: zap pages with read mmap_sem in
 munmap

On Sat, Sep 15, 2018 at 04:34:57AM +0800, Yang Shi wrote:
> Suggested-by: Michal Hocko <mhocko@...nel.org>
> Suggested-by: Kirill A. Shutemov <kirill@...temov.name>
> Suggested-by: Matthew Wilcox <willy@...radead.org>

Reviewed-by: Matthew Wilcox <willy@...radead.org>

Looks good!  Thanks for sticking with this patch series.

Minor spelling fixes:

> -	/*
> -	 * Remove the vma's, and unmap the actual pages
> -	 */
> +	/* Detatch vmas from rbtree */

"Detach"

> +	/*
> +	 * mpx unmap need to be handled with write mmap_sem. It is safe to
> +	 * deal with it before unmap_region().
> +	 */

	 * mpx unmap needs to be called with mmap_sem held for write.
	 * It is safe to call it before unmap_region()

> +	ret = __do_munmap(mm, start, len, &uf, downgrade);
> +	/*
> +	 * Returning 1 indicates mmap_sem is down graded.
> +	 * But 1 is not legal return value of vm_munmap() and munmap(), reset
> +	 * it to 0 before return.
> +	 */

"downgraded" is one word.