linux-kernel - Re: [PATCH] mm/dmapool.c: add WARN_ON() in dma_pool

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: <20200731133215.73cf5ce464e2b894aeac0773@linux-foundation.org>
Date:   Fri, 31 Jul 2020 13:32:15 -0700
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     Matthew Wilcox <willy@...radead.org>
Cc:     qiang.zhang@...driver.com, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mm/dmapool.c: add WARN_ON() in dma_pool_destroy

On Fri, 31 Jul 2020 03:38:58 +0100 Matthew Wilcox <willy@...radead.org> wrote:

> On Fri, Jul 31, 2020 at 10:39:39AM +0800, qiang.zhang@...driver.com wrote:
> > The pool is being destroyed, all page which in the pool,
> > should be free. if some page is still be use by somebody,
> > we should not just output error logs, also should also add
> > a warning message.
> 
> There's already a warning message.  What value does this actually have?

Presumably so we get a backtrace in order to identify the errant
caller.  

I added a bit to the changelog:

: The pool is being destroyed so all pages which are in the pool should be
: free.  If some page is still in use by somebody, we should not just output
: error logs, also should also add a WARN message so the stack backtrace may
: be used to identify the caller.