archive mirror
 help / color / mirror / Atom feed
From: Christoph Hellwig <>
To: Thomas Tai <>
	Christoph Hellwig <>
Subject: Re: [PATCH] dma-direct: Fix potential NULL pointer dereference
Date: Wed, 16 Sep 2020 08:19:49 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On Tue, Sep 15, 2020 at 04:46:17PM -0400, Thomas Tai wrote:
> I tried out the suggested changes, and it successfully warned the null 
> pointer without panic. I notice that there are some places outside the 
> dma-direct, which calls dma_capable().

All of these still come in throught the wrappers in kernel/dma/mapping.c.

> Given that the WARN_ON_ONCE already did the intended warning, would you be 
> ok that I keep the null checking in dma_capable()?

No, the generic dma mapping layer is the right place.
iommu mailing list

      reply	other threads:[~2020-09-16  6:19 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-15 14:03 [PATCH] dma-direct: Fix potential NULL pointer dereference Thomas Tai
2020-09-15 14:07 ` Christoph Hellwig
2020-09-15 14:08   ` Christoph Hellwig
2020-09-15 14:11   ` Thomas Tai
2020-09-15 14:26     ` Christoph Hellwig
2020-09-15 14:40       ` Thomas Tai
2020-09-15 15:09         ` Christoph Hellwig
2020-09-15 15:12           ` Thomas Tai
2020-09-15 20:46           ` Thomas Tai
2020-09-16  6:19             ` Christoph Hellwig [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).