public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Mark Brown <broonie@kernel.org>
To: Pratyush Yadav <p.yadav@ti.com>
Cc: Tudor Ambarus <tudor.ambarus@microchip.com>,
	Michael Walle <michael@walle.cc>,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Takahiro Kuwano <tkuw584924@gmail.com>,
	linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] spi: spi-mem: check if data buffers are on stack
Date: Mon, 31 Jan 2022 13:55:00 +0000	[thread overview]
Message-ID: <YffqNEzjIkApR1HS@sirena.org.uk> (raw)
In-Reply-To: <20220131114508.1028306-1-p.yadav@ti.com>

[-- Attachment #1: Type: text/plain, Size: 551 bytes --]

On Mon, Jan 31, 2022 at 05:15:08PM +0530, Pratyush Yadav wrote:
> The buffers passed in the data phase must be DMA-able. Programmers often
> don't realise this requirement and pass in buffers that reside on the
> stack. This can be hard to spot when reviewing code. Reject ops if their
> data buffer is on the stack to avoid this.

Acked-by: Mark Brown <broonie@kernel.org>

> +	/* Buffers must be DMA-able. */
> +	if (op->data.dir == SPI_MEM_DATA_IN &&
> +	    object_is_on_stack(op->data.buf.in))

Might be worth a WARN_ON_ONCE() for debuggability?

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

  parent reply	other threads:[~2022-01-31 13:55 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-31 11:45 [PATCH] spi: spi-mem: check if data buffers are on stack Pratyush Yadav
2022-01-31 13:48 ` Miquel Raynal
2022-01-31 13:55 ` Mark Brown [this message]
2022-01-31 17:07   ` Pratyush Yadav
2022-01-31 14:49 ` kernel test robot
2022-02-01  7:44 ` Tudor.Ambarus
2022-02-01  8:02   ` Pratyush Yadav

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=YffqNEzjIkApR1HS@sirena.org.uk \
    --to=broonie@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-spi@vger.kernel.org \
    --cc=michael@walle.cc \
    --cc=miquel.raynal@bootlin.com \
    --cc=p.yadav@ti.com \
    --cc=tkuw584924@gmail.com \
    --cc=tudor.ambarus@microchip.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* 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