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From: Christoph Hellwig <hch@infradead.org>
To: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: ysato@users.sourceforge.jp, dalias@libc.org,
	thomas.petazzoni@free-electrons.com, robin.murphy@arm.com,
	geert@linux-m68k.org, linux-renesas-soc@vger.kernel.org,
	linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sh: mm: Fix unprotected access to struct device
Date: Wed, 18 Apr 2018 03:47:03 -0700	[thread overview]
Message-ID: <20180418104703.GA12462@infradead.org> (raw)
In-Reply-To: <1523972123-5700-1-git-send-email-jacopo+renesas@jmondi.org>

On Tue, Apr 17, 2018 at 03:35:23PM +0200, Jacopo Mondi wrote:
> With commit ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping
> operations observe dev->dma_pfn_offset") the generic DMA allocation
> function on which the SH 'dma_alloc_coherent()' function relies on,
> access the 'dma_pfn_offset' field of struct device.
> 
> Unfortunately the 'dma_generic_alloc_coherent()' function is called from
> several places with a NULL struct device argument, halting the CPU
> during the boot process.
> 
> This patch fixes the issue protecting access to dev->dma_pfn_offset,
> with a trivial check for validity. It also passes a valid 'struct device'
> in the 'platform_resource_setup_memory' function which is the main user
> of 'dma_alloc_coherent()', and inserting a WARN_ON() check to make future
> (and existing) bogus users of this function they're should provide a valid
> 'struct device' whenever possible.

Please fix those callers to not pass a NULL pointer instead.

  parent reply	other threads:[~2018-04-18 10:47 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-17 13:35 Jacopo Mondi
2018-04-17 13:54 ` Thomas Petazzoni
2018-04-17 13:59   ` jacopo mondi
2018-04-20  8:30   ` Christoph Hellwig
2018-04-17 14:04 ` Geert Uytterhoeven
2018-04-17 14:20   ` jacopo mondi
2018-04-18  9:13 ` Sergei Shtylyov
2018-04-18 10:47 ` Christoph Hellwig [this message]
2018-04-18 13:13   ` jacopo mondi
2018-04-20  8:31     ` Christoph Hellwig
2018-04-20  9:59       ` Geert Uytterhoeven
2018-04-20 14:56         ` Rich Felker
2018-05-02  7:41         ` jacopo mondi

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