b9826a4929
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,
accesses 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 by 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 inserts a WARN_ON() check to remind to future
(and existing) bogus users of this function to provide a valid 'struct device'
whenever possible.
Fixes: ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset")
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Rich Felker <dalias@libc.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.