No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Chen-Yu Tsai ad7c38abe8 ARM: dma-api: fix max_pfn off-by-one error in __dma_supported()
commit f3cc4e1d44a813a0685f2e558b78ace3db559722 upstream.

max_pfn, as set in arch/arm/mm/init.c:

    static void __init find_limits(unsigned long *min,
				   unsigned long *max_low,
				   unsigned long *max_high)
    {
	    *max_low = PFN_DOWN(memblock_get_current_limit());
	    *min = PFN_UP(memblock_start_of_DRAM());
	    *max_high = PFN_DOWN(memblock_end_of_DRAM());
    }

with memblock_end_of_DRAM() pointing to the next byte after DRAM.  As
such, max_pfn points to the PFN after the end of DRAM.

Thus when using max_pfn to check DMA masks, we should subtract one when
checking DMA ranges against it.

Commit 8bf1268f48 ("ARM: dma-api: fix off-by-one error in
__dma_supported()") fixed the same issue, but missed this spot.

This issue was found while working on the sun4i-csi v4l2 driver on the
Allwinner R40 SoC.  On Allwinner SoCs, DRAM is offset at 0x40000000, and
we are starting to use of_dma_configure() with the "dma-ranges" property
in the device tree to have the DMA API handle the offset.

In this particular instance, dma-ranges was set to the same range as the
actual available (2 GiB) DRAM.  The following error appeared when the
driver attempted to allocate a buffer:

    sun4i-csi 1c09000.csi: Coherent DMA mask 0x7fffffff (pfn 0x40000-0xc0000)
    covers a smaller range of system memory than the DMA zone pfn 0x0-0xc0001
    sun4i-csi 1c09000.csi: dma_alloc_coherent of size 307200 failed

Fixing the off-by-one error makes things work.

Link: http://lkml.kernel.org/r/20191224030239.5656-1-wens@kernel.org
Fixes: 11a5aa3256 ("ARM: dma-mapping: check DMA mask against available memory")
Fixes: 9f28cde0bc ("ARM: another fix for the DMA mapping checks")
Fixes: ab746573c4 ("ARM: dma-mapping: allow larger DMA mask than supported")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:25 -08:00
arch ARM: dma-api: fix max_pfn off-by-one error in __dma_supported() 2020-02-11 04:35:25 -08:00
block block: fix memleak of bio integrity data 2020-01-26 10:01:09 +01:00
certs
crypto crypto: api - Check spawn->alg under lock in crypto_drop_spawn 2020-02-11 04:35:22 -08:00
Documentation PM / devfreq: Add new name attribute for sysfs 2020-02-05 21:22:40 +00:00
drivers of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc 2020-02-11 04:35:25 -08:00
fs f2fs: fix race conditions in ->d_compare() and ->d_hash() 2020-02-11 04:35:25 -08:00
include cpufreq: Avoid creating excessively large stack frames 2020-02-11 04:35:25 -08:00
init Revert "um: Enable CONFIG_CONSTRUCTORS" 2020-02-01 09:34:53 +00:00
ipc ipc/msg.c: consolidate all xxxctl_down() functions 2020-02-11 04:35:07 -08:00
kernel padata: Remove broken queue flushing 2020-02-11 04:35:22 -08:00
lib lib/test_kasan.c: fix memory leak in kmalloc_oob_krealloc_more() 2020-02-11 04:35:14 -08:00
LICENSES
mm mm: move_pages: report the number of non-attempted pages 2020-02-11 04:35:13 -08:00
net netfilter: ipset: fix suspicious RCU usage in find_set_and_id 2020-02-11 04:35:07 -08:00
samples samples/bpf: Fix broken xdp_rxq_info due to map order assumptions 2020-01-26 10:00:58 +01:00
scripts scripts/find-unused-docs: Fix massive false positives 2020-02-11 04:35:23 -08:00
security tomoyo: Use atomic_t for statistics counter 2020-02-05 21:22:41 +00:00
sound ASoC: SOF: core: free trace on errors 2020-02-11 04:35:21 -08:00
tools cpupower: Revert library ABI changes from commit ae2917093f 2020-02-11 04:35:24 -08:00
usr gen_initramfs_list.sh: fix 'bad variable name' error 2020-01-09 10:20:00 +01:00
virt KVM: arm64: Only sign-extend MMIO up to register width 2020-02-11 04:35:16 -08:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS MAINTAINERS: correct entries for ISDN/mISDN section 2020-02-11 04:35:06 -08:00
Makefile Linux 5.4.18 2020-02-05 21:22:53 +00:00
README

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.

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.