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b3b00e9b03
commit 539d80575b810c7a5987c7ac8915e3bc99c03695 upstream.
When swiotlb buffer is full, the dma_map_sg() returns 0 to
msdc_prepare_data(), but it does not check it and sets the
MSDC_PREPARE_FLAG.
swiotlb_tbl_map_single() /* prints "swiotlb buffer is full" */
<-swiotlb_map()
<-dma_direct_map_page()
<-dma_direct_map_sg()
<-__dma_map_sg_attrs()
<-dma_map_sg_attrs()
<-dma_map_sg() /* returns 0 (pages mapped) */
<-msdc_prepare_data()
Then, the msdc_unprepare_data() checks MSDC_PREPARE_FLAG and calls
dma_unmap_sg() with unmapped pages. It causes a page fault.
To fix this problem, Do not set MSDC_PREPARE_FLAG if dma_map_sg()
fails because this is not prepared.
Fixes: 208489032b ("mmc: mediatek: Add Mediatek MMC driver")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/174908565814.4056588.769599127120955383.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.
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.