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cbbb64f62a
In queue_skb(), skb->data is mapped to streaming DMA on line 850:
dma_map_single(..., skb->data, ...);
Then skb->data is accessed on lines 862 and 863:
tbd->word_4 = (skb->data[0] << 24) | (skb->data[1] << 16) |
(skb->data[2] << 8) | (skb->data[3] << 0);
and on lines 893 and 894:
tbd->word_4 = (skb->data[0] << 24) | (skb->data[1] << 16) |
(skb->data[2] << 8) | (skb->data[3] << 0);
These accesses may cause data inconsistency between CPU cache and
hardware.
To fix this problem, the calculation result of skb->data is stored in a
local variable before DMA mapping, and then the driver accesses this
local variable instead of skb->data.
Signed-off-by: Jia-Ju Bai <baijiaju@tsinghua.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
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.