Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
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2e43f95dd8
If first_sg and last_sg wraps around in the scatterlist ring, then we
need to account for that in the shift as well. E.g. crafting such msgs
where this is the case leads to a hang as shift becomes negative. E.g.
consider the following scenario:
first_sg := 14 |=> shift := -12 msg->sg_start := 10
last_sg := 3 | msg->sg_end := 5
round 1: i := 15, move_from := 3, sg[15] := sg[ 3]
round 2: i := 0, move_from := -12, sg[ 0] := sg[-12]
round 3: i := 1, move_from := -11, sg[ 1] := sg[-11]
round 4: i := 2, move_from := -10, sg[ 2] := sg[-10]
[...]
round 13: i := 11, move_from := -1, sg[ 2] := sg[ -1]
round 14: i := 12, move_from := 0, sg[ 2] := sg[ 0]
round 15: i := 13, move_from := 1, sg[ 2] := sg[ 1]
round 16: i := 14, move_from := 2, sg[ 2] := sg[ 2]
round 17: i := 15, move_from := 3, sg[ 2] := sg[ 3]
[...]
This means we will loop forever and never hit the msg->sg_end condition
to break out of the loop. When we see that the ring wraps around, then
the shift should be MAX_SKB_FRAGS - first_sg + last_sg - 1. Meaning,
the remainder slots from the tail of the ring and the head until last_sg
combined.
Fixes:
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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.
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.