The source for the Linux kernel used in Windows Subsystem for Linux 2 (WSL2)
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Tonghao Zhang 9f907439dc bpf: hash map, avoid deadlock with suitable hash mask
The deadlock still may occur while accessed in NMI and non-NMI
context. Because in NMI, we still may access the same bucket but with
different map_locked index.

For example, on the same CPU, .max_entries = 2, we update the hash map,
with key = 4, while running bpf prog in NMI nmi_handle(), to update
hash map with key = 20, so it will have the same bucket index but have
different map_locked index.

To fix this issue, using min mask to hash again.

Fixes: 20b6cc34ea ("bpf: Avoid hashtab deadlock with map_locked")
Signed-off-by: Tonghao Zhang <tong@infragraf.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Song Liu <song@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230111092903.92389-1-tong@infragraf.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-01-12 18:55:42 -08:00
Documentation Including fixes from bpf, wifi, and netfilter. 2023-01-05 12:40:50 -08:00
LICENSES
arch Including fixes from bpf, wifi, and netfilter. 2023-01-05 12:40:50 -08:00
block block-6.2-2022-12-29 2022-12-29 16:57:29 -08:00
certs
crypto
drivers net: usb: cdc_ether: add support for Thales Cinterion PLS62-W modem 2023-01-05 22:04:58 -08:00
fs f2fs-fix-6.2-rc3 2023-01-04 12:02:26 -08:00
include bpf: remove the do_idr_lock parameter from bpf_prog_free_id() 2023-01-09 19:47:59 -08:00
init
io_uring
ipc
kernel bpf: hash map, avoid deadlock with suitable hash mask 2023-01-12 18:55:42 -08:00
lib
mm
net tipc: fix unexpected link reset due to discovery messages 2023-01-06 12:53:10 +00:00
rust
samples
scripts fixdep: remove unneeded <stdarg.h> inclusion 2022-12-30 17:26:19 +09:00
security
sound ALSA: hda/hdmi: Static PCM mapping again with AMD HDMI codecs 2022-12-28 14:05:06 +01:00
tools Including fixes from bpf, wifi, and netfilter. 2023-01-05 12:40:50 -08:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore .gitignore: ignore *.rpm 2022-12-30 17:22:14 +09:00
.mailmap
.rustfmt.toml
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Including fixes from bpf, wifi, and netfilter. 2023-01-05 12:40:50 -08:00
Makefile Linux 6.2-rc2 2023-01-01 13:53:16 -08:00
README

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.