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Mainline Linux tree for various devices, only for fun :)
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Yonghong Song 05a68ce5fa bpf: Don't do bpf_cgroup_storage_set() for kuprobe/tp programs 
For kuprobe and tracepoint bpf programs, kernel calls
trace_call_bpf() which calls BPF_PROG_RUN_ARRAY_CHECK()
to run the program array. Currently, BPF_PROG_RUN_ARRAY_CHECK()
also calls bpf_cgroup_storage_set() to set percpu
cgroup local storage with NULL value. This is
due to Commit 394e40a297 ("bpf: extend bpf_prog_array to store
pointers to the cgroup storage") which modified
__BPF_PROG_RUN_ARRAY() to call bpf_cgroup_storage_set()
and this macro is also used by BPF_PROG_RUN_ARRAY_CHECK().

kuprobe and tracepoint programs are not allowed to call
bpf_get_local_storage() helper hence does not
access percpu cgroup local storage. Let us
change BPF_PROG_RUN_ARRAY_CHECK() not to
modify percpu cgroup local storage.

The issue is observed when I tried to debug [1] where
percpu data is overwritten due to
  preempt_disable -> migration_disable
change. This patch does not completely fix the above issue,
which will be addressed separately, e.g., multiple cgroup
prog runs may preempt each other. But it does fix
any potential issue caused by tracing program
overwriting percpu cgroup storage:
 - in a busy system, a tracing program is to run between
   bpf_cgroup_storage_set() and the cgroup prog run.
 - a kprobe program is triggered by a helper in cgroup prog
   before bpf_get_local_storage() is called.

 [1] https://lore.kernel.org/bpf/CAKH8qBuXCfUz=w8L+Fj74OaUpbosO29niYwTki7e3Ag044_aww@mail.gmail.com/T

Fixes: 394e40a297 ("bpf: extend bpf_prog_array to store pointers to the cgroup storage")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Link: https://lore.kernel.org/bpf/20210309185028.3763817-1-yhs@fb.com
2021-03-09 12:30:18 -08:00
arch Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2021-02-26 13:16:31 -08:00
block for-5.12/block-ipi-2021-02-21 2021-02-22 10:53:05 -08:00
certs certs: Replace K{U,G}IDT_INIT() with GLOBAL_ROOT_{U,G}ID 2021-01-21 16:16:10 +00:00
crypto Keyrings miscellany 2021-02-23 16:09:23 -08:00
Documentation docs: networking: drop special stable handling 2021-03-03 08:49:08 -08:00
drivers veth: Store queue_mapping independently of XDP prog presence 2021-03-06 00:04:52 +01:00
fs Miscellaneous ext4 cleanups and bug fixes. Pretty boring this 2021-02-25 10:06:55 -08:00
include bpf: Don't do bpf_cgroup_storage_set() for kuprobe/tp programs 2021-03-09 12:30:18 -08:00
init Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
ipc fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
kernel bpf: Change inode_storage's lookup_elem return value from NULL to -EBADF 2021-03-08 16:08:06 +01:00
lib Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
mm mm/hugetlb: change hugetlb_reserve_pages() to type bool 2021-02-24 13:38:35 -08:00
net bpf: BPF-helper for MTU checking add length input 2021-03-08 22:44:33 +01:00
samples samples, bpf: Add missing munmap in xdpsock 2021-03-04 15:53:32 +01:00
scripts Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
security Keyrings miscellany 2021-02-23 16:09:23 -08:00
sound ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
tools selftests/bpf: Tests using bpf_check_mtu BPF-helper input mtu_len param 2021-03-08 22:45:56 +01:00
usr Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
virt KVM/arm64 fixes for 5.11, take #2 2021-02-12 14:07:39 +00:00
.clang-format cxl for 5.12 2021-02-24 09:38:36 -08:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore clang-lto series for v5.12-rc1 2021-02-23 09:28:51 -08:00
.mailmap Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2021-02-21 17:23:56 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS CREDITS: update email address and home address 2021-01-27 21:03:50 +02:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS wireless-drivers fixes for v5.12 2021-02-26 13:17:44 -08:00
Makefile Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.