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Martin KaFai Lau c9ae8c966f Merge branch 'fixes for concurrent htab updates'
Hou Tao says:

====================

From: Hou Tao <houtao1@huawei.com>

Hi,

The patchset aims to fix the issues found during investigating the
syzkaller problem reported in [0]. It seems that the concurrent updates
to the same hash-table bucket may fail as shown in patch 1.

Patch 1 uses preempt_disable() to fix the problem for
htab_use_raw_lock() case. For !htab_use_raw_lock() case, the problem is
left to "BPF specific memory allocator" patchset [1] in which
!htab_use_raw_lock() will be removed.

Patch 2 fixes the out-of-bound memory read problem reported in [0]. The
problem has the root cause as patch 1 and it is fixed by handling -EBUSY
from htab_lock_bucket() correctly.

Patch 3 add two cases for hash-table update: one for the reentrancy of
bpf_map_update_elem(), and another one for concurrent updates of the
same hash-table bucket.

Comments are always welcome.

Regards,
Tao

[0]: https://lore.kernel.org/bpf/CACkBjsbuxaR6cv0kXJoVnBfL9ZJXjjoUcMpw_Ogc313jSrg14A@mail.gmail.com/
[1]: https://lore.kernel.org/bpf/20220819214232.18784-1-alexei.starovoitov@gmail.com/

Change Log:

v4:
 * rebased on bpf-next
 * add htab_update to DENYLIST.s390x

v3: https://lore.kernel.org/bpf/20220829023709.1958204-1-houtao@huaweicloud.com/
 * patch 1: update commit message and add Fixes tag
 * patch 2: add Fixes tag
 * patch 3: elaborate the description of test cases

v2: https://lore.kernel.org/bpf/bd60ef93-1c6a-2db2-557d-b09b92ad22bd@huaweicloud.com/
 * Note the fix is for CONFIG_PREEMPT case in commit message and add
   Reviewed-by tag for patch 1
 * Drop patch "bpf: Allow normally concurrent map updates for !htab_use_raw_lock() case"

v1: https://lore.kernel.org/bpf/20220821033223.2598791-1-houtao@huaweicloud.com/
====================

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-08-31 14:10:01 -07:00
arch bpf, mips: No need to use min() to get MAX_TAIL_CALL_CNT 2022-08-29 15:38:14 +02:00
block block: convert to advancing variants of iov_iter_get_pages{,_alloc}() 2022-08-08 22:37:22 -04:00
certs Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
crypto crypto: blake2b: effectively disable frame size warning 2022-08-10 17:59:11 -07:00
Documentation Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-08-17 20:29:36 -07:00
drivers net: ethernet: altera: Add use of ethtool_op_get_ts_info 2022-08-18 10:25:39 -07:00
fs New code for 6.0: 2022-08-11 13:11:49 -07:00
include bpf: Fix a few typos in BPF helpers documentation 2022-08-26 22:19:31 -07:00
init Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
io_uring iov_iter work, part 1 - isolated cleanups and optimizations. 2022-08-03 13:50:22 -07:00
ipc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
kernel bpf: Propagate error from htab_lock_bucket() to userspace 2022-08-31 14:10:01 -07:00
lib iov_iter stuff, part 2, rebased 2022-08-08 20:04:35 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm - hugetlb_vmemmap cleanups from Muchun Song 2022-08-10 11:18:00 -07:00
net bpf, net: Avoid loading module when calling bpf_setsockopt(TCP_CONGESTION) 2022-08-31 22:21:45 +02:00
samples Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
scripts bpf/scripts: Assert helper enum value is aligned with comment order 2022-08-25 11:49:14 -07:00
security + Features 2022-08-10 10:53:22 -07:00
sound sound updates for 6.0-rc1 2022-08-06 10:19:51 -07:00
tools selftests/bpf: Add test cases for htab update 2022-08-31 14:10:01 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: Actually create debugfs in kvm_create_vm() 2022-08-10 15:08:28 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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 kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
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 Including fixes from bluetooth, bpf, can and netfilter. 2022-08-11 13:45:37 -07:00
Makefile Makefile: link with -z noexecstack --no-warn-rwx-segments 2022-08-10 18:29:34 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.