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Amit Cohen d72fdef21f mlxsw: spectrum_ptp: Protect PTP configuration with a mutex
Currently the functions mlxsw_sp2_ptp_{configure, deconfigure}_port()
assume that they are called when RTNL is locked and they warn otherwise.

The deconfigure function can be called when port is removed, for example
as part of device reload, then there is no locked RTNL and the function
warns [1].

To avoid such case, do not assume that RTNL protects this code, add a
dedicated mutex instead. The mutex protects 'ptp_state->config' which
stores the existing global configuration in hardware. Use this mutex also
to protect the code which configures the hardware. Then, there will be
only one configuration in any time, which will be updated in 'ptp_state'
and a race will be avoided.

[1]:
RTNL: assertion failed at drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c (1600)
WARNING: CPU: 1 PID: 1583493 at drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c:1600 mlxsw_sp2_ptp_hwtstamp_set+0x2d3/0x300 [mlxsw_spectrum]
[...]
CPU: 1 PID: 1583493 Comm: devlink Not tainted5.19.0-rc8-custom-127022-gb371dffda095 #789
Hardware name: Mellanox Technologies Ltd.MSN3420/VMOD0005, BIOS 5.11 01/06/2019
RIP: 0010:mlxsw_sp2_ptp_hwtstamp_set+0x2d3/0x300[mlxsw_spectrum]
[...]
Call Trace:
 <TASK>
 mlxsw_sp_port_remove+0x7e/0x190 [mlxsw_spectrum]
 mlxsw_sp_fini+0xd1/0x270 [mlxsw_spectrum]
 mlxsw_core_bus_device_unregister+0x55/0x280 [mlxsw_core]
 mlxsw_devlink_core_bus_device_reload_down+0x1c/0x30[mlxsw_core]
 devlink_reload+0x1ee/0x230
 devlink_nl_cmd_reload+0x4de/0x580
 genl_family_rcv_msg_doit+0xdc/0x140
 genl_rcv_msg+0xd7/0x1d0
 netlink_rcv_skb+0x49/0xf0
 genl_rcv+0x1f/0x30
 netlink_unicast+0x22f/0x350
 netlink_sendmsg+0x208/0x440
 __sys_sendto+0xf0/0x140
 __x64_sys_sendto+0x1b/0x20
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 08ef8bc825 ("mlxsw: spectrum_ptp: Support SIOCGHWTSTAMP, SIOCSHWTSTAMP ioctls")
Reported-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-15 11:49:58 +01:00
arch Including fixes from bluetooth, bpf, can and netfilter. 2022-08-11 13:45:37 -07:00
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 Including fixes from bluetooth, bpf, can and netfilter. 2022-08-11 13:45:37 -07:00
drivers mlxsw: spectrum_ptp: Protect PTP configuration with a mutex 2022-08-15 11:49:58 +01:00
fs New code for 6.0: 2022-08-11 13:11:49 -07:00
include neighbour: make proxy_queue.qlen limit per-device 2022-08-15 11:25:09 +01:00
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 Including fixes from bluetooth, bpf, can and netfilter. 2022-08-11 13:45:37 -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 net_sched: cls_route: disallow handle of 0 2022-08-15 11:46:30 +01:00
samples Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
scripts Revert "Makefile.extrawarn: re-enable -Wformat for clang" 2022-08-11 08:40:01 -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 Including fixes from bluetooth, bpf, can and netfilter. 2022-08-11 13:45:37 -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
.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.