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Sascha Hauer 403f0e7714 net: macb: fix sleep inside spinlock
macb_set_tx_clk() is called under a spinlock but itself calls clk_set_rate()
which can sleep. This results in:

| BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
| pps pps1: new PPS source ptp1
| in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 40, name: kworker/u4:3
| preempt_count: 1, expected: 0
| RCU nest depth: 0, expected: 0
| 4 locks held by kworker/u4:3/40:
|  #0: ffff000003409148
| macb ff0c0000.ethernet: gem-ptp-timer ptp clock registered.
|  ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x14c/0x51c
|  #1: ffff8000833cbdd8 ((work_completion)(&pl->resolve)){+.+.}-{0:0}, at: process_one_work+0x14c/0x51c
|  #2: ffff000004f01578 (&pl->state_mutex){+.+.}-{4:4}, at: phylink_resolve+0x44/0x4e8
|  #3: ffff000004f06f50 (&bp->lock){....}-{3:3}, at: macb_mac_link_up+0x40/0x2ac
| irq event stamp: 113998
| hardirqs last  enabled at (113997): [<ffff800080e8503c>] _raw_spin_unlock_irq+0x30/0x64
| hardirqs last disabled at (113998): [<ffff800080e84478>] _raw_spin_lock_irqsave+0xac/0xc8
| softirqs last  enabled at (113608): [<ffff800080010630>] __do_softirq+0x430/0x4e4
| softirqs last disabled at (113597): [<ffff80008001614c>] ____do_softirq+0x10/0x1c
| CPU: 0 PID: 40 Comm: kworker/u4:3 Not tainted 6.5.0-11717-g9355ce8b2f50-dirty #368
| Hardware name: ... ZynqMP ... (DT)
| Workqueue: events_power_efficient phylink_resolve
| Call trace:
|  dump_backtrace+0x98/0xf0
|  show_stack+0x18/0x24
|  dump_stack_lvl+0x60/0xac
|  dump_stack+0x18/0x24
|  __might_resched+0x144/0x24c
|  __might_sleep+0x48/0x98
|  __mutex_lock+0x58/0x7b0
|  mutex_lock_nested+0x24/0x30
|  clk_prepare_lock+0x4c/0xa8
|  clk_set_rate+0x24/0x8c
|  macb_mac_link_up+0x25c/0x2ac
|  phylink_resolve+0x178/0x4e8
|  process_one_work+0x1ec/0x51c
|  worker_thread+0x1ec/0x3e4
|  kthread+0x120/0x124
|  ret_from_fork+0x10/0x20

The obvious fix is to move the call to macb_set_tx_clk() out of the
protected area. This seems safe as rx and tx are both disabled anyway at
this point.
It is however not entirely clear what the spinlock shall protect. It
could be the read-modify-write access to the NCFGR register, but this
is accessed in macb_set_rx_mode() and macb_set_rxcsum_feature() as well
without holding the spinlock. It could also be the register accesses
done in mog_init_rings() or macb_init_buffers(), but again these
functions are called without holding the spinlock in macb_hresp_error_task().
The locking seems fishy in this driver and it might deserve another look
before this patch is applied.

Fixes: 633e98a711 ("net: macb: use resolved link config in mac_link_up()")
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20230908112913.1701766-1-s.hauer@pengutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-09-12 14:58:44 +02:00
arch Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
block for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto This update includes the following changes: 2023-08-29 11:23:29 -07:00
Documentation Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
drivers net: macb: fix sleep inside spinlock 2023-09-12 14:58:44 +02:00
fs ntfs3: drop inode references in ntfs_put_super() 2023-09-07 10:23:37 -07:00
include Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring for-6.6/io_uring-2023-08-28 2023-08-29 20:11:33 -07:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
lib printk changes for 6.6 2023-09-04 13:20:19 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm Seven hotfixes. Four are cc:stable and the remainder pertain to issues 2023-09-05 12:22:39 -07:00
net net/tls: do not free tls_rec on async operation in bpf_exec_tx_verdict() 2023-09-12 09:51:49 +02:00
rust Documentation work keeps chugging along; stuff for 6.6 includes: 2023-08-30 20:05:42 -07:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
security Three cleanup patches, no behavior changes. 2023-09-04 10:38:35 -07:00
sound This pull request contains the following changes for UML: 2023-09-04 11:32:21 -07:00
tools selftests/net: Improve bind_bhash.sh to accommodate predictable network interface names 2023-09-10 18:49:29 +01:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap for-linus-2023083101 2023-09-01 12:31:44 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS RTC for 6.6 2023-09-07 16:07:35 -07:00
Makefile Kbuild updates for v6.6 2023-09-05 11:01:47 -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
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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.