Linux kernel source tree
Go to file
Shigeru Yoshida 5fc8cbe4cf rcu-tasks: Avoid pr_info() with spin lock in cblist_init_generic()
pr_info() is called with rtp->cbs_gbl_lock spin lock locked.  Because
pr_info() calls printk() that might sleep, this will result in BUG
like below:

[    0.206455] cblist_init_generic: Setting adjustable number of callback queues.
[    0.206463]
[    0.206464] =============================
[    0.206464] [ BUG: Invalid wait context ]
[    0.206465] 5.19.0-00428-g9de1f9c8ca51 #5 Not tainted
[    0.206466] -----------------------------
[    0.206466] swapper/0/1 is trying to lock:
[    0.206467] ffffffffa0167a58 (&port_lock_key){....}-{3:3}, at: serial8250_console_write+0x327/0x4a0
[    0.206473] other info that might help us debug this:
[    0.206473] context-{5:5}
[    0.206474] 3 locks held by swapper/0/1:
[    0.206474]  #0: ffffffff9eb597e0 (rcu_tasks.cbs_gbl_lock){....}-{2:2}, at: cblist_init_generic.constprop.0+0x14/0x1f0
[    0.206478]  #1: ffffffff9eb579c0 (console_lock){+.+.}-{0:0}, at: _printk+0x63/0x7e
[    0.206482]  #2: ffffffff9ea77780 (console_owner){....}-{0:0}, at: console_emit_next_record.constprop.0+0x111/0x330
[    0.206485] stack backtrace:
[    0.206486] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-00428-g9de1f9c8ca51 #5
[    0.206488] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
[    0.206489] Call Trace:
[    0.206490]  <TASK>
[    0.206491]  dump_stack_lvl+0x6a/0x9f
[    0.206493]  __lock_acquire.cold+0x2d7/0x2fe
[    0.206496]  ? stack_trace_save+0x46/0x70
[    0.206497]  lock_acquire+0xd1/0x2f0
[    0.206499]  ? serial8250_console_write+0x327/0x4a0
[    0.206500]  ? __lock_acquire+0x5c7/0x2720
[    0.206502]  _raw_spin_lock_irqsave+0x3d/0x90
[    0.206504]  ? serial8250_console_write+0x327/0x4a0
[    0.206506]  serial8250_console_write+0x327/0x4a0
[    0.206508]  console_emit_next_record.constprop.0+0x180/0x330
[    0.206511]  console_unlock+0xf7/0x1f0
[    0.206512]  vprintk_emit+0xf7/0x330
[    0.206514]  _printk+0x63/0x7e
[    0.206516]  cblist_init_generic.constprop.0.cold+0x24/0x32
[    0.206518]  rcu_init_tasks_generic+0x5/0xd9
[    0.206522]  kernel_init_freeable+0x15b/0x2a2
[    0.206523]  ? rest_init+0x160/0x160
[    0.206526]  kernel_init+0x11/0x120
[    0.206527]  ret_from_fork+0x1f/0x30
[    0.206530]  </TASK>
[    0.207018] cblist_init_generic: Setting shift to 1 and lim to 1.

This patch moves pr_info() so that it is called without
rtp->cbs_gbl_lock locked.

Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Tested-by: "Zhang, Qiang1" <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-05-09 17:27:42 -07:00
arch s390: remove the unneeded select GCC12_NO_ARRAY_BOUNDS 2023-05-05 18:56:23 -07:00
block for-6.4/block-2023-05-06 2023-05-06 08:28:58 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto This push fixes the following problems: 2023-05-07 10:57:14 -07:00
Documentation - mailbox api: allow direct registration to a channel 2023-05-07 10:17:33 -07:00
drivers This push fixes the following problems: 2023-05-07 10:57:14 -07:00
fs 9 smb3 client fixes, mostly DFS or reconnect related 2023-05-07 10:46:21 -07:00
include - mailbox api: allow direct registration to a channel 2023-05-07 10:17:33 -07:00
init Objtool changes for v6.4: 2023-04-28 14:02:54 -07:00
io_uring for-6.4/io_uring-2023-05-07 2023-05-07 10:00:09 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel rcu-tasks: Avoid pr_info() with spin lock in cblist_init_generic() 2023-05-09 17:27:42 -07:00
lib A single fix for debugobjects: 2023-05-07 11:04:26 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm Reinstate the dmapool changes which were accidentally removed by 2023-05-06 11:43:08 -07:00
net Including fixes from netfilter. 2023-05-05 19:12:01 -07:00
rust Rust changes for v6.4 2023-04-30 11:20:22 -07:00
samples LoongArch changes for v6.4 2023-05-04 12:40:16 -07:00
scripts Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
security integrity-v6.4 2023-04-29 10:11:32 -07:00
sound sound fixes for 6.4-rc1 2023-05-06 08:07:11 -07:00
tools Disable building BPF based features by default for v6.4. 2023-05-07 11:32:18 -07:00
usr initramfs: Check negative timestamp to prevent broken cpio archive 2023-04-16 17:37:01 +09:00
virt s390: 2023-05-01 12:06:20 -07:00
.clang-format cxl for v6.4 2023-04-30 11:51:51 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for *.dtso files 2023-02-26 15:28:23 +09:00
.gitignore linux-kselftest-kunit-6.4-rc1 2023-04-24 12:31:32 -07:00
.mailmap for-6.4/block-2023-05-06 2023-05-06 08:28:58 -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 A handful of late-arriving documentation fixes, plus one Spanish 2023-05-05 13:16:42 -07:00
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 Including fixes from netfilter. 2023-05-05 19:12:01 -07:00
Makefile Linux 6.4-rc1 2023-05-07 13:34:35 -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.