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Filename Latest commit message Latest commit date
Paul E. McKenney 69d4f3baa6 x86/smpboot: Move rcu_cpu_starting() earlier
commit 29368e09392123800e5e2bf0f3eda91f16972e52 upstream.

The call to rcu_cpu_starting() in mtrr_ap_init() is not early enough
in the CPU-hotplug onlining process, which results in lockdep splats
as follows:

=============================
WARNING: suspicious RCU usage
5.9.0+ #268 Not tainted
-----------------------------
kernel/kprobes.c:300 RCU-list traversed in non-reader section!!

other info that might help us debug this:

RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 1
no locks held by swapper/1/0.

stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0+ #268
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 dump_stack+0x77/0x97
 __is_insn_slot_addr+0x15d/0x170
 kernel_text_address+0xba/0xe0
 ? get_stack_info+0x22/0xa0
 __kernel_text_address+0x9/0x30
 show_trace_log_lvl+0x17d/0x380
 ? dump_stack+0x77/0x97
 dump_stack+0x77/0x97
 __lock_acquire+0xdf7/0x1bf0
 lock_acquire+0x258/0x3d0
 ? vprintk_emit+0x6d/0x2c0
 _raw_spin_lock+0x27/0x40
 ? vprintk_emit+0x6d/0x2c0
 vprintk_emit+0x6d/0x2c0
 printk+0x4d/0x69
 start_secondary+0x1c/0x100
 secondary_startup_64_no_verify+0xb8/0xbb

This is avoided by moving the call to rcu_cpu_starting up near
the beginning of the start_secondary() function.  Note that the
raw_smp_processor_id() is required in order to avoid calling into lockdep
before RCU has declared the CPU to be watched for readers.

Link: https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/
Reported-by: Qian Cai <cai@redhat.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-19 12:24:15 +01:00
arch x86/smpboot: Move rcu_cpu_starting() earlier 2022-12-19 12:24:15 +01:00
block block, bfq: fix null pointer dereference in bfq_bio_bfqg() 2022-12-08 11:22:57 +01:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:11:22 +02:00
crypto crypto: akcipher - default implementation for setting a private key 2022-10-26 13:22:45 +02:00
Documentation docs: update mediator contact information in CoC doc 2022-11-25 17:42:20 +01:00
drivers can: esd_usb: Allow REC and TEC to return to zero 2022-12-14 11:30:48 +01:00
fs btrfs: send: avoid unaligned encoded writes when attempting to clone range 2022-12-14 11:30:41 +01:00
include memcg: fix possible use-after-free in memcg_write_event_control() 2022-12-14 11:30:43 +01:00
init init/Kconfig: fix CC_HAS_ASM_GOTO_TIED_OUTPUT test with dash 2022-12-08 11:22:59 +01:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:23:06 +01:00
kernel memcg: fix possible use-after-free in memcg_write_event_control() 2022-12-14 11:30:43 +01:00
lib Kconfig.debug: provide a little extra FRAME_WARN leeway when KASAN is enabled 2022-12-08 11:23:05 +01:00
LICENSES
mm mm/gup: fix gup_pud_range() for dax 2022-12-14 11:30:43 +01:00
net net: bpf: Allow TC programs to call BPF_FUNC_skb_change_head 2022-12-19 12:24:15 +01:00
samples samples/kretprobes: Fix return value if register_kretprobe() failed 2021-11-17 09:48:39 +01:00
scripts scripts/faddr2line: Fix regression in name resolution on ppc64le 2022-12-08 11:23:02 +01:00
security capabilities: fix potential memleak on error path from vfs_getxattr_alloc() 2022-11-10 17:57:55 +01:00
sound ASoC: soc-pcm: Add NULL check in BE reparenting 2022-12-14 11:30:41 +01:00
tools ipv4: Fix incorrect route flushing when source address is deleted 2022-12-14 11:30:47 +01:00
usr
virt KVM: arm64: vgic: Fix exit condition in scan_its_table() 2022-10-29 10:20:35 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS MAINTAINERS: add Chandan as xfs maintainer for 5.4.y 2022-09-28 11:03:58 +02:00
Makefile Linux 5.4.227 2022-12-14 11:30:48 +01:00
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.