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Marco Elver 889a0d3a35 kcsan: Turn report_filterlist_lock into a raw_spinlock 
[ Upstream commit 59458fa4dd ]

Ran Xiaokai reports that with a KCSAN-enabled PREEMPT_RT kernel, we can see
splats like:

| BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
| in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
| preempt_count: 10002, expected: 0
| RCU nest depth: 0, expected: 0
| no locks held by swapper/1/0.
| irq event stamp: 156674
| hardirqs last  enabled at (156673): [<ffffffff81130bd9>] do_idle+0x1f9/0x240
| hardirqs last disabled at (156674): [<ffffffff82254f84>] sysvec_apic_timer_interrupt+0x14/0xc0
| softirqs last  enabled at (0): [<ffffffff81099f47>] copy_process+0xfc7/0x4b60
| softirqs last disabled at (0): [<0000000000000000>] 0x0
| Preemption disabled at:
| [<ffffffff814a3e2a>] paint_ptr+0x2a/0x90
| CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.11.0+ #3
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
| Call Trace:
|  <IRQ>
|  dump_stack_lvl+0x7e/0xc0
|  dump_stack+0x1d/0x30
|  __might_resched+0x1a2/0x270
|  rt_spin_lock+0x68/0x170
|  kcsan_skip_report_debugfs+0x43/0xe0
|  print_report+0xb5/0x590
|  kcsan_report_known_origin+0x1b1/0x1d0
|  kcsan_setup_watchpoint+0x348/0x650
|  __tsan_unaligned_write1+0x16d/0x1d0
|  hrtimer_interrupt+0x3d6/0x430
|  __sysvec_apic_timer_interrupt+0xe8/0x3a0
|  sysvec_apic_timer_interrupt+0x97/0xc0
|  </IRQ>

On a detected data race, KCSAN's reporting logic checks if it should
filter the report. That list is protected by the report_filterlist_lock
*non-raw* spinlock which may sleep on RT kernels.

Since KCSAN may report data races in any context, convert it to a
raw_spinlock.

This requires being careful about when to allocate memory for the filter
list itself which can be done via KCSAN's debugfs interface. Concurrent
modification of the filter list via debugfs should be rare: the chosen
strategy is to optimistically pre-allocate memory before the critical
section and discard if unused.

Link: https://lore.kernel.org/all/20240925143154.2322926-1-ranxiaokai627@163.com/
Reported-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Tested-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-12-14 20:03:37 +01:00
arch s390/cpum_sf: Handle CPU hotplug remove during sampling 2024-12-14 20:03:35 +01:00
block block: RCU protect disk->conv_zones_bitmap 2024-12-14 20:03:35 +01:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: ecdsa - Avoid signed integer overflow on signature decoding 2024-12-14 20:03:36 +01:00
Documentation dt-bindings: net: fec: add pps channel property 2024-12-09 10:41:11 +01:00
drivers scsi: ufs: pltfrm: Drop PM runtime reference count after ufshcd_remove() 2024-12-14 20:03:34 +01:00
fs ext4: partial zero eof block on unaligned inode size extension 2024-12-14 20:03:36 +01:00
include block: RCU protect disk->conv_zones_bitmap 2024-12-14 20:03:35 +01:00
init Compiler Attributes: disable __counted_by for clang < 19.1.3 2024-12-05 14:02:45 +01:00
io_uring io_uring: Change res2 parameter type in io_uring_cmd_done 2024-12-14 20:03:26 +01:00
ipc ipc: fix memleak if msg_init_ns failed in create_ipc_ns 2024-12-05 14:03:02 +01:00
kernel
lib lib: stackinit: hide never-taken branch from compiler 2024-12-14 20:03:32 +01:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm memblock: allow zero threshold in validate_numa_converage() 2024-12-14 20:03:34 +01:00
net xsk: fix OOB map writes when deleting elements 2024-12-14 20:03:31 +01:00
rust rust: enable arbitrary_self_types and remove Receiver 2024-12-14 20:03:34 +01:00
samples kfifo: don't include dma-mapping.h in kfifo.h 2024-12-05 14:03:03 +01:00
scripts rust: enable arbitrary_self_types and remove Receiver 2024-12-14 20:03:34 +01:00
security apparmor: test: Fix memory leak for aa_unpack_strdup() 2024-12-05 14:02:46 +01:00
sound ALSA: hda/realtek: Add support for Samsung Galaxy Book3 360 (NP730QFG) 2024-12-14 20:03:23 +01:00
tools kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all() 2024-12-14 20:03:36 +01:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt KVM: x86: switch hugepage recovery thread to vhost_task 2024-12-05 14:02:43 +01:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap mailmap: add entry for Thorsten Blum 2024-11-07 14:14:59 -08:00
.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 MAINTAINERS: Remove self from DSA entry 2024-11-03 12:52:38 -08:00
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 MAINTAINERS: update location of media main tree 2024-12-05 14:02:42 +01:00
Makefile rust: allow clippy::needless_lifetimes 2024-12-14 20:03:20 +01:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.