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Filename Latest commit message Latest commit date
Waiman Long 29d0c45cf1 tracing: Disable interrupt or preemption before acquiring arch_spinlock_t
commit c0a581d7126c0bbc96163276f585fd7b4e4d8d0e upstream.

It was found that some tracing functions in kernel/trace/trace.c acquire
an arch_spinlock_t with preemption and irqs enabled. An example is the
tracing_saved_cmdlines_size_read() function which intermittently causes
a "BUG: using smp_processor_id() in preemptible" warning when the LTP
read_all_proc test is run.

That can be problematic in case preemption happens after acquiring the
lock. Add the necessary preemption or interrupt disabling code in the
appropriate places before acquiring an arch_spinlock_t.

The convention here is to disable preemption for trace_cmdline_lock and
interupt for max_lock.

Link: https://lkml.kernel.org/r/20220922145622.1744826-1-longman@redhat.com

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: stable@vger.kernel.org
Fixes: a35873a099 ("tracing: Add conditional snapshot")
Fixes: 939c7a4f04 ("tracing: Introduce saved_cmdlines_size file")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:22:21 +02:00
arch KVM: VMX: Drop bits 31:16 when shoving exception error code into VMCS 2022-10-26 13:22:20 +02:00
block blk-mq: don't create hctx debugfs dir until q->debugfs_dir is created 2022-08-25 11:17:36 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:11:22 +02:00
crypto crypto: drbg - make reseeding from get_random_bytes() synchronous 2022-06-22 14:11:18 +02:00
Documentation ARM: dts: fix Moxa SDIO 'compatible', remove 'sdhci' misnomer 2022-10-15 07:54:37 +02:00
drivers drm/nouveau: fix a use-after-free in nouveau_gem_prime_import_sg_table() 2022-10-26 13:22:21 +02:00
fs ext4: place buffer head allocation before handle start 2022-10-26 13:22:18 +02:00
include scsi: stex: Properly zero out the passthrough command structure 2022-10-15 07:54:39 +02:00
init random: handle latent entropy and command line from random_init() 2022-06-22 14:11:17 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-14 18:11:41 +02:00
kernel tracing: Disable interrupt or preemption before acquiring arch_spinlock_t 2022-10-26 13:22:21 +02:00
lib lib/vdso: Mark do_hres() and do_coarse() as __always_inline 2022-09-05 10:27:47 +02:00
LICENSES
mm mm: pagewalk: Fix race between unmap and page walker 2022-10-15 07:54:36 +02:00
net wifi: mac80211: fix MBSSID parsing use-after-free 2022-10-17 17:24:32 +02:00
samples samples/kretprobes: Fix return value if register_kretprobe() failed 2021-11-17 09:48:39 +01:00
scripts selinux: use "grep -E" instead of "egrep" 2022-10-26 13:22:21 +02:00
security efi: Correct Macmini DMI match in uefi cert quirk 2022-10-15 07:54:39 +02:00
sound ASoC: wcd9335: fix order of Slimbus unprepare/disable 2022-10-26 13:22:14 +02:00
tools perf tools: Fixup get_current_dir_name() compilation 2022-10-15 07:54:36 +02:00
usr
virt KVM: Add infrastructure and macro to mark VM as bugged 2022-08-25 11:18:16 +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 5.4.219 2022-10-17 17:24:32 +02:00
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.