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Rafael J. Wysocki b7707176f8 ACPI: bus: Rework system-level device notification handling
[ Upstream commit c56610a869 ]

For ACPI drivers that provide a ->notify() callback and set
ACPI_DRIVER_ALL_NOTIFY_EVENTS in their flags, that callback can be
invoked while either the ->add() or the ->remove() callback is running
without any synchronization at the bus type level which is counter to
the common-sense expectation that notification handling should only be
enabled when the driver is actually bound to the device.  As a result,
if the driver is not careful enough, it's ->notify() callback may crash
when it is invoked too early or too late [1].

This issue has been amplified by commit d6fb6ee182 ("ACPI: bus: Drop
driver member of struct acpi_device") that made acpi_bus_notify() check
for the presence of the driver and its ->notify() callback directly
instead of using an extra driver pointer that was only set and cleared
by the bus type code, but it was present before that commit although
it was harder to reproduce then.

It can be addressed by using the observation that
acpi_device_install_notify_handler() can be modified to install the
handler for all types of events when ACPI_DRIVER_ALL_NOTIFY_EVENTS is
set in the driver flags, in which case acpi_bus_notify() will not need
to invoke the driver's ->notify() callback any more and that callback
will only be invoked after acpi_device_install_notify_handler() has run
and before acpi_device_remove_notify_handler() runs, which implies the
correct ordering with respect to the other ACPI driver callbacks.

Modify the code accordingly and while at it, drop two redundant local
variables from acpi_bus_notify() and turn its description comment into
a proper kerneldoc one.

Fixes: d6fb6ee182 ("ACPI: bus: Drop driver member of struct acpi_device")
Link: https://lore.kernel.org/linux-acpi/9f6cba7a8a57e5a687c934e8e406e28c.squirrel@mail.panix.com # [1]
Reported-by: Pierre Asselin <pa@panix.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Pierre Asselin <pa@panix.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-06 12:10:46 +02:00
Documentation docs: Correct missing "d_" prefix for dentry_operations member d_weak_revalidate 2023-03-22 13:33:40 +01:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
arch mips: bmips: BCM6358: disable RAC flush for TP1 2023-04-06 12:10:42 +02:00
block block: do not reverse request order when flushing plug list 2023-03-22 13:33:46 +01:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto crypto: rsa-pkcs1pad - Use akcipher_request_complete 2023-03-10 09:33:03 +01:00
drivers ACPI: bus: Rework system-level device notification handling 2023-04-06 12:10:46 +02:00
fs btrfs: use temporary variable for space_info in btrfs_update_block_group 2023-04-06 12:10:42 +02:00
include x86/PVH: obtain VGA console info in Dom0 2023-04-06 12:10:39 +02:00
init gcc: disable -Warray-bounds for gcc-11 too 2023-01-14 10:33:43 +01:00
io_uring io_uring/rsrc: fix null-ptr-deref in io_file_bitmap_get() 2023-03-30 12:49:25 +02:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel tracing: Fix wrong return in kprobe_event_gen_test.c 2023-04-06 12:10:41 +02:00
lib zstd: Fix definition of assert() 2023-04-06 12:10:38 +02:00
mm mm/ksm: fix race with VMA iteration and mm_struct teardown 2023-03-30 12:49:29 +02:00
net can: bcm: bcm_tx_setup(): fix KMSAN uninit-value in vfs_write 2023-04-06 12:10:46 +02:00
rust rust: print: avoid evaluating arguments in `pr_*` macros in `unsafe` blocks 2023-02-06 08:06:34 +01:00
samples ftrace: Export ftrace_free_filter() to modules 2023-02-01 08:34:37 +01:00
scripts kconfig: Update config changed flag before calling callback 2023-03-22 13:33:52 +01:00
security keys: Do not cache key in task struct if key is requested from kernel thread 2023-03-30 12:49:07 +02:00
sound ALSA: usb-audio: Fix recursive locking at XRUN during syncing 2023-04-06 12:10:43 +02:00
tools tools/power turbostat: fix decoding of HWP_STATUS 2023-04-06 12:10:41 +02:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Register /dev/kvm as the _very_ last thing during initialization 2023-03-10 09:34:11 +01:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.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 dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -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 Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
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 audit: update the mailing list in MAINTAINERS 2023-02-25 11:25:42 +01:00
Makefile Linux 6.1.22 2023-03-30 12:49:31 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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 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.