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Naman Jain f31fe8165d uio_hv_generic: Fix sysfs creation path for ring buffer
On regular bootup, devices get registered to VMBus first, so when
uio_hv_generic driver for a particular device type is probed,
the device is already initialized and added, so sysfs creation in
hv_uio_probe() works fine. However, when the device is removed
and brought back, the channel gets rescinded and the device again gets
registered to VMBus. However this time, the uio_hv_generic driver is
already registered to probe for that device and in this case sysfs
creation is tried before the device's kobject gets initialized
completely.

Fix this by moving the core logic of sysfs creation of ring buffer,
from uio_hv_generic to HyperV's VMBus driver, where the rest of the
sysfs attributes for the channels are defined. While doing that, make
use of attribute groups and macros, instead of creating sysfs
directly, to ensure better error handling and code flow.

Problematic path:
vmbus_process_offer (A new offer comes for the VMBus device)
  vmbus_add_channel_work
    vmbus_device_register
      |-> device_register
      |     |...
      |     |-> hv_uio_probe
      |           |...
      |           |-> sysfs_create_bin_file (leads to a warning as
      |                 the primary channel's kobject, which is used to
      |                 create the sysfs file, is not yet initialized)
      |-> kset_create_and_add
      |-> vmbus_add_channel_kobj (initialization of the primary
                                  channel's kobject happens later)

Above code flow is sequential and the warning is always reproducible in
this path.

Fixes: 9ab877a6cc ("uio_hv_generic: make ring buffer attribute for primary channel")
Cc: stable@kernel.org
Suggested-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Suggested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250502074811.2022-2-namjain@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-02 13:59:02 +02:00
Documentation OpenRISC updates for 6.15 2025-04-26 09:01:13 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
arch Misc fixes: 2025-04-26 09:45:54 -07:00
block block-6.15-20250424 2025-04-25 11:34:39 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: scomp - Fix off-by-one bug when calculating last page 2025-04-23 09:32:57 +08:00
drivers uio_hv_generic: Fix sysfs creation path for ring buffer 2025-05-02 13:59:02 +02:00
fs vfs-6.15-rc4.fixes 2025-04-25 15:57:21 -07:00
include uio_hv_generic: Fix sysfs creation path for ring buffer 2025-05-02 13:59:02 +02:00
init Kconfig: switch CONFIG_SYSFS_SYCALL default to n 2025-04-15 10:28:35 +02:00
io_uring io_uring: fix 'sync' handling of io_fallback_tw() 2025-04-24 10:32:43 -06:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel Fix sporadic crashes in dequeue_entities() due to ... bad math. 2025-04-26 09:23:20 -07:00
lib hardening fixes for v6.15-rc3 2025-04-18 13:20:20 -07:00
mm mm/migrate: fix sleep in atomic for large folios and buffer heads 2025-04-22 18:16:08 +02:00
net nfsd-6.15 fixes: 2025-04-26 10:43:03 -07:00
rust Driver core fixes for 6.15-rc4 2025-04-25 10:02:59 -07:00
samples samples/bpf: Fix compilation failure for samples/bpf on LoongArch Fedora 2025-04-25 09:32:02 -07:00
scripts Fix mis-uses of 'cc-option' for warning disablement 2025-04-23 10:08:29 -07:00
security Landlock fix for v6.15-rc4 2025-04-24 12:59:05 -07:00
sound ASoC: Fixes for v6.15 2025-04-11 15:51:19 +02:00
tools pci-v6.15-fixes-3 2025-04-26 13:02:36 -07:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt ARM: 2025-04-08 13:47:55 -07:00
.clang-format clang-format: Update the ForEachMacros list for v6.15-rc1 2025-04-13 11:03:59 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes
.gitignore kbuild: Create intermediate vmlinux build with relocations preserved 2025-03-17 00:29:50 +09:00
.mailmap sound fixes for 6.15-rc3 2025-04-17 10:14:51 -07:00
.rustfmt.toml
COPYING
CREDITS MAINTAINERS: update SLAB ALLOCATOR maintainers 2025-04-17 20:10:06 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS pci-v6.15-fixes-3 2025-04-26 13:02:36 -07:00
Makefile Linux 6.15-rc4 2025-04-27 15:19:23 -07:00
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.