mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2025-01-20 04:44:26 +08:00
8dbe4c5d5e
of_find_node_by_name() will do an of_node_put() on the "from" argument.
With CONFIG_OF_DYNAMIC enabled which checks for device_node reference
counts, we would be getting a warning like this:
[ 6.347230] refcount_t: increment on 0; use-after-free.
[ 6.352498] WARNING: CPU: 3 PID: 77 at lib/refcount.c:156
refcount_inc_checked+0x38/0x44
[ 6.360601] Modules linked in:
[ 6.363661] CPU: 3 PID: 77 Comm: kworker/3:1 Tainted: G W
5.4.46-gb78b3e9956e6 #13
[ 6.372546] Hardware name: BCM97278SV (DT)
[ 6.376649] Workqueue: events deferred_probe_work_func
[ 6.381796] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 6.386595] pc : refcount_inc_checked+0x38/0x44
[ 6.391133] lr : refcount_inc_checked+0x38/0x44
...
[ 6.478791] Call trace:
[ 6.481243] refcount_inc_checked+0x38/0x44
[ 6.485433] kobject_get+0x3c/0x4c
[ 6.488840] of_node_get+0x24/0x34
[ 6.492247] of_irq_find_parent+0x3c/0xe0
[ 6.496263] of_irq_parse_one+0xe4/0x1d0
[ 6.500191] irq_of_parse_and_map+0x44/0x84
[ 6.504381] bcm_sf2_sw_probe+0x22c/0x844
[ 6.508397] platform_drv_probe+0x58/0xa8
[ 6.512413] really_probe+0x238/0x3fc
[ 6.516081] driver_probe_device+0x11c/0x12c
[ 6.520358] __device_attach_driver+0xa8/0x100
[ 6.524808] bus_for_each_drv+0xb4/0xd0
[ 6.528650] __device_attach+0xd0/0x164
[ 6.532493] device_initial_probe+0x24/0x30
[ 6.536682] bus_probe_device+0x38/0x98
[ 6.540524] deferred_probe_work_func+0xa8/0xd4
[ 6.545061] process_one_work+0x178/0x288
[ 6.549078] process_scheduled_works+0x44/0x48
[ 6.553529] worker_thread+0x218/0x270
[ 6.557285] kthread+0xdc/0xe4
[ 6.560344] ret_from_fork+0x10/0x18
[ 6.563925] ---[ end trace 68f65caf69bb152a ]---
Fix this by adding a of_node_get() to increment the reference count
prior to the call.
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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.