059d0e3876
Enabling CONFIG_PROVE_RCU_LIST raises many warnings in wilc driver, even on some places already protected by a read critical section. An example of such case is in wilc_get_available_idx: ============================= WARNING: suspicious RCU usage 6.8.0-rc1+ #32 Not tainted ----------------------------- drivers/net/wireless/microchip/wilc1000/netdev.c:944 RCU-list traversed in non-reader section!! [...] stack backtrace: CPU: 0 PID: 26 Comm: kworker/0:3 Not tainted 6.8.0-rc1+ #32 Hardware name: Atmel SAMA5 Workqueue: events_freezable mmc_rescan unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x34/0x58 dump_stack_lvl from wilc_netdev_ifc_init+0x788/0x8ec wilc_netdev_ifc_init from wilc_cfg80211_init+0x690/0x910 wilc_cfg80211_init from wilc_sdio_probe+0x168/0x490 wilc_sdio_probe from sdio_bus_probe+0x230/0x3f4 sdio_bus_probe from really_probe+0x270/0xdf4 really_probe from __driver_probe_device+0x1dc/0x580 __driver_probe_device from driver_probe_device+0x60/0x140 driver_probe_device from __device_attach_driver+0x268/0x364 __device_attach_driver from bus_for_each_drv+0x15c/0x1cc bus_for_each_drv from __device_attach+0x1ec/0x3e8 __device_attach from bus_probe_device+0x190/0x1c0 bus_probe_device from device_add+0x10dc/0x18e4 device_add from sdio_add_func+0x1c0/0x2c0 sdio_add_func from mmc_attach_sdio+0xa08/0xe1c mmc_attach_sdio from mmc_rescan+0xa00/0xfe0 mmc_rescan from process_one_work+0x8d4/0x169c process_one_work from worker_thread+0x8cc/0x1340 worker_thread from kthread+0x448/0x510 kthread from ret_from_fork+0x14/0x28 This warning is due to the section being protected by a srcu critical read section, but the list traversal being done with classic RCU API. Fix the warning by using corresponding SRCU read lock/unlock APIs. While doing so, since we always manipulate the same list (managed through a pointer embedded in struct_wilc), add a macro to reduce the corresponding boilerplate in each call site. Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com> Signed-off-by: Kalle Valo <kvalo@kernel.org> Link: https://msgid.link/20240215-wilc_fix_rcu_usage-v1-2-f610e46c6f82@bootlin.com
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.