On Thu, Sep 07, 2023 at 11:23:16AM +0200, Paolo Abeni wrote:
On Wed, 2023-09-06 at 11:13 +0200, Remi Pommarel wrote:
Using netconsole netpoll_poll_dev could be called from interrupt context, thus using disable_irq() would cause the following kernel warning with CONFIG_DEBUG_ATOMIC_SLEEP enabled:
BUG: sleeping function called from invalid context at kernel/irq/manage.c:137 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 10, name: ksoftirqd/0 CPU: 0 PID: 10 Comm: ksoftirqd/0 Tainted: G W 5.15.42-00075-g816b502b2298-dirty #117 Hardware name: aml (r1) (DT) Call trace: dump_backtrace+0x0/0x270 show_stack+0x14/0x20 dump_stack_lvl+0x8c/0xac dump_stack+0x18/0x30 ___might_sleep+0x150/0x194 __might_sleep+0x64/0xbc synchronize_irq+0x8c/0x150 disable_irq+0x2c/0x40 stmmac_poll_controller+0x140/0x1a0 netpoll_poll_dev+0x6c/0x220 netpoll_send_skb+0x308/0x390 netpoll_send_udp+0x418/0x760 write_msg+0x118/0x140 [netconsole] console_unlock+0x404/0x500 vprintk_emit+0x118/0x250 dev_vprintk_emit+0x19c/0x1cc dev_printk_emit+0x90/0xa8 __dev_printk+0x78/0x9c _dev_warn+0xa4/0xbc ath10k_warn+0xe8/0xf0 [ath10k_core] ath10k_htt_txrx_compl_task+0x790/0x7fc [ath10k_core] ath10k_pci_napi_poll+0x98/0x1f4 [ath10k_pci] __napi_poll+0x58/0x1f4 net_rx_action+0x504/0x590 _stext+0x1b8/0x418 run_ksoftirqd+0x74/0xa4 smpboot_thread_fn+0x210/0x3c0 kthread+0x1fc/0x210 ret_from_fork+0x10/0x20
Since [0] .ndo_poll_controller is only needed if driver doesn't or partially use NAPI. Because stmmac does so, stmmac_poll_controller can be removed fixing the above warning.
[0] commit ac3d9dd034e5 ("netpoll: make ndo_poll_controller() optional")
Cc: stable@vger.kernel.org # 5.15.x Signed-off-by: Remi Pommarel repk@triplefau.lt
I'm sorry for the incremental feedback, but we also need a suitable Fixes tag, thanks!
I didn't include Fixes tag because it would go back up to the initial driver support commit [0]. I can't be sure that this commit includes necessary NAPI implementation to be able to get rid of .ndo_poll_controller callback back then. And I am not able to test it on older version than 5.15.x hence I only included the 5.15.x Cc tag version prerequisite.
But I surely can add a Fixed tag if it is ok for it to be [0].
Also sorry for the long replying delay.
[0] commit 47dd7a540b8a ("net: add support for STMicroelectronics Ethernet controllers")