From: Leon Yu <le...@nvidia.com>
Date: Fri, 22 May 2020 23:29:43 +0800
> Commit 14b41a2959fb ("net: stmmac: Delete txtimer in suspend") was the
> first attempt to fix a race between mod_timer() and setup_timer()
> during stmmac_resume(). However the issue still exists as the commit
> only addressed half of the issue.
>
> Same race can still happen as stmmac_resume() re-attaches interface
> way too early - even before hardware is fully initialized. Worse,
> doing so allows network traffic to restart and stmmac_tx_timer_arm()
> being called in the middle of stmmac_resume(), which re-init tx timers
> in stmmac_init_coalesce(). timer_list will be corrupted and system
> crashes as a result of race between mod_timer() and setup_timer().
>
> systemd--1995 2.... 552950018us : stmmac_suspend: 4994
> ksoftirq-9 0..s2 553123133us : stmmac_tx_timer_arm: 2276
> systemd--1995 0.... 553127896us : stmmac_resume: 5101
> systemd--320 7...2 553132752us : stmmac_tx_timer_arm: 2276
> (sd-exec-1999 5...2 553135204us : stmmac_tx_timer_arm: 2276
> ---------------------------------
> pc : run_timer_softirq+0x468/0x5e0
> lr : run_timer_softirq+0x570/0x5e0
> Call trace:
> run_timer_softirq+0x468/0x5e0
> __do_softirq+0x124/0x398
> irq_exit+0xd8/0xe0
> __handle_domain_irq+0x6c/0xc0
> gic_handle_irq+0x60/0xb0
> el1_irq+0xb8/0x180
> arch_cpu_idle+0x38/0x230
> default_idle_call+0x24/0x3c
> do_idle+0x1e0/0x2b8
> cpu_startup_entry+0x28/0x48
> secondary_start_kernel+0x1b4/0x208
>
> Fix this by deferring netif_device_attach() to the end of
> stmmac_resume().
>
> Signed-off-by: Leon Yu <le...@nvidia.com>
Applied, thank you.
