• Jisheng Zhang's avatar
    net: stmmac: fix incorrect rxq|txq_stats reference · 8070274b
    Jisheng Zhang authored
    commit 133466c3 ("net: stmmac: use per-queue 64 bit statistics
    where necessary") caused one regression as found by Uwe, the backtrace
    looks like:
    
    	INFO: trying to register non-static key.
    	The code is fine but needs lockdep annotation, or maybe
    	you didn't initialize this object before use?
    	turning off the locking correctness validator.
    	CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc1-00449-g133466c3-dirty #21
    	Hardware name: STM32 (Device Tree Support)
    	 unwind_backtrace from show_stack+0x18/0x1c
    	 show_stack from dump_stack_lvl+0x60/0x90
    	 dump_stack_lvl from register_lock_class+0x98c/0x99c
    	 register_lock_class from __lock_acquire+0x74/0x293c
    	 __lock_acquire from lock_acquire+0x134/0x398
    	 lock_acquire from stmmac_get_stats64+0x2ac/0x2fc
    	 stmmac_get_stats64 from dev_get_stats+0x44/0x130
    	 dev_get_stats from rtnl_fill_stats+0x38/0x120
    	 rtnl_fill_stats from rtnl_fill_ifinfo+0x834/0x17f4
    	 rtnl_fill_ifinfo from rtmsg_ifinfo_build_skb+0xc0/0x144
    	 rtmsg_ifinfo_build_skb from rtmsg_ifinfo+0x50/0x88
    	 rtmsg_ifinfo from __dev_notify_flags+0xc0/0xec
    	 __dev_notify_flags from dev_change_flags+0x50/0x5c
    	 dev_change_flags from ip_auto_config+0x2f4/0x1260
    	 ip_auto_config from do_one_initcall+0x70/0x35c
    	 do_one_initcall from kernel_init_freeable+0x2ac/0x308
    	 kernel_init_freeable from kernel_init+0x1c/0x138
    	 kernel_init from ret_from_fork+0x14/0x2c
    
    The reason is the rxq|txq_stats structures are not what expected
    because stmmac_open() -> __stmmac_open() the structure is overwritten
    by "memcpy(&priv->dma_conf, dma_conf, sizeof(*dma_conf));"
    This causes the well initialized syncp member of rxq|txq_stats is
    overwritten unexpectedly as pointed out by Johannes and Uwe.
    
    Fix this issue by moving rxq|txq_stats back to stmmac_extra_stats. For
    SMP cache friendly, we also mark stmmac_txq_stats and stmmac_rxq_stats
    as ____cacheline_aligned_in_smp.
    
    Fixes: 133466c3 ("net: stmmac: use per-queue 64 bit statistics where necessary")
    Signed-off-by: default avatarJisheng Zhang <jszhang@kernel.org>
    Reported-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
    Tested-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
    Link: https://lore.kernel.org/r/20230917165328.3403-1-jszhang@kernel.orgSigned-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
    8070274b
dwxgmac2_dma.c 18.3 KB