On Fri, May 6, 2016 at 11:01 AM, Larry Finger <Larry.Finger@xxxxxxxxxxxx> wrote: > On 05/06/2016 12:13 PM, Alexander Duyck wrote: >> >> On Fri, May 6, 2016 at 9:33 AM, Wang YanQing <udknight@xxxxxxxxx> wrote: >>> >>> We can't use kfree_skb in irq disable context, because spin_lock_irqsave >>> make sure we are always in irq disable context, use dev_kfree_skb_irq >>> instead of kfree_skb is better than dev_kfree_skb_any. >>> >>> This patch fix below kernel warning: >>> [ 7612.095528] ------------[ cut here ]------------ >>> [ 7612.095546] WARNING: CPU: 3 PID: 4460 at kernel/softirq.c:150 >>> __local_bh_enable_ip+0x58/0x80() >>> [ 7612.095550] Modules linked in: rtl8723be x86_pkg_temp_thermal >>> btcoexist rtl_pci rtlwifi rtl8723_common >>> [ 7612.095567] CPU: 3 PID: 4460 Comm: ifconfig Tainted: G W >>> 4.4.0+ #4 >>> [ 7612.095570] Hardware name: LENOVO 20DFA04FCD/20DFA04FCD, BIOS J5ET48WW >>> (1.19 ) 08/27/2015 >>> [ 7612.095574] 00000000 00000000 da37fc70 c12ce7c5 00000000 da37fca0 >>> c104cc59 c19d4454 >>> [ 7612.095584] 00000003 0000116c c19d4784 00000096 c10508a8 c10508a8 >>> 00000200 c1b42400 >>> [ 7612.095594] f29be780 da37fcb0 c104ccad 00000009 00000000 da37fcbc >>> c10508a8 f21f08b8 >>> [ 7612.095604] Call Trace: >>> [ 7612.095614] [<c12ce7c5>] dump_stack+0x41/0x5c >>> [ 7612.095620] [<c104cc59>] warn_slowpath_common+0x89/0xc0 >>> [ 7612.095628] [<c10508a8>] ? __local_bh_enable_ip+0x58/0x80 >>> [ 7612.095634] [<c10508a8>] ? __local_bh_enable_ip+0x58/0x80 >>> [ 7612.095640] [<c104ccad>] warn_slowpath_null+0x1d/0x20 >>> [ 7612.095646] [<c10508a8>] __local_bh_enable_ip+0x58/0x80 >>> [ 7612.095653] [<c16b7d34>] destroy_conntrack+0x64/0xa0 >>> [ 7612.095660] [<c16b300f>] nf_conntrack_destroy+0xf/0x20 >>> [ 7612.095665] [<c1677565>] skb_release_head_state+0x55/0xa0 >>> [ 7612.095670] [<c16775bb>] skb_release_all+0xb/0x20 >>> [ 7612.095674] [<c167760b>] __kfree_skb+0xb/0x60 >>> [ 7612.095679] [<c16776f0>] kfree_skb+0x30/0x70 >>> [ 7612.095686] [<f81b869d>] ? rtl_pci_reset_trx_ring+0x22d/0x370 >>> [rtl_pci] >>> [ 7612.095692] [<f81b869d>] rtl_pci_reset_trx_ring+0x22d/0x370 [rtl_pci] >>> [ 7612.095698] [<f81b87f9>] rtl_pci_start+0x19/0x190 [rtl_pci] >>> [ 7612.095705] [<f81970e6>] rtl_op_start+0x56/0x90 [rtlwifi] >>> [ 7612.095712] [<c17e3f16>] drv_start+0x36/0xc0 >>> [ 7612.095717] [<c17f5ab3>] ieee80211_do_open+0x2d3/0x890 >>> [ 7612.095725] [<c16820fe>] ? call_netdevice_notifiers_info+0x2e/0x60 >>> [ 7612.095730] [<c17f60bd>] ieee80211_open+0x4d/0x50 >>> [ 7612.095736] [<c16891b3>] __dev_open+0xa3/0x130 >>> [ 7612.095742] [<c183fa53>] ? _raw_spin_unlock_bh+0x13/0x20 >>> [ 7612.095748] [<c1689499>] __dev_change_flags+0x89/0x140 >>> [ 7612.095753] [<c127c70d>] ? selinux_capable+0xd/0x10 >>> [ 7612.095759] [<c1689589>] dev_change_flags+0x29/0x60 >>> [ 7612.095765] [<c1700b93>] devinet_ioctl+0x553/0x670 >>> [ 7612.095772] [<c12db758>] ? _copy_to_user+0x28/0x40 >>> [ 7612.095777] [<c17018b5>] inet_ioctl+0x85/0xb0 >>> [ 7612.095783] [<c166e647>] sock_ioctl+0x67/0x260 >>> [ 7612.095788] [<c166e5e0>] ? sock_fasync+0x80/0x80 >>> [ 7612.095795] [<c115c99b>] do_vfs_ioctl+0x6b/0x550 >>> [ 7612.095800] [<c127c812>] ? selinux_file_ioctl+0x102/0x1e0 >>> [ 7612.095807] [<c10a8914>] ? timekeeping_suspend+0x294/0x320 >>> [ 7612.095813] [<c10a256a>] ? __hrtimer_run_queues+0x14a/0x210 >>> [ 7612.095820] [<c1276e24>] ? security_file_ioctl+0x34/0x50 >>> [ 7612.095827] [<c115cef0>] SyS_ioctl+0x70/0x80 >>> [ 7612.095832] [<c1001804>] do_fast_syscall_32+0x84/0x120 >>> [ 7612.095839] [<c183ff91>] sysenter_past_esp+0x36/0x55 >>> [ 7612.095844] ---[ end trace 97e9c637a20e8348 ]--- >>> >>> Signed-off-by: Wang YanQing <udknight@xxxxxxxxx> >>> Cc: Stable <stable@xxxxxxxxxxxxxxx> >>> --- >>> Changes: >>> v1-v2: >>> 1: add a Cc to stable. >>> >>> drivers/net/wireless/realtek/rtlwifi/pci.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/net/wireless/realtek/rtlwifi/pci.c >>> b/drivers/net/wireless/realtek/rtlwifi/pci.c >>> index 1ac41b8..99a3a03 100644 >>> --- a/drivers/net/wireless/realtek/rtlwifi/pci.c >>> +++ b/drivers/net/wireless/realtek/rtlwifi/pci.c >>> @@ -1572,7 +1572,7 @@ int rtl_pci_reset_trx_ring(struct ieee80211_hw *hw) >>> true, >>> >>> HW_DESC_TXBUFF_ADDR), >>> skb->len, >>> PCI_DMA_TODEVICE); >>> - kfree_skb(skb); >>> + dev_kfree_skb_irq(skb); >>> ring->idx = (ring->idx + 1) % >>> ring->entries; >>> } >>> ring->idx = 0; >> >> >> Is this always called in IRQ context? You might be better off using >> dev_kfree_skb_any instead if this is something that can be called from >> net_device_ops since that way you avoid having to call into the Tx >> softirq cleanup routine to free the buffers later unless you really >> need it. >> >> - Alex >> > > Alex, > > Six lines below the change is a spin_unlock_irqrestore(), which is always > called. I believe that the patch is correct. Okay. That works then. Thanks. - Alex -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
