[ Upstream commit 1a2c070ae805910a853b4a14818481ed2e17c727 ]
If hip04_tx_reclaim is interrupted while it is running and then __napi_schedule continues to execute hip04_rx_poll->hip04_tx_reclaim, reentrancy occurs and oops is generated. So you need to mask the interrupt during the hip04_tx_reclaim run.
The kernel oops exception stack is as follows:
Unable to handle kernel NULL pointer dereference at virtual address 00000050 pgd = c0003000 [00000050] *pgd=80000000a04003, *pmd=00000000 Internal error: Oops: 206 [#1] SMP ARM Modules linked in: hip04_eth mtdblock mtd_blkdevs mtd ohci_platform ehci_platform ohci_hcd ehci_hcd vfat fat sd_mod usb_storage scsi_mod usbcore usb_common CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 4.4.185 #1 Hardware name: Hisilicon A15 task: c0a250e0 task.stack: c0a00000 PC is at hip04_tx_reclaim+0xe0/0x17c [hip04_eth] LR is at hip04_tx_reclaim+0x30/0x17c [hip04_eth] pc : [<bf30c3a4>] lr : [<bf30c2f4>] psr: 600e0313 sp : c0a01d88 ip : 00000000 fp : c0601f9c r10: 00000000 r9 : c3482380 r8 : 00000001 r7 : 00000000 r6 : 000000e1 r5 : c3482000 r4 : 0000000c r3 : f2209800 r2 : 00000000 r1 : 00000000 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 32c5387d Table: 03d28c80 DAC: 55555555 Process swapper/0 (pid: 0, stack limit = 0xc0a00190) Stack: (0xc0a01d88 to 0xc0a02000) [<bf30c3a4>] (hip04_tx_reclaim [hip04_eth]) from [<bf30d2e0>] (hip04_rx_poll+0x88/0x368 [hip04_eth]) [<bf30d2e0>] (hip04_rx_poll [hip04_eth]) from [<c04c2d9c>] (net_rx_action+0x114/0x34c) [<c04c2d9c>] (net_rx_action) from [<c021eed8>] (__do_softirq+0x218/0x318) [<c021eed8>] (__do_softirq) from [<c021f284>] (irq_exit+0x88/0xac) [<c021f284>] (irq_exit) from [<c0240090>] (msa_irq_exit+0x11c/0x1d4) [<c0240090>] (msa_irq_exit) from [<c02677e0>] (__handle_domain_irq+0x110/0x148) [<c02677e0>] (__handle_domain_irq) from [<c0201588>] (gic_handle_irq+0xd4/0x118) [<c0201588>] (gic_handle_irq) from [<c0551700>] (__irq_svc+0x40/0x58) Exception stack(0xc0a01f30 to 0xc0a01f78) 1f20: c0ae8b40 00000000 00000000 00000000 1f40: 00000002 ffffe000 c0601f9c 00000000 ffffffff c0a2257c c0a22440 c0831a38 1f60: c0a01ec4 c0a01f80 c0203714 c0203718 600e0213 ffffffff [<c0551700>] (__irq_svc) from [<c0203718>] (arch_cpu_idle+0x20/0x3c) [<c0203718>] (arch_cpu_idle) from [<c025bfd8>] (cpu_startup_entry+0x244/0x29c) [<c025bfd8>] (cpu_startup_entry) from [<c054b0d8>] (rest_init+0xc8/0x10c) [<c054b0d8>] (rest_init) from [<c0800c58>] (start_kernel+0x468/0x514) Code: a40599e5 016086e2 018088e2 7660efe6 (503090e5) ---[ end trace 1db21d6d09c49d74 ]--- Kernel panic - not syncing: Fatal exception in interrupt CPU3: stopping CPU: 3 PID: 0 Comm: swapper/3 Tainted: G D O 4.4.185 #1
Signed-off-by: Jiangfeng Xiao xiaojiangfeng@huawei.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/hisilicon/hip04_eth.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c index b5d18d95d7b99..1fabbbd4544e7 100644 --- a/drivers/net/ethernet/hisilicon/hip04_eth.c +++ b/drivers/net/ethernet/hisilicon/hip04_eth.c @@ -497,6 +497,9 @@ static int hip04_rx_poll(struct napi_struct *napi, int budget) u16 len; u32 err;
+ /* clean up tx descriptors */ + tx_remaining = hip04_tx_reclaim(ndev, false); + while (cnt && !last) { buf = priv->rx_buf[priv->rx_head]; skb = build_skb(buf, priv->rx_buf_size); @@ -557,8 +560,7 @@ refill: } napi_complete(napi); done: - /* clean up tx descriptors and start a new timer if necessary */ - tx_remaining = hip04_tx_reclaim(ndev, false); + /* start a new timer if necessary */ if (rx < budget && tx_remaining) hip04_start_tx_timer(priv);