| From 1b7680c6c1f6de9904f1d9b05c952f0c64a03350 Mon Sep 17 00:00:00 2001 |
| From: Sandor Bodo-Merle <sbodomerle@gmail.com> |
| Date: Mon, 8 Aug 2022 19:39:39 +0200 |
| Subject: net: bgmac: Fix a BUG triggered by wrong bytes_compl |
| |
| From: Sandor Bodo-Merle <sbodomerle@gmail.com> |
| |
| commit 1b7680c6c1f6de9904f1d9b05c952f0c64a03350 upstream. |
| |
| On one of our machines we got: |
| |
| kernel BUG at lib/dynamic_queue_limits.c:27! |
| Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM |
| CPU: 0 PID: 1166 Comm: irq/41-bgmac Tainted: G W O 4.14.275-rt132 #1 |
| Hardware name: BRCM XGS iProc |
| task: ee3415c0 task.stack: ee32a000 |
| PC is at dql_completed+0x168/0x178 |
| LR is at bgmac_poll+0x18c/0x6d8 |
| pc : [<c03b9430>] lr : [<c04b5a18>] psr: 800a0313 |
| sp : ee32be14 ip : 000005ea fp : 00000bd4 |
| r10: ee558500 r9 : c0116298 r8 : 00000002 |
| r7 : 00000000 r6 : ef128810 r5 : 01993267 r4 : 01993851 |
| r3 : ee558000 r2 : 000070e1 r1 : 00000bd4 r0 : ee52c180 |
| Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none |
| Control: 12c5387d Table: 8e88c04a DAC: 00000051 |
| Process irq/41-bgmac (pid: 1166, stack limit = 0xee32a210) |
| Stack: (0xee32be14 to 0xee32c000) |
| be00: ee558520 ee52c100 ef128810 |
| be20: 00000000 00000002 c0116298 c04b5a18 00000000 c0a0c8c4 c0951780 00000040 |
| be40: c0701780 ee558500 ee55d520 ef05b340 ef6f9780 ee558520 00000001 00000040 |
| be60: ffffe000 c0a56878 ef6fa040 c0952040 0000012c c0528744 ef6f97b0 fffcfb6a |
| be80: c0a04104 2eda8000 c0a0c4ec c0a0d368 ee32bf44 c0153534 ee32be98 ee32be98 |
| bea0: ee32bea0 ee32bea0 ee32bea8 ee32bea8 00000000 c01462e4 ffffe000 ef6f22a8 |
| bec0: ffffe000 00000008 ee32bee4 c0147430 ffffe000 c094a2a8 00000003 ffffe000 |
| bee0: c0a54528 00208040 0000000c c0a0c8c4 c0a65980 c0124d3c 00000008 ee558520 |
| bf00: c094a23c c0a02080 00000000 c07a9910 ef136970 ef136970 ee30a440 ef136900 |
| bf20: ee30a440 00000001 ef136900 ee30a440 c016d990 00000000 c0108db0 c012500c |
| bf40: ef136900 c016da14 ee30a464 ffffe000 00000001 c016dd14 00000000 c016db28 |
| bf60: ffffe000 ee21a080 ee30a400 00000000 ee32a000 ee30a440 c016dbfc ee25fd70 |
| bf80: ee21a09c c013edcc ee32a000 ee30a400 c013ec7c 00000000 00000000 00000000 |
| bfa0: 00000000 00000000 00000000 c0108470 00000000 00000000 00000000 00000000 |
| bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 |
| bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 |
| [<c03b9430>] (dql_completed) from [<c04b5a18>] (bgmac_poll+0x18c/0x6d8) |
| [<c04b5a18>] (bgmac_poll) from [<c0528744>] (net_rx_action+0x1c4/0x494) |
| [<c0528744>] (net_rx_action) from [<c0124d3c>] (do_current_softirqs+0x1ec/0x43c) |
| [<c0124d3c>] (do_current_softirqs) from [<c012500c>] (__local_bh_enable+0x80/0x98) |
| [<c012500c>] (__local_bh_enable) from [<c016da14>] (irq_forced_thread_fn+0x84/0x98) |
| [<c016da14>] (irq_forced_thread_fn) from [<c016dd14>] (irq_thread+0x118/0x1c0) |
| [<c016dd14>] (irq_thread) from [<c013edcc>] (kthread+0x150/0x158) |
| [<c013edcc>] (kthread) from [<c0108470>] (ret_from_fork+0x14/0x24) |
| Code: a83f15e0 0200001a 0630a0e1 c3ffffea (f201f0e7) |
| |
| The issue seems similar to commit 90b3b339364c ("net: hisilicon: Fix a BUG |
| trigered by wrong bytes_compl") and potentially introduced by commit |
| b38c83dd0866 ("bgmac: simplify tx ring index handling"). |
| |
| If there is an RX interrupt between setting ring->end |
| and netdev_sent_queue() we can hit the BUG_ON as bgmac_dma_tx_free() |
| can miscalculate the queue size while called from bgmac_poll(). |
| |
| The machine which triggered the BUG runs a v4.14 RT kernel - but the issue |
| seems present in mainline too. |
| |
| Fixes: b38c83dd0866 ("bgmac: simplify tx ring index handling") |
| Signed-off-by: Sandor Bodo-Merle <sbodomerle@gmail.com> |
| Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> |
| Link: https://lore.kernel.org/r/20220808173939.193804-1-sbodomerle@gmail.com |
| Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/ethernet/broadcom/bgmac.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/net/ethernet/broadcom/bgmac.c |
| +++ b/drivers/net/ethernet/broadcom/bgmac.c |
| @@ -189,8 +189,8 @@ static netdev_tx_t bgmac_dma_tx_add(stru |
| } |
| |
| slot->skb = skb; |
| - ring->end += nr_frags + 1; |
| netdev_sent_queue(net_dev, skb->len); |
| + ring->end += nr_frags + 1; |
| |
| wmb(); |
| |
