The bnxt_queue_mem_alloc() is called to allocate new queue memory when a queue is restarted. It internally accesses rx buffer descriptor corresponding to the index. The rx buffer descriptor is allocated and set when the interface is up and it's freed when the interface is down. So, if queue is restarted if interface is down, kernel panic occurs.
Splat looks like: BUG: unable to handle page fault for address: 000000000000b240 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 UID: 0 PID: 1563 Comm: ncdevmem2 Not tainted 6.14.0-rc2+ #9 844ddba6e7c459cafd0bf4db9a3198e Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 RIP: 0010:bnxt_queue_mem_alloc+0x3f/0x4e0 [bnxt_en] Code: 41 54 4d 89 c4 4d 69 c0 c0 05 00 00 55 48 89 f5 53 48 89 fb 4c 8d b5 40 05 00 00 48 83 ec 15 RSP: 0018:ffff9dcc83fef9e8 EFLAGS: 00010202 RAX: ffffffffc0457720 RBX: ffff934ed8d40000 RCX: 0000000000000000 RDX: 000000000000001f RSI: ffff934ea508f800 RDI: ffff934ea508f808 RBP: ffff934ea508f800 R08: 000000000000b240 R09: ffff934e84f4b000 R10: ffff9dcc83fefa30 R11: ffff934e84f4b000 R12: 000000000000001f R13: ffff934ed8d40ac0 R14: ffff934ea508fd40 R15: ffff934e84f4b000 FS: 00007fa73888c740(0000) GS:ffff93559f780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000b240 CR3: 0000000145a2e000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <TASK> ? __die+0x20/0x70 ? page_fault_oops+0x15a/0x460 ? exc_page_fault+0x6e/0x180 ? asm_exc_page_fault+0x22/0x30 ? __pfx_bnxt_queue_mem_alloc+0x10/0x10 [bnxt_en 7f85e76f4d724ba07471d7e39d9e773aea6597b7] ? bnxt_queue_mem_alloc+0x3f/0x4e0 [bnxt_en 7f85e76f4d724ba07471d7e39d9e773aea6597b7] netdev_rx_queue_restart+0xc5/0x240 net_devmem_bind_dmabuf_to_queue+0xf8/0x200 netdev_nl_bind_rx_doit+0x3a7/0x450 genl_family_rcv_msg_doit+0xd9/0x130 genl_rcv_msg+0x184/0x2b0 ? __pfx_netdev_nl_bind_rx_doit+0x10/0x10 ? __pfx_genl_rcv_msg+0x10/0x10 netlink_rcv_skb+0x54/0x100 genl_rcv+0x24/0x40 ...
Reviewed-by: Somnath Kotur somnath.kotur@broadcom.com Reviewed-by: Jakub Kicinski kuba@kernel.org Fixes: 2d694c27d32e ("bnxt_en: implement netdev_queue_mgmt_ops") Signed-off-by: Taehee Yoo ap420073@gmail.com ---
v2: - Add Review tags from Somnath and Jakub.
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 13c9be49216a..d09986308582 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -15439,6 +15439,9 @@ static int bnxt_queue_mem_alloc(struct net_device *dev, void *qmem, int idx) struct bnxt_ring_struct *ring; int rc;
+ if (!bp->rx_ring) + return -ENETDOWN; + rxr = &bp->rx_ring[idx]; clone = qmem; memcpy(clone, rxr, sizeof(*rxr));