[PATCH] net: mvpp2: Check for null pcs in mvpp2_acpi_start()

Jeremy Linton
2022-02-11T23:42:42Z

Booting a MACCHIATObin with 5.17 the system OOPs with
a null pointer deref when the network is started. This
is caused by the pcs->ops structure being null on this
particular platform/firmware.

Simply adding a null ptr check, reverts to a functional
system with networking.

The OOPs looks like:
[ 18.687760] Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000010
[ 18.698561] Mem abort info:
[ 18.698564] ESR = 0x96000004
[ 18.698567] EC = 0x25: DABT (current EL), IL = 32 bits
[ 18.709821] SET = 0, FnV = 0
[ 18.714292] EA = 0, S1PTW = 0
[ 18.718833] FSC = 0x04: level 0 translation fault
[ 18.725126] Data abort info:
[ 18.729408] ISV = 0, ISS = 0x00000004
[ 18.734655] CM = 0, WnR = 0
[ 18.738933] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000111bbf000
[ 18.745409] [0000000000000010] pgd=0000000000000000, p4d=0000000000000000
[ 18.752235] Internal error: Oops: 96000004 [#1] SMP
[ 18.757134] Modules linked in: rfkill ip_set nf_tables nfnetlink qrtr sunrpc vfat fat omap_rng fuse zram xfs crct10dif_ce mvpp2 ghash_ce sbsa_gwdt phylink xhci_plat_hcd ahci_plam
[ 18.773481] CPU: 0 PID: 681 Comm: NetworkManager Not tainted 5.17.0-0.rc3.89.fc36.aarch64 #1
[ 18.781954] Hardware name: Marvell Armada 7k/8k Family Board /Armada 7k/8k Family Board , BIOS EDK II Jun 4 2019
[ 18.795222] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 18.802213] pc : mvpp2_start_dev+0x2b0/0x300 [mvpp2]
[ 18.807208] lr : mvpp2_start_dev+0x298/0x300 [mvpp2]
[ 18.812197] sp : ffff80000b4732c0
[ 18.815522] x29: ffff80000b4732c0 x28: 0000000000000000 x27: ffffccab38ae57f8
[ 18.822689] x26: ffff6eeb03065a10 x25: ffff80000b473a30 x24: ffff80000b4735b8
[ 18.829855] x23: 0000000000000000 x22: 00000000000001e0 x21: ffff6eeb07b6ab68
[ 18.837021] x20: ffff6eeb07b6ab30 x19: ffff6eeb07b6a9c0 x18: 0000000000000014
[ 18.844187] x17: 00000000f6232bfe x16: ffffccab899b1dc0 x15: 000000006a30f9fa
[ 18.851353] x14: 000000003b77bd50 x13: 000006dc896f0e8e x12: 001bbbfccfd0d3a2
[ 18.858519] x11: 0000000000001528 x10: 0000000000001548 x9 : ffffccab38ad0fb0
[ 18.865685] x8 : ffff80000b473330 x7 : 0000000000000000 x6 : 0000000000000000
[ 18.872851] x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff80000b4732f8
[ 18.880017] x2 : 000000000000001a x1 : 0000000000000002 x0 : ffff6eeb07b6ab68
[ 18.887183] Call trace:
[ 18.889637] mvpp2_start_dev+0x2b0/0x300 [mvpp2]
[ 18.894279] mvpp2_open+0x134/0x2b4 [mvpp2]
[ 18.898483] __dev_open+0x128/0x1e4
[ 18.901988] __dev_change_flags+0x17c/0x1d0
[ 18.906187] dev_change_flags+0x30/0x70
[ 18.910038] do_setlink+0x278/0xa7c
[ 18.913540] __rtnl_newlink+0x44c/0x7d0
[ 18.917391] rtnl_newlink+0x5c/0x8c
[ 18.920892] rtnetlink_rcv_msg+0x254/0x314
[ 18.925006] netlink_rcv_skb+0x48/0x10c
[ 18.928858] rtnetlink_rcv+0x24/0x30
[ 18.932449] netlink_unicast+0x290/0x2f4
[ 18.936386] netlink_sendmsg+0x1d0/0x41c
[ 18.940323] sock_sendmsg+0x60/0x70
[ 18.943825] ____sys_sendmsg+0x248/0x260
[ 18.947762] ___sys_sendmsg+0x74/0xa0
[ 18.951438] __sys_sendmsg+0x64/0xcc
[ 18.955027] __arm64_sys_sendmsg+0x30/0x40
[ 18.959140] invoke_syscall+0x50/0x120
[ 18.962906] el0_svc_common.constprop.0+0x4c/0xf4
[ 18.967629] do_el0_svc+0x30/0x9c
[ 18.970958] el0_svc+0x28/0xb0
[ 18.974025] el0t_64_sync_handler+0x10c/0x140
[ 18.978400] el0t_64_sync+0x1a4/0x1a8
[ 18.982078] Code: 52800004 b9416262 aa1503e0 52800041 (f94008a5)
[ 18.988196] ---[ end trace 0000000000000000 ]---

Fixes: cff056322372 ("net: mvpp2: use .mac_select_pcs() interface")
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 7cdbf8b8bbf6..d53d7648625f 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -6631,8 +6631,9 @@ static void mvpp2_acpi_start(struct mvpp2_port *port)
mvpp2_mac_prepare(&port->phylink_config, MLO_AN_INBAND,
port->phy_interface);
mvpp2_mac_config(&port->phylink_config, MLO_AN_INBAND, &state);
- pcs->ops->pcs_config(pcs, MLO_AN_INBAND, port->phy_interface,
- state.advertising, false);
+ if (pcs && pcs->ops)
+ pcs->ops->pcs_config(pcs, MLO_AN_INBAND, port->phy_interface,
+ state.advertising, false);
mvpp2_mac_finish(&port->phylink_config, MLO_AN_INBAND,
port->phy_interface);
mvpp2_mac_link_up(&port->phylink_config, NULL,
--
2.34.1