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

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

[Jeremy Linton]

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

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

[Russell King (Oracle)]

On Fri, Feb 11, 2022 at 05:42:35PM -0600, Jeremy Linton wrote:
> 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.

pcs->ops should never be NULL. I'm surprised this fix results in any
kind of working networking.

Instead, the initialilsation of port->pcs_*.ops needs to be moved out
of the if (!mvpp2_use_acpi_compat_mode(..)) block. Please try this:

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index b45cc7bfcdb5..0fb65940c0a5 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -7036,6 +7036,9 @@ static int mvpp2_port_probe(struct platform_device *pdev,
 	dev->max_mtu = MVPP2_BM_JUMBO_PKT_SIZE;
 	dev->dev.of_node = port_node;
 
+	port->pcs_gmac.ops = &mvpp2_phylink_gmac_pcs_ops;
+	port->pcs_xlg.ops = &mvpp2_phylink_xlg_pcs_ops;
+
 	if (!mvpp2_use_acpi_compat_mode(port_fwnode)) {
 		port->phylink_config.dev = &dev->dev;
 		port->phylink_config.type = PHYLINK_NETDEV;
@@ -7106,9 +7109,6 @@ static int mvpp2_port_probe(struct platform_device *pdev,
 				  port->phylink_config.supported_interfaces);
 		}
 
-		port->pcs_gmac.ops = &mvpp2_phylink_gmac_pcs_ops;
-		port->pcs_xlg.ops = &mvpp2_phylink_xlg_pcs_ops;
-
 		phylink = phylink_create(&port->phylink_config, port_fwnode,
 					 phy_mode, &mvpp2_phylink_ops);
 		if (IS_ERR(phylink)) {

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

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

[Jeremy Linton]

Hi,

On 2/11/22 17:49, Russell King (Oracle) wrote:
> On Fri, Feb 11, 2022 at 05:42:35PM -0600, Jeremy Linton wrote:
>> 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.
> 
> pcs->ops should never be NULL. I'm surprised this fix results in any
> kind of working networking.
> 
> Instead, the initialilsation of port->pcs_*.ops needs to be moved out
> of the if (!mvpp2_use_acpi_compat_mode(..)) block. Please try this:

That appears to fix it as well, shall I re-post this with your fix, or 
will you?

> 
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index b45cc7bfcdb5..0fb65940c0a5 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -7036,6 +7036,9 @@ static int mvpp2_port_probe(struct platform_device *pdev,
>   	dev->max_mtu = MVPP2_BM_JUMBO_PKT_SIZE;
>   	dev->dev.of_node = port_node;
>   
> +	port->pcs_gmac.ops = &mvpp2_phylink_gmac_pcs_ops;
> +	port->pcs_xlg.ops = &mvpp2_phylink_xlg_pcs_ops;
> +
>   	if (!mvpp2_use_acpi_compat_mode(port_fwnode)) {
>   		port->phylink_config.dev = &dev->dev;
>   		port->phylink_config.type = PHYLINK_NETDEV;
> @@ -7106,9 +7109,6 @@ static int mvpp2_port_probe(struct platform_device *pdev,
>   				  port->phylink_config.supported_interfaces);
>   		}
>   
> -		port->pcs_gmac.ops = &mvpp2_phylink_gmac_pcs_ops;
> -		port->pcs_xlg.ops = &mvpp2_phylink_xlg_pcs_ops;
> -
>   		phylink = phylink_create(&port->phylink_config, port_fwnode,
>   					 phy_mode, &mvpp2_phylink_ops);
>   		if (IS_ERR(phylink)) {
> 
> Thanks.
> 

I did a bit more testing and as a side note, it seems ethtool tosses 
these errors too.


netlink error: failed to retrieve link settings
netlink error: Unknown error 524
netlink error: failed to retrieve link settings
netlink error: Unknown error 524
Settings for enamrvl110i0:
         Link detected: no

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

[Russell King (Oracle)]

On Fri, Feb 11, 2022 at 06:18:22PM -0600, Jeremy Linton wrote:
> Hi,
> 
> On 2/11/22 17:49, Russell King (Oracle) wrote:
> > On Fri, Feb 11, 2022 at 05:42:35PM -0600, Jeremy Linton wrote:
> > > 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.
> > 
> > pcs->ops should never be NULL. I'm surprised this fix results in any
> > kind of working networking.
> > 
> > Instead, the initialilsation of port->pcs_*.ops needs to be moved out
> > of the if (!mvpp2_use_acpi_compat_mode(..)) block. Please try this:
> 
> That appears to fix it as well, shall I re-post this with your fix, or will
> you?

I see you re-posted it anyway - that's fine. Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!