Re: [PATCH] net: usb: r8152: Check used MAC passthrough address
From: Aaron Ma
Date: Wed Jan 05 2022 - 03:01:38 EST
On 1/5/22 15:55, Henning Schild wrote:
Am Wed, 5 Jan 2022 15:38:51 +0800
schrieb Aaron Ma <aaron.ma@xxxxxxxxxxxxx>:
On 1/5/22 15:32, Henning Schild wrote:
Am Wed, 5 Jan 2022 08:23:55 +0100
schrieb Henning Schild <henning.schild@xxxxxxxxxxx>:
Hi Aaron,
if this or something similar goes in, please add another patch to
remove the left-over defines.
Sure, I will do it.
Am Wed, 5 Jan 2022 14:17:47 +0800
schrieb Aaron Ma <aaron.ma@xxxxxxxxxxxxx>:
When plugin multiple r8152 ethernet dongles to Lenovo Docks
or USB hub, MAC passthrough address from BIOS should be
checked if it had been used to avoid using on other dongles.
Currently builtin r8152 on Dock still can't be identified.
First detected r8152 will use the MAC passthrough address.
Signed-off-by: Aaron Ma <aaron.ma@xxxxxxxxxxxxx>
---
drivers/net/usb/r8152.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index f9877a3e83ac..77f11b3f847b 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -1605,6 +1605,7 @@ static int
vendor_mac_passthru_addr_read(struct r8152 *tp, struct sockaddr
*sa) char *mac_obj_name; acpi_object_type mac_obj_type;
int mac_strlen;
+ struct net_device *ndev;
if (tp->lenovo_macpassthru) {
mac_obj_name = "\\MACA";
@@ -1662,6 +1663,15 @@ static int
vendor_mac_passthru_addr_read(struct r8152 *tp, struct sockaddr
*sa) ret = -EINVAL; goto amacout;
}
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, ndev) {
+ if (strncmp(buf, ndev->dev_addr, 6) == 0) {
+ rcu_read_unlock();
+ goto amacout;
Since the original PCI netdev will always be there, that would
disable inheritance would it not?
I guess a strncmp(MODULE_NAME, info->driver, strlen(MODULE_NAME))
is needed as well.
PCI ethernet could be a builtin one on dock since there will be TBT4
dock.
In my X280 there is a PCI device in the laptop, always there. And its
MAC is the one found in ACPI. Did not try but i think for such devices
there would never be inheritance even if one wanted and used a Lenovo
dock that is supposed to do it.
There will more TBT4 docks in market, the new ethernet is just the same as
PCI device, connected by thunderbolt.
For exmaple, connect a TBT4 dock which uses i225 pcie base ethernet,
then connect another TBT3 dock which uses r8152.
If skip PCI check, then i225 and r8152 will use the same MAC.
Aaron
Maybe i should try the patch but it seems like it defeats inheritance
completely. Well depending on probe order ...
regards,
Henning
Maybe leave here with
netif_info()
Not good to print in rcu lock.
And move the whole block up, we can skip the whole ACPI story if we
find the MAC busy.
That is wrong, need to know that MAC so can not move up too much.
But maybe above the is_valid_ether_addr
The MAC passthough address is read from ACPI.
ACPI read only happens once during r8152 driver probe.
To keep the lock less time, do it after is_valid_ether_addr.
Henning
+ }
+ }
+ rcu_read_unlock();
Not sure if this function is guaranteed to only run once at a time,
otherwise i think that is a race. Multiple instances could make it
to this very point at the same time.
Run once for one device.
So add a safe lock.
Aaron
Henning
memcpy(sa->sa_data, buf, 6);
netif_info(tp, probe, tp->netdev,
"Using pass-thru MAC addr %pM\n",
sa->sa_data);