Unknown symbol "net_log" (err 0)

[AzeAstro]

I tried to compile rtl8188eus driver and while compiling I got 1 warning. Here is the full output(output was big): https://pastebin.com/Bh0ZL4Mc

Even if I got this warning, I still got 8188eu.ko and when I tried to load it to my Android, I got this error: Unknown symbol "net_log" (err 0)

Here you can find my kernel source: https://github.com/AzeAstro/samsung_kernel_sm7125/

Strange thing is that net_log function is defined both in header file (‎include/linux/netlog.h‎) and defined as function(net/core/net_ipc_log.c)

I thought that it might be missing somewhere and ran grep -rnw . -e "netlog.h" in the driver source directory and here is the output: https://pastebin.com/B52Gtn3L It is defined almost in every file.

I know it is more likely issue with kernel instead of driver but still. Why this error is happening and how can I fix this?

[gglluukk]

Unknown symbol "function..." in kernel log usually means for that function is missing or not exported (alike private inside the kernel).

Also you might missing #include linux/netlog.h

I'd try to add include or comment out any calls for net_log inside driver's source and see what's going on next

[AzeAstro]

Unknown symbol "function..." in kernel log usually means for that function is missing or not exported (alike private inside the kernel).

Also you might missing #include linux/netlog.h

I'd try to add include or comment out any calls for net_log inside driver's source and see what's going on next

Strange thing is that there is no call for net_log function in driver source. None. Completely zero And the netlog.h only mentioned in *.cmd files. Any possible ideas about where exactly it might happen?

[AzeAstro]

Alright, I found out that I can analyze module file using objdump. I disassembled the module file. You can find it at attachments. net_log only gets called in netdev_br_init and it is defined in os_dep/linux/os_initfs.c objdump.txt

[gglluukk]

in that case i'd rename calls to netdev_br_init() in driver's sources to my_netdev_br_init() and add my_netdev_br_init() function to driver's sources as in: https://elixir.bootlin.com/linux/v5.19.17/source/drivers/staging/r8188eu/os_dep/os_intfs.c#L600 :

void my_netdev_br_init(struct net_device *netdev)
{
        struct adapter *adapter = (struct adapter *)rtw_netdev_priv(netdev);

        rcu_read_lock();

        if (rcu_dereference(adapter->pnetdev->rx_handler_data)) {
                struct net_device *br_netdev;
                struct net *devnet = NULL;

                devnet = dev_net(netdev);
                br_netdev = dev_get_by_name(devnet, CONFIG_BR_EXT_BRNAME);
                if (br_netdev) {
                        memcpy(adapter->br_mac, br_netdev->dev_addr, ETH_ALEN);
                        dev_put(br_netdev);
                } else {
                        pr_info("%s()-%d: dev_get_by_name(%s) failed!",
                                __func__, __LINE__, CONFIG_BR_EXT_BRNAME);
                }
        }
        adapter->ethBrExtInfo.addPPPoETag = 1;

        rcu_read_unlock();
}

but you should use sources for netdev_br_init() function from samsung's kernel with version your device running but without that broken(?) net_log() call

[gglluukk]

or define your own version of net_log() in driver's source <-- that's most easiest way for trying to fix it

[AzeAstro]

Alright. Thanks for responding. I am not at home right now but I will try it and send results when I arrive.

[AzeAstro]

in that case i'd rename calls to netdev_br_init() in driver's sources to my_netdev_br_init() and add my_netdev_br_init() function to driver's sources as in: https://elixir.bootlin.com/linux/v5.19.17/source/drivers/staging/r8188eu/os_dep/os_intfs.c#L600 :

void my_netdev_br_init(struct net_device *netdev)
{
        struct adapter *adapter = (struct adapter *)rtw_netdev_priv(netdev);

        rcu_read_lock();

        if (rcu_dereference(adapter->pnetdev->rx_handler_data)) {
                struct net_device *br_netdev;
                struct net *devnet = NULL;

                devnet = dev_net(netdev);
                br_netdev = dev_get_by_name(devnet, CONFIG_BR_EXT_BRNAME);
                if (br_netdev) {
                        memcpy(adapter->br_mac, br_netdev->dev_addr, ETH_ALEN);
                        dev_put(br_netdev);
                } else {
                        pr_info("%s()-%d: dev_get_by_name(%s) failed!",
                                __func__, __LINE__, CONFIG_BR_EXT_BRNAME);
                }
        }
        adapter->ethBrExtInfo.addPPPoETag = 1;

        rcu_read_unlock();
}

but you should use sources for netdev_br_init() function from samsung's kernel with version your device running but without that broken(?) net_log() call

Thank you for your suggestion about making own netdev_br_init() function or just renaming it. Yesterday I asked this same question on stack overflow and comment from user named "Tsyvarev" worked. I took a look at file where net_log function got defined but not exported as symbol. Exporting that function as GPL symbol worked. Here you can find the post: https://stackoverflow.com/questions/76694952/unknown-symbol-net-log-err-0