On Sun, 10 Jun 2007 13:53:44 +0300, Octavian Purdila <tavi@xxxxxxxxx> wrote: > On Sunday 10 June 2007 13:03, Lukas Razik wrote: >> Hello! >> >> I'm new to kernel programming and I try to develop a fake ethernet > driver >> for v2.6.21.3 which I really need based on netdev but I ran into the >> following issue: >> If the kernel calls the 'dev->hard_start_xmit' function of my driver > then >> this calls another one which try to create a socket in the following >> "normal way": >> >> struct socket *ssock = NULL; >> ... >> sock_create(family, SOCK_STREAM, IPPROTO_TCP, &ssock); >> >> But at this point I get an error message from the kernel as appended > below. >> So what have I done wrong? >> > > Hi Lukas, > > The hard_start_xmit function is running in interrupt context, thus you > can't > call any functions that might sleep (and sock_create is one of them > because > it probably allocates memory with GFP_KERNEL) > > I'm not sure what is the purpose of you ethernet driver, but when you run > into > this types of problems, you need to deffer the work that might sleep and > run > it from process context. workqueues and kernel threads are the means for > that. > > > tavi > > Hi Tavi! I think I've understood you. In the future the hard_ximit_function won't create a socket. It will only send by the help of sock_sendmsg() through one which will be created before. BTW do you know if I can use sock_sendmsg() in interrupt context? Because this is only a test I'll try to work here with a kernel thread... Regards and many thanks for your fast answer! Lukas -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
