Hi Christina, thank you for your answer, it helped a lot.
Is it possible to aquire the thread's registers through simply reading them in the UTCB which is pointed by Thread_state::utcb? If yes, what is the layout of the UTCB in the memory? Or do I also have to pause the thread to find relevant registers? Kind regards, Denis On 19.08.2016 16:28, Christian Prochaska wrote: > Hi Denis, > > On 19.08.2016 10:30, Denis Huber wrote: >> I tried reading the registers through the "Thread_state >> Cpu_thread::state()" method, but it did not contain any information >> about (just zeros). >> >> I'm using Genode 16.05, kernel Fiasco.OC (pbax9 build). By inspecting >> the kernel API of foc, I found out that the function >> l4_thread_ex_regs_ret can read the sp and ip register. > > On Fiasco.OC, the 'Platform_thread::pause()' function forces the thread into > an exception state, which is handled by the pager, who > reads the register state (including r0-r12) from the UTCB in > 'Ipc_pager::_parse()'. The 'Platform_thread::state()' function then > returns this previously saved state. If you called 'Cpu_thread::pause()' > before 'Cpu_thread::state()' and did not get the correct > register state, perhaps the thread was just executing a syscall. In that > case, the exception would only occur after the syscall > returned, which might take a long time, so 'Platform_thread::pause()' returns > without waiting for the exception when it detects this > situation. A possible solution for this problem without having to block until > the thread returns from the syscall might be to extend > 'l4_thread_ex_regs_ret()' to return the missing registers in the UTCB. > > Regards, > Christian > > > ------------------------------------------------------------------------------ > _______________________________________________ > genode-main mailing list > genode-main@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/genode-main > ------------------------------------------------------------------------------ _______________________________________________ genode-main mailing list genode-main@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/genode-main
