> + ; --------- check for signals/restore-sigmask ------------ > + bbit0 r9, TIF_SIGPENDING, chk_next_work > + > + ; save CALLEE Regs. > + ; (i) If this signal causes coredump - full regfile needed > + ; (ii) If signal is SIGTRAP/SIGSTOP, task is being traced thus > + ; tracer might call PEEKUSR for a CALLEE reg > + ; > + ; NOTE: SP will grow up by size of CALLEE Reg-File > + SAVE_CALLEE_SAVED_USER ; clobbers r12 > + > + ; save location of saved Callee Regs @ thread_struct->callee > + GET_CURR_TASK_FIELD_PTR TASK_THREAD, r10 > + st sp, [r10, THREAD_CALLEE_REG] > + > + bl @do_signal > + > + ; unwind SP for cheap discard of Callee saved Regs > + DISCARD_CALLEE_SAVED_USER
Uh-oh... And what if tracer wanted to modify callee-saved regs? > + b resume_user_mode_begin ; loop back to start of U mode ret > + > + ; --- notify_resume --- > +chk_next_work: > + btst r9, TIF_NOTIFY_RESUME > + blnz @do_notify_resume > + > + ;--------- All things done, go back to Userland ------ > + > + b restore_regs No. After NOTIFY_RESUME stuff you need to recheck SIGPENDING. This should go to resume_user_mode_begin, not restore regs. Another problem here is IRQ handling - you hit do_signal()/do_notify_resume() with IRQs disabled, which is broken - you need to re-enable it before going into either. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
