void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs) { if (current->thread.fault_catcher != NULL) UML_LONGJMP(current->thread.fault_catcher, 1); else relay_signal(sig, si, regs); }
/*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/ static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu) { int err, syscall_nr, status; syscall_nr = PT_SYSCALL_NR(regs->skas.regs); UPT_SYSCALL_NR(regs) = syscall_nr; if(syscall_nr < 0){ relay_signal(SIGTRAP, regs); return; } if (!local_using_sysemu) { err = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET, __NR_getpid); if(err < 0) panic("handle_trap - nullifying syscall failed errno = %d\n", errno); err = ptrace(PTRACE_SYSCALL, pid, 0, 0); if(err < 0) panic("handle_trap - continuing to end of syscall failed, " "errno = %d\n", errno); CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED)); if((err < 0) || !WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP)) panic("handle_trap - failed to wait at end of syscall, " "errno = %d, status = %d\n", errno, status); } handle_syscall(regs); }
void userspace(union uml_pt_regs *regs) { int err, status, op, pid = userspace_pid[0]; int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/ while(1){ restore_registers(pid, regs); /* Now we set local_using_sysemu to be used for one loop */ local_using_sysemu = get_using_sysemu(); op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL)); err = ptrace(op, pid, 0, 0); if(err) panic("userspace - could not resume userspace process, " "pid=%d, ptrace operation = %d, errno = %d\n", op, errno); CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED)); if(err < 0) panic("userspace - waitpid failed, errno = %d\n", errno); regs->skas.is_user = 1; save_registers(pid, regs); UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */ if(WIFSTOPPED(status)){ switch(WSTOPSIG(status)){ case SIGSEGV: handle_segv(pid, regs); break; case SIGTRAP + 0x80: handle_trap(pid, regs, local_using_sysemu); break; case SIGTRAP: relay_signal(SIGTRAP, regs); break; case SIGIO: case SIGVTALRM: case SIGILL: case SIGBUS: case SIGFPE: case SIGWINCH: user_signal(WSTOPSIG(status), regs, pid); break; default: printk("userspace - child stopped with signal " "%d\n", WSTOPSIG(status)); } interrupt_end(); /* Avoid -ERESTARTSYS handling in host */ PT_SYSCALL_NR(regs->skas.regs) = -1; } } }
void bus_handler(int sig, union uml_pt_regs *regs) { if(current->thread.fault_catcher != NULL) do_longjmp(current->thread.fault_catcher, 1); else relay_signal(sig, regs); }