/* * arch/s390/kernel/signal.c * * S390 version * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com) * * Based on Intel version * * Copyright (C) 1991, 1992 Linus Torvalds * * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEBUG_SIG 0 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) /* pretcode & sig are used to store the return addr on Intel & the signal no as the first parameter we do this differently using gpr14 & gpr2. */ #define SIGFRAME_COMMON \ __u8 callee_used_stack[__SIGNAL_FRAMESIZE]; \ struct sigcontext sc; \ _sigregs sregs; \ __u8 retcode[S390_SYSCALL_SIZE]; typedef struct { SIGFRAME_COMMON } sigframe; typedef struct { SIGFRAME_COMMON struct siginfo info; struct ucontext uc; } rt_sigframe; asmlinkage int FASTCALL(do_signal(struct pt_regs *regs, sigset_t *oldset)); int copy_siginfo_to_user(siginfo_t *to, siginfo_t *from) { if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) return -EFAULT; if (from->si_code < 0) return __copy_to_user(to, from, sizeof(siginfo_t)); else { int err; /* If you change siginfo_t structure, please be sure this code is fixed accordingly. It should never copy any pad contained in the structure to avoid security leaks, but must copy the generic 3 ints plus the relevant union member. */ err = __put_user(from->si_signo, &to->si_signo); err |= __put_user(from->si_errno, &to->si_errno); err |= __put_user((short)from->si_code, &to->si_code); /* First 32bits of unions are always present. */ err |= __put_user(from->si_pid, &to->si_pid); switch (from->si_code >> 16) { case __SI_FAULT >> 16: break; case __SI_CHLD >> 16: err |= __put_user(from->si_utime, &to->si_utime); err |= __put_user(from->si_stime, &to->si_stime); err |= __put_user(from->si_status, &to->si_status); default: err |= __put_user(from->si_uid, &to->si_uid); break; /* case __SI_RT: This is not generated by the kernel as of now. */ } return err; } } /* * Atomically swap in the new signal mask, and wait for a signal. */ asmlinkage int sys_sigsuspend(struct pt_regs * regs,int history0, int history1, old_sigset_t mask) { sigset_t saveset; mask &= _BLOCKABLE; spin_lock_irq(¤t->sigmask_lock); saveset = current->blocked; siginitset(¤t->blocked, mask); recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); regs->gprs[2] = -EINTR; while (1) { set_current_state(TASK_INTERRUPTIBLE); schedule(); if (do_signal(regs, &saveset)) return -EINTR; } } asmlinkage int sys_rt_sigsuspend(struct pt_regs * regs,sigset_t *unewset, size_t sigsetsize) { sigset_t saveset, newset; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(sigset_t)) return -EINVAL; if (copy_from_user(&newset, unewset, sizeof(newset))) return -EFAULT; sigdelsetmask(&newset, ~_BLOCKABLE); spin_lock_irq(¤t->sigmask_lock); saveset = current->blocked; current->blocked = newset; recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); regs->gprs[2] = -EINTR; while (1) { set_current_state(TASK_INTERRUPTIBLE); schedule(); if (do_signal(regs, &saveset)) return -EINTR; } } asmlinkage int sys_sigaction(int sig, const struct old_sigaction *act, struct old_sigaction *oact) { struct k_sigaction new_ka, old_ka; int ret; if (act) { old_sigset_t mask; if (verify_area(VERIFY_READ, act, sizeof(*act)) || __get_user(new_ka.sa.sa_handler, &act->sa_handler) || __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) return -EFAULT; __get_user(new_ka.sa.sa_flags, &act->sa_flags); __get_user(mask, &act->sa_mask); siginitset(&new_ka.sa.sa_mask, mask); } ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); if (!ret && oact) { if (verify_area(VERIFY_WRITE, oact, sizeof(*oact)) || __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) return -EFAULT; __put_user(old_ka.sa.sa_flags, &oact->sa_flags); __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); } return ret; } asmlinkage int sys_sigaltstack(const stack_t *uss, stack_t *uoss, struct pt_regs *regs) { return do_sigaltstack(uss, uoss, regs->gprs[15]); } static int save_sigregs(struct pt_regs *regs,_sigregs *sregs) { int err; s390_fp_regs fpregs; err = __copy_to_user(&sregs->regs,regs,sizeof(s390_regs_common)); if(!err) { save_fp_regs(&fpregs); err=__copy_to_user(&sregs->fpregs,&fpregs,sizeof(fpregs)); } return(err); } static int restore_sigregs(struct pt_regs *regs,_sigregs *sregs) { int err; s390_fp_regs fpregs; psw_t saved_psw=regs->psw; err=__copy_from_user(regs,&sregs->regs,sizeof(s390_regs_common)); if(!err) { regs->orig_gpr2 = -1; /* disable syscall checks */ regs->psw.mask=(saved_psw.mask&~PSW_MASK_DEBUGCHANGE)| (regs->psw.mask&PSW_MASK_DEBUGCHANGE); regs->psw.addr=(saved_psw.addr&~PSW_ADDR_DEBUGCHANGE)| (regs->psw.addr&PSW_ADDR_DEBUGCHANGE); err=__copy_from_user(&fpregs,&sregs->fpregs,sizeof(fpregs)); if(!err) restore_fp_regs(&fpregs); } return(err); } static int restore_sigcontext(struct sigcontext *sc, pt_regs *regs, _sigregs *sregs,sigset_t *set) { unsigned int err; err=restore_sigregs(regs,sregs); if(!err) err=__copy_from_user(&set->sig,&sc->oldmask,_SIGMASK_COPY_SIZE); return(err); } int sigreturn_common(struct pt_regs *regs,int framesize) { sigframe *frame = (sigframe *)regs->gprs[15]; sigset_t set; if (verify_area(VERIFY_READ, frame, sizeof(*frame))) return -1; if (restore_sigcontext(&frame->sc,regs,&frame->sregs,&set)) return -1; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sigmask_lock); current->blocked = set; recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); return 0; } asmlinkage int sys_sigreturn(struct pt_regs *regs) { if (sigreturn_common(regs,sizeof(sigframe))) goto badframe; return regs->gprs[2]; badframe: force_sig(SIGSEGV, current); return 0; } asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) { rt_sigframe *frame = (rt_sigframe *)regs->gprs[15]; if (sigreturn_common(regs,sizeof(rt_sigframe))) goto badframe; /* It is more difficult to avoid calling this function than to call it and ignore errors. */ do_sigaltstack(&frame->uc.uc_stack, NULL, regs->gprs[15]); return regs->gprs[2]; badframe: force_sig(SIGSEGV, current); return 0; } /* * Set up a signal frame. */ /* * Determine which stack to use.. */ static inline void * get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) { unsigned long sp; /* Default to using normal stack */ sp = regs->gprs[15]; /* This is the X/Open sanctioned signal stack switching. */ if (ka->sa.sa_flags & SA_ONSTACK) { if (! on_sig_stack(sp)) sp = current->sas_ss_sp + current->sas_ss_size; } /* This is the legacy signal stack switching. */ else if (!user_mode(regs) && !(ka->sa.sa_flags & SA_RESTORER) && ka->sa.sa_restorer) { sp = (unsigned long) ka->sa.sa_restorer; } return (void *)((sp - frame_size) & -8ul); } static void *setup_frame_common(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs, int frame_size,u16 retcode) { sigframe *frame; int err; frame = get_sigframe(ka, regs,frame_size); if (!access_ok(VERIFY_WRITE, frame,frame_size)) return 0; err = save_sigregs(regs,&frame->sregs); if(!err) err=__put_user(&frame->sregs,&frame->sc.sregs); if(!err) err=__copy_to_user(&frame->sc.oldmask,&set->sig,_SIGMASK_COPY_SIZE); if(!err) { regs->gprs[2]=(current->exec_domain && current->exec_domain->signal_invmap && sig < 32 ? current->exec_domain->signal_invmap[sig] : sig); /* Set up registers for signal handler */ regs->gprs[15] = (addr_t)frame; regs->psw.addr = FIX_PSW(ka->sa.sa_handler); } /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa.sa_flags & SA_RESTORER) { regs->gprs[14] = FIX_PSW(ka->sa.sa_restorer); } else { regs->gprs[14] = FIX_PSW(frame->retcode); err |= __put_user(retcode, (u16 *)(frame->retcode)); } return(err ? 0:frame); } static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs) { sigframe *frame; if((frame=setup_frame_common(sig,ka,set,regs,sizeof(sigframe), (S390_SYSCALL_OPCODE|__NR_sigreturn)))==0) goto give_sigsegv; #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", current->comm, current->pid, frame, regs->eip, frame->pretcode); #endif /* Martin wants this for pthreads */ regs->gprs[3] = (addr_t)&frame->sc; return; give_sigsegv: if (sig == SIGSEGV) ka->sa.sa_handler = SIG_DFL; force_sig(SIGSEGV, current); } static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct pt_regs * regs) { rt_sigframe *frame; addr_t orig_sp=regs->gprs[15]; int err; if((frame=setup_frame_common(sig,ka,set,regs,sizeof(rt_sigframe), (S390_SYSCALL_OPCODE|__NR_rt_sigreturn)))==0) goto give_sigsegv; err = copy_siginfo_to_user(&frame->info, info); /* Create the ucontext. */ err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); err |= __put_user(sas_ss_flags(orig_sp), &frame->uc.uc_stack.ss_flags); err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); err |= __put_user(&frame->sc,&frame->uc.sc); regs->gprs[3] = (addr_t)&frame->info; regs->gprs[4] = (addr_t)&frame->uc; if (err) goto give_sigsegv; #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", current->comm, current->pid, frame, regs->eip, frame->pretcode); #endif return; give_sigsegv: if (sig == SIGSEGV) ka->sa.sa_handler = SIG_DFL; force_sig(SIGSEGV, current); } /* * OK, we're invoking a handler */ static void handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, struct pt_regs * regs) { /* Are we from a system call? */ if (regs->orig_gpr2 >= 0) { /* If so, check system call restarting.. */ switch (regs->gprs[2]) { case -ERESTARTNOHAND: regs->gprs[2] = -EINTR; break; case -ERESTARTSYS: if (!(ka->sa.sa_flags & SA_RESTART)) { regs->gprs[2] = -EINTR; break; } /* fallthrough */ case -ERESTARTNOINTR: regs->gprs[2] = regs->orig_gpr2; regs->psw.addr -= 2; } } /* Set up the stack frame */ if (ka->sa.sa_flags & SA_SIGINFO) setup_rt_frame(sig, ka, info, oldset, regs); else setup_frame(sig, ka, oldset, regs); if (ka->sa.sa_flags & SA_ONESHOT) ka->sa.sa_handler = SIG_DFL; if (!(ka->sa.sa_flags & SA_NODEFER)) { spin_lock_irq(¤t->sigmask_lock); sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); sigaddset(¤t->blocked,sig); recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); } } /* * Note that 'init' is a special process: it doesn't get signals it doesn't * want to handle. Thus you cannot kill init even with a SIGKILL even by * mistake. * * Note that we go through the signals twice: once to check the signals that * the kernel can handle, and then we build all the user-level signal handling * stack-frames in one go after that. */ int do_signal(struct pt_regs *regs, sigset_t *oldset) { siginfo_t info; struct k_sigaction *ka; /* * We want the common case to go fast, which * is why we may in certain cases get here from * kernel mode. Just return without doing anything * if so. */ if (!user_mode(regs)) return 1; if (!oldset) oldset = ¤t->blocked; for (;;) { unsigned long signr; spin_lock_irq(¤t->sigmask_lock); signr = dequeue_signal(¤t->blocked, &info); spin_unlock_irq(¤t->sigmask_lock); if (!signr) break; if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) { /* Let the debugger run. */ current->exit_code = signr; set_current_state(TASK_STOPPED); notify_parent(current, SIGCHLD); schedule(); /* We're back. Did the debugger cancel the sig? */ if (!(signr = current->exit_code)) continue; current->exit_code = 0; /* The debugger continued. Ignore SIGSTOP. */ if (signr == SIGSTOP) continue; /* Update the siginfo structure. Is this good? */ if (signr != info.si_signo) { info.si_signo = signr; info.si_errno = 0; info.si_code = SI_USER; info.si_pid = current->p_pptr->pid; info.si_uid = current->p_pptr->uid; } /* If the (new) signal is now blocked, requeue it. */ if (sigismember(¤t->blocked, signr)) { send_sig_info(signr, &info, current); continue; } } ka = ¤t->sig->action[signr-1]; if (ka->sa.sa_handler == SIG_IGN) { if (signr != SIGCHLD) continue; /* Check for SIGCHLD: it's special. */ while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0) /* nothing */; continue; } if (ka->sa.sa_handler == SIG_DFL) { int exit_code = signr; /* Init gets no signals it doesn't want. */ if (current->pid == 1) continue; switch (signr) { case SIGCONT: case SIGCHLD: case SIGWINCH: continue; case SIGTSTP: case SIGTTIN: case SIGTTOU: if (is_orphaned_pgrp(current->pgrp)) continue; /* FALLTHRU */ case SIGSTOP: set_current_state(TASK_STOPPED); current->exit_code = signr; if (!(current->p_pptr->sig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) notify_parent(current, SIGCHLD); schedule(); continue; case SIGQUIT: case SIGILL: case SIGTRAP: case SIGABRT: case SIGFPE: case SIGSEGV: if (do_coredump(signr, regs)) exit_code |= 0x80; /* FALLTHRU */ default: lock_kernel(); sigaddset(¤t->pending.signal, signr); recalc_sigpending(current); current->flags |= PF_SIGNALED; do_exit(exit_code); /* NOTREACHED */ } } /* Whee! Actually deliver the signal. */ handle_signal(signr, ka, &info, oldset, regs); return 1; } /* Did we come from a system call? */ if ( regs->trap == __LC_SVC_OLD_PSW /* System Call! */ ) { /* Restart the system call - no handlers present */ if (regs->gprs[2] == -ERESTARTNOHAND || regs->gprs[2] == -ERESTARTSYS || regs->gprs[2] == -ERESTARTNOINTR) { regs->gprs[2] = regs->orig_gpr2; regs->psw.addr -= 2; } } return 0; }