/* * Architecture-specific signal handling support. * * Copyright (C) 1999-2000 Hewlett-Packard Co * Copyright (C) 1999-2000 David Mosberger-Tang * * Derived from i386 and Alpha versions. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEBUG_SIG 0 #define STACK_ALIGN 16 /* minimal alignment for stack pointer */ #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) #if _NSIG_WORDS > 1 # define PUT_SIGSET(k,u) __copy_to_user((u)->sig, (k)->sig, sizeof(sigset_t)) # define GET_SIGSET(k,u) __copy_from_user((k)->sig, (u)->sig, sizeof(sigset_t)) #else # define PUT_SIGSET(k,u) __put_user((k)->sig[0], &(u)->sig[0]) # define GET_SIGSET(k,u) __get_user((k)->sig[0], &(u)->sig[0]) #endif struct sigscratch { #ifdef CONFIG_IA64_NEW_UNWIND unsigned long scratch_unat; /* ar.unat for the general registers saved in pt */ unsigned long pad; #else struct switch_stack sw; #endif struct pt_regs pt; }; struct sigframe { struct siginfo info; struct sigcontext sc; }; extern long sys_wait4 (int, int *, int, struct rusage *); extern long ia64_do_signal (sigset_t *, struct sigscratch *, long); /* forward decl */ long ia64_rt_sigsuspend (sigset_t *uset, size_t sigsetsize, struct sigscratch *scr) { sigset_t oldset, set; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(sigset_t)) return -EINVAL; if (GET_SIGSET(&set, uset)) return -EFAULT; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sigmask_lock); { oldset = current->blocked; current->blocked = set; recalc_sigpending(current); } spin_unlock_irq(¤t->sigmask_lock); /* * The return below usually returns to the signal handler. We need to * pre-set the correct error code here to ensure that the right values * get saved in sigcontext by ia64_do_signal. */ #ifdef CONFIG_IA32_SUPPORT if (IS_IA32_PROCESS(&scr->pt)) { scr->pt.r8 = -EINTR; } else #endif { scr->pt.r8 = EINTR; scr->pt.r10 = -1; } while (1) { set_current_state(TASK_INTERRUPTIBLE); schedule(); if (ia64_do_signal(&oldset, scr, 1)) return -EINTR; } } asmlinkage long sys_sigaltstack (const stack_t *uss, stack_t *uoss, long arg2, long arg3, long arg4, long arg5, long arg6, long arg7, long stack) { struct pt_regs *pt = (struct pt_regs *) &stack; return do_sigaltstack(uss, uoss, pt->r12); } static long restore_sigcontext (struct sigcontext *sc, struct sigscratch *scr) { unsigned long ip, flags, nat, um, cfm; long err; /* restore scratch that always needs gets updated during signal delivery: */ err = __get_user(flags, &sc->sc_flags); err |= __get_user(nat, &sc->sc_nat); err |= __get_user(ip, &sc->sc_ip); /* instruction pointer */ err |= __get_user(cfm, &sc->sc_cfm); err |= __get_user(um, &sc->sc_um); /* user mask */ err |= __get_user(scr->pt.ar_rsc, &sc->sc_ar_rsc); err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat); err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); err |= __get_user(scr->pt.pr, &sc->sc_pr); /* predicates */ err |= __get_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ err |= __get_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ err |= __get_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 3*8); /* r1-r3 */ err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8); /* r8-r11 */ err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 4*8); /* r12-r15 */ err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8); /* r16-r31 */ scr->pt.cr_ifs = cfm | (1UL << 63); /* establish new instruction pointer: */ scr->pt.cr_iip = ip & ~0x3UL; ia64_psr(&scr->pt)->ri = ip & 0x3; scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM); #ifdef CONFIG_IA64_NEW_UNWIND scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat); #else ia64_put_nat_bits(&scr->pt, &scr->sw, nat); /* restore the original scratch NaT bits */ #endif if (flags & IA64_SC_FLAG_FPH_VALID) { struct task_struct *fpu_owner = ia64_get_fpu_owner(); __copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16); if (fpu_owner == current) { __ia64_load_fpu(current->thread.fph); } } return err; } 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); switch (from->si_code >> 16) { case __SI_FAULT >> 16: err |= __put_user(from->si_isr, &to->si_isr); case __SI_POLL >> 16: err |= __put_user(from->si_addr, &to->si_addr); err |= __put_user(from->si_imm, &to->si_imm); 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); err |= __put_user(from->si_pid, &to->si_pid); break; /* case __SI_RT: This is not generated by the kernel as of now. */ } return err; } } long ia64_rt_sigreturn (struct sigscratch *scr) { extern char ia64_strace_leave_kernel, ia64_leave_kernel; struct sigcontext *sc; struct siginfo si; sigset_t set; long retval; sc = &((struct sigframe *) (scr->pt.r12 + 16))->sc; /* * When we return to the previously executing context, r8 and * r10 have already been setup the way we want them. Indeed, * if the signal wasn't delivered while in a system call, we * must not touch r8 or r10 as otherwise user-level stat could * be corrupted. */ retval = (long) &ia64_leave_kernel; if (current->ptrace & PT_TRACESYS) /* * strace expects to be notified after sigreturn * returns even though the context to which we return * may not be in the middle of a syscall. Thus, the * return-value that strace displays for sigreturn is * meaningless. */ retval = (long) &ia64_strace_leave_kernel; if (!access_ok(VERIFY_READ, sc, sizeof(*sc))) goto give_sigsegv; if (GET_SIGSET(&set, &sc->sc_mask)) goto give_sigsegv; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sigmask_lock); current->blocked = set; recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); if (restore_sigcontext(sc, scr)) goto give_sigsegv; #if DEBUG_SIG printk("SIG return (%s:%d): sp=%lx ip=%lx\n", current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip); #endif /* * It is more difficult to avoid calling this function than to * call it and ignore errors. */ do_sigaltstack(&sc->sc_stack, 0, scr->pt.r12); return retval; give_sigsegv: si.si_signo = SIGSEGV; si.si_errno = 0; si.si_code = SI_KERNEL; si.si_pid = current->pid; si.si_uid = current->uid; si.si_addr = sc; force_sig_info(SIGSEGV, &si, current); return retval; } /* * This does just the minimum required setup of sigcontext. * Specifically, it only installs data that is either not knowable at * the user-level or that gets modified before execution in the * trampoline starts. Everything else is done at the user-level. */ static long setup_sigcontext (struct sigcontext *sc, sigset_t *mask, struct sigscratch *scr) { struct task_struct *fpu_owner = ia64_get_fpu_owner(); unsigned long flags = 0, ifs, nat; long err; ifs = scr->pt.cr_ifs; if (on_sig_stack((unsigned long) sc)) flags |= IA64_SC_FLAG_ONSTACK; if ((ifs & (1UL << 63)) == 0) { /* if cr_ifs isn't valid, we got here through a syscall */ flags |= IA64_SC_FLAG_IN_SYSCALL; } if ((fpu_owner == current) || (current->thread.flags & IA64_THREAD_FPH_VALID)) { flags |= IA64_SC_FLAG_FPH_VALID; if (fpu_owner == current) { __ia64_save_fpu(current->thread.fph); } __copy_to_user(&sc->sc_fr[32], current->thread.fph, 96*16); } /* * Note: sw->ar_unat is UNDEFINED unless the process is being * PTRACED. However, this is OK because the NaT bits of the * preserved registers (r4-r7) are never being looked at by * the signal handler (registers r4-r7 are used instead). */ #ifdef CONFIG_IA64_NEW_UNWIND nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat); #else nat = ia64_get_nat_bits(&scr->pt, &scr->sw); #endif err = __put_user(flags, &sc->sc_flags); err |= __put_user(nat, &sc->sc_nat); err |= PUT_SIGSET(mask, &sc->sc_mask); err |= __put_user(scr->pt.cr_ipsr & IA64_PSR_UM, &sc->sc_um); err |= __put_user(scr->pt.ar_rsc, &sc->sc_ar_rsc); err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); err |= __put_user(scr->pt.ar_unat, &sc->sc_ar_unat); /* ar.unat */ err |= __put_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); /* ar.fpsr */ err |= __put_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); err |= __put_user(scr->pt.pr, &sc->sc_pr); /* predicates */ err |= __put_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ err |= __put_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ err |= __put_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 3*8); /* r1-r3 */ err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8); /* r8-r11 */ err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 4*8); /* r12-r15 */ err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8); /* r16-r31 */ err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip); return err; } static long setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct sigscratch *scr) { extern char ia64_sigtramp[], __start_gate_section[]; unsigned long tramp_addr, new_rbs = 0; struct sigframe *frame; struct siginfo si; long err; frame = (void *) scr->pt.r12; tramp_addr = GATE_ADDR + (ia64_sigtramp - __start_gate_section); if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack((unsigned long) frame)) { new_rbs = (current->sas_ss_sp + sizeof(long) - 1) & ~(sizeof(long) - 1); frame = (void *) ((current->sas_ss_sp + current->sas_ss_size) & ~(STACK_ALIGN - 1)); } frame = (void *) frame - ((sizeof(*frame) + STACK_ALIGN - 1) & ~(STACK_ALIGN - 1)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; err = copy_siginfo_to_user(&frame->info, info); err |= __put_user(current->sas_ss_sp, &frame->sc.sc_stack.ss_sp); err |= __put_user(current->sas_ss_size, &frame->sc.sc_stack.ss_size); err |= __put_user(sas_ss_flags(scr->pt.r12), &frame->sc.sc_stack.ss_flags); err |= setup_sigcontext(&frame->sc, set, scr); if (err) goto give_sigsegv; scr->pt.r12 = (unsigned long) frame - 16; /* new stack pointer */ scr->pt.r2 = sig; /* signal number */ scr->pt.r3 = (unsigned long) ka->sa.sa_handler; /* addr. of handler's proc desc */ scr->pt.r15 = new_rbs; scr->pt.ar_fpsr = FPSR_DEFAULT; /* reset fpsr for signal handler */ scr->pt.cr_iip = tramp_addr; ia64_psr(&scr->pt)->ri = 0; /* start executing in first slot */ #ifdef CONFIG_IA64_NEW_UNWIND /* * Note: this affects only the NaT bits of the scratch regs * (the ones saved in pt_regs), which is exactly what we want. */ scr->scratch_unat = 0; /* ensure NaT bits of at least r2, r3, r12, and r15 are clear */ #else /* * Note: this affects only the NaT bits of the scratch regs * (the ones saved in pt_regs), which is exactly what we want. * The NaT bits for the preserved regs (r4-r7) are in * sw->ar_unat iff this process is being PTRACED. */ scr->sw.caller_unat = 0; /* ensure NaT bits of at least r2, r3, r12, and r15 are clear */ #endif #if DEBUG_SIG printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%lx\n", current->comm, current->pid, sig, scr->pt.r12, scr->pt.cr_iip, scr->pt.r3); #endif return 1; give_sigsegv: if (sig == SIGSEGV) ka->sa.sa_handler = SIG_DFL; si.si_signo = SIGSEGV; si.si_errno = 0; si.si_code = SI_KERNEL; si.si_pid = current->pid; si.si_uid = current->uid; si.si_addr = frame; force_sig_info(SIGSEGV, &si, current); return 0; } static long handle_signal (unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, struct sigscratch *scr) { #ifdef CONFIG_IA32_SUPPORT if (IS_IA32_PROCESS(&scr->pt)) { /* send signal to IA-32 process */ if (!ia32_setup_frame1(sig, ka, info, oldset, &scr->pt)) return 0; } else #endif /* send signal to IA-64 process */ if (!setup_frame(sig, ka, info, oldset, scr)) return 0; 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); } return 1; } /* * 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. */ long ia64_do_signal (sigset_t *oldset, struct sigscratch *scr, long in_syscall) { struct k_sigaction *ka; siginfo_t info; long restart = in_syscall; long errno = scr->pt.r8; /* * In the ia64_leave_kernel code path, 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(&scr->pt)) return 0; if (!oldset) oldset = ¤t->blocked; #ifdef CONFIG_IA32_SUPPORT if (IS_IA32_PROCESS(&scr->pt)) { if (in_syscall) { if (errno >= 0) restart = 0; else errno = -errno; } } else #endif if (scr->pt.r10 != -1) { /* * A system calls has to be restarted only if one of * the error codes ERESTARTNOHAND, ERESTARTSYS, or * ERESTARTNOINTR is returned. If r10 isn't -1 then * r8 doesn't hold an error code and we don't need to * restart the syscall, so we set in_syscall to zero. */ restart = 0; } 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; current->thread.siginfo = &info; set_current_state(TASK_STOPPED); notify_parent(current, SIGCHLD); schedule(); signr = current->exit_code; current->thread.siginfo = 0; /* We're back. Did the debugger cancel the sig? */ if (!signr) 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: case SIGBUS: case SIGSYS: case SIGXCPU: case SIGXFSZ: if (do_coredump(signr, &scr->pt)) exit_code |= 0x80; /* FALLTHRU */ default: sigaddset(¤t->signal, signr); recalc_sigpending(current); current->flags |= PF_SIGNALED; do_exit(exit_code); /* NOTREACHED */ } } if (restart) { switch (errno) { case ERESTARTSYS: if ((ka->sa.sa_flags & SA_RESTART) == 0) { case ERESTARTNOHAND: #ifdef CONFIG_IA32_SUPPORT if (IS_IA32_PROCESS(&scr->pt)) scr->pt.r8 = -EINTR; else #endif scr->pt.r8 = EINTR; /* note: scr->pt.r10 is already -1 */ break; } case ERESTARTNOINTR: #ifdef CONFIG_IA32_SUPPORT if (IS_IA32_PROCESS(&scr->pt)) { scr->pt.r8 = scr->pt.r1; scr->pt.cr_iip -= 2; } else #endif ia64_decrement_ip(&scr->pt); } } /* Whee! Actually deliver the signal. If the delivery failed, we need to continue to iterate in this loop so we can deliver the SIGSEGV... */ if (handle_signal(signr, ka, &info, oldset, scr)) return 1; } /* Did we come from a system call? */ if (restart) { /* Restart the system call - no handlers present */ if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR) { #ifdef CONFIG_IA32_SUPPORT if (IS_IA32_PROCESS(&scr->pt)) { scr->pt.r8 = scr->pt.r1; scr->pt.cr_iip -= 2; } else #endif /* * Note: the syscall number is in r15 which is * saved in pt_regs so all we need to do here * is adjust ip so that the "break" * instruction gets re-executed. */ ia64_decrement_ip(&scr->pt); } } return 0; }