|  | /* | 
|  | *  linux/arch/alpha/kernel/signal.c | 
|  | * | 
|  | *  Copyright (C) 1995  Linus Torvalds | 
|  | * | 
|  | *  1997-11-02  Modified for POSIX.1b signals by Richard Henderson | 
|  | */ | 
|  |  | 
|  | #include <linux/sched.h> | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/signal.h> | 
|  | #include <linux/errno.h> | 
|  | #include <linux/wait.h> | 
|  | #include <linux/ptrace.h> | 
|  | #include <linux/unistd.h> | 
|  | #include <linux/mm.h> | 
|  | #include <linux/smp.h> | 
|  | #include <linux/stddef.h> | 
|  | #include <linux/tty.h> | 
|  | #include <linux/binfmts.h> | 
|  | #include <linux/bitops.h> | 
|  |  | 
|  | #include <asm/uaccess.h> | 
|  | #include <asm/sigcontext.h> | 
|  | #include <asm/ucontext.h> | 
|  |  | 
|  | #include "proto.h" | 
|  |  | 
|  |  | 
|  | #define DEBUG_SIG 0 | 
|  |  | 
|  | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | 
|  |  | 
|  | asmlinkage void ret_from_sys_call(void); | 
|  | static void do_signal(struct pt_regs *, struct switch_stack *, | 
|  | unsigned long, unsigned long); | 
|  |  | 
|  |  | 
|  | /* | 
|  | * The OSF/1 sigprocmask calling sequence is different from the | 
|  | * C sigprocmask() sequence.. | 
|  | * | 
|  | * how: | 
|  | * 1 - SIG_BLOCK | 
|  | * 2 - SIG_UNBLOCK | 
|  | * 3 - SIG_SETMASK | 
|  | * | 
|  | * We change the range to -1 .. 1 in order to let gcc easily | 
|  | * use the conditional move instructions. | 
|  | * | 
|  | * Note that we don't need to acquire the kernel lock for SMP | 
|  | * operation, as all of this is local to this thread. | 
|  | */ | 
|  | asmlinkage unsigned long | 
|  | do_osf_sigprocmask(int how, unsigned long newmask, struct pt_regs *regs) | 
|  | { | 
|  | unsigned long oldmask = -EINVAL; | 
|  |  | 
|  | if ((unsigned long)how-1 <= 2) { | 
|  | long sign = how-2;		/* -1 .. 1 */ | 
|  | unsigned long block, unblock; | 
|  |  | 
|  | newmask &= _BLOCKABLE; | 
|  | spin_lock_irq(¤t->sighand->siglock); | 
|  | oldmask = current->blocked.sig[0]; | 
|  |  | 
|  | unblock = oldmask & ~newmask; | 
|  | block = oldmask | newmask; | 
|  | if (!sign) | 
|  | block = unblock; | 
|  | if (sign <= 0) | 
|  | newmask = block; | 
|  | if (_NSIG_WORDS > 1 && sign > 0) | 
|  | sigemptyset(¤t->blocked); | 
|  | current->blocked.sig[0] = newmask; | 
|  | recalc_sigpending(); | 
|  | spin_unlock_irq(¤t->sighand->siglock); | 
|  |  | 
|  | regs->r0 = 0;		/* special no error return */ | 
|  | } | 
|  | return oldmask; | 
|  | } | 
|  |  | 
|  | asmlinkage int | 
|  | osf_sigaction(int sig, const struct osf_sigaction __user *act, | 
|  | struct osf_sigaction __user *oact) | 
|  | { | 
|  | struct k_sigaction new_ka, old_ka; | 
|  | int ret; | 
|  |  | 
|  | if (act) { | 
|  | old_sigset_t mask; | 
|  | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | 
|  | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | 
|  | __get_user(new_ka.sa.sa_flags, &act->sa_flags)) | 
|  | return -EFAULT; | 
|  | __get_user(mask, &act->sa_mask); | 
|  | siginitset(&new_ka.sa.sa_mask, mask); | 
|  | new_ka.ka_restorer = NULL; | 
|  | } | 
|  |  | 
|  | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | 
|  |  | 
|  | if (!ret && oact) { | 
|  | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | 
|  | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | 
|  | __put_user(old_ka.sa.sa_flags, &oact->sa_flags)) | 
|  | return -EFAULT; | 
|  | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | 
|  | } | 
|  |  | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | asmlinkage long | 
|  | sys_rt_sigaction(int sig, const struct sigaction __user *act, | 
|  | struct sigaction __user *oact, | 
|  | size_t sigsetsize, void __user *restorer) | 
|  | { | 
|  | struct k_sigaction new_ka, old_ka; | 
|  | int ret; | 
|  |  | 
|  | /* XXX: Don't preclude handling different sized sigset_t's.  */ | 
|  | if (sigsetsize != sizeof(sigset_t)) | 
|  | return -EINVAL; | 
|  |  | 
|  | if (act) { | 
|  | new_ka.ka_restorer = restorer; | 
|  | if (copy_from_user(&new_ka.sa, act, sizeof(*act))) | 
|  | return -EFAULT; | 
|  | } | 
|  |  | 
|  | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | 
|  |  | 
|  | if (!ret && oact) { | 
|  | if (copy_to_user(oact, &old_ka.sa, sizeof(*oact))) | 
|  | return -EFAULT; | 
|  | } | 
|  |  | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Atomically swap in the new signal mask, and wait for a signal. | 
|  | */ | 
|  | asmlinkage int | 
|  | do_sigsuspend(old_sigset_t mask, struct pt_regs *regs, struct switch_stack *sw) | 
|  | { | 
|  | mask &= _BLOCKABLE; | 
|  | spin_lock_irq(¤t->sighand->siglock); | 
|  | current->saved_sigmask = current->blocked; | 
|  | siginitset(¤t->blocked, mask); | 
|  | recalc_sigpending(); | 
|  | spin_unlock_irq(¤t->sighand->siglock); | 
|  |  | 
|  | /* Indicate EINTR on return from any possible signal handler, | 
|  | which will not come back through here, but via sigreturn.  */ | 
|  | regs->r0 = EINTR; | 
|  | regs->r19 = 1; | 
|  |  | 
|  | current->state = TASK_INTERRUPTIBLE; | 
|  | schedule(); | 
|  | set_thread_flag(TIF_RESTORE_SIGMASK); | 
|  | return -ERESTARTNOHAND; | 
|  | } | 
|  |  | 
|  | asmlinkage int | 
|  | do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize, | 
|  | struct pt_regs *regs, struct switch_stack *sw) | 
|  | { | 
|  | sigset_t set; | 
|  |  | 
|  | /* XXX: Don't preclude handling different sized sigset_t's.  */ | 
|  | if (sigsetsize != sizeof(sigset_t)) | 
|  | return -EINVAL; | 
|  | if (copy_from_user(&set, uset, sizeof(set))) | 
|  | return -EFAULT; | 
|  |  | 
|  | sigdelsetmask(&set, ~_BLOCKABLE); | 
|  | spin_lock_irq(¤t->sighand->siglock); | 
|  | current->saved_sigmask = current->blocked; | 
|  | current->blocked = set; | 
|  | recalc_sigpending(); | 
|  | spin_unlock_irq(¤t->sighand->siglock); | 
|  |  | 
|  | /* Indicate EINTR on return from any possible signal handler, | 
|  | which will not come back through here, but via sigreturn.  */ | 
|  | regs->r0 = EINTR; | 
|  | regs->r19 = 1; | 
|  |  | 
|  | current->state = TASK_INTERRUPTIBLE; | 
|  | schedule(); | 
|  | set_thread_flag(TIF_RESTORE_SIGMASK); | 
|  | return -ERESTARTNOHAND; | 
|  | } | 
|  |  | 
|  | asmlinkage int | 
|  | sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss) | 
|  | { | 
|  | return do_sigaltstack(uss, uoss, rdusp()); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Do a signal return; undo the signal stack. | 
|  | */ | 
|  |  | 
|  | #if _NSIG_WORDS > 1 | 
|  | # error "Non SA_SIGINFO frame needs rearranging" | 
|  | #endif | 
|  |  | 
|  | struct sigframe | 
|  | { | 
|  | struct sigcontext sc; | 
|  | unsigned int retcode[3]; | 
|  | }; | 
|  |  | 
|  | struct rt_sigframe | 
|  | { | 
|  | struct siginfo info; | 
|  | struct ucontext uc; | 
|  | unsigned int retcode[3]; | 
|  | }; | 
|  |  | 
|  | /* If this changes, userland unwinders that Know Things about our signal | 
|  | frame will break.  Do not undertake lightly.  It also implies an ABI | 
|  | change wrt the size of siginfo_t, which may cause some pain.  */ | 
|  | extern char compile_time_assert | 
|  | [offsetof(struct rt_sigframe, uc.uc_mcontext) == 176 ? 1 : -1]; | 
|  |  | 
|  | #define INSN_MOV_R30_R16	0x47fe0410 | 
|  | #define INSN_LDI_R0		0x201f0000 | 
|  | #define INSN_CALLSYS		0x00000083 | 
|  |  | 
|  | static long | 
|  | restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | 
|  | struct switch_stack *sw) | 
|  | { | 
|  | unsigned long usp; | 
|  | long i, err = __get_user(regs->pc, &sc->sc_pc); | 
|  |  | 
|  | sw->r26 = (unsigned long) ret_from_sys_call; | 
|  |  | 
|  | err |= __get_user(regs->r0, sc->sc_regs+0); | 
|  | err |= __get_user(regs->r1, sc->sc_regs+1); | 
|  | err |= __get_user(regs->r2, sc->sc_regs+2); | 
|  | err |= __get_user(regs->r3, sc->sc_regs+3); | 
|  | err |= __get_user(regs->r4, sc->sc_regs+4); | 
|  | err |= __get_user(regs->r5, sc->sc_regs+5); | 
|  | err |= __get_user(regs->r6, sc->sc_regs+6); | 
|  | err |= __get_user(regs->r7, sc->sc_regs+7); | 
|  | err |= __get_user(regs->r8, sc->sc_regs+8); | 
|  | err |= __get_user(sw->r9, sc->sc_regs+9); | 
|  | err |= __get_user(sw->r10, sc->sc_regs+10); | 
|  | err |= __get_user(sw->r11, sc->sc_regs+11); | 
|  | err |= __get_user(sw->r12, sc->sc_regs+12); | 
|  | err |= __get_user(sw->r13, sc->sc_regs+13); | 
|  | err |= __get_user(sw->r14, sc->sc_regs+14); | 
|  | err |= __get_user(sw->r15, sc->sc_regs+15); | 
|  | err |= __get_user(regs->r16, sc->sc_regs+16); | 
|  | err |= __get_user(regs->r17, sc->sc_regs+17); | 
|  | err |= __get_user(regs->r18, sc->sc_regs+18); | 
|  | err |= __get_user(regs->r19, sc->sc_regs+19); | 
|  | err |= __get_user(regs->r20, sc->sc_regs+20); | 
|  | err |= __get_user(regs->r21, sc->sc_regs+21); | 
|  | err |= __get_user(regs->r22, sc->sc_regs+22); | 
|  | err |= __get_user(regs->r23, sc->sc_regs+23); | 
|  | err |= __get_user(regs->r24, sc->sc_regs+24); | 
|  | err |= __get_user(regs->r25, sc->sc_regs+25); | 
|  | err |= __get_user(regs->r26, sc->sc_regs+26); | 
|  | err |= __get_user(regs->r27, sc->sc_regs+27); | 
|  | err |= __get_user(regs->r28, sc->sc_regs+28); | 
|  | err |= __get_user(regs->gp, sc->sc_regs+29); | 
|  | err |= __get_user(usp, sc->sc_regs+30); | 
|  | wrusp(usp); | 
|  |  | 
|  | for (i = 0; i < 31; i++) | 
|  | err |= __get_user(sw->fp[i], sc->sc_fpregs+i); | 
|  | err |= __get_user(sw->fp[31], &sc->sc_fpcr); | 
|  |  | 
|  | return err; | 
|  | } | 
|  |  | 
|  | /* Note that this syscall is also used by setcontext(3) to install | 
|  | a given sigcontext.  This because it's impossible to set *all* | 
|  | registers and transfer control from userland.  */ | 
|  |  | 
|  | asmlinkage void | 
|  | do_sigreturn(struct sigcontext __user *sc, struct pt_regs *regs, | 
|  | struct switch_stack *sw) | 
|  | { | 
|  | sigset_t set; | 
|  |  | 
|  | /* Verify that it's a good sigcontext before using it */ | 
|  | if (!access_ok(VERIFY_READ, sc, sizeof(*sc))) | 
|  | goto give_sigsegv; | 
|  | if (__get_user(set.sig[0], &sc->sc_mask)) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | sigdelsetmask(&set, ~_BLOCKABLE); | 
|  | spin_lock_irq(¤t->sighand->siglock); | 
|  | current->blocked = set; | 
|  | recalc_sigpending(); | 
|  | spin_unlock_irq(¤t->sighand->siglock); | 
|  |  | 
|  | if (restore_sigcontext(sc, regs, sw)) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | /* Send SIGTRAP if we're single-stepping: */ | 
|  | if (ptrace_cancel_bpt (current)) { | 
|  | siginfo_t info; | 
|  |  | 
|  | info.si_signo = SIGTRAP; | 
|  | info.si_errno = 0; | 
|  | info.si_code = TRAP_BRKPT; | 
|  | info.si_addr = (void __user *) regs->pc; | 
|  | info.si_trapno = 0; | 
|  | send_sig_info(SIGTRAP, &info, current); | 
|  | } | 
|  | return; | 
|  |  | 
|  | give_sigsegv: | 
|  | force_sig(SIGSEGV, current); | 
|  | } | 
|  |  | 
|  | asmlinkage void | 
|  | do_rt_sigreturn(struct rt_sigframe __user *frame, struct pt_regs *regs, | 
|  | struct switch_stack *sw) | 
|  | { | 
|  | sigset_t set; | 
|  |  | 
|  | /* Verify that it's a good ucontext_t before using it */ | 
|  | if (!access_ok(VERIFY_READ, &frame->uc, sizeof(frame->uc))) | 
|  | goto give_sigsegv; | 
|  | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | sigdelsetmask(&set, ~_BLOCKABLE); | 
|  | spin_lock_irq(¤t->sighand->siglock); | 
|  | current->blocked = set; | 
|  | recalc_sigpending(); | 
|  | spin_unlock_irq(¤t->sighand->siglock); | 
|  |  | 
|  | if (restore_sigcontext(&frame->uc.uc_mcontext, regs, sw)) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | /* Send SIGTRAP if we're single-stepping: */ | 
|  | if (ptrace_cancel_bpt (current)) { | 
|  | siginfo_t info; | 
|  |  | 
|  | info.si_signo = SIGTRAP; | 
|  | info.si_errno = 0; | 
|  | info.si_code = TRAP_BRKPT; | 
|  | info.si_addr = (void __user *) regs->pc; | 
|  | info.si_trapno = 0; | 
|  | send_sig_info(SIGTRAP, &info, current); | 
|  | } | 
|  | return; | 
|  |  | 
|  | give_sigsegv: | 
|  | force_sig(SIGSEGV, current); | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * Set up a signal frame. | 
|  | */ | 
|  |  | 
|  | static inline void __user * | 
|  | get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) | 
|  | { | 
|  | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) | 
|  | sp = current->sas_ss_sp + current->sas_ss_size; | 
|  |  | 
|  | return (void __user *)((sp - frame_size) & -32ul); | 
|  | } | 
|  |  | 
|  | static long | 
|  | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | 
|  | struct switch_stack *sw, unsigned long mask, unsigned long sp) | 
|  | { | 
|  | long i, err = 0; | 
|  |  | 
|  | err |= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack); | 
|  | err |= __put_user(mask, &sc->sc_mask); | 
|  | err |= __put_user(regs->pc, &sc->sc_pc); | 
|  | err |= __put_user(8, &sc->sc_ps); | 
|  |  | 
|  | err |= __put_user(regs->r0 , sc->sc_regs+0); | 
|  | err |= __put_user(regs->r1 , sc->sc_regs+1); | 
|  | err |= __put_user(regs->r2 , sc->sc_regs+2); | 
|  | err |= __put_user(regs->r3 , sc->sc_regs+3); | 
|  | err |= __put_user(regs->r4 , sc->sc_regs+4); | 
|  | err |= __put_user(regs->r5 , sc->sc_regs+5); | 
|  | err |= __put_user(regs->r6 , sc->sc_regs+6); | 
|  | err |= __put_user(regs->r7 , sc->sc_regs+7); | 
|  | err |= __put_user(regs->r8 , sc->sc_regs+8); | 
|  | err |= __put_user(sw->r9   , sc->sc_regs+9); | 
|  | err |= __put_user(sw->r10  , sc->sc_regs+10); | 
|  | err |= __put_user(sw->r11  , sc->sc_regs+11); | 
|  | err |= __put_user(sw->r12  , sc->sc_regs+12); | 
|  | err |= __put_user(sw->r13  , sc->sc_regs+13); | 
|  | err |= __put_user(sw->r14  , sc->sc_regs+14); | 
|  | err |= __put_user(sw->r15  , sc->sc_regs+15); | 
|  | err |= __put_user(regs->r16, sc->sc_regs+16); | 
|  | err |= __put_user(regs->r17, sc->sc_regs+17); | 
|  | err |= __put_user(regs->r18, sc->sc_regs+18); | 
|  | err |= __put_user(regs->r19, sc->sc_regs+19); | 
|  | err |= __put_user(regs->r20, sc->sc_regs+20); | 
|  | err |= __put_user(regs->r21, sc->sc_regs+21); | 
|  | err |= __put_user(regs->r22, sc->sc_regs+22); | 
|  | err |= __put_user(regs->r23, sc->sc_regs+23); | 
|  | err |= __put_user(regs->r24, sc->sc_regs+24); | 
|  | err |= __put_user(regs->r25, sc->sc_regs+25); | 
|  | err |= __put_user(regs->r26, sc->sc_regs+26); | 
|  | err |= __put_user(regs->r27, sc->sc_regs+27); | 
|  | err |= __put_user(regs->r28, sc->sc_regs+28); | 
|  | err |= __put_user(regs->gp , sc->sc_regs+29); | 
|  | err |= __put_user(sp, sc->sc_regs+30); | 
|  | err |= __put_user(0, sc->sc_regs+31); | 
|  |  | 
|  | for (i = 0; i < 31; i++) | 
|  | err |= __put_user(sw->fp[i], sc->sc_fpregs+i); | 
|  | err |= __put_user(0, sc->sc_fpregs+31); | 
|  | err |= __put_user(sw->fp[31], &sc->sc_fpcr); | 
|  |  | 
|  | err |= __put_user(regs->trap_a0, &sc->sc_traparg_a0); | 
|  | err |= __put_user(regs->trap_a1, &sc->sc_traparg_a1); | 
|  | err |= __put_user(regs->trap_a2, &sc->sc_traparg_a2); | 
|  |  | 
|  | return err; | 
|  | } | 
|  |  | 
|  | static int | 
|  | setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, | 
|  | struct pt_regs *regs, struct switch_stack * sw) | 
|  | { | 
|  | unsigned long oldsp, r26, err = 0; | 
|  | struct sigframe __user *frame; | 
|  |  | 
|  | oldsp = rdusp(); | 
|  | frame = get_sigframe(ka, oldsp, sizeof(*frame)); | 
|  | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | err |= setup_sigcontext(&frame->sc, regs, sw, set->sig[0], oldsp); | 
|  | if (err) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | /* Set up to return from userspace.  If provided, use a stub | 
|  | already in userspace.  */ | 
|  | if (ka->ka_restorer) { | 
|  | r26 = (unsigned long) ka->ka_restorer; | 
|  | } else { | 
|  | err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0); | 
|  | err |= __put_user(INSN_LDI_R0+__NR_sigreturn, frame->retcode+1); | 
|  | err |= __put_user(INSN_CALLSYS, frame->retcode+2); | 
|  | imb(); | 
|  | r26 = (unsigned long) frame->retcode; | 
|  | } | 
|  |  | 
|  | /* Check that everything was written properly.  */ | 
|  | if (err) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | /* "Return" to the handler */ | 
|  | regs->r26 = r26; | 
|  | regs->r27 = regs->pc = (unsigned long) ka->sa.sa_handler; | 
|  | regs->r16 = sig;			/* a0: signal number */ | 
|  | regs->r17 = 0;				/* a1: exception code */ | 
|  | regs->r18 = (unsigned long) &frame->sc;	/* a2: sigcontext pointer */ | 
|  | wrusp((unsigned long) frame); | 
|  |  | 
|  | #if DEBUG_SIG | 
|  | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | 
|  | current->comm, current->pid, frame, regs->pc, regs->r26); | 
|  | #endif | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | give_sigsegv: | 
|  | force_sigsegv(sig, current); | 
|  | return -EFAULT; | 
|  | } | 
|  |  | 
|  | static int | 
|  | setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | 
|  | sigset_t *set, struct pt_regs *regs, struct switch_stack * sw) | 
|  | { | 
|  | unsigned long oldsp, r26, err = 0; | 
|  | struct rt_sigframe __user *frame; | 
|  |  | 
|  | oldsp = rdusp(); | 
|  | frame = get_sigframe(ka, oldsp, sizeof(*frame)); | 
|  | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | 
|  | 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(set->sig[0], &frame->uc.uc_osf_sigmask); | 
|  | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | 
|  | err |= __put_user(sas_ss_flags(oldsp), &frame->uc.uc_stack.ss_flags); | 
|  | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | 
|  | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, sw, | 
|  | set->sig[0], oldsp); | 
|  | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | 
|  | if (err) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | /* Set up to return from userspace.  If provided, use a stub | 
|  | already in userspace.  */ | 
|  | if (ka->ka_restorer) { | 
|  | r26 = (unsigned long) ka->ka_restorer; | 
|  | } else { | 
|  | err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0); | 
|  | err |= __put_user(INSN_LDI_R0+__NR_rt_sigreturn, | 
|  | frame->retcode+1); | 
|  | err |= __put_user(INSN_CALLSYS, frame->retcode+2); | 
|  | imb(); | 
|  | r26 = (unsigned long) frame->retcode; | 
|  | } | 
|  |  | 
|  | if (err) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | /* "Return" to the handler */ | 
|  | regs->r26 = r26; | 
|  | regs->r27 = regs->pc = (unsigned long) ka->sa.sa_handler; | 
|  | regs->r16 = sig;			  /* a0: signal number */ | 
|  | regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */ | 
|  | regs->r18 = (unsigned long) &frame->uc;	  /* a2: ucontext pointer */ | 
|  | wrusp((unsigned long) frame); | 
|  |  | 
|  | #if DEBUG_SIG | 
|  | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | 
|  | current->comm, current->pid, frame, regs->pc, regs->r26); | 
|  | #endif | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | give_sigsegv: | 
|  | force_sigsegv(sig, current); | 
|  | return -EFAULT; | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * OK, we're invoking a handler. | 
|  | */ | 
|  | static inline int | 
|  | handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, | 
|  | sigset_t *oldset, struct pt_regs * regs, struct switch_stack *sw) | 
|  | { | 
|  | int ret; | 
|  |  | 
|  | if (ka->sa.sa_flags & SA_SIGINFO) | 
|  | ret = setup_rt_frame(sig, ka, info, oldset, regs, sw); | 
|  | else | 
|  | ret = setup_frame(sig, ka, oldset, regs, sw); | 
|  |  | 
|  | if (ret == 0) { | 
|  | spin_lock_irq(¤t->sighand->siglock); | 
|  | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | 
|  | if (!(ka->sa.sa_flags & SA_NODEFER)) | 
|  | sigaddset(¤t->blocked,sig); | 
|  | recalc_sigpending(); | 
|  | spin_unlock_irq(¤t->sighand->siglock); | 
|  | } | 
|  |  | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static inline void | 
|  | syscall_restart(unsigned long r0, unsigned long r19, | 
|  | struct pt_regs *regs, struct k_sigaction *ka) | 
|  | { | 
|  | switch (regs->r0) { | 
|  | case ERESTARTSYS: | 
|  | if (!(ka->sa.sa_flags & SA_RESTART)) { | 
|  | case ERESTARTNOHAND: | 
|  | regs->r0 = EINTR; | 
|  | break; | 
|  | } | 
|  | /* fallthrough */ | 
|  | case ERESTARTNOINTR: | 
|  | regs->r0 = r0;	/* reset v0 and a3 and replay syscall */ | 
|  | regs->r19 = r19; | 
|  | regs->pc -= 4; | 
|  | break; | 
|  | case ERESTART_RESTARTBLOCK: | 
|  | current_thread_info()->restart_block.fn = do_no_restart_syscall; | 
|  | regs->r0 = EINTR; | 
|  | break; | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * 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. | 
|  | * | 
|  | * "r0" and "r19" are the registers we need to restore for system call | 
|  | * restart. "r0" is also used as an indicator whether we can restart at | 
|  | * all (if we get here from anything but a syscall return, it will be 0) | 
|  | */ | 
|  | static void | 
|  | do_signal(struct pt_regs * regs, struct switch_stack * sw, | 
|  | unsigned long r0, unsigned long r19) | 
|  | { | 
|  | siginfo_t info; | 
|  | int signr; | 
|  | unsigned long single_stepping = ptrace_cancel_bpt(current); | 
|  | struct k_sigaction ka; | 
|  | sigset_t *oldset; | 
|  |  | 
|  | if (test_thread_flag(TIF_RESTORE_SIGMASK)) | 
|  | oldset = ¤t->saved_sigmask; | 
|  | else | 
|  | oldset = ¤t->blocked; | 
|  |  | 
|  | /* This lets the debugger run, ... */ | 
|  | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | 
|  |  | 
|  | /* ... so re-check the single stepping. */ | 
|  | single_stepping |= ptrace_cancel_bpt(current); | 
|  |  | 
|  | if (signr > 0) { | 
|  | /* Whee!  Actually deliver the signal.  */ | 
|  | if (r0) | 
|  | syscall_restart(r0, r19, regs, &ka); | 
|  | if (handle_signal(signr, &ka, &info, oldset, regs, sw) == 0) { | 
|  | /* A signal was successfully delivered, and the | 
|  | saved sigmask was stored on the signal frame, | 
|  | and will be restored by sigreturn.  So we can | 
|  | simply clear the restore sigmask flag.  */ | 
|  | if (test_thread_flag(TIF_RESTORE_SIGMASK)) | 
|  | clear_thread_flag(TIF_RESTORE_SIGMASK); | 
|  | } | 
|  | if (single_stepping) | 
|  | ptrace_set_bpt(current); /* re-set bpt */ | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (r0) { | 
|  | switch (regs->r0) { | 
|  | case ERESTARTNOHAND: | 
|  | case ERESTARTSYS: | 
|  | case ERESTARTNOINTR: | 
|  | /* Reset v0 and a3 and replay syscall.  */ | 
|  | regs->r0 = r0; | 
|  | regs->r19 = r19; | 
|  | regs->pc -= 4; | 
|  | break; | 
|  | case ERESTART_RESTARTBLOCK: | 
|  | /* Force v0 to the restart syscall and reply.  */ | 
|  | regs->r0 = __NR_restart_syscall; | 
|  | regs->pc -= 4; | 
|  | break; | 
|  | } | 
|  | } | 
|  |  | 
|  | /* If there's no signal to deliver, we just restore the saved mask.  */ | 
|  | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { | 
|  | clear_thread_flag(TIF_RESTORE_SIGMASK); | 
|  | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | 
|  | } | 
|  |  | 
|  | if (single_stepping) | 
|  | ptrace_set_bpt(current);	/* re-set breakpoint */ | 
|  | } | 
|  |  | 
|  | void | 
|  | do_notify_resume(struct pt_regs *regs, struct switch_stack *sw, | 
|  | unsigned long thread_info_flags, | 
|  | unsigned long r0, unsigned long r19) | 
|  | { | 
|  | if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) | 
|  | do_signal(regs, sw, r0, r19); | 
|  | } |