patch-2.3.16 linux/arch/sh/kernel/signal.c

• Lines: 598
• Date: Mon Aug 30 18:12:59 1999
• Orig file: v2.3.15/linux/arch/sh/kernel/signal.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.15/linux/arch/sh/kernel/signal.c linux/arch/sh/kernel/signal.c
@@ -0,0 +1,597 @@
+/*
+ *  linux/arch/sh/kernel/signal.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
+ *
+ *  SuperH version:  Copyright (C) 1999  Niibe Yutaka
+ *
+ */
+
+#include <linux/config.h>
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.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/stddef.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+
+#define DEBUG_SIG 0
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+asmlinkage int sys_wait4(pid_t pid, unsigned long *stat_addr,
+			 int options, unsigned long *ru);
+asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+asmlinkage int
+sys_sigsuspend(old_sigset_t mask,
+	       unsigned long r5, unsigned long r6, unsigned long r7,
+	       struct pt_regs regs)
+{
+	sigset_t saveset;
+
+	mask &= _BLOCKABLE;
+	spin_lock_irq(&current->sigmask_lock);
+	saveset = current->blocked;
+	siginitset(&current->blocked, mask);
+	recalc_sigpending(current);
+	spin_unlock_irq(&current->sigmask_lock);
+
+	regs.u_regs[0] = -EINTR;
+	while (1) {
+		current->state = TASK_INTERRUPTIBLE;
+		schedule();
+		if (do_signal(&regs,&saveset))
+			return -EINTR;
+	}
+}
+
+asmlinkage int
+sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
+		  unsigned long r6, unsigned long r7,
+		  struct pt_regs regs)
+{
+	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(&current->sigmask_lock);
+	saveset = current->blocked;
+	current->blocked = newset;
+	recalc_sigpending(current);
+	spin_unlock_irq(&current->sigmask_lock);
+
+	regs.u_regs[0] = -EINTR;
+	while (1) {
+		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,
+		unsigned long r6, unsigned long r7,
+		struct pt_regs regs)
+{
+	return do_sigaltstack(uss, uoss, regs.u_regs[UREG_SP]);
+}
+
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+struct sigframe
+{
+	struct sigcontext sc;
+	/* FPU should come here: SH-3 has no FPU */
+	unsigned long extramask[_NSIG_WORDS-1];
+	char retcode[4];
+};
+
+struct rt_sigframe
+{
+	struct siginfo *pinfo;
+	void *puc;
+	struct siginfo info;
+	struct ucontext uc;
+	/* FPU should come here: SH-3 has no FPU */
+	char retcode[4];
+};
+
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *r0_p)
+{
+	unsigned int err = 0;
+
+#define COPY(x)		err |= __get_user(regs->x, &sc->x)
+				COPY(u_regs[1]);
+	COPY(u_regs[2]);	COPY(u_regs[3]);
+	COPY(u_regs[4]);	COPY(u_regs[5]);
+	COPY(u_regs[6]);	COPY(u_regs[7]);
+	COPY(u_regs[8]);	COPY(u_regs[9]);
+	COPY(u_regs[10]);	COPY(u_regs[11]);
+	COPY(u_regs[12]);	COPY(u_regs[13]);
+	COPY(u_regs[14]);	COPY(u_regs[15]);
+	COPY(gbr);		COPY(mach);
+	COPY(macl);		COPY(pr);
+	COPY(sr);		COPY(pc);
+#undef COPY
+
+	regs->syscall_nr = -1;		/* disable syscall checks */
+	err |= __get_user(*r0_p, &sc->u_regs[0]);
+
+	return err;
+}
+
+asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
+			     unsigned long r6, unsigned long r7,
+			     struct pt_regs regs)
+{
+	struct sigframe *frame = (struct sigframe *)regs.u_regs[UREG_SP];
+	sigset_t set;
+	int r0;
+
+	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(set.sig[0], &frame->sc.oldmask)
+	    || (_NSIG_WORDS > 1
+		&& __copy_from_user(&set.sig[1], &frame->extramask,
+				    sizeof(frame->extramask))))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sigmask_lock);
+	current->blocked = set;
+	recalc_sigpending(current);
+	spin_unlock_irq(&current->sigmask_lock);
+
+	if (restore_sigcontext(&regs, &frame->sc, &r0))
+		goto badframe;
+	return r0;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
+				unsigned long r6, unsigned long r7,
+				struct pt_regs regs)
+{
+	struct rt_sigframe *frame = (struct rt_sigframe *)regs.u_regs[UREG_SP];
+	sigset_t set;
+	stack_t st;
+	int r0;
+
+	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sigmask_lock);
+	current->blocked = set;
+	recalc_sigpending(current);
+	spin_unlock_irq(&current->sigmask_lock);
+	
+	if (restore_sigcontext(&regs, &frame->uc.uc_mcontext, &r0))
+		goto badframe;
+
+	if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
+		goto badframe;
+	/* It is more difficult to avoid calling this function than to
+	   call it and ignore errors.  */
+	do_sigaltstack(&st, NULL, regs.u_regs[UREG_SP]);
+
+	return r0;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}	
+
+/*
+ * Set up a signal frame.
+ */
+
+static int
+setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
+		 unsigned long mask)
+{
+	int err = 0;
+
+#define COPY(x)		err |= __put_user(regs->x, &sc->x)
+	COPY(u_regs[0]);	COPY(u_regs[1]);
+	COPY(u_regs[2]);	COPY(u_regs[3]);
+	COPY(u_regs[4]);	COPY(u_regs[5]);
+	COPY(u_regs[6]);	COPY(u_regs[7]);
+	COPY(u_regs[8]);	COPY(u_regs[9]);
+	COPY(u_regs[10]);	COPY(u_regs[11]);
+	COPY(u_regs[12]);	COPY(u_regs[13]);
+	COPY(u_regs[14]);	COPY(u_regs[15]);
+	COPY(gbr);		COPY(mach);
+	COPY(macl);		COPY(pr);
+	COPY(sr);		COPY(pc);
+#undef COPY
+
+	/* non-iBCS2 extensions.. */
+	err |= __put_user(mask, &sc->oldmask);
+
+	return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void *
+get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
+{
+	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp))
+		sp = current->sas_ss_sp + current->sas_ss_size;
+
+	return (void *)((sp - frame_size) & -8ul);
+}
+
+static void setup_frame(int sig, struct k_sigaction *ka,
+			sigset_t *set, struct pt_regs *regs)
+{
+	struct sigframe *frame;
+	int err = 0;
+	int signal;
+
+	frame = get_sigframe(ka, regs->u_regs[UREG_SP], sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		goto give_sigsegv;
+
+	signal = current->exec_domain
+		&& current->exec_domain->signal_invmap
+		&& sig < 32
+		? current->exec_domain->signal_invmap[sig]
+		: sig;
+
+	err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
+
+	if (_NSIG_WORDS > 1) {
+		err |= __copy_to_user(frame->extramask, &set->sig[1],
+				      sizeof(frame->extramask));
+	}
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ka->sa.sa_flags & SA_RESTORER) {
+		regs->pr = (unsigned long) ka->sa.sa_restorer;
+	} else {
+		/* This is ; mov  #__NR_sigreturn,r0 ; trapa #0 */
+#ifdef CONFIG_LITTLE_ENDIAN
+		unsigned long code = 0x00c300e0 | (__NR_sigreturn << 8);
+#else
+		unsigned long code = 0xe000c300 | (__NR_sigreturn << 16);
+#endif
+
+		regs->pr = (unsigned long) frame->retcode;
+		err |= __put_user(code, (long *)(frame->retcode+0));
+	}
+
+	if (err)
+		goto give_sigsegv;
+
+	/* Set up registers for signal handler */
+	regs->u_regs[UREG_SP] = (unsigned long) frame;
+	regs->u_regs[4] = signal; /* Arg for signal handler */
+	regs->pc = (unsigned long) ka->sa.sa_handler;
+
+	set_fs(USER_DS);
+
+#if DEBUG_SIG
+	printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
+		current->comm, current->pid, frame, regs->pc, regs->pr);
+#endif
+
+	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)
+{
+	struct rt_sigframe *frame;
+	int err = 0;
+	int signal;
+
+	frame = get_sigframe(ka, regs->u_regs[UREG_SP], sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		goto give_sigsegv;
+
+	signal = current->exec_domain
+		&& current->exec_domain->signal_invmap
+		&& sig < 32
+		? current->exec_domain->signal_invmap[sig]
+		: sig;
+
+	err |= __put_user(&frame->info, &frame->pinfo);
+	err |= __put_user(&frame->uc, &frame->puc);
+	err |= __copy_to_user(&frame->info, info, sizeof(*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(regs->u_regs[UREG_SP]),
+			  &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, set->sig[0]);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ka->sa.sa_flags & SA_RESTORER) {
+		regs->pr = (unsigned long) ka->sa.sa_restorer;
+	} else {
+		/* This is ; mov  #__NR_sigreturn,r0 ; trapa #0 */
+#ifdef CONFIG_LITTLE_ENDIAN
+		unsigned long code = 0x00c300e0 | (__NR_sigreturn << 8);
+#else
+		unsigned long code = 0xe000c300 | (__NR_sigreturn << 16);
+#endif
+
+		regs->pr = (unsigned long) frame->retcode;
+		err |= __put_user(code, (long *)(frame->retcode+0));
+	}
+
+	if (err)
+		goto give_sigsegv;
+
+	/* Set up registers for signal handler */
+	regs->u_regs[UREG_SP] = (unsigned long) frame;
+	regs->u_regs[4] = signal; /* Arg for signal handler */
+	regs->pc = (unsigned long) ka->sa.sa_handler;
+
+	set_fs(USER_DS);
+
+#if DEBUG_SIG
+	printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
+		current->comm, current->pid, frame, regs->pc, regs->pr);
+#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->syscall_nr >= 0) {
+		/* If so, check system call restarting.. */
+		switch (regs->u_regs[0]) {
+			case -ERESTARTNOHAND:
+				regs->u_regs[0] = -EINTR;
+				break;
+
+			case -ERESTARTSYS:
+				if (!(ka->sa.sa_flags & SA_RESTART)) {
+					regs->u_regs[0] = -EINTR;
+					break;
+				}
+			/* fallthrough */
+			case -ERESTARTNOINTR:
+				regs->u_regs[0] = regs->syscall_nr;
+				regs->pc -= 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(&current->sigmask_lock);
+		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+		sigaddset(&current->blocked,sig);
+		recalc_sigpending(current);
+		spin_unlock_irq(&current->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;
+
+	if (!oldset)
+		oldset = &current->blocked;
+
+	for (;;) {
+		unsigned long signr;
+
+		spin_lock_irq(&current->sigmask_lock);
+		signr = dequeue_signal(&current->blocked, &info);
+		spin_unlock_irq(&current->sigmask_lock);
+
+		if (!signr)
+			break;
+
+		if ((current->flags & PF_PTRACED) && signr != SIGKILL) {
+			/* Let the debugger run.  */
+			current->exit_code = signr;
+			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(&current->blocked, signr)) {
+				send_sig_info(signr, &info, current);
+				continue;
+			}
+		}
+
+		ka = &current->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:
+				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(&current->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->syscall_nr >= 0) {
+		/* Restart the system call - no handlers present */
+		if (regs->u_regs[0] == -ERESTARTNOHAND ||
+		    regs->u_regs[0] == -ERESTARTSYS ||
+		    regs->u_regs[0] == -ERESTARTNOINTR) {
+			regs->u_regs[0] = regs->syscall_nr;
+			regs->pc -= 2;
+		}
+	}
+	return 0;
+}