patch-2.1.80 linux/arch/arm/kernel/signal.c

• Lines: 515
• Date: Tue Jan 20 16:39:41 1998
• Orig file: v2.1.79/linux/arch/arm/kernel/signal.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.79/linux/arch/arm/kernel/signal.c linux/arch/arm/kernel/signal.c
@@ -0,0 +1,514 @@
+/*
+ *  linux/arch/arm/kernel/signal.c
+ *
+ *  Copyright (C) 1995, 1996 Russell King
+ */
+
+#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>
+#include <asm/pgtable.h>
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+#define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn))
+#define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn))
+
+asmlinkage int sys_wait4(pid_t pid, unsigned long * stat_addr,
+			 int options, unsigned long *ru);
+asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs);
+extern int ptrace_cancel_bpt (struct task_struct *);
+extern int ptrace_set_bpt (struct task_struct *);
+
+/*
+ * atomically swap in the new signal mask, and wait for a signal.
+ */
+asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, 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->ARM_r0 = -EINTR;
+
+	while (1) {
+		current->state = TASK_INTERRUPTIBLE;
+		schedule();
+		if (do_signal(&saveset, regs))
+			return regs->ARM_r0;
+	}
+}
+
+asmlinkage int
+sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, 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->ARM_r0 = -EINTR;
+
+	while (1) {
+		current->state = TASK_INTERRUPTIBLE;
+		schedule();
+		if (do_signal(&saveset, regs))
+			return regs->ARM_r0;
+	}
+}
+
+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;
+}
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+struct sigframe
+{
+	struct sigcontext sc;
+	unsigned long extramask[_NSIG_WORDS-1];
+	unsigned long retcode;
+};
+
+struct rt_sigframe
+{
+	struct siginfo *pinfo;
+	void *puc;
+	struct siginfo info;
+	struct ucontext uc;
+	unsigned long retcode;
+};
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
+{
+	__get_user(regs->ARM_r0, &sc->arm_r0);
+	__get_user(regs->ARM_r1, &sc->arm_r1);
+	__get_user(regs->ARM_r2, &sc->arm_r2);
+	__get_user(regs->ARM_r3, &sc->arm_r3);
+	__get_user(regs->ARM_r4, &sc->arm_r4);
+	__get_user(regs->ARM_r5, &sc->arm_r5);
+	__get_user(regs->ARM_r6, &sc->arm_r6);
+	__get_user(regs->ARM_r7, &sc->arm_r7);
+	__get_user(regs->ARM_r8, &sc->arm_r8);
+	__get_user(regs->ARM_r9, &sc->arm_r9);
+	__get_user(regs->ARM_r10, &sc->arm_r10);
+	__get_user(regs->ARM_fp, &sc->arm_fp);
+	__get_user(regs->ARM_ip, &sc->arm_ip);
+	__get_user(regs->ARM_sp, &sc->arm_sp);
+	__get_user(regs->ARM_lr, &sc->arm_lr);
+	__get_user(regs->ARM_pc, &sc->arm_pc);		/* security! */
+#if defined(CONFIG_CPU_ARM6) || defined(CONFIG_CPU_SA110)
+	__get_user(regs->ARM_cpsr, &sc->arm_cpsr);	/* security! */
+#endif
+
+	/* send SIGTRAP if we're single-stepping */
+	if (ptrace_cancel_bpt (current))
+		send_sig (SIGTRAP, current, 1);
+
+	return regs->ARM_r0;
+}
+
+asmlinkage int sys_sigreturn(struct pt_regs *regs)
+{
+	struct sigframe *frame;
+	sigset_t set;
+
+	frame = (struct sigframe *)regs->ARM_sp;
+
+	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);
+
+	return restore_sigcontext(regs, &frame->sc);
+
+badframe:
+	lock_kernel();
+	do_exit(SIGSEGV);
+}
+
+asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
+{
+	struct rt_sigframe *frame;
+	sigset_t set;
+
+	frame = (struct rt_sigframe *)regs->ARM_sp;
+
+	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);
+
+	return restore_sigcontext(regs, &frame->uc.uc_mcontext);
+
+badframe:
+	lock_kernel();
+	do_exit(SIGSEGV);
+}
+
+static void
+setup_sigcontext(struct sigcontext *sc, /*struct _fpstate *fpstate,*/
+		 struct pt_regs *regs, unsigned long mask)
+{
+	__put_user (regs->ARM_r0, &sc->arm_r0);
+	__put_user (regs->ARM_r1, &sc->arm_r1);
+	__put_user (regs->ARM_r2, &sc->arm_r2);
+	__put_user (regs->ARM_r3, &sc->arm_r3);
+	__put_user (regs->ARM_r4, &sc->arm_r4);
+	__put_user (regs->ARM_r5, &sc->arm_r5);
+	__put_user (regs->ARM_r6, &sc->arm_r6);
+	__put_user (regs->ARM_r7, &sc->arm_r7);
+	__put_user (regs->ARM_r8, &sc->arm_r8);
+	__put_user (regs->ARM_r9, &sc->arm_r9);
+	__put_user (regs->ARM_r10, &sc->arm_r10);
+	__put_user (regs->ARM_fp, &sc->arm_fp);
+	__put_user (regs->ARM_ip, &sc->arm_ip);
+	__put_user (regs->ARM_sp, &sc->arm_sp);
+	__put_user (regs->ARM_lr, &sc->arm_lr);
+	__put_user (regs->ARM_pc, &sc->arm_pc);		/* security! */
+#if defined(CONFIG_CPU_ARM6) || defined(CONFIG_CPU_SA110)
+	__put_user (regs->ARM_cpsr, &sc->arm_cpsr);	/* security! */
+#endif
+
+	__put_user (current->tss.trap_no, &sc->trap_no);
+	__put_user (current->tss.error_code, &sc->error_code);
+	__put_user (mask, &sc->oldmask);
+}
+
+static void setup_frame(int sig, struct k_sigaction *ka,
+			sigset_t *set, struct pt_regs *regs)
+{
+	struct sigframe *frame;
+	unsigned long retcode;
+
+	frame = (struct sigframe *)regs->ARM_sp - 1;
+
+	if (!access_ok(VERIFT_WRITE, frame, sizeof (*frame)))
+		goto segv_and_exit;
+
+	setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);
+
+	if (_NSIG_WORDS > 1) {
+		__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) {
+		retcode = (unsigned long)ka->sa.sa_restorer; /* security! */
+	} else {
+		retcode = (unsigned long)&frame->retcode;
+		__put_user(SWI_SYS_SIGRETURN, &frame->retcode);
+		__flush_entry_to_ram (&frame->retcode);
+	}
+
+	if (current->exec_domain && current->exec_domain->signal_invmap && sig < 32)
+		regs->ARM_r0 = current->exec_domain->signal_invmap[sig];
+	else
+		regs->ARM_r0 = sig;
+	regs->ARM_sp = (unsigned long)frame;
+	regs->ARM_lr = retcode;
+	regs->ARM_pc = (unsigned long)ka->sa.sa_handler;		/* security! */
+	return;
+
+segv_and_exit:
+	lock_kernel();
+	do_exit (SIGSEGV);
+}
+
+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;
+	unsigned long retcode;
+
+	frame = (struct rt_sigframe *)regs->ARM_sp - 1;
+	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+		goto segv_and_exit;
+
+	__put_user(&frame->info, &frame->pinfo);
+	__put_user(&frame->uc, &frame->puc);
+	__copy_to_user(&frame->info, info, sizeof(*info));
+
+	/* Clear all the bits of the ucontext we don't use.  */
+	__clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
+
+	setup_sigcontext(&frame->uc.uc_mcontext, /*&frame->fpstate,*/
+			 regs, set->sig[0]);
+	__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) {
+		retcode = (unsigned long)ka->sa.sa_restorer; /* security! */
+	} else {
+		retcode = (unsigned long)&frame->retcode;
+		__put_user(SWI_SYS_RT_SIGRETURN, &frame->retcode);
+		__flush_entry_to_ram (&frame->retcode);
+	}
+
+	if (current->exec_domain && current->exec_domain->signal_invmap && sig < 32)
+		regs->ARM_r0 = current->exec_domain->signal_invmap[sig];
+	else
+		regs->ARM_r0 = sig;
+	regs->ARM_sp = (unsigned long)frame;
+	regs->ARM_lr = retcode;
+	regs->ARM_pc = (unsigned long)ka->sa.sa_handler;		/* security! */
+	return;
+
+segv_and_exit:
+	lock_kernel();
+	do_exit (SIGSEGV);
+}
+
+/*
+ * 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)
+{
+	/* 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.
+ */
+asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs)
+{
+	unsigned long instr, *pc = (unsigned long *)(instruction_pointer(regs)-4);
+	struct k_sigaction *ka;
+	siginfo_t info;
+	int single_stepping, swi_instr;
+
+	if (!oldset)
+		oldset = &current->blocked;
+
+	single_stepping = ptrace_cancel_bpt (current);
+	swi_instr = (!get_user (instr, pc) && (instr & 0x0f000000) == 0x0f000000);
+
+	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();
+			single_stepping |= ptrace_cancel_bpt (current);
+
+			/* 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:
+				lock_kernel();
+				if (current->binfmt
+				    && current->binfmt->core_dump
+				    && current->binfmt->core_dump(signr, regs))
+					exit_code |= 0x80;
+				unlock_kernel();
+				/* FALLTHRU */
+
+			default:
+				lock_kernel();
+				sigaddset(&current->signal, signr);
+				current->flags |= PF_SIGNALED;
+				do_exit(exit_code);
+				/* NOTREACHED */
+			}
+		}
+
+		/* Are we from a system call? */
+		if (swi_instr) {
+			switch (regs->ARM_r0) {
+			case -ERESTARTNOHAND:
+				regs->ARM_r0 = -EINTR;
+				break;
+
+			case -ERESTARTSYS:
+				if (!(ka->sa.sa_flags & SA_RESTART)) {
+					regs->ARM_r0 = -EINTR;
+					break;
+				}
+				/* fallthrough */
+			case -ERESTARTNOINTR:
+				regs->ARM_r0 = regs->ARM_ORIG_r0;
+				regs->ARM_pc -= 4;
+			}
+		}
+		/* Whee!  Actually deliver the signal.  */
+		handle_signal(signr, ka, &info, oldset, regs);
+		if (single_stepping)
+		    	ptrace_set_bpt (current);
+		return 1;
+	}
+
+	if (swi_instr &&
+	    (regs->ARM_r0 == -ERESTARTNOHAND ||
+	     regs->ARM_r0 == -ERESTARTSYS ||
+	     regs->ARM_r0 == -ERESTARTNOINTR)) {
+		regs->ARM_r0 = regs->ARM_ORIG_r0;
+		regs->ARM_pc -= 4;
+	}
+	if (single_stepping)
+		ptrace_set_bpt (current);
+	return 0;
+}