patch-2.1.40 linux/arch/sparc64/kernel/signal.c

• Lines: 439
• Date: Sun May 18 17:10:37 1997
• Orig file: v2.1.39/linux/arch/sparc64/kernel/signal.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.39/linux/arch/sparc64/kernel/signal.c linux/arch/sparc64/kernel/signal.c
@@ -0,0 +1,438 @@
+/*  $Id: signal.c,v 1.2 1997/05/18 08:42:15 davem Exp $
+ *  arch/sparc64/kernel/signal.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
+ *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
+ *  Copyright (C) 1997 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
+ */
+
+#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 <asm/uaccess.h>
+#include <asm/bitops.h>
+#include <asm/ptrace.h>
+#include <asm/svr4.h>
+#include <asm/pgtable.h>
+#include <asm/fpumacro.h>
+#include <asm/smp_lock.h>
+
+#define _S(nr) (1<<((nr)-1))
+
+#define _BLOCKABLE (~(_S(SIGKILL) | _S(SIGSTOP)))
+
+asmlinkage int sys_wait4(pid_t pid, unsigned long *stat_addr,
+			 int options, unsigned long *ru);
+
+asmlinkage int do_signal(unsigned long oldmask, struct pt_regs * regs,
+			 unsigned long orig_o0, int ret_from_syscall);
+
+/* This turned off for production... */
+/* #define DEBUG_SIGNALS 1 */
+
+/* 
+ * The new signal frame, intended to be used for Linux applications only
+ * (we have enough in there to work with clone).
+ * All the interesting bits are in the info field.
+ */
+
+struct new_signal_frame {
+	struct sparc_stackf	ss;
+	__siginfo_t		info;
+	__siginfo_fpu_t *	fpu_save;
+	unsigned int		insns [2];
+	__siginfo_fpu_t		fpu_state;
+};
+
+/* Align macros */
+#define NF_ALIGNEDSZ  (((sizeof(struct new_signal_frame) + 7) & (~7)))
+
+/*
+ * atomically swap in the new signal mask, and wait for a signal.
+ * This is really tricky on the Sparc, watch out...
+ */
+asmlinkage void _sigpause_common(unsigned int set, struct pt_regs *regs)
+{
+	unsigned int mask;
+
+#ifdef CONFIG_SPARC32_COMPAT
+	if (current->tss.flags & SPARC_FLAG_32BIT) {
+		extern asmlinkage void _sigpause32_common(unsigned int, struct pt_regs *);
+		_sigpause32_common(set, regs);
+		return;
+	}
+#endif
+	spin_lock_irq(&current->sigmask_lock);
+	mask = current->blocked;
+	current->blocked = set & _BLOCKABLE;
+	spin_unlock_irq(&current->sigmask_lock);
+	
+	regs->tpc = regs->tnpc;
+	regs->tnpc += 4;
+
+	/* Condition codes and return value where set here for sigpause,
+	 * and so got used by setup_frame, which again causes sigreturn()
+	 * to return -EINTR.
+	 */
+	while (1) {
+		current->state = TASK_INTERRUPTIBLE;
+		schedule();
+		/*
+		 * Return -EINTR and set condition code here,
+		 * so the interrupted system call actually returns
+		 * these.
+		 */
+		regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
+		regs->u_regs[UREG_I0] = EINTR;
+		if (do_signal(mask, regs, 0, 0))
+			return;
+	}
+}
+
+asmlinkage void do_sigpause(unsigned int set, struct pt_regs *regs)
+{
+	_sigpause_common(set, regs);
+}
+
+asmlinkage void do_sigsuspend(struct pt_regs *regs)
+{
+	_sigpause_common(regs->u_regs[UREG_I0], regs);
+}
+
+
+static inline void
+restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t *fpu)
+{
+#ifdef __SMP__
+	if (current->flags & PF_USEDFPU)
+		regs->tstate &= ~(TSTATE_PEF);
+#else
+	if (current == last_task_used_math) {
+		last_task_used_math = 0;
+		regs->tstate &= ~(TSTATE_PEF);
+	}
+#endif
+	current->used_math = 1;
+	current->flags &= ~PF_USEDFPU;
+
+	copy_from_user(&current->tss.float_regs[0],
+		       &fpu->si_float_regs[0],
+		       (sizeof(unsigned int) * 64));
+	__get_user(current->tss.fsr, &fpu->si_fsr);
+}
+
+void do_sigreturn(struct pt_regs *regs)
+{
+	struct new_signal_frame *sf;
+	unsigned long tpc, tnpc, tstate;
+	__siginfo_fpu_t *fpu_save;
+	int mask;
+
+#ifdef CONFIG_SPARC32_COMPAT
+	if (current->tss.flags & SPARC_FLAG_32BIT) {
+		extern asmlinkage void do_sigreturn32(struct pt_regs *);
+		do_sigreturn32(regs);
+		return;
+	}
+#endif	
+	synchronize_user_stack ();
+	sf = (struct new_signal_frame *) regs->u_regs [UREG_FP];
+	/* 1. Make sure we are not getting garbage from the user */
+	if (verify_area (VERIFY_READ, sf, sizeof (*sf))){
+		goto segv;
+	}
+	if (((unsigned long) sf) & 3){
+		goto segv;
+	}
+	get_user(tpc, &sf->info.si_regs.tpc);
+	__get_user(tnpc, &sf->info.si_regs.tnpc);
+	if ((tpc | tnpc) & 3){
+		goto segv;
+	}
+	regs->tpc = tpc;
+	regs->tnpc = tnpc;
+
+	/* 2. Restore the state */
+	__get_user(regs->y, &sf->info.si_regs.y);
+	__get_user(tstate, &sf->info.si_regs.tstate);
+	copy_from_user(regs->u_regs, sf->info.si_regs.u_regs, sizeof(regs->u_regs));
+
+	/* User can only change condition codes and FPU enabling in %tstate. */
+	regs->tstate &= ~(TSTATE_ICC | TSTATE_PEF);
+	regs->tstate |= (tstate & (TSTATE_ICC | TSTATE_PEF));
+
+	__get_user(fpu_save, &sf->fpu_save);
+	if (fpu_save)
+		restore_fpu_state(regs, &sf->fpu_state);
+	__get_user(mask, &sf->info.si_mask);
+	current->blocked = mask & _BLOCKABLE;
+	return;
+segv:
+	lock_kernel();
+	do_exit(SIGSEGV);
+}
+
+/* Checks if the fp is valid */
+static int invalid_frame_pointer(void *fp, int fplen)
+{
+	if ((((unsigned long) fp) & 7) || ((unsigned long)fp) > 0x80000000000ULL - fplen)
+		return 1;
+	return 0;
+}
+
+static inline void
+save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t *fpu)
+{
+#ifdef __SMP__
+	if (current->flags & PF_USEDFPU) {
+		fpsave(&current->tss.float_regs[0], &current->tss.fsr);
+		regs->tstate &= ~(TSTATE_PEF);
+		current->flags &= ~(PF_USEDFPU);
+	}
+#else
+	if (current == last_task_used_math) {
+		fpsave((unsigned long *)&current->tss.float_regs[0], &current->tss.fsr);
+		last_task_used_math = 0;
+		regs->tstate &= ~(TSTATE_PEF);
+	}
+#endif
+	copy_to_user(&fpu->si_float_regs[0], &current->tss.float_regs[0],
+		     (sizeof(unsigned int) * 64));
+	__put_user(current->tss.fsr, &fpu->si_fsr);
+	current->used_math = 0;
+}
+
+static inline void
+new_setup_frame(struct sigaction *sa, struct pt_regs *regs,
+		  int signo, unsigned long oldmask)
+{
+	struct new_signal_frame *sf;
+	int sigframe_size;
+	unsigned long tmp;
+	int i;
+
+	/* 1. Make sure everything is clean */
+	synchronize_user_stack();
+	sigframe_size = NF_ALIGNEDSZ;
+	if (!current->used_math)
+		sigframe_size -= sizeof(__siginfo_fpu_t);
+
+	sf = (struct new_signal_frame *)(regs->u_regs[UREG_FP] - sigframe_size);
+	
+	if (invalid_frame_pointer (sf, sigframe_size)){
+		lock_kernel ();
+		do_exit(SIGILL);
+	}
+
+	if (current->tss.w_saved != 0){
+		printk ("%s[%d]: Invalid user stack frame for "
+			"signal delivery.\n", current->comm, current->pid);
+		lock_kernel ();
+		do_exit (SIGILL);
+	}
+
+	/* 2. Save the current process state */
+	copy_to_user(&sf->info.si_regs, regs, sizeof (*regs));
+
+	if (current->used_math) {
+		save_fpu_state(regs, &sf->fpu_state);
+		__put_user((u64)&sf->fpu_state, &sf->fpu_save);
+	} else {
+		__put_user(0, &sf->fpu_save);
+	}
+
+	__put_user(oldmask, &sf->info.si_mask);
+	for (i = 0; i < sizeof(struct reg_window)/8; i++) {
+		__get_user(tmp, (((u64 *)regs->u_regs[UREG_FP])+i));
+		__put_user(tmp, (((u64 *)sf)+i));
+	}
+	
+	/* 3. return to kernel instructions */
+	__put_user(0x821020d8, &sf->insns[0]); /* mov __NR_sigreturn, %g1 */
+	__put_user(0x91d02011, &sf->insns[1]); /* t 0x11 */
+
+	/* 4. signal handler back-trampoline and parameters */
+	regs->u_regs[UREG_FP] = (unsigned long) sf;
+	regs->u_regs[UREG_I0] = signo;
+	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
+	regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
+
+	/* 5. signal handler */
+	regs->tpc = (unsigned long) sa->sa_handler;
+	regs->tnpc = (regs->tpc + 4);
+
+	/* Flush instruction space. */
+	__asm__ __volatile__ ("flush %0; flush %0 + 4" : : "r" (&(sf->insns[0])));
+		
+}
+
+static inline void handle_signal(unsigned long signr, struct sigaction *sa,
+				 unsigned long oldmask, struct pt_regs *regs)
+{
+	new_setup_frame(sa, regs, signr, oldmask);
+	if(sa->sa_flags & SA_ONESHOT)
+		sa->sa_handler = NULL;
+	if(!(sa->sa_flags & SA_NOMASK))
+		current->blocked |= (sa->sa_mask | _S(signr)) & _BLOCKABLE;
+}
+
+static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
+				     struct sigaction *sa)
+{
+	switch(regs->u_regs[UREG_I0]) {
+		case ERESTARTNOHAND:
+		no_system_call_restart:
+			regs->u_regs[UREG_I0] = EINTR;
+			regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
+			break;
+		case ERESTARTSYS:
+			if(!(sa->sa_flags & SA_RESTART))
+				goto no_system_call_restart;
+		/* fallthrough */
+		case ERESTARTNOINTR:
+			regs->u_regs[UREG_I0] = orig_i0;
+			regs->tpc -= 4;
+			regs->tnpc -= 4;
+	}
+}
+
+/* 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.
+ */
+asmlinkage int do_signal(unsigned long oldmask, struct pt_regs * regs,
+			   unsigned long orig_i0, int restart_syscall)
+{
+	unsigned long signr, mask = ~current->blocked;
+	struct sigaction *sa;
+
+#ifdef CONFIG_SPARC32_COMPAT
+	if (current->tss.flags & SPARC_FLAG_32BIT) {
+		extern asmlinkage int do_signal32(unsigned long, struct pt_regs *,
+						  unsigned long, int);
+		return do_signal32(oldmask, regs, orig_i0, restart_syscall);
+	}
+#endif	
+	while ((signr = current->signal & mask) != 0) {
+		signr = ffz(~signr);
+		clear_bit(signr, &current->signal);
+		sa = current->sig->action + signr;
+		signr++;
+		if ((current->flags & PF_PTRACED) && signr != SIGKILL) {
+			current->exit_code = signr;
+			current->state = TASK_STOPPED;
+			notify_parent(current);
+			schedule();
+			if (!(signr = current->exit_code))
+				continue;
+			current->exit_code = 0;
+			if (signr == SIGSTOP)
+				continue;
+			if (_S(signr) & current->blocked) {
+				current->signal |= _S(signr);
+				continue;
+			}
+			sa = current->sig->action + signr - 1;
+		}
+		if(sa->sa_handler == SIG_IGN) {
+			if(signr != SIGCHLD)
+				continue;
+
+                        /* sys_wait4() grabs the master kernel lock, so
+                         * we need not do so, that sucker should be
+                         * threaded and would not be that difficult to
+                         * do anyways.
+                         */
+                        while(sys_wait4(-1, NULL, WNOHANG, NULL) > 0)
+                                ;
+			continue;
+		}
+		if(sa->sa_handler == SIG_DFL) {
+			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;
+
+			case SIGSTOP:
+				if (current->flags & PF_PTRACED)
+					continue;
+				current->state = TASK_STOPPED;
+				current->exit_code = signr;
+				if(!(current->p_pptr->sig->action[SIGCHLD-1].sa_flags &
+				     SA_NOCLDSTOP))
+					notify_parent(current);
+				schedule();
+				continue;
+
+			case SIGQUIT: case SIGILL: case SIGTRAP:
+			case SIGABRT: case SIGFPE: case SIGSEGV: case SIGBUS:
+				if(current->binfmt && current->binfmt->core_dump) {
+					if(current->binfmt->core_dump(signr, regs))
+						signr |= 0x80;
+				}
+#ifdef DEBUG_SIGNALS
+				/* Very useful to debug dynamic linker problems */
+				printk ("Sig ILL going...\n");
+				show_regs (regs);
+#endif
+				/* fall through */
+			default:
+				current->signal |= _S(signr & 0x7f);
+				current->flags |= PF_SIGNALED;
+				do_exit(signr);
+			}
+		}
+		if(restart_syscall)
+			syscall_restart(orig_i0, regs, sa);
+		handle_signal(signr, sa, oldmask, regs);
+		return 1;
+	}
+	if(restart_syscall &&
+	   (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
+	    regs->u_regs[UREG_I0] == ERESTARTSYS ||
+	    regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
+		/* replay the system call when we are done */
+		regs->u_regs[UREG_I0] = orig_i0;
+		regs->tpc -= 4;
+		regs->tnpc -= 4;
+	}
+	return 0;
+}
+
+asmlinkage int
+sys_sigstack(struct sigstack *ssptr, struct sigstack *ossptr)
+{
+	int ret = -EFAULT;
+
+	lock_kernel();
+	/* First see if old state is wanted. */
+	if(ossptr) {
+		if (put_user ((u64)current->tss.sstk_info.the_stack, &ossptr->the_stack) ||
+		    __put_user (current->tss.sstk_info.cur_status, &ossptr->cur_status))
+			goto out;
+	}
+
+	/* Now see if we want to update the new state. */
+	if(ssptr) {
+		if (get_user ((u64)current->tss.sstk_info.the_stack, &ssptr->the_stack) ||
+		    __put_user (current->tss.sstk_info.cur_status, &ssptr->cur_status))
+			goto out;
+	}
+	ret = 0;
+out:
+	unlock_kernel();
+	return ret;
+}