patch-2.4.2 linux/arch/s390x/kernel/signal.c

• Lines: 596
• Date: Fri Feb 16 16:02:35 2001
• Orig file: v2.4.1/linux/arch/s390x/kernel/signal.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.1/linux/arch/s390x/kernel/signal.c linux/arch/s390x/kernel/signal.c
@@ -0,0 +1,595 @@
+/*
+ *  arch/s390/kernel/signal.c
+ *
+ *  S390 version
+ *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+ *
+ *    Based on Intel version
+ * 
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
+ */
+
+#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)))
+
+/* pretcode & sig are used to store the return addr on Intel
+   & the signal no as the first parameter we do this differently
+   using gpr14 & gpr2. */
+
+#define SIGFRAME_COMMON \
+__u8     callee_used_stack[__SIGNAL_FRAMESIZE]; \
+struct sigcontext sc; \
+_sigregs sregs; \
+__u8 retcode[S390_SYSCALL_SIZE];
+
+typedef struct 
+{
+	SIGFRAME_COMMON
+} sigframe;
+
+typedef struct 
+{
+	SIGFRAME_COMMON
+	struct siginfo info;
+	struct ucontext uc;
+} rt_sigframe;
+
+asmlinkage int FASTCALL(do_signal(struct pt_regs *regs, sigset_t *oldset));
+
+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);
+		/* First 32bits of unions are always present.  */
+		err |= __put_user(from->si_pid, &to->si_pid);
+		switch (from->si_code >> 16) {
+		case __SI_FAULT >> 16:
+			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);
+			break;
+		/* case __SI_RT: This is not generated by the kernel as of now.  */
+		}
+		return err;
+	}
+}
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+asmlinkage int
+sys_sigsuspend(struct pt_regs * regs,int history0, int history1, old_sigset_t mask)
+{
+	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->gprs[2] = -EINTR;
+
+	while (1) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule();
+		if (do_signal(regs, &saveset))
+			return -EINTR;
+	}
+}
+
+asmlinkage int
+sys_rt_sigsuspend(struct pt_regs * regs,sigset_t *unewset, size_t sigsetsize)
+{
+	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->gprs[2] = -EINTR;
+
+	while (1) {
+		set_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, struct pt_regs *regs)
+{
+	return do_sigaltstack(uss, uoss, regs->gprs[15]);
+}
+
+
+
+
+static int save_sigregs(struct pt_regs *regs,_sigregs *sregs)
+{
+	int err;
+	s390_fp_regs fpregs;
+  
+	err = __copy_to_user(&sregs->regs,regs,sizeof(s390_regs_common));
+	if(!err)
+	{
+		save_fp_regs(&fpregs);
+		err=__copy_to_user(&sregs->fpregs,&fpregs,sizeof(fpregs));
+	}
+	return(err);
+	
+}
+
+static int restore_sigregs(struct pt_regs *regs,_sigregs *sregs)
+{
+	int err;
+	s390_fp_regs fpregs;
+	psw_t saved_psw=regs->psw;
+	err=__copy_from_user(regs,&sregs->regs,sizeof(s390_regs_common));
+	if(!err)
+	{
+		regs->orig_gpr2 = -1;		/* disable syscall checks */
+		regs->psw.mask=(saved_psw.mask&~PSW_MASK_DEBUGCHANGE)|
+		(regs->psw.mask&PSW_MASK_DEBUGCHANGE);
+		regs->psw.addr=(saved_psw.addr&~PSW_ADDR_DEBUGCHANGE)|
+		(regs->psw.addr&PSW_ADDR_DEBUGCHANGE);
+		err=__copy_from_user(&fpregs,&sregs->fpregs,sizeof(fpregs));
+		if(!err)
+			restore_fp_regs(&fpregs);
+	}
+	return(err);
+}
+
+static int
+restore_sigcontext(struct sigcontext *sc, pt_regs *regs,
+		 _sigregs *sregs,sigset_t *set)
+{
+	unsigned int err;
+
+	err=restore_sigregs(regs,sregs);
+	if(!err)
+		err=__copy_from_user(&set->sig,&sc->oldmask,_SIGMASK_COPY_SIZE);
+		return(err);
+}
+
+int sigreturn_common(struct pt_regs *regs,int framesize)
+{
+	sigframe *frame = (sigframe *)regs->gprs[15];
+	sigset_t set;
+
+	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
+		return -1;
+	if (restore_sigcontext(&frame->sc,regs,&frame->sregs,&set))
+	        return -1;
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sigmask_lock);
+	current->blocked = set;
+	recalc_sigpending(current);
+	spin_unlock_irq(&current->sigmask_lock);
+	return 0;
+}
+
+asmlinkage long sys_sigreturn(struct pt_regs *regs)
+{
+
+	if (sigreturn_common(regs,sizeof(sigframe)))
+		goto badframe;
+	return regs->gprs[2];
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}	
+
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+	rt_sigframe *frame = (rt_sigframe *)regs->gprs[15];
+
+	if (sigreturn_common(regs,sizeof(rt_sigframe)))
+		goto badframe;
+	/* It is more difficult to avoid calling this function than to
+	   call it and ignore errors.  */
+	do_sigaltstack(&frame->uc.uc_stack, NULL, regs->gprs[15]);
+	return regs->gprs[2];
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}	
+
+/*
+ * Set up a signal frame.
+ */
+
+
+/*
+ * Determine which stack to use..
+ */
+static inline void *
+get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
+{
+	unsigned long sp;
+
+	/* Default to using normal stack */
+	sp = regs->gprs[15];
+
+	/* This is the X/Open sanctioned signal stack switching.  */
+	if (ka->sa.sa_flags & SA_ONSTACK) {
+		if (! on_sig_stack(sp))
+			sp = current->sas_ss_sp + current->sas_ss_size;
+	}
+
+	/* This is the legacy signal stack switching. */
+	else if (!user_mode(regs) &&
+		 !(ka->sa.sa_flags & SA_RESTORER) &&
+		 ka->sa.sa_restorer) {
+		sp = (unsigned long) ka->sa.sa_restorer;
+	}
+
+	return (void *)((sp - frame_size) & -8ul);
+}
+
+static void *setup_frame_common(int sig, struct k_sigaction *ka,
+			sigset_t *set, struct pt_regs * regs,
+				int frame_size,u16 retcode)
+{
+	sigframe *frame;
+	int err;
+
+	frame = get_sigframe(ka, regs,frame_size);
+	if (!access_ok(VERIFY_WRITE, frame,frame_size))
+		return 0;
+	err = save_sigregs(regs,&frame->sregs);
+	if(!err)
+		err=__put_user(&frame->sregs,&frame->sc.sregs);
+	if(!err)
+
+		err=__copy_to_user(&frame->sc.oldmask,&set->sig,_SIGMASK_COPY_SIZE);
+	if(!err)
+	{
+		regs->gprs[2]=(current->exec_domain
+		           && current->exec_domain->signal_invmap
+		           && sig < 32
+		           ? current->exec_domain->signal_invmap[sig]
+		           : sig);
+		/* Set up registers for signal handler */
+		regs->gprs[15] = (addr_t)frame;
+		regs->psw.addr = FIX_PSW(ka->sa.sa_handler);
+	}
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ka->sa.sa_flags & SA_RESTORER) {
+                regs->gprs[14] = FIX_PSW(ka->sa.sa_restorer);
+	} else {
+                regs->gprs[14] = FIX_PSW(frame->retcode);
+		err |= __put_user(retcode, (u16 *)(frame->retcode));
+	}
+	return(err ? 0:frame);
+}
+
+static void setup_frame(int sig, struct k_sigaction *ka,
+			sigset_t *set, struct pt_regs * regs)
+{
+	sigframe *frame;
+
+	if((frame=setup_frame_common(sig,ka,set,regs,sizeof(sigframe),
+		    (S390_SYSCALL_OPCODE|__NR_sigreturn)))==0)
+		goto give_sigsegv;
+#if DEBUG_SIG
+	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
+		current->comm, current->pid, frame, regs->eip, frame->pretcode);
+#endif
+	/* Martin wants this for pthreads */
+	regs->gprs[3] = (addr_t)&frame->sc;
+	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)
+{
+	rt_sigframe *frame;
+	addr_t      orig_sp=regs->gprs[15];
+	int err;
+
+	if((frame=setup_frame_common(sig,ka,set,regs,sizeof(rt_sigframe),
+		    (S390_SYSCALL_OPCODE|__NR_rt_sigreturn)))==0)
+		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(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+	err |= __put_user(sas_ss_flags(orig_sp),
+			  &frame->uc.uc_stack.ss_flags);
+	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+	err |= __put_user(&frame->sc,&frame->uc.sc);
+	regs->gprs[3] = (addr_t)&frame->info;
+	regs->gprs[4] = (addr_t)&frame->uc;
+
+	if (err)
+		goto give_sigsegv;
+
+#if DEBUG_SIG
+	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
+		current->comm, current->pid, frame, regs->eip, frame->pretcode);
+#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->orig_gpr2 >= 0) {
+		/* If so, check system call restarting.. */
+		switch (regs->gprs[2]) {
+			case -ERESTARTNOHAND:
+				regs->gprs[2] = -EINTR;
+				break;
+
+			case -ERESTARTSYS:
+				if (!(ka->sa.sa_flags & SA_RESTART)) {
+					regs->gprs[2] = -EINTR;
+					break;
+				}
+			/* fallthrough */
+			case -ERESTARTNOINTR:
+				regs->gprs[2] = regs->orig_gpr2;
+				regs->psw.addr -= 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;
+
+	/*
+	 * 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(regs))
+		return 1;
+
+	if (!oldset)
+		oldset = &current->blocked;
+#ifdef CONFIG_S390_SUPPORT 
+	if (current->thread.flags & S390_FLAG_31BIT) {
+		extern asmlinkage int do_signal32(struct pt_regs *regs, sigset_t *oldset); 
+		return do_signal32(regs, oldset);
+        }
+#endif 
+
+	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->ptrace & PT_PTRACED) && signr != SIGKILL) {
+			/* Let the debugger run.  */
+			current->exit_code = signr;
+			set_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:
+				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:
+                                if (do_coredump(signr, regs))
+                                        exit_code |= 0x80;
+                                /* FALLTHRU */
+
+			default:
+				lock_kernel();
+				sigaddset(&current->pending.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->trap == __LC_SVC_OLD_PSW /* System Call! */ ) {
+		/* Restart the system call - no handlers present */
+		if (regs->gprs[2] == -ERESTARTNOHAND ||
+		    regs->gprs[2] == -ERESTARTSYS ||
+		    regs->gprs[2] == -ERESTARTNOINTR) {
+			regs->gprs[2] = regs->orig_gpr2;
+			regs->psw.addr -= 2;
+		}
+	}
+	return 0;
+}