1 files changed, 527 insertions, 0 deletions

diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
new file mode 100644
index 000000000000..610c1d03e975
--- /dev/null
+++ b/arch/s390/kernel/signal.c
@@ -0,0 +1,527 @@
+/*
+ *  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 <linux/tty.h>
+#include <linux/personality.h>
+#include <linux/binfmts.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/lowcore.h>
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+
+typedef struct 
+{
+	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
+	struct sigcontext sc;
+	_sigregs sregs;
+	int signo;
+	__u8 retcode[S390_SYSCALL_SIZE];
+} sigframe;
+
+typedef struct 
+{
+	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
+	__u8 retcode[S390_SYSCALL_SIZE];
+	struct siginfo info;
+	struct ucontext uc;
+} rt_sigframe;
+
+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(struct pt_regs * regs, int history0, int history1,
+	       old_sigset_t mask)
+{
+	sigset_t saveset;
+
+	mask &= _BLOCKABLE;
+	spin_lock_irq(&current->sighand->siglock);
+	saveset = current->blocked;
+	siginitset(&current->blocked, mask);
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+	regs->gprs[2] = -EINTR;
+
+	while (1) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule();
+		if (do_signal(regs, &saveset))
+			return -EINTR;
+	}
+}
+
+asmlinkage long
+sys_rt_sigsuspend(struct pt_regs *regs, sigset_t __user *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->sighand->siglock);
+	saveset = current->blocked;
+	current->blocked = newset;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+	regs->gprs[2] = -EINTR;
+
+	while (1) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule();
+		if (do_signal(regs, &saveset))
+			return -EINTR;
+	}
+}
+
+asmlinkage long
+sys_sigaction(int sig, const struct old_sigaction __user *act,
+	      struct old_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_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 (!access_ok(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 long
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
+					struct pt_regs *regs)
+{
+	return do_sigaltstack(uss, uoss, regs->gprs[15]);
+}
+
+
+
+/* Returns non-zero on fault. */
+static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
+{
+	unsigned long old_mask = regs->psw.mask;
+	int err;
+  
+	save_access_regs(current->thread.acrs);
+
+	/* Copy a 'clean' PSW mask to the user to avoid leaking
+	   information about whether PER is currently on.  */
+	regs->psw.mask = PSW_MASK_MERGE(PSW_USER_BITS, regs->psw.mask);
+	err = __copy_to_user(&sregs->regs.psw, &regs->psw,
+			     sizeof(sregs->regs.psw)+sizeof(sregs->regs.gprs));
+	regs->psw.mask = old_mask;
+	if (err != 0)
+		return err;
+	err = __copy_to_user(&sregs->regs.acrs, current->thread.acrs,
+			     sizeof(sregs->regs.acrs));
+	if (err != 0)
+		return err;
+	/* 
+	 * We have to store the fp registers to current->thread.fp_regs
+	 * to merge them with the emulated registers.
+	 */
+	save_fp_regs(&current->thread.fp_regs);
+	return __copy_to_user(&sregs->fpregs, &current->thread.fp_regs,
+			      sizeof(s390_fp_regs));
+}
+
+/* Returns positive number on error */
+static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
+{
+	unsigned long old_mask = regs->psw.mask;
+	int err;
+
+	/* Alwys make any pending restarted system call return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+	err = __copy_from_user(&regs->psw, &sregs->regs.psw,
+			       sizeof(sregs->regs.psw)+sizeof(sregs->regs.gprs));
+	regs->psw.mask = PSW_MASK_MERGE(old_mask, regs->psw.mask);
+	regs->psw.addr |= PSW_ADDR_AMODE;
+	if (err)
+		return err;
+	err = __copy_from_user(&current->thread.acrs, &sregs->regs.acrs,
+			       sizeof(sregs->regs.acrs));
+	if (err)
+		return err;
+	restore_access_regs(current->thread.acrs);
+
+	err = __copy_from_user(&current->thread.fp_regs, &sregs->fpregs,
+			       sizeof(s390_fp_regs));
+	current->thread.fp_regs.fpc &= FPC_VALID_MASK;
+	if (err)
+		return err;
+
+	restore_fp_regs(&current->thread.fp_regs);
+	regs->trap = -1;	/* disable syscall checks */
+	return 0;
+}
+
+asmlinkage long sys_sigreturn(struct pt_regs *regs)
+{
+	sigframe __user *frame = (sigframe __user *)regs->gprs[15];
+	sigset_t set;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sighand->siglock);
+	current->blocked = set;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	if (restore_sigregs(regs, &frame->sregs))
+		goto badframe;
+
+	return regs->gprs[2];
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+	rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
+	sigset_t set;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sighand->siglock);
+	current->blocked = set;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	if (restore_sigregs(regs, &frame->uc.uc_mcontext))
+		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 __user *
+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 (! sas_ss_flags(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 __user *)((sp - frame_size) & -8ul);
+}
+
+static inline int map_signal(int sig)
+{
+	if (current_thread_info()->exec_domain
+	    && current_thread_info()->exec_domain->signal_invmap
+	    && sig < 32)
+		return current_thread_info()->exec_domain->signal_invmap[sig];
+	else
+		return sig;
+}
+
+static void setup_frame(int sig, struct k_sigaction *ka,
+			sigset_t *set, struct pt_regs * regs)
+{
+	sigframe __user *frame;
+
+	frame = get_sigframe(ka, regs, sizeof(sigframe));
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
+		goto give_sigsegv;
+
+	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
+		goto give_sigsegv;
+
+	if (save_sigregs(regs, &frame->sregs))
+		goto give_sigsegv;
+	if (__put_user(&frame->sregs, &frame->sc.sregs))
+		goto give_sigsegv;
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ka->sa.sa_flags & SA_RESTORER) {
+                regs->gprs[14] = (unsigned long)
+			ka->sa.sa_restorer | PSW_ADDR_AMODE;
+	} else {
+                regs->gprs[14] = (unsigned long)
+			frame->retcode | PSW_ADDR_AMODE;
+		if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
+	                       (u16 __user *)(frame->retcode)))
+			goto give_sigsegv;
+	}
+
+	/* Set up backchain. */
+	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
+		goto give_sigsegv;
+
+	/* Set up registers for signal handler */
+	regs->gprs[15] = (unsigned long) frame;
+	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
+
+	regs->gprs[2] = map_signal(sig);
+	regs->gprs[3] = (unsigned long) &frame->sc;
+
+	/* We forgot to include these in the sigcontext.
+	   To avoid breaking binary compatibility, they are passed as args. */
+	regs->gprs[4] = current->thread.trap_no;
+	regs->gprs[5] = current->thread.prot_addr;
+
+	/* Place signal number on stack to allow backtrace from handler.  */
+	if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
+		goto give_sigsegv;
+	return;
+
+give_sigsegv:
+	force_sigsegv(sig, current);
+}
+
+static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+			   sigset_t *set, struct pt_regs * regs)
+{
+	int err = 0;
+	rt_sigframe __user *frame;
+
+	frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
+		goto give_sigsegv;
+
+	if (copy_siginfo_to_user(&frame->info, info))
+		goto give_sigsegv;
+
+	/* Create the ucontext.  */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(0, &frame->uc.uc_link);
+	err |= __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+	err |= __put_user(sas_ss_flags(regs->gprs[15]),
+			  &frame->uc.uc_stack.ss_flags);
+	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+	err |= save_sigregs(regs, &frame->uc.uc_mcontext);
+	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->sa.sa_flags & SA_RESTORER) {
+                regs->gprs[14] = (unsigned long)
+			ka->sa.sa_restorer | PSW_ADDR_AMODE;
+	} else {
+                regs->gprs[14] = (unsigned long)
+			frame->retcode | PSW_ADDR_AMODE;
+		err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
+	                          (u16 __user *)(frame->retcode));
+	}
+
+	/* Set up backchain. */
+	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
+		goto give_sigsegv;
+
+	/* Set up registers for signal handler */
+	regs->gprs[15] = (unsigned long) frame;
+	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
+
+	regs->gprs[2] = map_signal(sig);
+	regs->gprs[3] = (unsigned long) &frame->info;
+	regs->gprs[4] = (unsigned long) &frame->uc;
+	return;
+
+give_sigsegv:
+	force_sigsegv(sig, 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)
+{
+	/* 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_NODEFER)) {
+		spin_lock_irq(&current->sighand->siglock);
+		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+		sigaddset(&current->blocked,sig);
+		recalc_sigpending();
+		spin_unlock_irq(&current->sighand->siglock);
+	}
+}
+
+/*
+ * 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)
+{
+	unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
+	siginfo_t info;
+	int signr;
+	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;
+
+	/* Are we from a system call? */
+	if (regs->trap == __LC_SVC_OLD_PSW) {
+		continue_addr = regs->psw.addr;
+		restart_addr = continue_addr - regs->ilc;
+		retval = regs->gprs[2];
+
+		/* Prepare for system call restart.  We do this here so that a
+		   debugger will see the already changed PSW. */
+		if (retval == -ERESTARTNOHAND ||
+		    retval == -ERESTARTSYS ||
+		    retval == -ERESTARTNOINTR) {
+			regs->gprs[2] = regs->orig_gpr2;
+			regs->psw.addr = restart_addr;
+		} else if (retval == -ERESTART_RESTARTBLOCK) {
+			regs->gprs[2] = -EINTR;
+		}
+	}
+
+	/* Get signal to deliver.  When running under ptrace, at this point
+	   the debugger may change all our registers ... */
+	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+
+	/* Depending on the signal settings we may need to revert the
+	   decision to restart the system call. */
+	if (signr > 0 && regs->psw.addr == restart_addr) {
+		if (retval == -ERESTARTNOHAND
+		    || (retval == -ERESTARTSYS
+			 && !(current->sighand->action[signr-1].sa.sa_flags
+			      & SA_RESTART))) {
+			regs->gprs[2] = -EINTR;
+			regs->psw.addr = continue_addr;
+		}
+	}
+
+	if (signr > 0) {
+		/* Whee!  Actually deliver the signal.  */
+#ifdef CONFIG_S390_SUPPORT
+		if (test_thread_flag(TIF_31BIT)) {
+			extern void handle_signal32(unsigned long sig,
+						    struct k_sigaction *ka,
+						    siginfo_t *info,
+						    sigset_t *oldset,
+						    struct pt_regs *regs);
+			handle_signal32(signr, &ka, &info, oldset, regs);
+			return 1;
+	        }
+#endif
+		handle_signal(signr, &ka, &info, oldset, regs);
+		return 1;
+	}
+
+	/* Restart a different system call. */
+	if (retval == -ERESTART_RESTARTBLOCK
+	    && regs->psw.addr == continue_addr) {
+		regs->gprs[2] = __NR_restart_syscall;
+		set_thread_flag(TIF_RESTART_SVC);
+	}
+	return 0;
+}