1 files changed, 89 insertions, 100 deletions

diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index abbb3c3c7aab..05a85bc14c98 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -30,6 +30,7 @@
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/lowcore.h>
+#include <asm/compat.h>
 #include "entry.h"
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
@@ -57,17 +58,15 @@ typedef struct
  */
 SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
 {
-	mask &= _BLOCKABLE;
-	spin_lock_irq(&current->sighand->siglock);
-	current->saved_sigmask = current->blocked;
-	siginitset(&current->blocked, mask);
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	sigset_t blocked;
 
+	current->saved_sigmask = current->blocked;
+	mask &= _BLOCKABLE;
+	siginitset(&blocked, mask);
+	set_current_blocked(&blocked);
 	set_current_state(TASK_INTERRUPTIBLE);
 	schedule();
-	set_thread_flag(TIF_RESTORE_SIGMASK);
-
+	set_restore_sigmask();
 	return -ERESTARTNOHAND;
 }
 
@@ -118,7 +117,8 @@ static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
 
 	/* Copy a 'clean' PSW mask to the user to avoid leaking
 	   information about whether PER is currently on.  */
-	user_sregs.regs.psw.mask = PSW_MASK_MERGE(psw_user_bits, regs->psw.mask);
+	user_sregs.regs.psw.mask = psw_user_bits |
+		(regs->psw.mask & PSW_MASK_USER);
 	user_sregs.regs.psw.addr = regs->psw.addr;
 	memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
 	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
@@ -145,9 +145,13 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
 	err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
 	if (err)
 		return err;
-	regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
-					user_sregs.regs.psw.mask);
-	regs->psw.addr = PSW_ADDR_AMODE | user_sregs.regs.psw.addr;
+	/* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
+	regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
+		(user_sregs.regs.psw.mask & PSW_MASK_USER);
+	/* Check for invalid amode */
+	if (regs->psw.mask & PSW_MASK_EA)
+		regs->psw.mask |= PSW_MASK_BA;
+	regs->psw.addr = user_sregs.regs.psw.addr;
 	memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
 	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
 	       sizeof(sregs->regs.acrs));
@@ -158,7 +162,7 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
 	current->thread.fp_regs.fpc &= FPC_VALID_MASK;
 
 	restore_fp_regs(&current->thread.fp_regs);
-	regs->svcnr = 0;	/* disable syscall checks */
+	clear_thread_flag(TIF_SYSCALL);	/* No longer in a system call */
 	return 0;
 }
 
@@ -172,18 +176,11 @@ SYSCALL_DEFINE0(sigreturn)
 		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);
-
+	set_current_blocked(&set);
 	if (restore_sigregs(regs, &frame->sregs))
 		goto badframe;
-
 	return regs->gprs[2];
-
 badframe:
 	force_sig(SIGSEGV, current);
 	return 0;
@@ -199,21 +196,14 @@ SYSCALL_DEFINE0(rt_sigreturn)
 		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);
-
+	set_current_blocked(&set);
 	if (restore_sigregs(regs, &frame->uc.uc_mcontext))
 		goto badframe;
-
 	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
 			   regs->gprs[15]) == -EFAULT)
 		goto badframe;
 	return regs->gprs[2];
-
 badframe:
 	force_sig(SIGSEGV, current);
 	return 0;
@@ -304,6 +294,7 @@ static int setup_frame(int sig, struct k_sigaction *ka,
 
 	/* Set up registers for signal handler */
 	regs->gprs[15] = (unsigned long) frame;
+	regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA;	/* 64 bit amode */
 	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
 
 	regs->gprs[2] = map_signal(sig);
@@ -372,6 +363,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 
 	/* Set up registers for signal handler */
 	regs->gprs[15] = (unsigned long) frame;
+	regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA;	/* 64 bit amode */
 	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
 
 	regs->gprs[2] = map_signal(sig);
@@ -385,14 +377,11 @@ give_sigsegv:
 	return -EFAULT;
 }
 
-/*
- * OK, we're invoking a handler
- */	
-
-static int
-handle_signal(unsigned long sig, struct k_sigaction *ka,
-	      siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
+static int handle_signal(unsigned long sig, struct k_sigaction *ka,
+			 siginfo_t *info, sigset_t *oldset,
+			 struct pt_regs *regs)
 {
+	sigset_t blocked;
 	int ret;
 
 	/* Set up the stack frame */
@@ -400,17 +389,13 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 		ret = setup_rt_frame(sig, ka, info, oldset, regs);
 	else
 		ret = setup_frame(sig, ka, oldset, regs);
-
-	if (ret == 0) {
-		spin_lock_irq(&current->sighand->siglock);
-		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
-		if (!(ka->sa.sa_flags & SA_NODEFER))
-			sigaddset(&current->blocked,sig);
-		recalc_sigpending();
-		spin_unlock_irq(&current->sighand->siglock);
-	}
-
-	return ret;
+	if (ret)
+		return ret;
+	sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
+	if (!(ka->sa.sa_flags & SA_NODEFER))
+		sigaddset(&blocked, sig);
+	set_current_blocked(&blocked);
+	return 0;
 }
 
 /*
@@ -424,7 +409,6 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
  */
 void do_signal(struct pt_regs *regs)
 {
-	unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
 	siginfo_t info;
 	int signr;
 	struct k_sigaction ka;
@@ -444,54 +428,45 @@ void do_signal(struct pt_regs *regs)
 	else
 		oldset = &current->blocked;
 
-	/* Are we from a system call? */
-	if (regs->svcnr) {
-		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. */
-		switch (retval) {
-		case -ERESTARTNOHAND:
-		case -ERESTARTSYS:
-		case -ERESTARTNOINTR:
-			regs->gprs[2] = regs->orig_gpr2;
-			regs->psw.addr = restart_addr;
-			break;
-		case -ERESTART_RESTARTBLOCK:
-			regs->gprs[2] = -EINTR;
-		}
-		regs->svcnr = 0;	/* Don't deal with this again. */
-	}
-
-	/* Get signal to deliver.  When running under ptrace, at this point
-	   the debugger may change all our registers ... */
+	/*
+	 * Get signal to deliver. When running under ptrace, at this point
+	 * the debugger may change all our registers, including the system
+	 * call information.
+	 */
+	current_thread_info()->system_call =
+		test_thread_flag(TIF_SYSCALL) ? regs->svc_code : 0;
 	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.  */
-		int ret;
-#ifdef CONFIG_COMPAT
-		if (is_compat_task()) {
-			ret = handle_signal32(signr, &ka, &info, oldset, regs);
-	        }
-		else
-#endif
-			ret = handle_signal(signr, &ka, &info, oldset, regs);
-		if (!ret) {
+		if (current_thread_info()->system_call) {
+			regs->svc_code = current_thread_info()->system_call;
+			/* Check for system call restarting. */
+			switch (regs->gprs[2]) {
+			case -ERESTART_RESTARTBLOCK:
+			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 =
+					__rewind_psw(regs->psw,
+						     regs->svc_code >> 16);
+				break;
+			}
+			/* No longer in a system call */
+			clear_thread_flag(TIF_SYSCALL);
+		}
+
+		if ((is_compat_task() ?
+		     handle_signal32(signr, &ka, &info, oldset, regs) :
+		     handle_signal(signr, &ka, &info, oldset, regs)) == 0) {
 			/*
 			 * A signal was successfully delivered; the saved
 			 * sigmask will have been stored in the signal frame,
@@ -505,11 +480,32 @@ void do_signal(struct pt_regs *regs)
 			 * Let tracing know that we've done the handler setup.
 			 */
 			tracehook_signal_handler(signr, &info, &ka, regs,
-					test_thread_flag(TIF_SINGLE_STEP));
+					 test_thread_flag(TIF_SINGLE_STEP));
 		}
 		return;
 	}
 
+	/* No handlers present - check for system call restart */
+	if (current_thread_info()->system_call) {
+		regs->svc_code = current_thread_info()->system_call;
+		switch (regs->gprs[2]) {
+		case -ERESTART_RESTARTBLOCK:
+			/* Restart with sys_restart_syscall */
+			regs->svc_code = __NR_restart_syscall;
+		/* fallthrough */
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+			/* Restart system call with magic TIF bit. */
+			regs->gprs[2] = regs->orig_gpr2;
+			set_thread_flag(TIF_SYSCALL);
+			break;
+		default:
+			clear_thread_flag(TIF_SYSCALL);
+			break;
+		}
+	}
+
 	/*
 	 * If there's no signal to deliver, we just put the saved sigmask back.
 	 */
@@ -517,13 +513,6 @@ void do_signal(struct pt_regs *regs)
 		clear_thread_flag(TIF_RESTORE_SIGMASK);
 		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 	}
-
-	/* 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);
-	}
 }
 
 void do_notify_resume(struct pt_regs *regs)