diff --git a/CREDITS b/CREDITS
index e818eb6a3e71..0175098d4776 100644
--- a/CREDITS
+++ b/CREDITS
@@ -842,10 +842,9 @@ D: ax25-utils maintainer.
 
 N: Helge Deller
 E: deller@gmx.de
-E: hdeller@redhat.de
-D: PA-RISC Linux hacker, LASI-, ASP-, WAX-, LCD/LED-driver
-S: Schimmelsrain 1
-S: D-69231 Rauenberg
+W: http://www.parisc-linux.org/
+D: PA-RISC Linux architecture maintainer
+D: LASI-, ASP-, WAX-, LCD/LED-driver
 S: Germany
 
 N: Jean Delvare
@@ -1361,7 +1360,7 @@ S: Stellenbosch, Western Cape
 S: South Africa
 
 N: Grant Grundler
-E: grundler@parisc-linux.org
+E: grantgrundler@gmail.com
 W: http://obmouse.sourceforge.net/
 W: http://www.parisc-linux.org/
 D: obmouse - rewrote Olivier Florent's Omnibook 600 "pop-up" mouse driver
@@ -2492,7 +2491,7 @@ S: Syracuse, New York 13206
 S: USA
 
 N: Kyle McMartin
-E: kyle@parisc-linux.org
+E: kyle@mcmartin.ca
 D: Linux/PARISC hacker
 D: AD1889 sound driver
 S: Ottawa, Canada
@@ -3780,14 +3779,13 @@ S: 21513 Conradia Ct
 S: Cupertino, CA 95014
 S: USA
 
-N: Thibaut Varene
-E: T-Bone@parisc-linux.org
-W: http://www.parisc-linux.org/~varenet/
-P: 1024D/B7D2F063 E67C 0D43 A75E 12A5 BB1C  FA2F 1E32 C3DA B7D2 F063
+N: Thibaut Varène
+E: hacks+kernel@slashdirt.org
+W: http://hacks.slashdirt.org/
 D: PA-RISC port minion, PDC and GSCPS2 drivers, debuglocks and other bits
 D: Some ARM at91rm9200 bits, S1D13XXX FB driver, random patches here and there
 D: AD1889 sound driver
-S: Paris, France
+S: France
 
 N: Heikki Vatiainen
 E: hessu@cs.tut.fi
diff --git a/MAINTAINERS b/MAINTAINERS
index 41ce5f4ad838..e6e17d8c5aae 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -409,8 +409,7 @@ F:	drivers/platform/x86/wmi.c
 F:	include/uapi/linux/wmi.h
 
 AD1889 ALSA SOUND DRIVER
-M:	Thibaut Varene <T-Bone@parisc-linux.org>
-W:	http://wiki.parisc-linux.org/AD1889
+W:	https://parisc.wiki.kernel.org/index.php/AD1889
 L:	linux-parisc@vger.kernel.org
 S:	Maintained
 F:	sound/pci/ad1889.*
@@ -11488,7 +11487,7 @@ F:	Documentation/blockdev/paride.txt
 F:	drivers/block/paride/
 
 PARISC ARCHITECTURE
-M:	"James E.J. Bottomley" <jejb@parisc-linux.org>
+M:	"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
 M:	Helge Deller <deller@gmx.de>
 L:	linux-parisc@vger.kernel.org
 W:	http://www.parisc-linux.org/
diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
index 2582df1c529b..0964c236e3e5 100644
--- a/arch/parisc/kernel/ptrace.c
+++ b/arch/parisc/kernel/ptrace.c
@@ -308,15 +308,29 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 
 long do_syscall_trace_enter(struct pt_regs *regs)
 {
-	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
-	    tracehook_report_syscall_entry(regs)) {
+	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
+		int rc = tracehook_report_syscall_entry(regs);
+
 		/*
-		 * Tracing decided this syscall should not happen or the
-		 * debugger stored an invalid system call number. Skip
-		 * the system call and the system call restart handling.
+		 * As tracesys_next does not set %r28 to -ENOSYS
+		 * when %r20 is set to -1, initialize it here.
 		 */
-		regs->gr[20] = -1UL;
-		goto out;
+		regs->gr[28] = -ENOSYS;
+
+		if (rc) {
+			/*
+			 * A nonzero return code from
+			 * tracehook_report_syscall_entry() tells us
+			 * to prevent the syscall execution.  Skip
+			 * the syscall call and the syscall restart handling.
+			 *
+			 * Note that the tracer may also just change
+			 * regs->gr[20] to an invalid syscall number,
+			 * that is handled by tracesys_next.
+			 */
+			regs->gr[20] = -1UL;
+			return -1;
+		}
 	}
 
 	/* Do the secure computing check after ptrace. */
@@ -340,7 +354,6 @@ long do_syscall_trace_enter(struct pt_regs *regs)
 			regs->gr[24] & 0xffffffff,
 			regs->gr[23] & 0xffffffff);
 
-out:
 	/*
 	 * Sign extend the syscall number to 64bit since it may have been
 	 * modified by a compat ptrace call