Index: arch/amd64/amd64/netbsd32_syscall.c
===================================================================
RCS file: /cvsroot/src/sys/arch/amd64/amd64/netbsd32_syscall.c,v
retrieving revision 1.33
diff -p -u -r1.33 netbsd32_syscall.c
--- arch/amd64/amd64/netbsd32_syscall.c	7 Mar 2015 18:41:40 -0000	1.33
+++ arch/amd64/amd64/netbsd32_syscall.c	30 Apr 2020 04:55:21 -0000
@@ -50,6 +50,10 @@ __KERNEL_RCSID(0, "$NetBSD: netbsd32_sys
 #include <machine/psl.h>
 #include <machine/userret.h>
 
+// XXXMRG
+#include <machine/db_machdep.h>
+#include <ddb/db_interface.h>
+
 void netbsd32_syscall_intern(struct proc *);
 static void netbsd32_syscall(struct trapframe *);
 
@@ -121,6 +125,12 @@ out:
 		frame->tf_rflags &= ~PSL_C;	/* carry bit */
 	} else {
 		switch (error) {
+#if 1 /* COMPAT_DRM */
+		case ELAST+1: /* linux-y ERESTARTSYS */
+			uprintf("%s: got linux ERESTARTSYS\n", __func__);
+			db_stacktrace();
+#endif
+		/* FALLTHROUGH */
 		case ERESTART:
 			/*
 			 * The offset to adjust the PC by depends on whether we
Index: arch/x86/x86/syscall.c
===================================================================
RCS file: /cvsroot/src/sys/arch/x86/x86/syscall.c,v
retrieving revision 1.18
diff -p -u -r1.18 syscall.c
--- arch/x86/x86/syscall.c	6 Apr 2019 11:54:21 -0000	1.18
+++ arch/x86/x86/syscall.c	30 Apr 2020 04:55:21 -0000
@@ -47,6 +47,10 @@ __KERNEL_RCSID(0, "$NetBSD: syscall.c,v 
 #include <machine/psl.h>
 #include <machine/userret.h>
 
+// XXXMRG
+#include <machine/db_machdep.h>
+#include <ddb/db_interface.h>
+
 #include "opt_dtrace.h"
 
 #ifndef __x86_64__
@@ -143,6 +147,12 @@ syscall(struct trapframe *frame)
 		X86_TF_RFLAGS(frame) &= ~PSL_C;	/* carry bit */
 	} else {
 		switch (error) {
+#if 1 /* COMPAT_DRM */
+		case ELAST+1: /* linux-y ERESTARTSYS */
+			uprintf("%s: got linux ERESTARTSYS\n", __func__);
+			db_stacktrace();
+#endif
+		/* FALLTHROUGH */
 		case ERESTART:
 			/*
 			 * The offset to adjust the PC by depends on whether we