diff --git a/sys/arch/amd64/conf/MODULAR b/sys/arch/amd64/conf/MODULAR
index 848172f92785..129b3acde59e 100644
--- a/sys/arch/amd64/conf/MODULAR
+++ b/sys/arch/amd64/conf/MODULAR
@@ -1,11 +1,9 @@
-# $NetBSD: MODULAR,v 1.17 2020/09/27 13:48:49 roy Exp $
+# $NetBSD: MODULAR,v 1.18 2020/10/19 19:33:01 christos Exp $
 #
 # Try to exclude all the drivers in GENERIC that have been modularized
 # XXX: incomplete
 
 include "arch/amd64/conf/GENERIC"
-options 	MODULAR		# new style module(7) framework
-options 	MODULAR_DEFAULT_AUTOLOAD
 
 -no acpicpu*	at cpu?
 -no est0		at cpu0
@@ -85,6 +83,9 @@ options 	MODULAR_DEFAULT_AUTOLOAD
 
 -no options	AIO
 
+-no options	PTRACE
+-no options	COREDUMP
+
 -no acpiacad*	at acpi?		# ACPI AC Adapter
 -no acpibat*	at acpi?		# ACPI Battery
 -no acpibut*	at acpi?		# ACPI Button
diff --git a/sys/arch/amd64/conf/files.amd64 b/sys/arch/amd64/conf/files.amd64
index 82cda467701a..3229087651d0 100644
--- a/sys/arch/amd64/conf/files.amd64
+++ b/sys/arch/amd64/conf/files.amd64
@@ -1,4 +1,4 @@
-#	$NetBSD: files.amd64,v 1.117 2020/10/15 17:40:13 mgorny Exp $
+#	$NetBSD: files.amd64,v 1.118 2020/10/19 19:33:01 christos Exp $
 #
 # new style config file for amd64 architecture
 #
@@ -47,7 +47,7 @@ file	kern/subr_disk_mbr.c			disk
 file	arch/amd64/amd64/gdt.c			machdep
 file	arch/amd64/amd64/machdep.c		machdep
 file	arch/amd64/amd64/prekern.c		kaslr
-file	arch/amd64/amd64/process_machdep.c	machdep
+file	arch/amd64/amd64/process_machdep.c	machdep & ptrace
 file	arch/amd64/amd64/trap.c			machdep
 file	arch/x86/x86/fpu.c			machdep
 file	arch/x86/x86/dbregs.c			machdep
diff --git a/sys/kern/compat_stub.c b/sys/kern/compat_stub.c
index 23d50887c4fa..9dafb6c1d3db 100644
--- a/sys/kern/compat_stub.c
+++ b/sys/kern/compat_stub.c
@@ -1,4 +1,4 @@
-/* $NetBSD: compat_stub.c,v 1.19 2019/11/20 19:37:53 pgoyette Exp $	*/
+/* $NetBSD: compat_stub.c,v 1.20 2020/10/19 19:33:02 christos Exp $	*/
 
 /*-
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -280,6 +280,8 @@ struct coredump_hook_t coredump_hook;
 struct coredump_offset_hook_t coredump_offset_hook;
 struct coredump_write_hook_t coredump_write_hook;
 struct coredump_netbsd_hook_t coredump_netbsd_hook;
+struct coredump_elf32_hook_t coredump_elf32_hook;
+struct coredump_elf64_hook_t coredump_elf64_hook;
 struct uvm_coredump_walkmap_hook_t uvm_coredump_walkmap_hook;
 struct uvm_coredump_count_segs_hook_t uvm_coredump_count_segs_hook;
 
diff --git a/sys/kern/core_elf32.c b/sys/kern/core_elf32.c
index 892dc3e91161..af46b332d7c9 100644
--- a/sys/kern/core_elf32.c
+++ b/sys/kern/core_elf32.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: core_elf32.c,v 1.65 2020/10/10 00:10:06 rin Exp $	*/
+/*	$NetBSD: core_elf32.c,v 1.66 2020/10/19 19:33:02 christos Exp $	*/
 
 /*
  * Copyright (c) 2001 Wasabi Systems, Inc.
@@ -40,7 +40,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: core_elf32.c,v 1.65 2020/10/10 00:10:06 rin Exp $");
+__KERNEL_RCSID(1, "$NetBSD: core_elf32.c,v 1.66 2020/10/19 19:33:02 christos Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_compat_netbsd32.h"
@@ -109,7 +109,7 @@ static int	ELFNAMEEND(coredump_note)(struct lwp *, struct note_state *);
 #define elf_fpreg		CONCAT(process_fpreg, ELFSIZE)
 
 int
-ELFNAMEEND(coredump)(struct lwp *l, struct coredump_iostate *cookie)
+ELFNAMEEND(real_coredump)(struct lwp *l, struct coredump_iostate *cookie)
 {
 	Elf_Ehdr ehdr;
 	Elf_Shdr shdr;
diff --git a/sys/kern/files.kern b/sys/kern/files.kern
index 553cb77ee3fb..b9bb766d72a5 100644
--- a/sys/kern/files.kern
+++ b/sys/kern/files.kern
@@ -1,4 +1,4 @@
-#	$NetBSD: files.kern,v 1.52 2020/09/07 03:50:41 thorpej Exp $
+#	$NetBSD: files.kern,v 1.53 2020/10/19 19:33:02 christos Exp $
 
 #
 # kernel sources
@@ -16,8 +16,8 @@ file	kern/bufq_fcfs.c		bufq_fcfs
 file	kern/bufq_priocscan.c		bufq_priocscan
 file	kern/bufq_readprio.c		bufq_readprio | new_bufq_strategy
 file	kern/compat_stub.c		kern
-file	kern/core_elf32.c		exec_elf32
-file	kern/core_elf64.c		exec_elf64
+file	kern/core_elf32.c		exec_elf32 & coredump
+file	kern/core_elf64.c		exec_elf64 & coredump
 file	kern/core_netbsd.c		coredump
 file	kern/cnmagic.c			kern
 file	kern/exec_aout.c		exec_aout
diff --git a/sys/kern/kern_core.c b/sys/kern/kern_core.c
index 24a7f643e0f6..5264f38c9789 100644
--- a/sys/kern/kern_core.c
+++ b/sys/kern/kern_core.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: kern_core.c,v 1.30 2020/05/23 23:42:43 ad Exp $	*/
+/*	$NetBSD: kern_core.c,v 1.31 2020/10/19 19:33:02 christos Exp $	*/
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
@@ -37,7 +37,11 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_core.c,v 1.30 2020/05/23 23:42:43 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_core.c,v 1.31 2020/10/19 19:33:02 christos Exp $");
+
+#ifdef _KERNEL_OPT
+#include "opt_compat_netbsd32.h"
+#endif
 
 #include <sys/param.h>
 #include <sys/vnode.h>
@@ -51,8 +55,15 @@ __KERNEL_RCSID(0, "$NetBSD: kern_core.c,v 1.30 2020/05/23 23:42:43 ad Exp $");
 #include <sys/kauth.h>
 #include <sys/module.h>
 #include <sys/compat_stub.h>
+#include <sys/exec_elf.h>
 
-MODULE(MODULE_CLASS_MISC, coredump, NULL);
+#ifdef COMPAT_NETBSD32
+#define COREDUMP_MODULE_DEP	"compat_netbsd32_ptrace"
+#else
+#define COREDUMP_MODULE_DEP	NULL
+#endif
+
+MODULE(MODULE_CLASS_MISC, coredump, COREDUMP_MODULE_DEP);
 
 struct coredump_iostate {
 	struct lwp *io_lwp;
@@ -77,6 +88,10 @@ coredump_modcmd(modcmd_t cmd, void *arg)
 		MODULE_HOOK_SET(coredump_write_hook, coredump_write);
 		MODULE_HOOK_SET(coredump_offset_hook, coredump_offset);
 		MODULE_HOOK_SET(coredump_netbsd_hook, real_coredump_netbsd);
+		MODULE_HOOK_SET(coredump_elf32_hook, real_coredump_elf32);
+#ifdef _LP64
+		MODULE_HOOK_SET(coredump_elf64_hook, real_coredump_elf64);
+#endif
 		MODULE_HOOK_SET(uvm_coredump_walkmap_hook,
 		    uvm_coredump_walkmap);
 		MODULE_HOOK_SET(uvm_coredump_count_segs_hook,
@@ -85,6 +100,10 @@ coredump_modcmd(modcmd_t cmd, void *arg)
 	case MODULE_CMD_FINI:
 		MODULE_HOOK_UNSET(uvm_coredump_count_segs_hook);
 		MODULE_HOOK_UNSET(uvm_coredump_walkmap_hook);
+#ifdef _LP64
+		MODULE_HOOK_UNSET(coredump_elf64_hook);
+#endif
+		MODULE_HOOK_UNSET(coredump_elf32_hook);
 		MODULE_HOOK_UNSET(coredump_netbsd_hook);
 		MODULE_HOOK_UNSET(coredump_offset_hook);
 		MODULE_HOOK_UNSET(coredump_write_hook);
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 1e4c4449bb49..232a0b931611 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: kern_sig.c,v 1.390 2020/05/23 23:42:43 ad Exp $	*/
+/*	$NetBSD: kern_sig.c,v 1.391 2020/10/19 19:33:02 christos Exp $	*/
 
 /*-
  * Copyright (c) 2006, 2007, 2008, 2019 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.390 2020/05/23 23:42:43 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.391 2020/10/19 19:33:02 christos Exp $");
 
 #include "opt_ptrace.h"
 #include "opt_dtrace.h"
@@ -100,6 +100,7 @@ __KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.390 2020/05/23 23:42:43 ad Exp $");
 #include <sys/cpu.h>
 #include <sys/module.h>
 #include <sys/sdt.h>
+#include <sys/exec_elf.h>
 #include <sys/compat_stub.h>
 
 #ifdef PAX_SEGVGUARD
@@ -2343,12 +2344,9 @@ sigexit(struct lwp *l, int signo)
 }
 
 /*
- * Many emulations have a common coredump_netbsd() established as their
- * dump routine.  Since the "real" code may (or may not) be present in
- * loadable module, we provide a routine here which calls the module
- * hook.
+ * Since the "real" code may (or may not) be present in loadable module,
+ * we provide routines here which calls the module hooks.
  */
-
 int
 coredump_netbsd(struct lwp *l, struct coredump_iostate *iocookie)
 {
@@ -2358,6 +2356,26 @@ coredump_netbsd(struct lwp *l, struct coredump_iostate *iocookie)
 	return retval;
 }
 
+int
+coredump_elf32(struct lwp *l, struct coredump_iostate *iocookie)
+{
+	int retval;
+
+	MODULE_HOOK_CALL(coredump_elf32_hook, (l, iocookie), ENOSYS, retval);
+	return retval;
+}
+
+#ifdef _LP64
+int
+coredump_elf64(struct lwp *l, struct coredump_iostate *iocookie)
+{
+	int retval;
+
+	MODULE_HOOK_CALL(coredump_elf64_hook, (l, iocookie), ENOSYS, retval);
+	return retval;
+}
+#endif
+
 /*
  * Put process 'p' into the stopped state and optionally, notify the parent.
  */
diff --git a/sys/modules/coredump/Makefile b/sys/modules/coredump/Makefile
index c2deed72c0d7..b515b4cc0a72 100644
--- a/sys/modules/coredump/Makefile
+++ b/sys/modules/coredump/Makefile
@@ -1,26 +1,25 @@
-#	$NetBSD: Makefile,v 1.6 2019/11/20 19:37:54 pgoyette Exp $
+#	$NetBSD: Makefile,v 1.7 2020/10/19 19:33:02 christos Exp $
 
 .include "../Makefile.inc"
 
 KMOD=	coredump
 
 .PATH:	${S}/kern
-SRCS=	kern_core.c core_netbsd.c 
+SRCS=	kern_core.c core_netbsd.c
+SRCS+=	${OBJECT_FMTS:S/^/core_/:S/$/.c/}
 
 .PATH:	${S}/uvm
 SRCS+=	uvm_coredump.c
 
-.PATH:	${S}/arch/${MACHINE}/${MACHINE}
-.PATH:	${S}/arch/${MACHINE_ARCH}/${MACHINE_ARCH}
-.PATH:	${S}/arch/${MACHINE_CPU}/${MACHINE_CPU}
-.if ${MACHINE_ARCH} == "i386" || ${MACHINE_ARCH} == "x86_64"
-.PATH:	${S}/arch/x86/x86
-.endif
-.if ${MACHINE_ARCH} == "powerpc64"
-.PATH:	${S}/arch/powerpc/powerpc
-.endif
+.include "../ptrace_common/machdep.mk"
 SRCS+=	core_machdep.c
 
+.include "${.CURDIR}/../../compat/netbsd32/netbsd32.mk"
+.if ${COMPAT_USE_NETBSD32} != "no"
+CPPFLAGS.core_elf32.c+=     -DCOMPAT_NETBSD32
+CPPFLAGS.kern_core.c+=     -DCOMPAT_NETBSD32
+.endif
+
 WARNS=	3
 
 COPTS.kern_core.c+=	${GCC_NO_CAST_FUNCTION_TYPE}
diff --git a/sys/modules/exec_elf32/Makefile b/sys/modules/exec_elf32/Makefile
index e8307249141a..222799b4bdd7 100644
--- a/sys/modules/exec_elf32/Makefile
+++ b/sys/modules/exec_elf32/Makefile
@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.5 2019/11/20 19:37:54 pgoyette Exp $
+#	$NetBSD: Makefile,v 1.6 2020/10/19 19:33:02 christos Exp $
 
 .include "../Makefile.inc"
 
@@ -19,7 +19,7 @@ CPPFLAGS+=	-DPAX_ASLR
 .endif
 
 .PATH:	${S}/kern
-SRCS=	exec_elf32.c core_elf32.c
+SRCS=	exec_elf32.c
 
 WARNS=	3
 
diff --git a/sys/modules/exec_elf64/Makefile b/sys/modules/exec_elf64/Makefile
index 50a6a90d13cf..5e7e121622a1 100644
--- a/sys/modules/exec_elf64/Makefile
+++ b/sys/modules/exec_elf64/Makefile
@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.4 2019/11/20 19:37:54 pgoyette Exp $
+#	$NetBSD: Makefile,v 1.5 2020/10/19 19:33:02 christos Exp $
 
 .include "../Makefile.inc"
 
@@ -11,7 +11,7 @@ CPPFLAGS+=	-DPAX_ASLR
 .endif
 
 .PATH:	${S}/kern
-SRCS=	exec_elf64.c core_elf64.c
+SRCS=	exec_elf64.c
 
 WARNS=	3
 
diff --git a/sys/modules/ptrace_common/Makefile b/sys/modules/ptrace_common/Makefile
index 611eeb1cfce9..72285c33dd04 100644
--- a/sys/modules/ptrace_common/Makefile
+++ b/sys/modules/ptrace_common/Makefile
@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.3 2019/10/13 07:28:13 mrg Exp $
+#	$NetBSD: Makefile,v 1.4 2020/10/19 19:33:02 christos Exp $
 #
 .include "../Makefile.inc"
 
@@ -6,8 +6,10 @@
 
 CPPFLAGS+=	-DPTRACE
 
+.include "machdep.mk"
+
 KMOD=	ptrace_common
-SRCS=	sys_ptrace_common.c
+SRCS=	sys_ptrace_common.c process_machdep.c
 
 WARNS=	3
 
diff --git a/sys/modules/ptrace_common/machdep.mk b/sys/modules/ptrace_common/machdep.mk
new file mode 100644
index 000000000000..54253d630ea5
--- /dev/null
+++ b/sys/modules/ptrace_common/machdep.mk
@@ -0,0 +1,13 @@
+# $NetBSD: machdep.mk,v 1.1 2020/10/19 19:33:02 christos Exp $
+
+# Paths to find machine dependent sources
+
+.PATH:	${S}/arch/${MACHINE}/${MACHINE}
+.PATH:	${S}/arch/${MACHINE_ARCH}/${MACHINE_ARCH}
+.PATH:	${S}/arch/${MACHINE_CPU}/${MACHINE_CPU}
+.if ${MACHINE_ARCH} == "i386" || ${MACHINE_ARCH} == "x86_64"
+.PATH:	${S}/arch/x86/x86
+.endif
+.if ${MACHINE_ARCH} == "powerpc64"
+.PATH:	${S}/arch/powerpc/powerpc
+.endif
diff --git a/sys/sys/compat_stub.h b/sys/sys/compat_stub.h
index dd6926b9f489..f2274f8c6ad9 100644
--- a/sys/sys/compat_stub.h
+++ b/sys/sys/compat_stub.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: compat_stub.h,v 1.23 2020/03/08 00:53:13 pgoyette Exp $	*/
+/*	$NetBSD: compat_stub.h,v 1.24 2020/10/19 19:33:02 christos Exp $	*/
 
 /*-
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -377,6 +377,10 @@ MODULE_HOOK(coredump_write_hook, int,
     (struct coredump_iostate *, enum uio_seg, const void *, size_t));
 MODULE_HOOK(coredump_netbsd_hook, int,
     (struct lwp *, struct coredump_iostate *));
+MODULE_HOOK(coredump_elf32_hook, int,
+    (struct lwp *, struct coredump_iostate *));
+MODULE_HOOK(coredump_elf64_hook, int,
+    (struct lwp *, struct coredump_iostate *));
 MODULE_HOOK(uvm_coredump_walkmap_hook, int,
     (struct proc *, int (*)(struct uvm_coredump_state *), void *));
 MODULE_HOOK(uvm_coredump_count_segs_hook, int, (struct proc *));
diff --git a/sys/sys/exec_elf.h b/sys/sys/exec_elf.h
index d57f3ad02834..1b62ac97aedb 100644
--- a/sys/sys/exec_elf.h
+++ b/sys/sys/exec_elf.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: exec_elf.h,v 1.167 2020/10/10 21:25:51 thorpej Exp $	*/
+/*	$NetBSD: exec_elf.h,v 1.168 2020/10/19 19:33:02 christos Exp $	*/
 
 /*-
  * Copyright (c) 1994 The NetBSD Foundation, Inc.
@@ -1439,12 +1439,14 @@ int	elf32_populate_auxv(struct lwp *, struct exec_package *, char **);
 int	elf32_copyargs(struct lwp *, struct exec_package *,
     struct ps_strings *, char **, void *);
 
+int	elf32_check_header(Elf32_Ehdr *);
+#endif
+
+int	real_coredump_elf32(struct lwp *, struct coredump_iostate *);
 int	coredump_elf32(struct lwp *, struct coredump_iostate *);
 void	coredump_savenote_elf32(struct note_state *, unsigned int,
 	    const char *, void *, size_t);
 
-int	elf32_check_header(Elf32_Ehdr *);
-#endif
 
 #ifdef EXEC_ELF64
 int	exec_elf64_makecmds(struct lwp *, struct exec_package *);
@@ -1452,12 +1454,14 @@ int	elf64_populate_auxv(struct lwp *, struct exec_package *, char **);
 int	elf64_copyargs(struct lwp *, struct exec_package *,
     struct ps_strings *, char **, void *);
 
+int	elf64_check_header(Elf64_Ehdr *);
+#endif
+
+int	real_coredump_elf64(struct lwp *, struct coredump_iostate *);
 int	coredump_elf64(struct lwp *, struct coredump_iostate *);
 void	coredump_savenote_elf64(struct note_state *, unsigned int,
 	    const char *, void *, size_t);
 
-int	elf64_check_header(Elf64_Ehdr *);
-#endif
 
 #endif /* _KERNEL */