Index: head/sys/kern/imgact_elf.c
===================================================================
--- head/sys/kern/imgact_elf.c
+++ head/sys/kern/imgact_elf.c
@@ -1055,6 +1055,8 @@
 	imgp->interpreted = 0;
 	imgp->reloc_base = addr;
 	imgp->proc->p_osrel = osrel;
+	imgp->proc->p_elf_machine = hdr->e_machine;
+	imgp->proc->p_elf_flags = hdr->e_flags;
 
 ret:
 	free(interp_buf, M_TEMP);
@@ -1655,15 +1657,11 @@
 	ehdr->e_ident[EI_ABIVERSION] = 0;
 	ehdr->e_ident[EI_PAD] = 0;
 	ehdr->e_type = ET_CORE;
-#if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
-	ehdr->e_machine = ELF_ARCH32;
-#else
-	ehdr->e_machine = ELF_ARCH;
-#endif
+	ehdr->e_machine = td->td_proc->p_elf_machine;
 	ehdr->e_version = EV_CURRENT;
 	ehdr->e_entry = 0;
 	ehdr->e_phoff = sizeof(Elf_Ehdr);
-	ehdr->e_flags = 0;
+	ehdr->e_flags = td->td_proc->p_elf_flags;
 	ehdr->e_ehsize = sizeof(Elf_Ehdr);
 	ehdr->e_phentsize = sizeof(Elf_Phdr);
 	ehdr->e_shentsize = sizeof(Elf_Shdr);
Index: head/sys/sys/proc.h
===================================================================
--- head/sys/sys/proc.h
+++ head/sys/sys/proc.h
@@ -617,8 +617,11 @@
 					       our subtree. */
 	u_int		p_xexit;	/* (c) Exit code. */
 	u_int		p_xsig;		/* (c) Stop/kill sig. */
+	uint16_t	p_elf_machine;	/* (x) ELF machine type */
+	uint64_t	p_elf_flags;	/* (x) ELF flags */
+	
 /* End area that is copied on creation. */
-#define	p_endcopy	p_xsig
+#define	p_endcopy	p_elf_flags
 	struct pgrp	*p_pgrp;	/* (c + e) Pointer to process group. */
 	struct knlist	*p_klist;	/* (c) Knotes attached to this proc. */
 	int		p_numthreads;	/* (c) Number of threads. */
Index: head/usr.bin/gcore/elfcore.c
===================================================================
--- head/usr.bin/gcore/elfcore.c
+++ head/usr.bin/gcore/elfcore.c
@@ -117,8 +117,8 @@
 static void *elf_note_procstat_rlimit(void *, size_t *);
 static void *elf_note_procstat_umask(void *, size_t *);
 static void *elf_note_procstat_vmmap(void *, size_t *);
-static void elf_puthdr(pid_t, vm_map_entry_t, void *, size_t, size_t, size_t,
-    int);
+static void elf_puthdr(int, pid_t, vm_map_entry_t, void *, size_t, size_t,
+    size_t, int);
 static void elf_putnote(int, notefunc_t, void *, struct sbuf *);
 static void elf_putnotes(pid_t, struct sbuf *, size_t *);
 static void freemap(vm_map_entry_t);
@@ -178,7 +178,7 @@
  * Write an ELF coredump for the given pid to the given fd.
  */
 static void
-elf_coredump(int efd __unused, int fd, pid_t pid)
+elf_coredump(int efd, int fd, pid_t pid)
 {
 	vm_map_entry_t map;
 	struct sseg_closure seginfo;
@@ -230,7 +230,7 @@
 	hdr = sbuf_data(sb);
 	segoff = sbuf_len(sb);
 	/* Fill in the header. */
-	elf_puthdr(pid, map, hdr, hdrsize, notesz, segoff, seginfo.count);
+	elf_puthdr(efd, pid, map, hdr, hdrsize, notesz, segoff, seginfo.count);
 
 	n = write(fd, hdr, segoff);
 	if (n == -1)
@@ -420,14 +420,21 @@
  * Generate the ELF coredump header.
  */
 static void
-elf_puthdr(pid_t pid, vm_map_entry_t map, void *hdr, size_t hdrsize,
+elf_puthdr(int efd, pid_t pid, vm_map_entry_t map, void *hdr, size_t hdrsize,
     size_t notesz, size_t segoff, int numsegs)
 {
-	Elf_Ehdr *ehdr;
+	Elf_Ehdr *ehdr, binhdr;
 	Elf_Phdr *phdr;
 	Elf_Shdr *shdr;
 	struct phdr_closure phc;
+	ssize_t cnt;
 
+	cnt = read(efd, &binhdr, sizeof(binhdr));
+	if (cnt < 0)
+		err(1, "Failed to re-read ELF header");
+	else if (cnt != sizeof(binhdr))
+		errx(1, "Failed to re-read ELF header");
+	
 	ehdr = (Elf_Ehdr *)hdr;
 
 	ehdr->e_ident[EI_MAG0] = ELFMAG0;
@@ -441,11 +448,11 @@
 	ehdr->e_ident[EI_ABIVERSION] = 0;
 	ehdr->e_ident[EI_PAD] = 0;
 	ehdr->e_type = ET_CORE;
-	ehdr->e_machine = ELF_ARCH;
+	ehdr->e_machine = binhdr.e_machine;
 	ehdr->e_version = EV_CURRENT;
 	ehdr->e_entry = 0;
 	ehdr->e_phoff = sizeof(Elf_Ehdr);
-	ehdr->e_flags = 0;
+	ehdr->e_flags = binhdr.e_flags;
 	ehdr->e_ehsize = sizeof(Elf_Ehdr);
 	ehdr->e_phentsize = sizeof(Elf_Phdr);
 	ehdr->e_shentsize = sizeof(Elf_Shdr);