diff --git a/sys/arm/arm/dump_machdep.c b/sys/arm/arm/dump_machdep.c
index e8ba5768..d4d6504 100644
--- a/sys/arm/arm/dump_machdep.c
+++ b/sys/arm/arm/dump_machdep.c
@@ -72,11 +72,7 @@ struct md_pa {
 typedef int callback_t(struct md_pa *, int, void *);
 
 static struct kerneldumpheader kdh;
-static off_t dumplo, fileofs;
-
-/* Handle buffered writes. */
-static char buffer[DEV_BSIZE];
-static size_t fragsz;
+static off_t fileofs;
 
 /* XXX: I suppose 20 should be enough. */
 static struct md_pa dump_map[20];
@@ -113,47 +109,6 @@ md_pa_next(struct md_pa *mdp)
 	return (mdp);
 }
 
-static int
-buf_write(struct dumperinfo *di, char *ptr, size_t sz)
-{
-	size_t len;
-	int error;
-
-	while (sz) {
-		len = DEV_BSIZE - fragsz;
-		if (len > sz)
-			len = sz;
-		bcopy(ptr, buffer + fragsz, len);
-		fragsz += len;
-		ptr += len;
-		sz -= len;
-		if (fragsz == DEV_BSIZE) {
-			error = dump_write(di, buffer, 0, dumplo,
-			    DEV_BSIZE);
-			if (error)
-				return error;
-			dumplo += DEV_BSIZE;
-			fragsz = 0;
-		}
-	}
-
-	return (0);
-}
-
-static int
-buf_flush(struct dumperinfo *di)
-{
-	int error;
-
-	if (fragsz == 0)
-		return (0);
-
-	error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
-	dumplo += DEV_BSIZE;
-	fragsz = 0;
-	return (error);
-}
-
 extern vm_offset_t kernel_l1kva;
 extern char *pouet2;
 
@@ -198,10 +153,10 @@ cb_dumpdata(struct md_pa *mdp, int seqnr, void *arg)
 		wdog_kern_pat(WD_LASTVAL);
 #endif
 		error = dump_write(di,
-		    (void *)(pa - (pa & L1_ADDR_BITS)),0, dumplo, sz);
+		    (void *)(pa - (pa & L1_ADDR_BITS)),0, di->dumplo, sz);
 		if (error)
 			break;
-		dumplo += sz;
+		di->dumplo += sz;
 		pgs -= chunk;
 		pa += sz;
 
@@ -235,7 +190,7 @@ cb_dumphdr(struct md_pa *mdp, int seqnr, void *arg)
 	phdr.p_memsz = size;
 	phdr.p_align = PAGE_SIZE;
 
-	error = buf_write(di, (char*)&phdr, sizeof(phdr));
+	error = dump_buf_write(di, (char*)&phdr, sizeof(phdr));
 	fileofs += phdr.p_filesz;
 	return (error);
 }
@@ -316,8 +271,8 @@ dumpsys(struct dumperinfo *di)
 		error = ENOSPC;
 		goto fail;
 	}
-	dumplo = di->mediaoffset + di->mediasize - dumpsize;
-	dumplo -= sizeof(kdh) * 2;
+	di->dumplo = di->mediaoffset + di->mediasize - dumpsize;
+	di->dumplo -= sizeof(kdh) * 2;
 
 	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_ARM_VERSION, dumpsize, di->blocksize);
 
@@ -325,13 +280,13 @@ dumpsys(struct dumperinfo *di)
 	    ehdr.e_phnum);
 
 	/* Dump leader */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
-	dumplo += sizeof(kdh);
+	di->dumplo += sizeof(kdh);
 
 	/* Dump ELF header */
-	error = buf_write(di, (char*)&ehdr, sizeof(ehdr));
+	error = dump_buf_write(di, (char*)&ehdr, sizeof(ehdr));
 	if (error)
 		goto fail;
 
@@ -339,7 +294,7 @@ dumpsys(struct dumperinfo *di)
 	error = foreach_chunk(cb_dumphdr, di);
 	if (error < 0)
 		goto fail;
-	buf_flush(di);
+	dump_buf_flush(di);
 
 	/*
 	 * All headers are written using blocked I/O, so we know the
@@ -348,7 +303,7 @@ dumpsys(struct dumperinfo *di)
 	 * boundary. We cannot use MD_ALIGN on dumplo, because we don't
 	 * care and may very well be unaligned within the dump device.
 	 */
-	dumplo += hdrgap;
+	di->dumplo += hdrgap;
 
 	/* Dump memory chunks (updates dumplo) */
 	error = foreach_chunk(cb_dumpdata, di);
@@ -356,7 +311,7 @@ dumpsys(struct dumperinfo *di)
 		goto fail;
 
 	/* Dump trailer */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
 
diff --git a/sys/ia64/ia64/dump_machdep.c b/sys/ia64/ia64/dump_machdep.c
index 6fa8608..e1c0a9c 100644
--- a/sys/ia64/ia64/dump_machdep.c
+++ b/sys/ia64/ia64/dump_machdep.c
@@ -59,52 +59,7 @@ CTASSERT(sizeof(struct kerneldumpheader) == 512);
 typedef int callback_t(struct efi_md*, int, void*);
 
 static struct kerneldumpheader kdh;
-static off_t dumplo, fileofs;
-
-/* Handle buffered writes. */
-static char buffer[DEV_BSIZE];
-static size_t fragsz;
-
-static int
-buf_write(struct dumperinfo *di, char *ptr, size_t sz)
-{
-	size_t len;
-	int error;
-
-	while (sz) {
-		len = DEV_BSIZE - fragsz;
-		if (len > sz)
-			len = sz;
-		bcopy(ptr, buffer + fragsz, len);
-		fragsz += len;
-		ptr += len;
-		sz -= len;
-		if (fragsz == DEV_BSIZE) {
-			error = dump_write(di, buffer, 0, dumplo,
-			    DEV_BSIZE);
-			if (error)
-				return error;
-			dumplo += DEV_BSIZE;
-			fragsz = 0;
-		}
-	}
-
-	return (0);
-}
-
-static int
-buf_flush(struct dumperinfo *di)
-{
-	int error;
-
-	if (fragsz == 0)
-		return (0);
-
-	error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
-	dumplo += DEV_BSIZE;
-	fragsz = 0;
-	return (error);
-}
+static off_t fileofs;
 
 static int
 cb_dumpdata(struct efi_md *mdp, int seqnr, void *arg)
@@ -134,10 +89,10 @@ cb_dumpdata(struct efi_md *mdp, int seqnr, void *arg)
 #ifdef SW_WATCHDOG
 		wdog_kern_pat(WD_LASTVAL);
 #endif
-		error = dump_write(di, (void*)pa, 0, dumplo, sz);
+		error = dump_write(di, (void*)pa, 0, di->dumplo, sz);
 		if (error)
 			break;
-		dumplo += sz;
+		di->dumplo += sz;
 		pgs -= sz >> EFI_PAGE_SHIFT;
 		pa += sz;
 
@@ -169,7 +124,7 @@ cb_dumphdr(struct efi_md *mdp, int seqnr, void *arg)
 	phdr.p_memsz = mdp->md_pages << EFI_PAGE_SHIFT;
 	phdr.p_align = EFI_PAGE_SIZE;
 
-	error = buf_write(di, (char*)&phdr, sizeof(phdr));
+	error = dump_buf_write(di, (char*)&phdr, sizeof(phdr));
 	fileofs += phdr.p_filesz;
 	return (error);
 }
@@ -250,8 +205,8 @@ dumpsys(struct dumperinfo *di)
 		error = ENOSPC;
 		goto fail;
 	}
-	dumplo = di->mediaoffset + di->mediasize - dumpsize;
-	dumplo -= sizeof(kdh) * 2;
+	di->dumplo = di->mediaoffset + di->mediasize - dumpsize;
+	di->dumplo -= sizeof(kdh) * 2;
 
 	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_IA64_VERSION, dumpsize, di->blocksize);
 
@@ -259,13 +214,13 @@ dumpsys(struct dumperinfo *di)
 	    ehdr.e_phnum);
 
 	/* Dump leader */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
-	dumplo += sizeof(kdh);
+	di->dumplo += sizeof(kdh);
 
 	/* Dump ELF header */
-	error = buf_write(di, (char*)&ehdr, sizeof(ehdr));
+	error = dump_buf_write(di, (char*)&ehdr, sizeof(ehdr));
 	if (error)
 		goto fail;
 
@@ -273,7 +228,7 @@ dumpsys(struct dumperinfo *di)
 	error = foreach_chunk(cb_dumphdr, di);
 	if (error < 0)
 		goto fail;
-	buf_flush(di);
+	dump_buf_flush(di);
 
 	/*
 	 * All headers are written using blocked I/O, so we know the
@@ -282,7 +237,7 @@ dumpsys(struct dumperinfo *di)
 	 * boundary. We cannot use MD_ALIGN on dumplo, because we don't
 	 * care and may very well be unaligned within the dump device.
 	 */
-	dumplo += hdrgap;
+	di->dumplo += hdrgap;
 
 	/* Dump memory chunks (updates dumplo) */
 	error = foreach_chunk(cb_dumpdata, di);
@@ -290,7 +245,7 @@ dumpsys(struct dumperinfo *di)
 		goto fail;
 
 	/* Dump trailer */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
 
diff --git a/sys/kern/kern_shutdown.c b/sys/kern/kern_shutdown.c
index b120263..83d29cf 100644
--- a/sys/kern/kern_shutdown.c
+++ b/sys/kern/kern_shutdown.c
@@ -855,6 +855,48 @@ set_dumper(struct dumperinfo *di, const char *devname)
 	return (0);
 }
 
+int
+dump_buf_write(struct dumperinfo *di, char *ptr, size_t sz)
+{
+	size_t len;
+	int error;
+
+	while (sz) {
+		len = DEV_BSIZE - di->fragsz;
+		if (len > sz)
+			len = sz;
+		bcopy(ptr, di->buffer + di->fragsz, len);
+		di->fragsz += len;
+		ptr += len;
+		sz -= len;
+		if (di->fragsz == DEV_BSIZE) {
+			error = dump_write(di, di->buffer, 0, di->dumplo,
+			    DEV_BSIZE);
+			if (error)
+				return (error);
+			di->dumplo += DEV_BSIZE;
+			di->fragsz = 0;
+		}
+	}
+
+	return (0);
+}
+
+int
+dump_buf_flush(struct dumperinfo *di)
+{
+	int error;
+
+	if (di->fragsz == 0)
+		return (0);
+
+	error = dump_write(di, di->buffer, 0, di->dumplo, DEV_BSIZE);
+	di->dumplo += DEV_BSIZE;
+	di->fragsz = 0;
+
+	return (error);
+}
+
 /* Call dumper with bounds checking. */
 int
 dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
@@ -869,6 +911,8 @@ dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
 		    (uintmax_t)length, (intmax_t)di->mediasize);
 		return (ENOSPC);
 	}
+
+
 	return (di->dumper(di->priv, virtual, physical, offset, length));
 }
 
diff --git a/sys/mips/mips/dump_machdep.c b/sys/mips/mips/dump_machdep.c
index bf8c4a3..280447d 100644
--- a/sys/mips/mips/dump_machdep.c
+++ b/sys/mips/mips/dump_machdep.c
@@ -72,11 +72,7 @@ struct md_pa {
 typedef int callback_t(struct md_pa *, int, void *);
 
 static struct kerneldumpheader kdh;
-static off_t dumplo, fileofs;
-
-/* Handle buffered writes. */
-static char buffer[DEV_BSIZE];
-static size_t fragsz;
+static off_t fileofs;
 
 /* XXX: I suppose 20 should be enough. */
 static struct md_pa dump_map[20];
@@ -113,47 +109,6 @@ md_pa_next(struct md_pa *mdp)
 	return (mdp);
 }
 
-static int
-buf_write(struct dumperinfo *di, char *ptr, size_t sz)
-{
-	size_t len;
-	int error;
-
-	while (sz) {
-		len = DEV_BSIZE - fragsz;
-		if (len > sz)
-			len = sz;
-		bcopy(ptr, buffer + fragsz, len);
-		fragsz += len;
-		ptr += len;
-		sz -= len;
-		if (fragsz == DEV_BSIZE) {
-			error = dump_write(di, buffer, 0, dumplo,
-			    DEV_BSIZE);
-			if (error)
-				return error;
-			dumplo += DEV_BSIZE;
-			fragsz = 0;
-		}
-	}
-
-	return (0);
-}
-
-static int
-buf_flush(struct dumperinfo *di)
-{
-	int error;
-
-	if (fragsz == 0)
-		return (0);
-
-	error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
-	dumplo += DEV_BSIZE;
-	fragsz = 0;
-	return (error);
-}
-
 extern vm_offset_t kernel_l1kva;
 extern char *pouet2;
 
@@ -190,10 +145,11 @@ cb_dumpdata(struct md_pa *mdp, int seqnr, void *arg)
 #ifdef SW_WATCHDOG
 		wdog_kern_pat(WD_LASTVAL);
 #endif
-		error = dump_write(di, (void *)(intptr_t)(pa),0, dumplo, sz); /* XXX fix PA */
+		error = dump_write(di, (void *)(intptr_t)(pa),0, di->dumplo,
+		    sz); /* XXX fix PA */
 		if (error)
 			break;
-		dumplo += sz;
+		di->dumplo += sz;
 		pgs -= chunk;
 		pa += sz;
 
@@ -227,7 +183,7 @@ cb_dumphdr(struct md_pa *mdp, int seqnr, void *arg)
 	phdr.p_memsz = size;
 	phdr.p_align = PAGE_SIZE;
 
-	error = buf_write(di, (char*)&phdr, sizeof(phdr));
+	error = dump_buf_write(di, (char*)&phdr, sizeof(phdr));
 	fileofs += phdr.p_filesz;
 	return (error);
 }
@@ -308,8 +264,8 @@ dumpsys(struct dumperinfo *di)
 		error = ENOSPC;
 		goto fail;
 	}
-	dumplo = di->mediaoffset + di->mediasize - dumpsize;
-	dumplo -= sizeof(kdh) * 2;
+	di->dumplo = di->mediaoffset + di->mediasize - dumpsize;
+	di->dumplo -= sizeof(kdh) * 2;
 
 	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_MIPS_VERSION, dumpsize, di->blocksize);
 
@@ -317,13 +273,13 @@ dumpsys(struct dumperinfo *di)
 	    ehdr.e_phnum);
 
 	/* Dump leader */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
-	dumplo += sizeof(kdh);
+	di->dumplo += sizeof(kdh);
 
 	/* Dump ELF header */
-	error = buf_write(di, (char*)&ehdr, sizeof(ehdr));
+	error = dump_buf_write(di, (char*)&ehdr, sizeof(ehdr));
 	if (error)
 		goto fail;
 
@@ -331,7 +287,7 @@ dumpsys(struct dumperinfo *di)
 	error = foreach_chunk(cb_dumphdr, di);
 	if (error < 0)
 		goto fail;
-	buf_flush(di);
+	dump_buf_flush(di);
 
 	/*
 	 * All headers are written using blocked I/O, so we know the
@@ -340,7 +296,7 @@ dumpsys(struct dumperinfo *di)
 	 * boundary. We cannot use MD_ALIGN on dumplo, because we don't
 	 * care and may very well be unaligned within the dump device.
 	 */
-	dumplo += hdrgap;
+	di->dumplo += hdrgap;
 
 	/* Dump memory chunks (updates dumplo) */
 	error = foreach_chunk(cb_dumpdata, di);
@@ -348,7 +304,7 @@ dumpsys(struct dumperinfo *di)
 		goto fail;
 
 	/* Dump trailer */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
 
diff --git a/sys/powerpc/powerpc/dump_machdep.c b/sys/powerpc/powerpc/dump_machdep.c
index 043505f..9a91fd6 100644
--- a/sys/powerpc/powerpc/dump_machdep.c
+++ b/sys/powerpc/powerpc/dump_machdep.c
@@ -58,58 +58,13 @@ CTASSERT(sizeof(struct kerneldumpheader) == 512);
 typedef int callback_t(struct pmap_md *, int, void *);
 
 static struct kerneldumpheader kdh;
-static off_t dumplo, fileofs;
-
-/* Handle buffered writes. */
-static char buffer[DEV_BSIZE];
-static size_t fragsz;
+static off_t fileofs;
 
 int dumpsys_minidump = 1;
 SYSCTL_INT(_debug, OID_AUTO, minidump, CTLFLAG_RD, &dumpsys_minidump, 0,
     "Kernel makes compressed crash dumps");
 
 static int
-buf_write(struct dumperinfo *di, char *ptr, size_t sz)
-{
-	size_t len;
-	int error;
-
-	while (sz) {
-		len = DEV_BSIZE - fragsz;
-		if (len > sz)
-			len = sz;
-		bcopy(ptr, buffer + fragsz, len);
-		fragsz += len;
-		ptr += len;
-		sz -= len;
-		if (fragsz == DEV_BSIZE) {
-			error = di->dumper(di->priv, buffer, 0, dumplo,
-			    DEV_BSIZE);
-			if (error)
-				return error;
-			dumplo += DEV_BSIZE;
-			fragsz = 0;
-		}
-	}
-
-	return (0);
-}
-
-static int
-buf_flush(struct dumperinfo *di)
-{
-	int error;
-
-	if (fragsz == 0)
-		return (0);
-
-	error = di->dumper(di->priv, buffer, 0, dumplo, DEV_BSIZE);
-	dumplo += DEV_BSIZE;
-	fragsz = 0;
-	return (error);
-}
-
-static int
 cb_dumpdata(struct pmap_md *md, int seqnr, void *arg)
 {
 	struct dumperinfo *di = (struct dumperinfo*)arg;
@@ -137,11 +92,11 @@ cb_dumpdata(struct pmap_md *md, int seqnr, void *arg)
 #ifdef SW_WATCHDOG
 		wdog_kern_pat(WD_LASTVAL);
 #endif
-		error = di->dumper(di->priv, (void*)va, 0, dumplo, sz);
+		error = di->dumper(di->priv, (void*)va, 0, di->dumplo, sz);
 		pmap_dumpsys_unmap(md, ofs, va);
 		if (error)
 			break;
-		dumplo += sz;
+		di->dumplo += sz;
 		resid -= sz;
 		ofs += sz;
 
@@ -173,7 +128,7 @@ cb_dumphdr(struct pmap_md *md, int seqnr, void *arg)
 	phdr.p_memsz = md->md_size;
 	phdr.p_align = PAGE_SIZE;
 
-	error = buf_write(di, (char*)&phdr, sizeof(phdr));
+	error = dump_buf_write(di, (char*)&phdr, sizeof(phdr));
 	fileofs += phdr.p_filesz;
 	return (error);
 }
@@ -248,10 +203,10 @@ dumpsys(struct dumperinfo *di)
 			error = ENOSPC;
 			goto fail;
 		}
-		dumplo = di->mediaoffset + di->mediasize - dumpsize;
-		dumplo -= sizeof(kdh) * 2;
+		di->dumplo = di->mediaoffset + di->mediasize - dumpsize;
+		di->dumplo -= sizeof(kdh) * 2;
 	} else
-		dumplo = 0;
+		di->dumplo = 0;
 
 	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_POWERPC_VERSION, dumpsize,
 	    di->blocksize);
@@ -260,13 +215,13 @@ dumpsys(struct dumperinfo *di)
 	    ehdr.e_phnum);
 
 	/* Dump leader */
-	error = di->dumper(di->priv, &kdh, 0, dumplo, sizeof(kdh));
+	error = di->dumper(di->priv, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
-	dumplo += sizeof(kdh);
+	di->dumplo += sizeof(kdh);
 
 	/* Dump ELF header */
-	error = buf_write(di, (char*)&ehdr, sizeof(ehdr));
+	error = dump_buf_write(di, (char*)&ehdr, sizeof(ehdr));
 	if (error)
 		goto fail;
 
@@ -274,7 +229,7 @@ dumpsys(struct dumperinfo *di)
 	error = foreach_chunk(cb_dumphdr, di);
 	if (error < 0)
 		goto fail;
-	buf_flush(di);
+	dump_buf_flush(di);
 
 	/*
 	 * All headers are written using blocked I/O, so we know the
@@ -283,7 +238,7 @@ dumpsys(struct dumperinfo *di)
 	 * boundary. We cannot use MD_ALIGN on dumplo, because we don't
 	 * care and may very well be unaligned within the dump device.
 	 */
-	dumplo += hdrgap;
+	di->dumplo += hdrgap;
 
 	/* Dump memory chunks (updates dumplo) */
 	error = foreach_chunk(cb_dumpdata, di);
@@ -291,7 +246,7 @@ dumpsys(struct dumperinfo *di)
 		goto fail;
 
 	/* Dump trailer */
-	error = di->dumper(di->priv, &kdh, 0, dumplo, sizeof(kdh));
+	error = di->dumper(di->priv, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
 
diff --git a/sys/sparc64/sparc64/dump_machdep.c b/sys/sparc64/sparc64/dump_machdep.c
index d5409ac..360db38 100644
--- a/sys/sparc64/sparc64/dump_machdep.c
+++ b/sys/sparc64/sparc64/dump_machdep.c
@@ -48,56 +48,11 @@ __FBSDID("$FreeBSD$");
 CTASSERT(sizeof(struct kerneldumpheader) == DEV_BSIZE);
 
 static struct kerneldumpheader kdh;
-static off_t dumplo, dumppos;
-
-/* Handle buffered writes. */
-static char buffer[DEV_BSIZE];
-static vm_size_t fragsz;
+static off_t dumppos;
 
 #define	MAXDUMPSZ	(MAXDUMPPGS << PAGE_SHIFT)
 
 static int
-buf_write(struct dumperinfo *di, char *ptr, size_t sz)
-{
-	size_t len;
-	int error;
-
-	while (sz) {
-		len = DEV_BSIZE - fragsz;
-		if (len > sz)
-			len = sz;
-		bcopy(ptr, buffer + fragsz, len);
-		fragsz += len;
-		ptr += len;
-		sz -= len;
-		if (fragsz == DEV_BSIZE) {
-			error = dump_write(di, buffer, 0, dumplo,
-			    DEV_BSIZE);
-			if (error)
-				return error;
-			dumplo += DEV_BSIZE;
-			fragsz = 0;
-		}
-	}
-
-	return (0);
-}
-
-static int
-buf_flush(struct dumperinfo *di)
-{
-	int error;
-
-	if (fragsz == 0)
-		return (0);
-
-	error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
-	dumplo += DEV_BSIZE;
-	fragsz = 0;
-	return (error);
-}
-
-static int
 reg_write(struct dumperinfo *di, vm_paddr_t pa, vm_size_t size)
 {
 	struct sparc64_dump_reg r;
@@ -106,7 +61,7 @@ reg_write(struct dumperinfo *di, vm_paddr_t pa, vm_size_t size)
 	r.dr_size = size;
 	r.dr_offs = dumppos;
 	dumppos += size;
-	return (buf_write(di, (char *)&r, sizeof(r)));
+	return (dump_buf_write(di, (char *)&r, sizeof(r)));
 }
 
 static int
@@ -126,10 +81,10 @@ blk_dump(struct dumperinfo *di, vm_paddr_t pa, vm_size_t size)
 		rsz = size - pos;
 		rsz = (rsz > MAXDUMPSZ) ? MAXDUMPSZ : rsz;
 		va = TLB_PHYS_TO_DIRECT(pa + pos);
-		error = dump_write(di, (void *)va, 0, dumplo, rsz);
+		error = dump_write(di, (void *)va, 0, di->dumplo, rsz);
 		if (error)
 			break;
-		dumplo += rsz;
+		di->dumplo += rsz;
 
 		/* Check for user abort. */
 		c = cncheckc();
@@ -169,7 +124,7 @@ dumpsys(struct dumperinfo *di)
 	}
 
 	/* Determine dump offset on device. */
-	dumplo = di->mediaoffset + di->mediasize - totsize;
+	di->dumplo = di->mediaoffset + di->mediasize - totsize;
 
 	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_SPARC64_VERSION, size,
 	    di->blocksize);
@@ -177,10 +132,10 @@ dumpsys(struct dumperinfo *di)
 	printf("Dumping %lu MB (%d chunks)\n", (u_long)(size >> 20), nreg);
 
 	/* Dump leader */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
-	dumplo += sizeof(kdh);
+	di->dumplo += sizeof(kdh);
 
 	/* Dump the private header. */
 	hdr.dh_hdr_size = hdrsize;
@@ -189,7 +144,7 @@ dumpsys(struct dumperinfo *di)
 	hdr.dh_tsb_mask = tsb_kernel_mask;
 	hdr.dh_nregions = nreg;
 
-	if (buf_write(di, (char *)&hdr, sizeof(hdr)) != 0)
+	if (dump_buf_write(di, (char *)&hdr, sizeof(hdr)) != 0)
 		goto fail;
 
 	dumppos = hdrsize;
@@ -200,7 +155,7 @@ dumpsys(struct dumperinfo *di)
 		if (error != 0)
 			goto fail;
 	}
-	buf_flush(di);
+	dump_buf_flush(di);
 
 	/* Dump memory chunks. */
 	for (i = 0; i < sparc64_nmemreg; i++) {
@@ -211,7 +166,7 @@ dumpsys(struct dumperinfo *di)
 	}
 
 	/* Dump trailer */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
 
diff --git a/sys/sys/conf.h b/sys/sys/conf.h
index 5a579b4..f18d9d4 100644
--- a/sys/sys/conf.h
+++ b/sys/sys/conf.h
@@ -328,15 +328,20 @@ struct dumperinfo {
 	dumper_t *dumper;	/* Dumping function. */
 	void    *priv;		/* Private parts. */
 	u_int   blocksize;	/* Size of block in bytes. */
-	u_int	maxiosize;	/* Max size allowed for an individual I/O */
+	u_int	maxiosize;	/* Max size allowed for an individual I/O. */
 	off_t   mediaoffset;	/* Initial offset in bytes. */
 	off_t   mediasize;	/* Space available in bytes. */
+	char	buffer[DEV_BSIZE]; /* Space for buffered writes. */
+	size_t	fragsz;		/* Number of buffered bytes. */
+	off_t	dumplo;		/* Bytes written to media so far. */
 };
 
-int set_dumper(struct dumperinfo *, const char *_devname);
-int dump_write(struct dumperinfo *, void *, vm_offset_t, off_t, size_t);
-void dumpsys(struct dumperinfo *);
-int doadump(boolean_t);
+int	set_dumper(struct dumperinfo *, const char *_devname);
+int	dump_buf_write(struct dumperinfo *, char *, size_t);
+int	dump_buf_flush(struct dumperinfo *);
+int	dump_write(struct dumperinfo *, void *, vm_offset_t, off_t, size_t);
+void	dumpsys(struct dumperinfo *);
+int	doadump(boolean_t);
 extern int dumping;		/* system is dumping */
 
 #endif /* _KERNEL */
diff --git a/sys/x86/x86/dump_machdep.c b/sys/x86/x86/dump_machdep.c
index 5c874f4..ba46399 100644
--- a/sys/x86/x86/dump_machdep.c
+++ b/sys/x86/x86/dump_machdep.c
@@ -74,11 +74,7 @@ struct md_pa {
 typedef int callback_t(struct md_pa *, int, void *);
 
 static struct kerneldumpheader kdh;
-static off_t dumplo, fileofs;
-
-/* Handle buffered writes. */
-static char buffer[DEV_BSIZE];
-static size_t fragsz;
+static off_t fileofs;
 
 /* 20 phys_avail entry pairs correspond to 10 md_pa's */
 static struct md_pa dump_map[10];
@@ -115,47 +111,6 @@ md_pa_next(struct md_pa *mdp)
 	return (mdp);
 }
 
-static int
-buf_write(struct dumperinfo *di, char *ptr, size_t sz)
-{
-	size_t len;
-	int error;
-
-	while (sz) {
-		len = DEV_BSIZE - fragsz;
-		if (len > sz)
-			len = sz;
-		bcopy(ptr, buffer + fragsz, len);
-		fragsz += len;
-		ptr += len;
-		sz -= len;
-		if (fragsz == DEV_BSIZE) {
-			error = dump_write(di, buffer, 0, dumplo,
-			    DEV_BSIZE);
-			if (error)
-				return error;
-			dumplo += DEV_BSIZE;
-			fragsz = 0;
-		}
-	}
-
-	return (0);
-}
-
-static int
-buf_flush(struct dumperinfo *di)
-{
-	int error;
-
-	if (fragsz == 0)
-		return (0);
-
-	error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
-	dumplo += DEV_BSIZE;
-	fragsz = 0;
-	return (error);
-}
-
 #define PG2MB(pgs) ((pgs + (1 << 8) - 1) >> 8)
 
 static int
@@ -199,10 +154,10 @@ cb_dumpdata(struct md_pa *mdp, int seqnr, void *arg)
 
 		wdog_kern_pat(WD_LASTVAL);
 
-		error = dump_write(di, va, 0, dumplo, sz);
+		error = dump_write(di, va, 0, di->dumplo, sz);
 		if (error)
 			break;
-		dumplo += sz;
+		di->dumplo += sz;
 		pgs -= chunk;
 		pa += sz;
 
@@ -236,7 +191,7 @@ cb_dumphdr(struct md_pa *mdp, int seqnr, void *arg)
 	phdr.p_memsz = size;
 	phdr.p_align = PAGE_SIZE;
 
-	error = buf_write(di, (char*)&phdr, sizeof(phdr));
+	error = dump_buf_write(di, (char*)&phdr, sizeof(phdr));
 	fileofs += phdr.p_filesz;
 	return (error);
 }
@@ -316,8 +271,8 @@ dumpsys(struct dumperinfo *di)
 		error = ENOSPC;
 		goto fail;
 	}
-	dumplo = di->mediaoffset + di->mediasize - dumpsize;
-	dumplo -= sizeof(kdh) * 2;
+	di->dumplo = di->mediaoffset + di->mediasize - dumpsize;
+	di->dumplo -= sizeof(kdh) * 2;
 
 	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_VERSION, dumpsize,
 	    di->blocksize);
@@ -326,13 +281,13 @@ dumpsys(struct dumperinfo *di)
 	    ehdr.e_phnum);
 
 	/* Dump leader */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;
-	dumplo += sizeof(kdh);
+	di->dumplo += sizeof(kdh);
 
 	/* Dump ELF header */
-	error = buf_write(di, (char*)&ehdr, sizeof(ehdr));
+	error = dump_buf_write(di, (char*)&ehdr, sizeof(ehdr));
 	if (error)
 		goto fail;
 
@@ -340,7 +295,7 @@ dumpsys(struct dumperinfo *di)
 	error = foreach_chunk(cb_dumphdr, di);
 	if (error < 0)
 		goto fail;
-	buf_flush(di);
+	dump_buf_flush(di);
 
 	/*
 	 * All headers are written using blocked I/O, so we know the
@@ -349,7 +304,7 @@ dumpsys(struct dumperinfo *di)
 	 * boundary. We cannot use MD_ALIGN on dumplo, because we don't
 	 * care and may very well be unaligned within the dump device.
 	 */
-	dumplo += hdrgap;
+	di->dumplo += hdrgap;
 
 	/* Dump memory chunks (updates dumplo) */
 	error = foreach_chunk(cb_dumpdata, di);
@@ -357,7 +312,7 @@ dumpsys(struct dumperinfo *di)
 		goto fail;
 
 	/* Dump trailer */
-	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
+	error = dump_write(di, &kdh, 0, di->dumplo, sizeof(kdh));
 	if (error)
 		goto fail;