Add support for AArch64.

5 files changed, 701 insertions, 0 deletions

diff --git a/libexec/ld.so/aarch64/Makefile.inc b/libexec/ld.so/aarch64/Makefile.inc
new file mode 100644
index 00000000000..1eaf4504070
--- /dev/null
+++ b/libexec/ld.so/aarch64/Makefile.inc
@@ -0,0 +1,6 @@
+#	$OpenBSD: Makefile.inc,v 1.1 2017/01/11 14:11:27 patrick Exp $
+
+CFLAGS += -fpic -fno-stack-protector
+CFLAGS += -mcpu=cortex-a57+nofp+nosimd # this is -msoft-float
+AFLAGS += -D_STANDALONE
+CPPFLAGS += -I${.CURDIR}/../../lib/libc/arch/aarch64
diff --git a/libexec/ld.so/aarch64/archdep.h b/libexec/ld.so/aarch64/archdep.h
new file mode 100644
index 00000000000..48f763c940e
--- /dev/null
+++ b/libexec/ld.so/aarch64/archdep.h
@@ -0,0 +1,73 @@
+/*	$OpenBSD: archdep.h,v 1.1 2017/01/11 14:11:27 patrick Exp $ */
+
+/*
+ * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#ifndef _AARCH64_ARCHDEP_H_
+#define _AARCH64_ARCHDEP_H_
+
+#define	RELOC_TAG	DT_RELA
+
+#define	DL_MALLOC_ALIGN	4	/* Arch constraint or otherwise */
+
+#define	MACHID	EM_AARCH64	/* ELF e_machine ID value checked */
+
+#define	RELTYPE	Elf64_Rela
+#define	RELSIZE	sizeof(Elf64_Rela)
+
+#include <elf_abi.h>
+#include <machine/reloc.h>
+#include "syscall.h"
+#include "util.h"
+
+static inline void *
+_dl_mmap(void *addr, size_t len, int prot, int flags, int fd, off_t offset)
+{
+	return((void *)_dl__syscall((quad_t)SYS_mmap, addr, len, prot,
+	    flags, fd, 0, offset));
+}
+
+
+static inline void
+RELOC_DYN(Elf64_Rela *r, const Elf64_Sym *s, Elf64_Addr *p, unsigned long v)
+{
+	if (ELF64_R_TYPE(r->r_info) == R_AARCH64_RELATIVE) {
+		*p = v + r->r_addend;
+	} else if (ELF64_R_TYPE(r->r_info) == R_AARCH64_GLOB_DAT) {
+		*p = v + s->st_value + r->r_addend;
+	} else if (ELF64_R_TYPE(r->r_info) == R_AARCH64_ABS64) {
+		*p = v + s->st_value + r->r_addend;
+	} else {
+#if !defined(RCRT0)
+		_dl_printf("unknown bootstrap relocation\n");
+#endif
+		_dl_exit(6);
+	}
+}
+
+#define RELOC_GOT(obj, offs)
+
+#endif /* _AARCH64_ARCHDEP_H_ */
diff --git a/libexec/ld.so/aarch64/ldasm.S b/libexec/ld.so/aarch64/ldasm.S
new file mode 100644
index 00000000000..491d05d5e17
--- /dev/null
+++ b/libexec/ld.so/aarch64/ldasm.S
@@ -0,0 +1,182 @@
+/*	$OpenBSD: ldasm.S,v 1.1 2017/01/11 14:11:27 patrick Exp $ */
+
+/*
+ * Copyright (c) 2016 Dale Rahn
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#define DL_DATA_SIZE	(16 * 8)	/* XXX */
+#include <machine/asm.h>
+#include <sys/syscall.h>
+#include <SYS.h>
+
+ENTRY(_dl_start)
+	mov	x29, sp
+	// need to worry about alignment, I think not?
+	mov	x19, sp
+	sub	sp, sp, #8+8+DL_DATA_SIZE	// dl_data size
+	add	x20, sp, #4			// dl_data
+	mov	x21, lr				// save old lr
+
+	mov	x0, x29				// original stack
+	mov	x1, x20				// dl_data
+
+	adrp	x2, :got:_DYNAMIC		/* &_DYNAMIC */
+	add	x2, x2, #:lo12:_DYNAMIC
+
+	bl	_dl_boot_bind
+
+	add	x0, x29, #8			// argv
+	ldr	x1, [x29]			// load argc
+	add	x1, x0, x1, lsl #3		// envp = argv + argc * 8
+	add	x1, x1, #8			//                        + 8
+	ldr	x2, [x20, #7*8]			// loff from dl_data
+	mov	x3, x20				// dl_data
+	bl	_dl_boot
+
+	mov	sp, x29				// move stack back
+	mov	x29, xzr			// clear frame back pointer
+	mov	lr, xzr
+
+	adrp	x8, :got:_dl_dtors
+	ldr	x2, [x8, :got_lo12:_dl_dtors]
+
+	br	x0
+
+ENTRY(_dl_bind_start)
+	/*
+	 * ip is pointer to got entry for this relocation
+	 * lr is pointer to pltgot[2], which is entry -1 of got plt reloc.
+	 * return address is on stack
+	 */
+	stp	x29, x30, [sp, #-160]!
+	stp	 x0,  x1, [sp,#16]
+	stp	 x2,  x3, [sp,#32]
+	stp	 x4,  x5, [sp,#48]
+	stp	 x6,  x7, [sp,#64]
+	stp	 x8,  x9, [sp,#80]
+	stp	x10, x11, [sp,#96]
+	stp	x12, x13, [sp,#112]
+	stp	x14, x15, [sp,#128]
+	str	x18,      [sp,#144]
+
+	mov	x1, x16		// reladdr
+
+
+	ldp	 x0,  x1, [sp,#16]
+	ldp	 x2,  x3, [sp,#32]
+	ldp	 x4,  x5, [sp,#48]
+	ldp	 x6,  x7, [sp,#64]
+	ldp	 x8,  x9, [sp,#80]
+	ldp	x10, x11, [sp,#96]
+	ldp	x12, x13, [sp,#112]
+	ldp	x14, x15, [sp,#128]
+	ldr	x18,      [sp,#144]
+	ldp	x29, x30, [sp], #-160
+	br x16
+
+
+#if 0
+	stmdb	sp!, {r0-r4,sl,fp}
+
+	sub	r1, ip, lr		/* r1 = 4 * (n + 1) */
+	sub	r1, r1, #4		/* r1 = 4 * n */
+	mov	r1, r1, lsr #2		/* r1 = n */
+
+	ldr	r0, [lr, #-4]
+	bl	_dl_bind
+	mov	ip, r0
+	ldmia	sp!, {r0-r4,sl,fp,lr}
+	mov	pc, ip
+#endif
+
+	/* STUB */
+
+
+/* ld.so SYSCALLS */
+
+#define DL_SYSCALL(n) DL_SYSCALL2(n,n)
+#define DL_SYSCALL2(n,c)					\
+	.global		__CONCAT(_dl_,n)		;\
+	.type		__CONCAT(_dl_,n)%function	;\
+__CONCAT(_dl_,n):					;\
+	SYSTRAP(c)					;\
+	bcs	.L_cerr					;\
+	ret
+
+	.section	".text"
+	.align		4
+DL_SYSCALL(close)
+
+
+	.global		_dl_exit
+	.type		_dl_exit%function
+_dl_exit:
+	SYSTRAP(exit)
+	1:
+		b 1b
+
+DL_SYSCALL(issetugid)
+DL_SYSCALL(getthrid)
+DL_SYSCALL2(_syscall,__syscall)
+DL_SYSCALL(munmap)
+DL_SYSCALL(mprotect)
+DL_SYSCALL(open)
+DL_SYSCALL(read)
+DL_SYSCALL(write)
+DL_SYSCALL(fstat)
+DL_SYSCALL(readlink)
+DL_SYSCALL(utrace)
+DL_SYSCALL(getentropy)
+DL_SYSCALL(sendsyslog)
+DL_SYSCALL(pledge)
+DL_SYSCALL2(getcwd,__getcwd)
+DL_SYSCALL(sysctl)
+DL_SYSCALL2(set_tcb,__set_tcb)
+
+DL_SYSCALL(getdents)
+
+	.global		_dl_sigprocmask
+	.type		_dl_sigprocmask%function
+_dl_sigprocmask:
+#if 0
+	teq	r1, #0
+	moveq	r0, #1
+	moveq	r1, #0
+	ldrne	r1, [r1]
+	SYSTRAP(sigprocmask)
+	bcs	.L_cerr
+	teq	r2, #0
+	strne	r0, [r2]
+	mov	r0, #0
+	mov	pc, lr
+#endif
+
+.L_cerr:
+	neg	w0, w0		/* r0 = -errno */
+	ret
+
+ENTRY(_rtld_tlsdesc)
+	ldr	x0, [x0, #8]
+	ret
diff --git a/libexec/ld.so/aarch64/rtld_machine.c b/libexec/ld.so/aarch64/rtld_machine.c
new file mode 100644
index 00000000000..bfed15414e8
--- /dev/null
+++ b/libexec/ld.so/aarch64/rtld_machine.c
@@ -0,0 +1,378 @@
+/*	$OpenBSD: rtld_machine.c,v 1.1 2017/01/11 14:11:27 patrick Exp $ */
+
+/*
+ * Copyright (c) 2004 Dale Rahn
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#define _DYN_LOADER
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/syscall.h>
+#include <sys/unistd.h>
+
+#include <nlist.h>
+#include <link.h>
+
+#include "syscall.h"
+#include "archdep.h"
+#include "resolve.h"
+
+int64_t pcookie __attribute__((section(".openbsd.randomdata"))) __dso_hidden;
+
+void _dl_bind_start(void); /* XXX */
+Elf_Addr _dl_bind(elf_object_t *object, int index);
+#define _RF_S		0x80000000		/* Resolve symbol */
+#define _RF_A		0x40000000		/* Use addend */
+#define _RF_P		0x20000000		/* Location relative */
+#define _RF_G		0x10000000		/* GOT offset */
+#define _RF_B		0x08000000		/* Load address relative */
+#define _RF_U		0x04000000		/* Unaligned */
+#define _RF_V		0x02000000		/* ERROR */
+#define _RF_SZ(s)	(((s) & 0xff) << 8)	/* memory target size */
+#define _RF_RS(s)	((s) & 0xff)		/* right shift */
+static int reloc_target_flags[] = {
+	0,						/*  0 NONE */
+	[ R_AARCH64_ABS64 ] =
+	  _RF_V|_RF_S|_RF_A|		_RF_SZ(64) | _RF_RS(0),	/* ABS64 */
+	[ R_AARCH64_GLOB_DAT ] =
+	  _RF_V|_RF_S|_RF_A|		_RF_SZ(64) | _RF_RS(0),	/* GLOB_DAT */
+	[ R_AARCH64_JUMP_SLOT ] =
+	  _RF_V|_RF_S|			_RF_SZ(64) | _RF_RS(0),	/* JUMP_SLOT */
+	[ R_AARCH64_RELATIVE ] =
+	  _RF_V|_RF_B|_RF_A|		_RF_SZ(64) | _RF_RS(0),	/* REL64 */
+	[ R_AARCH64_TLSDESC ] =
+	  _RF_V|_RF_S,
+	[ R_AARCH64_TLS_TPREL64 ] =
+	  _RF_V|_RF_S,
+	[ R_AARCH64_COPY ] =
+	  _RF_V|_RF_S|			_RF_SZ(32) | _RF_RS(0),	/* 20 COPY */
+
+};
+
+#define RELOC_RESOLVE_SYMBOL(t)		((reloc_target_flags[t] & _RF_S) != 0)
+#define RELOC_PC_RELATIVE(t)		((reloc_target_flags[t] & _RF_P) != 0)
+#define RELOC_BASE_RELATIVE(t)		((reloc_target_flags[t] & _RF_B) != 0)
+#define RELOC_UNALIGNED(t)		((reloc_target_flags[t] & _RF_U) != 0)
+#define RELOC_USE_ADDEND(t)		((reloc_target_flags[t] & _RF_A) != 0)
+#define RELOC_TARGET_SIZE(t)		((reloc_target_flags[t] >> 8) & 0xff)
+#define RELOC_VALUE_RIGHTSHIFT(t)	(reloc_target_flags[t] & 0xff)
+static Elf_Addr reloc_target_bitmask[] = {
+#define _BM(x)  (~(Elf_Addr)0 >> ((8*sizeof(reloc_target_bitmask[0])) - (x)))
+	0,		/*  0 NONE */
+	[ R_AARCH64_ABS64 ] = _BM(64),
+	[ R_AARCH64_GLOB_DAT ] = _BM(64),
+	[ R_AARCH64_JUMP_SLOT ] = _BM(64),
+	[ R_AARCH64_RELATIVE ] = _BM(64),
+	[ R_AARCH64_TLSDESC ] = _BM(64),
+	[ R_AARCH64_TLS_TPREL64 ] = _BM(64),
+	[ R_AARCH64_COPY ] = _BM(64),
+#undef _BM
+};
+#define RELOC_VALUE_BITMASK(t)	(reloc_target_bitmask[t])
+
+#define R_TYPE(x) R_AARCH64_ ## x
+
+void _dl_reloc_plt(Elf_Word *where, Elf_Addr value, Elf_RelA *rel);
+
+#define nitems(_a)     (sizeof((_a)) / sizeof((_a)[0]))
+
+int
+_dl_md_reloc(elf_object_t *object, int rel, int relsz)
+{
+	long	i;
+	long	numrel;
+	long	relrel;
+	int	fails = 0;
+	Elf_Addr loff;
+	Elf_Addr prev_value = 0;
+	const Elf_Sym *prev_sym = NULL;
+	Elf_RelA *rels;
+	struct load_list *llist;
+
+	loff = object->obj_base;
+	numrel = object->Dyn.info[relsz] / sizeof(Elf_RelA);
+	relrel = rel == DT_RELA ? object->relcount : 0;
+	rels = (Elf_RelA *)(object->Dyn.info[rel]);
+
+	if (rels == NULL)
+		return(0);
+
+	if (relrel > numrel) {
+		_dl_printf("relcount > numrel: %ld > %ld\n", relrel, numrel);
+		_dl_exit(20);
+	}
+
+	/*
+	 * unprotect some segments if we need it.
+	 */
+	if ((object->dyn.textrel == 1) && (rel == DT_REL || rel == DT_RELA)) {
+		for (llist = object->load_list;
+		    llist != NULL;
+		    llist = llist->next) {
+			if (!(llist->prot & PROT_WRITE))
+				_dl_mprotect(llist->start, llist->size,
+				    llist->prot|PROT_WRITE);
+		}
+	}
+
+	/* tight loop for leading RELATIVE relocs */
+	for (i = 0; i < relrel; i++, rels++) {
+		Elf_Addr *where;
+
+#ifdef DEBUG
+		if (ELF_R_TYPE(rels->r_info) != R_TYPE(RELATIVE)) {
+			_dl_printf("RELCOUNT wrong\n");
+			_dl_exit(20);
+		}
+#endif
+		where = (Elf_Addr *)(rels->r_offset + loff);
+		*where += loff;
+	}
+	for (; i < numrel; i++, rels++) {
+		Elf_Addr *where, value, ooff, mask;
+		Elf_Word type;
+		const Elf_Sym *sym, *this;
+		const char *symn;
+
+		type = ELF_R_TYPE(rels->r_info);
+
+		if (type >= nitems(reloc_target_flags)) {
+			_dl_printf(" bad relocation %d %d\n", i, type);
+			_dl_exit(1);
+		}
+		if ((reloc_target_flags[type] & _RF_V)==0) {
+			_dl_printf(" bad relocation %d %d\n", i, type);
+			_dl_exit(1);
+		}
+		if (type == R_TYPE(NONE))
+			continue;
+
+		if (type == R_TYPE(JUMP_SLOT) && rel != DT_JMPREL)
+			continue;
+
+		where = (Elf_Addr *)(rels->r_offset + loff);
+
+		if (RELOC_USE_ADDEND(type))
+			value = rels->r_addend;
+		else
+			value = 0;
+
+		sym = NULL;
+		symn = NULL;
+		if (RELOC_RESOLVE_SYMBOL(type)) {
+			sym = object->dyn.symtab;
+			sym += ELF_R_SYM(rels->r_info);
+			symn = object->dyn.strtab + sym->st_name;
+
+			if (sym->st_shndx != SHN_UNDEF &&
+			    ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
+				value += loff;
+			} else if (sym == prev_sym) {
+				value += prev_value;
+			} else {
+				this = NULL;
+				ooff = _dl_find_symbol_bysym(object,
+				    ELF_R_SYM(rels->r_info), &this,
+				    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|
+				    ((type == R_TYPE(JUMP_SLOT)) ?
+					SYM_PLT : SYM_NOTPLT),
+				    sym, NULL);
+				if (this == NULL) {
+resolve_failed:
+					if (ELF_ST_BIND(sym->st_info) !=
+					    STB_WEAK)
+						fails++;
+					continue;
+				}
+				prev_sym = sym;
+				prev_value = (Elf_Addr)(ooff + this->st_value);
+				value += prev_value;
+			}
+		}
+
+		if (type == R_TYPE(JUMP_SLOT)) {
+			/*
+			_dl_reloc_plt((Elf_Word *)where, value, rels);
+			*/
+			*where = value;
+			continue;
+		}
+
+		if (type == R_TYPE(COPY)) {
+			void *dstaddr = where;
+			const void *srcaddr;
+			const Elf_Sym *dstsym = sym, *srcsym = NULL;
+			Elf_Addr soff;
+
+			soff = _dl_find_symbol(symn, &srcsym,
+			    SYM_SEARCH_OTHER|SYM_WARNNOTFOUND|SYM_NOTPLT,
+			    dstsym, object, NULL);
+			if (srcsym == NULL)
+				goto resolve_failed;
+
+			srcaddr = (void *)(soff + srcsym->st_value);
+			_dl_bcopy(srcaddr, dstaddr, dstsym->st_size);
+			continue;
+		}
+
+		if (RELOC_PC_RELATIVE(type))
+			value -= (Elf_Addr)where;
+		if (RELOC_BASE_RELATIVE(type))
+			value += loff;
+
+		mask = RELOC_VALUE_BITMASK(type);
+		value >>= RELOC_VALUE_RIGHTSHIFT(type);
+		value &= mask;
+
+		if (RELOC_UNALIGNED(type)) {
+			/* Handle unaligned relocations. */
+			Elf_Addr tmp = 0;
+			char *ptr = (char *)where;
+			int i, size = RELOC_TARGET_SIZE(type)/8;
+
+			/* Read it in one byte at a time. */
+			for (i=0; i<size; i++)
+				tmp = (tmp << 8) | ptr[i];
+
+			tmp &= ~mask;
+			tmp |= value;
+
+			/* Write it back out. */
+			for (i=0; i<size; i++)
+				ptr[i] = ((tmp >> (8*i)) & 0xff);
+		} else {
+			*where &= ~mask;
+			*where |= value;
+		}
+	}
+
+	/* reprotect the unprotected segments */
+	if ((object->dyn.textrel == 1) && (rel == DT_REL || rel == DT_RELA)) {
+		for (llist = object->load_list;
+		    llist != NULL;
+		    llist = llist->next) {
+			if (!(llist->prot & PROT_WRITE))
+				_dl_mprotect(llist->start, llist->size,
+				    llist->prot);
+		}
+	}
+
+	return (fails);
+}
+
+/*
+ *	Relocate the Global Offset Table (GOT).
+ *	This is done by calling _dl_md_reloc on DT_JMPREL for DL_BIND_NOW,
+ *	otherwise the lazy binding plt initialization is performed.
+ */
+int
+_dl_md_reloc_got(elf_object_t *object, int lazy)
+{
+	int	fails = 0;
+	Elf_Addr *pltgot = (Elf_Addr *)object->Dyn.info[DT_PLTGOT];
+	int i, num;
+	Elf_RelA *rel;
+
+	if (object->Dyn.info[DT_PLTREL] != DT_RELA)
+		return (0);
+
+	if (object->traced)
+		lazy = 1;
+
+	lazy = 0; // until support is written.
+
+	if (!lazy) {
+		fails = _dl_md_reloc(object, DT_JMPREL, DT_PLTRELSZ);
+	} else {
+		rel = (Elf_RelA *)(object->Dyn.info[DT_JMPREL]);
+		num = (object->Dyn.info[DT_PLTRELSZ]);
+
+		for (i = 0; i < num/sizeof(Elf_RelA); i++, rel++) {
+			Elf_Addr *where;
+			where = (Elf_Addr *)(rel->r_offset + object->obj_base);
+			*where += object->obj_base;
+		}
+
+		pltgot[1] = (Elf_Addr)object;
+		pltgot[2] = (Elf_Addr)_dl_bind_start;
+	}
+
+	/* mprotect the GOT */
+	_dl_protect_segment(object, 0, "__got_start", "__got_end", PROT_READ);
+
+	return (fails);
+}
+
+Elf_Addr
+_dl_bind(elf_object_t *object, int relidx)
+{
+	Elf_RelA *rel;
+	const Elf_Sym *sym, *this;
+	const char *symn;
+	const elf_object_t *sobj;
+	Elf_Addr ooff;
+	int64_t cookie = pcookie;
+	struct {
+		struct __kbind param;
+		Elf_Addr newval;
+	} buf;
+
+	rel = ((Elf_RelA *)object->Dyn.info[DT_JMPREL]) + (relidx);
+
+	sym = object->dyn.symtab;
+	sym += ELF_R_SYM(rel->r_info);
+	symn = object->dyn.strtab + sym->st_name;
+
+	this = NULL;
+	ooff = _dl_find_symbol(symn,  &this,
+	    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_PLT, sym, object, &sobj);
+	if (this == NULL) {
+		_dl_printf("lazy binding failed!\n");
+		*(volatile int *)0 = 0;		/* XXX */
+	}
+
+	buf.newval = ooff + this->st_value;
+
+	if (sobj->traced && _dl_trace_plt(sobj, symn))
+		return buf.newval;
+
+	buf.param.kb_addr = (Elf_Word *)(object->obj_base + rel->r_offset);
+	buf.param.kb_size = sizeof(Elf_Addr);
+
+	/* directly code the syscall, so that it's actually inline here */
+	{
+		register long syscall_num __asm("x8") = SYS_kbind;
+		register void *arg1 __asm("x0") = &buf;
+		register long  arg2 __asm("x1") = sizeof(buf);
+		register long  arg3 __asm("x2") = cookie;
+
+		__asm volatile("svc 0" : "+r" (arg1), "+r" (arg2)
+		    : "r" (syscall_num), "r" (arg3)
+		    : "cc", "memory");
+	}
+
+	return buf.newval;
+}
diff --git a/libexec/ld.so/aarch64/syscall.h b/libexec/ld.so/aarch64/syscall.h
new file mode 100644
index 00000000000..6160e700a55
--- /dev/null
+++ b/libexec/ld.so/aarch64/syscall.h
@@ -0,0 +1,62 @@
+/*	$OpenBSD: syscall.h,v 1.1 2017/01/11 14:11:27 patrick Exp $ */
+
+/*
+ * Copyright (c) 2001 Niklas Hallqvist
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#ifndef __DL_SYSCALL_H__
+#define __DL_SYSCALL_H__
+
+#include <sys/syscall.h>
+#include <sys/stat.h>
+
+#ifndef _dl_MAX_ERRNO
+#define _dl_MAX_ERRNO 512L
+#endif
+#define _dl_mmap_error(__res) \
+    ((long)__res < 0 && (long)__res >= -_dl_MAX_ERRNO)
+
+int	_dl_close(int);
+__dead
+int	_dl_exit(int);
+int	_dl_issetugid(void);
+int	_dl_getthrid(void);
+long	_dl__syscall(quad_t, ...);
+int	_dl_mprotect(const void *, size_t, int);
+int	_dl_munmap(const void *, size_t);
+int	_dl_open(const char *, int);
+ssize_t	_dl_read(int, const char *, size_t);
+int	_dl_fstat(int, struct stat *);
+ssize_t	_dl_getdents(int, char *, size_t);
+int	_dl_sysctl(const int *, u_int, void *, size_t *, void *, size_t);
+ssize_t	_dl_readlink(const char *, char *, size_t);
+int	_dl_pledge(const char *, const char **);
+int	_dl_getcwd(char *, size_t);
+int	_dl_utrace(const char *, const void *, size_t);
+int	_dl_getentropy(char *, size_t);
+int	_dl_sendsyslog(const char *, size_t, int);
+void	_dl_set_tcb(void *);
+
+#endif /*__DL_SYSCALL_H__*/