Add the arm64 code to the runtime linker. It's not able to be built as we

still need libc_pic for a few things, but this is expected to be ready
soon.

Differential Revision:	https://reviews.freebsd.org/D2136
Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation

libexec/rtld-elf/aarch64/reloc.c

@@ -0,0 +1,317 @@
+/*-
+ * Copytight (c) 2014-2015 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Andrew Turner
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+
+#include <stdlib.h>
+
+#include "debug.h"
+#include "rtld.h"
+#include "rtld_printf.h"
+
+/*
+ * It is possible for the compiler to emit relocations for unaligned data.
+ * We handle this situation with these inlines.
+ */
+#define	RELOC_ALIGNED_P(x) \
+	(((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
+
+/*
+ * This is not the correct prototype, but we only need it for
+ * a function pointer to a simple asm function.
+ */
+void *_rtld_tlsdesc(void *);
+void _exit(int);
+
+void
+init_pltgot(Obj_Entry *obj)
+{
+
+	if (obj->pltgot != NULL) {
+		obj->pltgot[1] = (Elf_Addr) obj;
+		obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
+	}
+}
+
+int
+do_copy_relocations(Obj_Entry *dstobj)
+{
+	const Obj_Entry *srcobj, *defobj;
+	const Elf_Rela *relalim;
+	const Elf_Rela *rela;
+	const Elf_Sym *srcsym;
+	const Elf_Sym *dstsym;
+	const void *srcaddr;
+	const char *name;
+	void *dstaddr;
+	SymLook req;
+	size_t size;
+	int res;
+
+	/*
+	 * COPY relocs are invalid outside of the main program
+	 */
+	assert(dstobj->mainprog);
+
+	relalim = (const Elf_Rela *)((char *)dstobj->rela +
+	    dstobj->relasize);
+	for (rela = dstobj->rela; rela < relalim; rela++) {
+		if (ELF_R_TYPE(rela->r_info) != R_AARCH64_COPY)
+			continue;
+
+		dstaddr = (void *)(dstobj->relocbase + rela->r_offset);
+		dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info);
+		name = dstobj->strtab + dstsym->st_name;
+		size = dstsym->st_size;
+
+		symlook_init(&req, name);
+		req.ventry = fetch_ventry(dstobj, ELF_R_SYM(rela->r_info));
+		req.flags = SYMLOOK_EARLY;
+
+		for (srcobj = dstobj->next; srcobj != NULL;
+		     srcobj = srcobj->next) {
+			res = symlook_obj(&req, srcobj);
+			if (res == 0) {
+				srcsym = req.sym_out;
+				defobj = req.defobj_out;
+				break;
+			}
+		}
+		if (srcobj == NULL) {
+			_rtld_error(
+"Undefined symbol \"%s\" referenced from COPY relocation in %s",
+			    name, dstobj->path);
+			return (-1);
+		}
+
+		srcaddr = (const void *)(defobj->relocbase + srcsym->st_value);
+		memcpy(dstaddr, srcaddr, size);
+	}
+
+	return (0);
+}
+
+/*
+ * Process the PLT relocations.
+ */
+int
+reloc_plt(Obj_Entry *obj)
+{
+	const Elf_Rela *relalim;
+	const Elf_Rela *rela;
+
+	relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
+	for (rela = obj->pltrela; rela < relalim; rela++) {
+		Elf_Addr *where;
+
+		where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
+
+		switch(ELF_R_TYPE(rela->r_info)) {
+		case R_AARCH64_JUMP_SLOT:
+			*where += (Elf_Addr)obj->relocbase;
+			break;
+		case R_AARCH64_TLSDESC:
+			if (ELF_R_SYM(rela->r_info) == 0) {
+				where[0] = (Elf_Addr)_rtld_tlsdesc;
+				where[1] = rela->r_addend;
+			} else {
+				_rtld_error("Unable to handle "
+				    "R_AARCH64_TLSDESC with a symbol set");
+				return (-1);
+			}
+			break;
+		default:
+			_rtld_error("Unknown relocation type %u in PLT",
+			    (unsigned int)ELF_R_TYPE(rela->r_info));
+			return (-1);
+		}
+	}
+
+	return (0);
+}
+
+/*
+ * LD_BIND_NOW was set - force relocation for all jump slots
+ */
+int
+reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate)
+{
+	const Obj_Entry *defobj;
+	const Elf_Rela *relalim;
+	const Elf_Rela *rela;
+	const Elf_Sym *def;
+
+	relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
+	for (rela = obj->pltrela; rela < relalim; rela++) {
+		Elf_Addr *where;
+
+		switch(ELF_R_TYPE(rela->r_info)) {
+		case R_AARCH64_JUMP_SLOT:
+			where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
+			def = find_symdef(ELF_R_SYM(rela->r_info), obj,
+			    &defobj, SYMLOOK_IN_PLT | flags, NULL, lockstate);
+			if (def == NULL) {
+				dbg("reloc_jmpslots: sym not found");
+				return (-1);
+			}
+
+			*where = (Elf_Addr)(defobj->relocbase + def->st_value);
+			break;
+		case R_AARCH64_TLSDESC:
+			break;
+		default:
+			_rtld_error("Unknown relocation type %x in jmpslot",
+			    (unsigned int)ELF_R_TYPE(rela->r_info));
+			return (-1);
+		}
+	}
+
+	return (0);
+}
+
+int
+reloc_iresolve(Obj_Entry *obj, struct Struct_RtldLockState *lockstate)
+{
+
+	/* XXX not implemented */
+	return (0);
+}
+
+int
+reloc_gnu_ifunc(Obj_Entry *obj, int flags,
+   struct Struct_RtldLockState *lockstate)
+{
+
+	/* XXX not implemented */
+	return (0);
+}
+
+Elf_Addr
+reloc_jmpslot(Elf_Addr *where, Elf_Addr target, const Obj_Entry *defobj,
+    const Obj_Entry *obj, const Elf_Rel *rel)
+{
+
+	assert(ELF_R_TYPE(rel->r_info) == R_AARCH64_JUMP_SLOT);
+
+	if (*where != target)
+		*where = target;
+
+	return target;
+}
+
+/*
+ * Process non-PLT relocations
+ */
+int
+reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
+    RtldLockState *lockstate)
+{
+	const Obj_Entry *defobj;
+	const Elf_Rela *relalim;
+	const Elf_Rela *rela;
+	const Elf_Sym *def;
+	SymCache *cache;
+	Elf_Addr *where;
+	unsigned long symnum;
+
+	if ((flags & SYMLOOK_IFUNC) != 0)
+		/* XXX not implemented */
+		return (0);
+
+	/*
+	 * The dynamic loader may be called from a thread, we have
+	 * limited amounts of stack available so we cannot use alloca().
+	 */
+	if (obj == obj_rtld)
+		cache = NULL;
+	else
+		cache = calloc(obj->dynsymcount, sizeof(SymCache));
+		/* No need to check for NULL here */
+
+	relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize);
+	for (rela = obj->rela; rela < relalim; rela++) {
+		where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
+		symnum = ELF_R_SYM(rela->r_info);
+
+		switch (ELF_R_TYPE(rela->r_info)) {
+		case R_AARCH64_ABS64:
+		case R_AARCH64_GLOB_DAT:
+			def = find_symdef(symnum, obj, &defobj, flags, cache,
+			    lockstate);
+			if (def == NULL)
+				return (-1);
+
+			*where = (Elf_Addr)defobj->relocbase + def->st_value;
+			break;
+		case R_AARCH64_COPY:
+			/*
+			 * These are deferred until all other relocations have
+			 * been done. All we do here is make sure that the
+			 * COPY relocation is not in a shared library. They
+			 * are allowed only in executable files.
+			 */
+			if (!obj->mainprog) {
+				_rtld_error("%s: Unexpected R_AARCH64_COPY "
+				    "relocation in shared library", obj->path);
+				return (-1);
+			}
+			break;
+		case R_AARCH64_RELATIVE:
+			*where = (Elf_Addr)(obj->relocbase + rela->r_addend);
+			break;
+		default:
+			rtld_printf("%s: Unhandled relocation %lu\n",
+			    obj->path, ELF_R_TYPE(rela->r_info));
+			return (-1);
+		}
+	}
+
+	return (0);
+}
+
+void
+allocate_initial_tls(Obj_Entry *objs)
+{
+	Elf_Addr **tp;
+
+	/*
+	* Fix the size of the static TLS block by using the maximum
+	* offset allocated so far and adding a bit for dynamic modules to
+	* use.
+	*/
+	tls_static_space = tls_last_offset + tls_last_size +
+	    RTLD_STATIC_TLS_EXTRA;
+
+	tp = (Elf_Addr **) allocate_tls(objs, NULL, TLS_TCB_SIZE, 16);
+
+	asm volatile("msr	tpidr_el0, %0" : : "r"(tp));
+}

libexec/rtld-elf/aarch64/rtld_machdep.h

@@ -0,0 +1,83 @@
+/*-
+ * Copyright (c) 1999, 2000 John D. Polstra.
+ * Copyright (c) 2014 the FreeBSD Foundation
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Andrew Turner
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef RTLD_MACHDEP_H
+#define	RTLD_MACHDEP_H	1
+
+#include <sys/types.h>
+#include <machine/atomic.h>
+
+struct Struct_Obj_Entry;
+
+/* Return the address of the .dynamic section in the dynamic linker. */
+#define	rtld_dynamic(obj)						\
+({									\
+	Elf_Addr _dynamic_addr;						\
+	asm volatile("adr	%0, _DYNAMIC" : "=&r"(_dynamic_addr));	\
+	(const Elf_Dyn *)_dynamic_addr;					\
+})
+#define	RTLD_IS_DYNAMIC() (1)
+
+Elf_Addr reloc_jmpslot(Elf_Addr *where, Elf_Addr target,
+		       const struct Struct_Obj_Entry *defobj,
+		       const struct Struct_Obj_Entry *obj,
+		       const Elf_Rel *rel);
+
+#define	make_function_pointer(def, defobj) \
+	((defobj)->relocbase + (def)->st_value)
+
+#define	call_initfini_pointer(obj, target) \
+	(((InitFunc)(target))())
+
+#define	call_init_pointer(obj, target) \
+	(((InitArrFunc)(target))(main_argc, main_argv, environ))
+
+#define	round(size, align) \
+	(((size) + (align) - 1) & ~((align) - 1))
+#define	calculate_first_tls_offset(size, align) \
+	round(size, align)
+#define	calculate_tls_offset(prev_offset, prev_size, size, align) \
+	round((prev_offset) + (size), align)
+#define	calculate_tls_end(off, size) 	((off) + (size))
+
+#define	TLS_TCB_SIZE	8
+typedef struct {
+    unsigned long ti_module;
+    unsigned long ti_offset;
+} tls_index;
+
+extern void *__tls_get_addr(tls_index *ti);
+
+#define	RTLD_DEFAULT_STACK_PF_EXEC	PF_X
+#define	RTLD_DEFAULT_STACK_EXEC		PROT_EXEC
+
+#endif

libexec/rtld-elf/aarch64/rtld_start.S

@@ -0,0 +1,113 @@
+/*-
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Andrew Turner under
+ * sponsorship from the FreeBSD Foundation.
+ *
+ * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ */
+
+#include <machine/asm.h>
+__FBSDID("$FreeBSD$");
+
+ENTRY(.rtld_start)
+	mov	x19, x0		/* Put ps_strings in a callee-saved register */
+	mov	x20, sp		/* And the stack pointer */
+
+	sub	x8, x20, #16	/* Make room for obj_main & exit proc */
+	mov	sp, x8		/* Update the stack pointer */
+
+	mov	x0, x20		/* Pass the stack we were given to _rtld */
+	mov	x1, sp		/* exit_proc */
+	add	x2, x1, #8	/* obj_main */
+	bl	_rtld		/* Call the loader */
+	mov	x8, x0		/* Backup the entry point */
+
+	ldr	x2, [sp]	/* Load cleanup */
+	ldr	x1, [sp, #8]	/* Load obj_main */
+	mov	x0, x19		/* Restore ps_strings */
+	mov	sp, x20		/* Restore the stack pointer */
+	br	x8		/* Jump to the entry point */
+END(.rtld_start)
+
+/*
+ * sp + 0 = &GOT[x + 3]
+ * sp + 8 = RA
+ * x16 = &GOT[2]
+ * x17 = &_rtld_bind_start
+ */
+ENTRY(_rtld_bind_start)
+	mov	x17, sp
+
+	/* Save the arguments */
+	stp	x0, x1, [sp, #-16]!
+	stp	x2, x3, [sp, #-16]!
+	stp	x4, x5, [sp, #-16]!
+	stp	x6, x7, [sp, #-16]!
+
+	/* Calculate reloff */
+	ldr	x2, [x17, #0]	/* Get the address of the entry */
+	sub	x1, x2, x16	/* Find its offset */
+	sub	x1, x1, #8	/* Adjust for x16 not being at offset 0 */
+	/* Each rela item has 3 entriesso we need reloff = 3 * index */
+	lsl	x3, x1, #1	/* x3 = 2 * offset */
+	add	x1, x1, x3	/* x1 = x3 + offset = 3 * offset */
+
+	/* Load obj */
+	ldr	x0, [x16, #-8]
+
+	/* Call into rtld */
+	bl	_rtld_bind
+
+	/* Restore the registers saved by the plt code */
+	ldp	xzr, x30, [sp, #(4 * 16)]
+
+	/* Backup the address to branch to */
+	mov	x16, x0
+
+	/* restore the arguments */
+	ldp	x6, x7, [sp], #16
+	ldp	x4, x5, [sp], #16
+	ldp	x2, x3, [sp], #16
+	ldp	x0, x1, [sp], #16
+	/* And the part of the stack the plt entry handled */
+	add	sp, sp, #16
+
+	/* Call into the correct function */
+	br	x16
+END(_rtld_bind_start)
+
+/*
+ * uint64_t _rtld_tlsdesc(struct tlsdesc *);
+ *
+ * struct tlsdesc {
+ *  uint64_t ptr;
+ *  uint64_t data;
+ * };
+ *
+ * Returns the data.
+ */
+ENTRY(_rtld_tlsdesc)
+	ldr	x0, [x0, #8]
+	RET
+END(_rtld_tlsdesc)

libexec/rtld-elf/rtld.c

@@ -4368,7 +4368,8 @@ tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset)
 	return (tls_get_addr_slow(dtvp, index, offset));
 }
 
-#if defined(__arm__) || defined(__mips__) || defined(__powerpc__)
+#if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \
+    defined(__powerpc__)
 
 /*
  * Allocate Static TLS using the Variant I method.