freebsd-skq/libexec/rtld-elf/i386/rtld_machdep.h
Konstantin Belousov 83aa9cc00c Add support for preinit, init and fini arrays. Some ABIs, in
particular on ARM, do require working init arrays.

Traditional FreeBSD crt1 calls _init and _fini of the binary, instead
of allowing runtime linker to arrange the calls.  This was probably
done to have the same crt code serve both statically and dynamically
linked binaries.  Since ABI mandates that first is called preinit
array functions, then init, and then init array functions, the init
have to be called from rtld now.

To provide binary compatibility to old FreeBSD crt1, which calls _init
itself, rtld only calls intializers and finalizers for main binary if
binary has a note indicating that new crt was used for linking.  Add
parsing of ELF notes to rtld, and cache p_osrel value since we parsed
it anyway.

The patch is inspired by init_array support for DragonflyBSD, written
by John Marino.

Reviewed by:	kan
Tested by:	andrew (arm, previous version), flo (sparc64, previous version)
MFC after:	3 weeks
2012-03-11 20:03:09 +00:00

84 lines
2.9 KiB
C

/*-
* Copyright (c) 1999, 2000 John D. Polstra.
* All rights reserved.
*
* 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) \
((const Elf_Dyn *)((obj)->relocbase + (Elf_Addr)&_DYNAMIC))
/* Fixup the jump slot at "where" to transfer control to "target". */
static inline Elf_Addr
reloc_jmpslot(Elf_Addr *where, Elf_Addr target,
const struct Struct_Obj_Entry *obj,
const struct Struct_Obj_Entry *refobj, const Elf_Rel *rel)
{
#ifdef dbg
dbg("reloc_jmpslot: *%p = %p", (void *)(where),
(void *)(target));
#endif
(*(Elf_Addr *)(where) = (Elf_Addr)(target));
return target;
}
#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)
typedef struct {
unsigned long ti_module;
unsigned long ti_offset;
} tls_index;
extern void *___tls_get_addr(tls_index *ti) __attribute__((__regparm__(1)));
extern void *__tls_get_addr(tls_index *ti);
#define RTLD_DEFAULT_STACK_PF_EXEC PF_X
#define RTLD_DEFAULT_STACK_EXEC PROT_EXEC
#endif