freebsd-dev/libexec/rtld-elf/mips/rtld_start.S

290 lines
8.4 KiB
ArmAsm

/* $NetBSD: rtld_start.S,v 1.10 2009/12/14 00:41:19 matt Exp $ */
/*
* Copyright 1997 Michael L. Hitch <mhitch@montana.edu>
* Portions copyright 2002 Charles M. Hannum <root@ihack.net>
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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.
*
* $FreeBSD$
*/
#include <machine/asm.h>
#if defined(__clang__) || (defined(__GNUC__) && __GNUC__ > 4)
.cfi_sections .debug_frame
#endif
.globl _C_LABEL(_rtld_relocate_nonplt_self)
.globl _C_LABEL(_rtld)
#define PTR_SIZE (1<<PTR_SCALESHIFT)
/*
* a0 stack pointer
* a1 rtld cleanup (filled in by dynamic loader)
* a2 rtld object (filled in by dynamic loader)
* a3 ps_strings
*/
NESTED(rtld_start, 4*PTR_SIZE, ra)
.mask 0x10090000,-PTR_SIZE
.set noreorder
SETUP_GP
PTR_SUBU sp, 4*PTR_SIZE /* adjust stack pointer */
SETUP_GP64(s4, rtld_start)
SAVE_GP(0)
/* -> 1*PTR_SIZE(sp) for atexit */
/* -> 2*PTR_SIZE(sp) for obj_main */
move s0, a0 /* save stack pointer from a0 */
move s3, a3 /* save ps_strings pointer */
PTR_LA a1, 1f
bal 1f
PTR_LA t0, _C_LABEL(_rtld_relocate_nonplt_self)
1: PTR_SUBU a1, ra, a1 /* relocbase */
PTR_LA a0, _DYNAMIC
PTR_ADDU t9, a1, t0
jalr t9 /* _rtld_relocate_nonplt_self(dynp, relocabase) */
PTR_ADDU a0, a1, a0 /* &_DYNAMIC */
move a0, s0 /* sp */
PTR_ADDU a1, sp, 2*PTR_SIZE /* &our atexit function */
PTR_ADDU a2, sp, 3*PTR_SIZE /* obj_main entry */
PTR_SUBU sp, 4*SZREG /* ABI requires to reserve memory for 4 regs */
PTR_LA t9, _C_LABEL(_rtld)
jalr t9 /* v0 = _rtld(sp, cleanup, objp) */
nop
PTR_ADDU sp, 4*SZREG
PTR_L a1, 2*PTR_SIZE(sp) /* our atexit function */
PTR_L a2, 3*PTR_SIZE(sp) /* obj_main entry */
PTR_ADDU sp, 4*PTR_SIZE /* readjust stack */
move a0, s0 /* stack pointer */
move t9, v0
PTR_SUBU sp, 4*SZREG /* ABI requires to reserve memory for 4 regs */
move ra,t9 /* RA == PC signals backtrace routine to stop */
j t9 /* _start(sp, cleanup, obj); */
move a3, s3 /* restore ps_strings */
END(rtld_start)
#define XCALLFRAME_SIZ (12*SZREG)
#define XCALLFRAME_RA (10*SZREG)
#define XCALLFRAME_GP (9*SZREG)
#define XCALLFRAME_S0 (8*SZREG)
#define XCALLFRAME_A3 (7*SZREG)
#define XCALLFRAME_A2 (6*SZREG)
#define XCALLFRAME_A1 (5*SZREG)
#define XCALLFRAME_A0 (4*SZREG)
#if defined(__mips_n32) || defined(__mips_n64)
#define XCALLFRAME_A7 (3*SZREG)
#define XCALLFRAME_A6 (2*SZREG)
#define XCALLFRAME_A5 (1*SZREG)
#define XCALLFRAME_A4 (0*SZREG)
#endif
/*
* Trampoline for "old" PLT stubs which use .got entries.
*/
.globl _rtld_bind_start
.ent _rtld_bind_start
_rtld_bind_start:
.frame sp, XCALLFRAME_SIZ, $15
.cfi_startproc simple
.cfi_def_cfa sp, 0
.cfi_register ra, $15
move v1, gp /* save old GP */
#if defined(__mips_o32) || defined(__mips_o64)
PTR_ADDU t9, 8 /* modify T9 to point at .cpload */
#endif
SETUP_GP
PTR_SUBU sp, XCALLFRAME_SIZ /* save arguments and sp value in stack */
.cfi_def_cfa_offset XCALLFRAME_SIZ
SETUP_GP64(XCALLFRAME_GP, _rtld_bind_start)
SAVE_GP(XCALLFRAME_GP)
#if defined(__mips_n32) || defined(__mips_n64)
REG_S a4, XCALLFRAME_A4(sp)
.cfi_rel_offset a4, XCALLFRAME_A4
REG_S a5, XCALLFRAME_A5(sp)
.cfi_rel_offset a5, XCALLFRAME_A5
REG_S a6, XCALLFRAME_A6(sp)
.cfi_rel_offset a6, XCALLFRAME_A6
REG_S a7, XCALLFRAME_A7(sp)
.cfi_rel_offset a7, XCALLFRAME_A7
#endif
REG_S a0, XCALLFRAME_A0(sp)
.cfi_rel_offset a0, XCALLFRAME_A0
REG_S a1, XCALLFRAME_A1(sp)
.cfi_rel_offset a1, XCALLFRAME_A1
REG_S a2, XCALLFRAME_A2(sp)
.cfi_rel_offset a2, XCALLFRAME_A2
REG_S a3, XCALLFRAME_A3(sp)
.cfi_rel_offset a3, XCALLFRAME_A3
REG_S $15, XCALLFRAME_RA(sp) /* ra is in t7/t3 */
.cfi_rel_offset ra, XCALLFRAME_RA
REG_S s0, XCALLFRAME_S0(sp)
.cfi_rel_offset s0, XCALLFRAME_S0
move s0, sp
move a0, v1 /* old GP */
PTR_SUBU a0, a0, 0x7ff0 /* The offset of $gp from the */
/* beginning of the .got section: */
/* $gp = .got + 0x7ff0, so */
/* .got = $gp - 0x7ff0 */
/* Simple math as you can see. */
#if defined(__mips_n64)
ld a0, 8(a0) /* object = pltgot[1] */
and a0, a0, 0x7fffffffffffffff
#else
lw a0, 4(a0) /* object = pltgot[1] & 0x7fffffff */
and a0, a0, 0x7fffffff
#endif
move a1, t8 /* symbol index */
PTR_LA t9, _C_LABEL(_mips_rtld_bind)
jalr t9
nop
move sp, s0
REG_L ra, XCALLFRAME_RA(sp)
.cfi_restore ra
REG_L s0, XCALLFRAME_S0(sp)
.cfi_restore s0
REG_L a0, XCALLFRAME_A0(sp)
.cfi_restore a0
REG_L a1, XCALLFRAME_A1(sp)
.cfi_restore a1
REG_L a2, XCALLFRAME_A2(sp)
.cfi_restore a2
REG_L a3, XCALLFRAME_A3(sp)
.cfi_restore a3
#if defined(__mips_n32) || defined(__mips_n64)
REG_L a4, XCALLFRAME_A4(sp)
.cfi_restore a4
REG_L a5, XCALLFRAME_A5(sp)
.cfi_restore a5
REG_L a6, XCALLFRAME_A6(sp)
.cfi_restore a6
REG_L a7, XCALLFRAME_A7(sp)
.cfi_restore a7
#endif
RESTORE_GP64
PTR_ADDU sp, XCALLFRAME_SIZ
move t9, v0
jr t9
nop
.cfi_endproc
END(_rtld_bind_start)
/*
* Trampoline for PLT stubs using .pltrel entries and .got.plt.
*/
.globl _rtld_pltbind_start
.ent _rtld_pltbind_start
_rtld_pltbind_start:
.frame sp, XCALLFRAME_SIZ, $15
.cfi_startproc simple
.cfi_def_cfa sp, 0
.cfi_register ra, $15
#if defined(__mips_o32)
move v1, gp /* save pointer to .got.plt */
#else
move v1, t2 /* save pointer to .got.plt */
#endif
#if defined(__mips_o32) || defined(__mips_o64)
PTR_ADDU t9, 8 /* modify T9 to point at .cpload */
#endif
SETUP_GP
PTR_SUBU sp, XCALLFRAME_SIZ /* save arguments and sp value in stack */
.cfi_def_cfa_offset XCALLFRAME_SIZ
SETUP_GP64(XCALLFRAME_GP, _rtld_pltbind_start)
SAVE_GP(XCALLFRAME_GP)
#if defined(__mips_n32) || defined(__mips_n64)
REG_S a4, XCALLFRAME_A4(sp)
.cfi_rel_offset a4, XCALLFRAME_A4
REG_S a5, XCALLFRAME_A5(sp)
.cfi_rel_offset a5, XCALLFRAME_A5
REG_S a6, XCALLFRAME_A6(sp)
.cfi_rel_offset a6, XCALLFRAME_A6
REG_S a7, XCALLFRAME_A7(sp)
.cfi_rel_offset a7, XCALLFRAME_A7
#endif
REG_S a0, XCALLFRAME_A0(sp)
.cfi_rel_offset a0, XCALLFRAME_A0
REG_S a1, XCALLFRAME_A1(sp)
.cfi_rel_offset a1, XCALLFRAME_A1
REG_S a2, XCALLFRAME_A2(sp)
.cfi_rel_offset a2, XCALLFRAME_A2
REG_S a3, XCALLFRAME_A3(sp)
.cfi_rel_offset a3, XCALLFRAME_A3
REG_S $15, XCALLFRAME_RA(sp) /* ra is in t7/t3 */
.cfi_rel_offset ra, XCALLFRAME_RA
REG_S s0, XCALLFRAME_S0(sp)
.cfi_rel_offset s0, XCALLFRAME_S0
move s0, sp
move a0, v1 /* .got.plt */
#if defined(__mips_n64)
ld a0, 8(a0) /* object = .got.plt[1] */
sll a1, t8, 4 /* PLT entry index to .rel.plt offset */
#else
lw a0, 4(a0) /* object = .got.plt[1] */
sll a1, t8, 3 /* PLT entry index to .rel.plt offset */
#endif
PTR_LA t9, _C_LABEL(_rtld_bind)
jalr t9
nop
move sp, s0
REG_L ra, XCALLFRAME_RA(sp)
.cfi_restore ra
REG_L s0, XCALLFRAME_S0(sp)
.cfi_restore s0
REG_L a0, XCALLFRAME_A0(sp)
.cfi_restore a0
REG_L a1, XCALLFRAME_A1(sp)
.cfi_restore a1
REG_L a2, XCALLFRAME_A2(sp)
.cfi_restore a2
REG_L a3, XCALLFRAME_A3(sp)
.cfi_restore a3
#if defined(__mips_n32) || defined(__mips_n64)
REG_L a4, XCALLFRAME_A4(sp)
.cfi_restore a4
REG_L a5, XCALLFRAME_A5(sp)
.cfi_restore a5
REG_L a6, XCALLFRAME_A6(sp)
.cfi_restore a6
REG_L a7, XCALLFRAME_A7(sp)
.cfi_restore a7
#endif
RESTORE_GP64
PTR_ADDU sp, XCALLFRAME_SIZ
move t9, v0
jr t9
nop
.cfi_endproc
END(_rtld_pltbind_start)