glibc/sysdeps/s390/s390-32/dl-trampoline.S
2013-02-21 09:47:55 +01:00

146 lines
4.4 KiB
ArmAsm

/* PLT trampolines. s390 version.
Copyright (C) 2005-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
/* This code is used in dl-runtime.c to call the `fixup' function
and then redirect to the address it returns. */
/* The PLT stubs will call _dl_runtime_resolve/_dl_runtime_profile
* with the following linkage:
* r2 - r6 : parameter registers
* f0, f2 : floating point parameter registers
* 24(r15), 28(r15) : PLT arguments PLT1, PLT2
* 96(r15) : additional stack parameters
* The normal clobber rules for function calls apply:
* r0 - r5 : call clobbered
* r6 - r13 : call saved
* r14 : return address (call clobbered)
* r15 : stack pointer (call saved)
* f4, f6 : call saved
* f0 - f3, f5, f7 - f15 : call clobbered
*/
#include <sysdep.h>
.text
.globl _dl_runtime_resolve
.type _dl_runtime_resolve, @function
cfi_startproc
.align 16
_dl_runtime_resolve:
stm %r2,%r5,32(%r15) # save registers
st %r14,8(%r15)
cfi_offset (r14, -88)
lr %r0,%r15 # create stack frame
ahi %r15,-96
cfi_adjust_cfa_offset (96)
st 0,0(%r15)
lm %r2,%r3,120(%r15) # load args saved by PLT
basr %r1,0
0: l %r14,1f-0b(%r1)
bas %r14,0(%r14,%r1) # call resolver
lr %r1,%r2 # function addr returned in r2
ahi %r15,96 # remove stack frame
cfi_adjust_cfa_offset (-96)
l %r14,8(15) # restore registers
lm %r2,%r5,32(%r15)
br %r1
1: .long _dl_fixup - 0b
cfi_endproc
.size _dl_runtime_resolve, .-_dl_runtime_resolve
#ifndef PROF
.globl _dl_runtime_profile
.type _dl_runtime_profile, @function
cfi_startproc
.align 16
_dl_runtime_profile:
stm %r2,%r6,32(%r15) # save registers
std %f0,56(%r15)
std %f2,64(%r15)
st %r6,8(%r15)
st %r12,12(%r15)
st %r14,16(%r15)
cfi_offset (r6, -64)
cfi_offset (f0, -40)
cfi_offset (f2, -32)
cfi_offset (r12, -84)
cfi_offset (r14, -80)
lr %r12,%r15 # create stack frame
cfi_def_cfa_register (12)
ahi %r15,-96
st %r12,0(%r15)
lm %r2,%r3,24(%r12) # load arguments saved by PLT
lr %r4,%r14 # return address as third parameter
basr %r1,0
0: l %r14,6f-0b(%r1)
la %r5,32(%r12) # pointer to struct La_s390_32_regs
la %r6,20(%r12) # long int * framesize
bas %r14,0(%r14,%r1) # call resolver
lr %r1,%r2 # function addr returned in r2
icm %r0,15,20(%r12) # load & test framesize
jnm 2f
lm %r2,%r6,32(%r12)
ld %f0,56(%r12)
ld %f2,64(%r12)
lr %r15,%r12 # remove stack frame
cfi_def_cfa_register (15)
l %r14,16(%r15) # restore registers
l %r12,12(%r15)
br %r1 # tail-call to the resolved function
cfi_def_cfa_register (12)
2: jz 4f # framesize == 0 ?
ahi %r0,7 # align framesize to 8
lhi %r2,-8
nr %r0,%r2
slr %r15,%r0 # make room for framesize bytes
st %r12,0(%r15)
la %r2,96(%r15)
la %r3,96(%r12)
srl %r0,3
3: mvc 0(8,%r2),0(%r3) # copy additional parameters
la %r2,8(%r2)
la %r3,8(%r3)
brct %r0,3b
4: lm %r2,%r6,32(%r12) # load register parameters
ld %f0,56(%r12)
ld %f2,64(%r12)
basr %r14,%r1 # call resolved function
stm %r2,%r3,72(%r12)
std %f0,80(%r12)
lm %r2,%r3,24(%r12) # load arguments saved by PLT
basr %r1,0
5: l %r14,7f-5b(%r1)
la %r4,32(%r12) # pointer to struct La_s390_32_regs
la %r5,72(%r12) # pointer to struct La_s390_32_retval
basr %r14,%r1 # call _dl_call_pltexit
lr %r15,%r12 # remove stack frame
cfi_def_cfa_register (15)
l %r14,16(%r15) # restore registers
l %r12,12(%r15)
br %r14
6: .long _dl_profile_fixup - 0b
7: .long _dl_call_pltexit - 5b
cfi_endproc
.size _dl_runtime_profile, .-_dl_runtime_profile
#endif