glibc/sysdeps/s390/s390-64/dl-trampoline.S
2013-02-18 10:29:40 +01:00

142 lines
4.5 KiB
ArmAsm

/* PLT trampolines. s390x 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/>. */
/* The PLT stubs will call _dl_runtime_resolve/_dl_runtime_profile
* with the following linkage:
* r2 - r6 : parameter registers
* f0, f2, f4, f6 : floating point parameter registers
* 48(r15), 56(r15) : PLT arguments PLT1, PLT2
* 160(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)
* f1, f3, f5, f7 : 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:
stmg %r2,%r5,64(15) # save call-clobbered argument registers
stg %r14,96(15)
cfi_offset (r14, -64)
lgr %r0,%r15
aghi %r15,-160 # create stack frame
cfi_adjust_cfa_offset (160)
stg %r0,0(%r15) # write backchain
lmg %r2,%r3,208(%r15)# load args saved by PLT
brasl %r14,_dl_fixup # call fixup
lgr %r1,%r2 # function addr returned in r2
aghi %r15,160 # remove stack frame
cfi_adjust_cfa_offset (-160)
lg %r14,96(15) # restore registers
lmg %r2,%r5,64(15)
br %r1
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:
stmg %r2,%r6,64(%r15) # save call-clobbered arg regs
std %f0,104(%r15) # + r6 needed as arg for
std %f2,112(%r15) # _dl_profile_fixup
std %f4,120(%r15)
std %f6,128(%r15)
stg %r12,24(%r15) # r12 is used as backup of r15
stg %r14,32(%r15)
cfi_offset (r6, -96)
cfi_offset (f0, -56)
cfi_offset (f2, -48)
cfi_offset (f4, -40)
cfi_offset (f6, -32)
cfi_offset (r12, -136)
cfi_offset (r14, -128)
lgr %r12,%r15 # backup stack pointer
cfi_def_cfa_register (12)
aghi %r15,-160 # create stack frame
stg %r12,0(%r15) # save backchain
lmg %r2,%r3,48(%r12) # load arguments saved by PLT
lgr %r4,%r14 # return address as third parameter
la %r5,64(%r12) # pointer to struct La_s390_32_regs
la %r6,40(%r12) # long int * framesize
brasl %r14,_dl_profile_fixup # call resolver
lgr %r1,%r2 # function addr returned in r2
lg %r0,40(%r12) # load framesize
ltgr %r0,%r0
jnm 1f
lmg %r2,%r6,64(%r12) # framesize < 0 means no pltexit call
ld %f0,104(%r12) # so we can do a tail call without
ld %f2,112(%r12) # copying the arg overflow area
ld %f4,120(%r12)
ld %f6,128(%r12)
lgr %r15,%r12 # remove stack frame
cfi_def_cfa_register (15)
lg %r14,32(%r15) # restore registers
lg %r12,24(%r15)
br %r1 # tail-call to resolved function
cfi_def_cfa_register (12)
1: jz 4f # framesize == 0 ?
aghi %r0,7 # align framesize to 8
nill %r0,0xfff8
slgr %r15,%r0 # make room for framesize bytes
stg %r12,0(%r15)
la %r2,160(%r15)
la %r3,160(%r12)
srlg %r0,%r0,3
3: mvc 0(8,%r2),0(%r3) # copy additional parameters
la %r2,8(%r2)
la %r3,8(%r3)
brctg %r0,3b
4: lmg %r2,%r6,64(%r12) # load register parameters
ld %f0,104(%r12) # restore call-clobbered arg regs
ld %f2,112(%r12)
ld %f4,120(%r12)
ld %f6,128(%r12)
basr %r14,%r1 # call resolved function
stg %r2,136(%r12)
std %f0,144(%r12)
lmg %r2,%r3,48(%r12) # load arguments saved by PLT
la %r4,32(%r12) # pointer to struct La_s390_32_regs
la %r5,72(%r12) # pointer to struct La_s390_32_retval
brasl %r14,_dl_call_pltexit
lgr %r15,%r12 # remove stack frame
cfi_def_cfa_register (15)
lg %r14,32(%r15) # restore registers
lg %r12,24(%r15)
br %r14
cfi_endproc
.size _dl_runtime_profile, .-_dl_runtime_profile
#endif