glibc/sysdeps/s390/s390-32/dl-trampoline.h
Stefan Liebler dee943668f S390: Add CFI rule in _dl_runtime_resolve[_vx] for unwinding.
In _dl_runtime_resolve[_vx], unwinding fails after the new stack frame
is created as there is no CFI rule for r15. This is also observeable in
GDB: Backtrace stopped: previous frame inner to this frame (corrupt stack?)

Therefore this patch is now storing r15 on stack and is using cfi_offset rule.
The stmg/lmg instruction is used to store/load r14 and r15 with one instruction.
On 64bit, the offsets of the fprs have moved to store r15 directly after r14.
On 31bit, the r14/r15 is now stored between the other gprs and fprs as the space
wasn't used.

ChangeLog:

	* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_resolve):
	Store r15 on stack and add cfi rule.
	* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_resolve):
	Likewise.
2017-12-11 08:47:51 +01:00

231 lines
6.9 KiB
C

/* PLT trampolines. s390 version.
Copyright (C) 2016-2017 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
* v24, v26, v28, v30, v25, v27, v29, v31 : vector 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
* v0 - v3, v5, v7 - v15 : bytes 0-7 overlap with fprs: call clobbered
bytes 8-15: call clobbered
* v4, v6 : bytes 0-7 overlap with f4, f6: call saved
bytes 8-15: call clobbered
* v16 - v31 : call clobbered
*/
.globl _dl_runtime_resolve
.type _dl_runtime_resolve, @function
cfi_startproc
.align 16
_dl_runtime_resolve:
stm %r2,%r5,32(%r15) # save registers
cfi_offset (r2, -64)
cfi_offset (r3, -60)
cfi_offset (r4, -56)
cfi_offset (r5, -52)
stm %r14,%r15,48(%r15)
cfi_offset (r14, -48)
cfi_offset (r15, -44)
std %f0,56(%r15)
cfi_offset (f0, -40)
std %f2,64(%r15)
cfi_offset (f2, -32)
lr %r0,%r15
lm %r2,%r3,24(%r15) # load args saved by PLT
#ifdef RESTORE_VRS
ahi %r15,-224 # create stack frame
cfi_adjust_cfa_offset (224)
.machine push
.machine "z13"
.machinemode "zarch_nohighgprs"
vstm %v24,%v31,96(%r15) # store call-clobbered vr arguments
cfi_offset (v24, -224)
cfi_offset (v25, -208)
cfi_offset (v26, -192)
cfi_offset (v27, -176)
cfi_offset (v28, -160)
cfi_offset (v29, -144)
cfi_offset (v30, -128)
cfi_offset (v31, -112)
.machine pop
#else
ahi %r15,-96 # create stack frame
cfi_adjust_cfa_offset (96)
#endif
st %r0,0(%r15) # write backchain
basr %r1,0
0: l %r14,1f-0b(%r1)
bas %r14,0(%r14,%r1) # call _dl_fixup
lr %r1,%r2 # function addr returned in r2
#ifdef RESTORE_VRS
.machine push
.machine "z13"
.machinemode "zarch_nohighgprs"
vlm %v24,%v31,96(%r15) # restore vector registers
.machine pop
lm %r14,%r15,272(%r15)# remove stack frame and restore registers
#else
lm %r14,%r15,144(%r15)# remove stack frame and restore registers
#endif
cfi_def_cfa_offset (96)
ld %f0,56(%r15)
ld %f2,64(%r15)
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:
st %r12,12(%r15) # r12 is used as backup of r15
cfi_offset (r12, -84)
st %r14,16(%r15)
cfi_offset (r14, -80)
lr %r12,%r15 # backup stack pointer
cfi_def_cfa_register (12)
ahi %r15,-264 # create stack frame:
# 96 + sizeof(La_s390_32_regs)
st %r12,0(%r15) # save backchain
stm %r2,%r6,96(%r15) # save registers
cfi_offset (r2, -264) # + r6 needed as arg for
cfi_offset (r3, -260) # _dl_profile_fixup
cfi_offset (r4, -256)
cfi_offset (r5, -252)
cfi_offset (r6, -248)
std %f0,120(%r15)
cfi_offset (f0, -240)
std %f2,128(%r15)
cfi_offset (f2, -232)
#ifdef RESTORE_VRS
.machine push
.machine "z13"
.machinemode "zarch_nohighgprs"
vstm %v24,%v31,136(%r15) # store call-clobbered vr arguments
cfi_offset (v24, -224)
cfi_offset (v25, -208)
cfi_offset (v26, -192)
cfi_offset (v27, -176)
cfi_offset (v28, -160)
cfi_offset (v29, -144)
cfi_offset (v30, -128)
cfi_offset (v31, -112)
.machine pop
#endif
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 %r5,96(%r15) # 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
ld %f0,120(%r15) # restore call-clobbered arg fprs
ld %f2,128(%r15)
#ifdef RESTORE_VRS
.machine push
.machine "z13"
.machinemode "zarch_nohighgprs"
vlm %v24,%v31,136(%r15) # restore call-clobbered arg vrs
.machine pop
#endif
icm %r0,15,20(%r12) # load & test framesize
jnm 2f
lm %r2,%r6,96(%r15) # framesize < 0 means no pltexit call
# so we can do a tail call without
# copying the arg overflow area
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: la %r4,96(%r15) # pointer to struct La_s390_32_regs
st %r4,32(%r12)
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) # save backchain
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,%r6,0(%r4) # load register parameters
basr %r14,%r1 # call resolved function
stm %r2,%r3,40(%r12) # store return values r2, r3, f0
std %f0,48(%r12) # to struct La_s390_32_retval
#ifdef RESTORE_VRS
.machine push
.machine "z13"
vst %v24,56(%r12) # store return value v24
.machine pop
#endif
lm %r2,%r4,24(%r12) # r2, r3: load arguments saved by PLT
# r4: pointer to struct La_s390_32_regs
basr %r1,0
5: l %r14,7f-5b(%r1)
la %r5,40(%r12) # pointer to struct La_s390_32_retval
bas %r14,0(%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)
lm %r2,%r3,40(%r15) # restore return values
ld %f0,48(%r15)
#ifdef RESTORE_VRS
.machine push
.machine "z13"
vl %v24,56(%r15) # restore return value v24
.machine pop
#endif
br %r14
6: .long _dl_profile_fixup - 0b
7: .long _dl_call_pltexit - 5b
cfi_endproc
.size _dl_runtime_profile, .-_dl_runtime_profile
#endif