Commit 26ec75ae authored by Martin Storsjö's avatar Martin Storsjö

checkasm: Check register clobbering on arm

Use two separate functions, depending on whether VFP/NEON is available.

This is set to require armv5te - it uses blx, which is only available
since armv5t, but we don't have a separate configure item for that.
(It also uses ldrd, which requires armv5te, but this could be avoided
if necessary.)
Signed-off-by: 's avatarMartin Storsjö <martin@martin.st>
parent fa463aa8
CHECKASMOBJS-$(HAVE_ARMV5TE_EXTERNAL) += arm/checkasm.o
/****************************************************************************
* Assembly testing and benchmarking tool
* Copyright (c) 2015 Martin Storsjo
* Copyright (c) 2015 Janne Grunau
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Libav 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA.
*****************************************************************************/
#include "libavutil/arm/asm.S"
const register_init
.quad 0x21f86d66c8ca00ce
.quad 0x75b6ba21077c48ad
.quad 0xed56bb2dcb3c7736
.quad 0x8bda43d3fd1a7e06
.quad 0xb64a9c9e5d318408
.quad 0xdf9a54b303f1d3a3
.quad 0x4a75479abd64e097
.quad 0x249214109d5d1c88
endconst
const error_message
.asciz "failed to preserve register"
endconst
@ max number of args used by any asm function.
#define MAX_ARGS 15
#define ARG_STACK 4*(MAX_ARGS - 2)
.macro clobbercheck variant
.equ pushed, 4*9
function checkasm_checked_call_\variant, export=1
push {r4-r11, lr}
.ifc \variant, vfp
vpush {d8-d15}
fmrx r4, FPSCR
push {r4}
.equ pushed, pushed + 16*4 + 4
.endif
movrel r12, register_init
.ifc \variant, vfp
vldm r12, {d8-d15}
.endif
ldm r12, {r4-r11}
sub sp, sp, #ARG_STACK
.equ pos, 0
.rept MAX_ARGS-2
ldr r12, [sp, #ARG_STACK + pushed + 8 + pos]
str r12, [sp, #pos]
.equ pos, pos + 4
.endr
mov r12, r0
mov r0, r2
mov r1, r3
ldrd r2, r3, [sp, #ARG_STACK + pushed]
blx r12
add sp, sp, #ARG_STACK
push {r0, r1}
movrel r12, register_init
mov r3, #0
.ifc \variant, vfp
.macro check_reg_vfp, dreg, inc=8
ldrd r0, r1, [r12], #\inc
vmov r2, lr, \dreg
eor r0, r0, r2
eor r1, r1, lr
orr r3, r3, r0
orr r3, r3, r1
.endm
.irp n, 8, 9, 10, 11, 12, 13, 14
check_reg_vfp d\n
.endr
check_reg_vfp d15, -56
.purgem check_reg_vfp
fmrx r0, FPSCR
ldr r1, [sp, #8]
eor r0, r0, r1
@ Ignore changes in the topmost 5 bits
lsl r0, r0, #5
orr r3, r3, r0
.endif
.macro check_reg reg1, reg2=
ldrd r0, r1, [r12], #8
eor r0, r0, \reg1
orrs r3, r3, r0
.ifnb \reg2
eor r1, r1, \reg2
orrs r3, r3, r1
.endif
.endm
check_reg r4, r5
check_reg r6, r7
@ r9 is a volatile register in the ios ABI
#ifdef __APPLE__
check_reg r8
#else
check_reg r8, r9
#endif
check_reg r10, r11
.purgem check_reg
beq 0f
movrel r0, error_message
blx X(checkasm_fail_func)
0:
pop {r0, r1}
.ifc \variant, vfp
pop {r2}
fmxr FPSCR, r2
vpop {d8-d15}
.endif
pop {r4-r11, pc}
endfunc
.endm
#if HAVE_VFP || HAVE_NEON
clobbercheck vfp
#endif
clobbercheck novfp
......@@ -53,6 +53,12 @@
#define isatty(fd) 1
#endif
#if ARCH_ARM && HAVE_ARMV5TE_EXTERNAL
#include "libavutil/arm/cpu.h"
void (*checkasm_checked_call)(void *func, int dummy, ...) = checkasm_checked_call_novfp;
#endif
/* List of tests to invoke */
static const struct {
const char *name;
......@@ -463,6 +469,11 @@ int main(int argc, char *argv[])
{
int i, seed, ret = 0;
#if ARCH_ARM && HAVE_ARMV5TE_EXTERNAL
if (have_vfp(av_get_cpu_flags()) || have_neon(av_get_cpu_flags()))
checkasm_checked_call = checkasm_checked_call_vfp;
#endif
if (!tests[0].func || !cpus[0].flag) {
fprintf(stderr, "checkasm: no tests to perform\n");
return 0;
......
......@@ -116,6 +116,15 @@ void checkasm_stack_clobber(uint64_t clobber, ...);
(void *)checkasm_checked_call;
#define call_new(...) checked_call(func_new, __VA_ARGS__)
#endif
#elif ARCH_ARM && HAVE_ARMV5TE_EXTERNAL
/* Use a dummy argument, to offset the real parameters by 2, not only 1.
* This makes sure that potential 8-byte-alignment of parameters is kept the same
* even when the extra parameters have been removed. */
void checkasm_checked_call_vfp(void *func, int dummy, ...);
void checkasm_checked_call_novfp(void *func, int dummy, ...);
extern void (*checkasm_checked_call)(void *func, int dummy, ...);
#define declare_new(ret, ...) ret (*checked_call)(void *, int dummy, __VA_ARGS__) = (void *)checkasm_checked_call;
#define call_new(...) checked_call(func_new, 0, __VA_ARGS__)
#else
#define declare_new(ret, ...)
#define declare_new_emms(cpu_flags, ret, ...)
......@@ -123,6 +132,10 @@ void checkasm_stack_clobber(uint64_t clobber, ...);
#define call_new(...) ((func_type *)func_new)(__VA_ARGS__)
#endif
#ifndef declare_new_emms
#define declare_new_emms(cpu_flags, ret, ...) declare_new(ret, __VA_ARGS__)
#endif
/* Benchmark the function */
#ifdef AV_READ_TIME
#define bench_new(...)\
......
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