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6cb2d4d94b
Figure out the number of stack parameters and make sure that the value on the stack after those is untouched. Signed-off-by: Martin Storsjö <martin@martin.st>
198 lines
6.0 KiB
ArmAsm
198 lines
6.0 KiB
ArmAsm
/****************************************************************************
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* Assembly testing and benchmarking tool
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* Copyright (c) 2015 Martin Storsjo
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* Copyright (c) 2015 Janne Grunau
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA.
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*****************************************************************************/
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#include "libavutil/arm/asm.S"
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/* override fpu so that NEON instructions are rejected */
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#if HAVE_VFP
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FPU .fpu vfp
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ELF .eabi_attribute 10, 0 @ suppress Tag_FP_arch
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#endif
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const register_init, align=3
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.quad 0x21f86d66c8ca00ce
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.quad 0x75b6ba21077c48ad
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.quad 0xed56bb2dcb3c7736
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.quad 0x8bda43d3fd1a7e06
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.quad 0xb64a9c9e5d318408
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.quad 0xdf9a54b303f1d3a3
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.quad 0x4a75479abd64e097
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.quad 0x249214109d5d1c88
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endconst
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const error_message_fpscr
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.asciz "failed to preserve register FPSCR, changed bits: %x"
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error_message_gpr:
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.asciz "failed to preserve register r%d"
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error_message_vfp:
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.asciz "failed to preserve register d%d"
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error_message_stack:
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.asciz "failed to preserve stack"
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endconst
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@ max number of args used by any asm function.
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#define MAX_ARGS 15
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#define ARG_STACK 4*(MAX_ARGS - 4)
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@ Align the used stack space to 8 to preserve the stack alignment.
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@ +8 for stack canary reference.
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#define ARG_STACK_A (((ARG_STACK + pushed + 7) & ~7) - pushed + 8)
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.macro clobbercheck variant
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.equ pushed, 4*9
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function checkasm_checked_call_\variant, export=1
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push {r4-r11, lr}
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.ifc \variant, vfp
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vpush {d8-d15}
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fmrx r4, FPSCR
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push {r4}
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.equ pushed, pushed + 16*4 + 4
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.endif
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movrel r12, register_init
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.ifc \variant, vfp
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vldm r12, {d8-d15}
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.endif
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ldm r12, {r4-r11}
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sub sp, sp, #ARG_STACK_A
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.equ pos, 0
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.rept MAX_ARGS-4
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ldr r12, [sp, #ARG_STACK_A + pushed + 8 + pos]
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str r12, [sp, #pos]
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.equ pos, pos + 4
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.endr
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@ For stack overflows, the callee is free to overwrite the parameters
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@ that were passed on the stack (if any), so we can only check after
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@ that point. First figure out how many parameters the function
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@ really took on the stack:
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ldr r12, [sp, #ARG_STACK_A + pushed + 8 + 4*(MAX_ARGS-4)]
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@ Load the first non-parameter value from the stack, that should be
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@ left untouched by the function. Store a copy of it inverted, so that
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@ e.g. overwriting everything with zero would be noticed.
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ldr r12, [sp, r12, lsl #2]
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mvn r12, r12
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str r12, [sp, #ARG_STACK_A - 4]
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mov r12, r0
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mov r0, r2
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mov r1, r3
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ldrd r2, r3, [sp, #ARG_STACK_A + pushed]
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@ Call the target function
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blx r12
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@ Load the number of stack parameters, stack canary and its reference
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ldr r12, [sp, #ARG_STACK_A + pushed + 8 + 4*(MAX_ARGS-4)]
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ldr r2, [sp, r12, lsl #2]
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ldr r3, [sp, #ARG_STACK_A - 4]
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add sp, sp, #ARG_STACK_A
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push {r0, r1}
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mvn r3, r3
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cmp r2, r3
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bne 5f
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movrel r12, register_init
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.ifc \variant, vfp
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.macro check_reg_vfp, dreg, offset
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ldrd r2, r3, [r12, #8 * (\offset)]
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vmov r0, lr, \dreg
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eor r2, r2, r0
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eor r3, r3, lr
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orrs r2, r2, r3
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bne 4f
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.endm
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.irp n, 8, 9, 10, 11, 12, 13, 14, 15
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@ keep track of the checked double/SIMD register
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mov r1, #\n
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check_reg_vfp d\n, \n-8
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.endr
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.purgem check_reg_vfp
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fmrx r1, FPSCR
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ldr r3, [sp, #8]
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eor r1, r1, r3
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@ Ignore changes in bits 0-4 and 7
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bic r1, r1, #0x9f
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@ Ignore changes in the topmost 5 bits
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bics r1, r1, #0xf8000000
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bne 3f
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.endif
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@ keep track of the checked GPR
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mov r1, #4
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.macro check_reg reg1, reg2=
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ldrd r2, r3, [r12], #8
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eors r2, r2, \reg1
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bne 2f
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add r1, r1, #1
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.ifnb \reg2
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eors r3, r3, \reg2
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bne 2f
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.endif
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add r1, r1, #1
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.endm
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check_reg r4, r5
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check_reg r6, r7
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@ r9 is a volatile register in the ios ABI
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#ifdef __APPLE__
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check_reg r8
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#else
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check_reg r8, r9
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#endif
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check_reg r10, r11
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.purgem check_reg
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b 0f
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5:
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movrel r0, error_message_stack
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b 1f
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4:
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movrel r0, error_message_vfp
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b 1f
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3:
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movrel r0, error_message_fpscr
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b 1f
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2:
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movrel r0, error_message_gpr
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1:
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bl X(checkasm_fail_func)
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0:
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pop {r0, r1}
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.ifc \variant, vfp
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pop {r2}
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fmxr FPSCR, r2
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vpop {d8-d15}
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.endif
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pop {r4-r11, pc}
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endfunc
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.endm
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#if HAVE_VFP || HAVE_NEON
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clobbercheck vfp
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#endif
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clobbercheck novfp
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