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/*
* Copyright (C) 2013-2015 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#if ENABLE(ASSEMBLER) && CPU(ARM_THUMB2)
#include "MacroAssemblerARMv7.h"
#include <wtf/InlineASM.h>
namespace JSC {
#if ENABLE(MASM_PROBE)
extern "C" void ctiMasmProbeTrampoline();
#if COMPILER(GCC_OR_CLANG)
// The following are offsets for MacroAssemblerARMv7::ProbeContext fields accessed
// by the ctiMasmProbeTrampoline stub.
#define PTR_SIZE 4
#define PROBE_PROBE_FUNCTION_OFFSET (0 * PTR_SIZE)
#define PROBE_ARG1_OFFSET (1 * PTR_SIZE)
#define PROBE_ARG2_OFFSET (2 * PTR_SIZE)
#define PROBE_FIRST_GPREG_OFFSET (3 * PTR_SIZE)
#define GPREG_SIZE 4
#define PROBE_CPU_R0_OFFSET (PROBE_FIRST_GPREG_OFFSET + (0 * GPREG_SIZE))
#define PROBE_CPU_R1_OFFSET (PROBE_FIRST_GPREG_OFFSET + (1 * GPREG_SIZE))
#define PROBE_CPU_R2_OFFSET (PROBE_FIRST_GPREG_OFFSET + (2 * GPREG_SIZE))
#define PROBE_CPU_R3_OFFSET (PROBE_FIRST_GPREG_OFFSET + (3 * GPREG_SIZE))
#define PROBE_CPU_R4_OFFSET (PROBE_FIRST_GPREG_OFFSET + (4 * GPREG_SIZE))
#define PROBE_CPU_R5_OFFSET (PROBE_FIRST_GPREG_OFFSET + (5 * GPREG_SIZE))
#define PROBE_CPU_R6_OFFSET (PROBE_FIRST_GPREG_OFFSET + (6 * GPREG_SIZE))
#define PROBE_CPU_R7_OFFSET (PROBE_FIRST_GPREG_OFFSET + (7 * GPREG_SIZE))
#define PROBE_CPU_R8_OFFSET (PROBE_FIRST_GPREG_OFFSET + (8 * GPREG_SIZE))
#define PROBE_CPU_R9_OFFSET (PROBE_FIRST_GPREG_OFFSET + (9 * GPREG_SIZE))
#define PROBE_CPU_R10_OFFSET (PROBE_FIRST_GPREG_OFFSET + (10 * GPREG_SIZE))
#define PROBE_CPU_R11_OFFSET (PROBE_FIRST_GPREG_OFFSET + (11 * GPREG_SIZE))
#define PROBE_CPU_IP_OFFSET (PROBE_FIRST_GPREG_OFFSET + (12 * GPREG_SIZE))
#define PROBE_CPU_SP_OFFSET (PROBE_FIRST_GPREG_OFFSET + (13 * GPREG_SIZE))
#define PROBE_CPU_LR_OFFSET (PROBE_FIRST_GPREG_OFFSET + (14 * GPREG_SIZE))
#define PROBE_CPU_PC_OFFSET (PROBE_FIRST_GPREG_OFFSET + (15 * GPREG_SIZE))
#define PROBE_CPU_APSR_OFFSET (PROBE_FIRST_GPREG_OFFSET + (16 * GPREG_SIZE))
#define PROBE_CPU_FPSCR_OFFSET (PROBE_FIRST_GPREG_OFFSET + (17 * GPREG_SIZE))
#define PROBE_FIRST_FPREG_OFFSET (PROBE_FIRST_GPREG_OFFSET + (18 * GPREG_SIZE))
#define FPREG_SIZE 8
#define PROBE_CPU_D0_OFFSET (PROBE_FIRST_FPREG_OFFSET + (0 * FPREG_SIZE))
#define PROBE_CPU_D1_OFFSET (PROBE_FIRST_FPREG_OFFSET + (1 * FPREG_SIZE))
#define PROBE_CPU_D2_OFFSET (PROBE_FIRST_FPREG_OFFSET + (2 * FPREG_SIZE))
#define PROBE_CPU_D3_OFFSET (PROBE_FIRST_FPREG_OFFSET + (3 * FPREG_SIZE))
#define PROBE_CPU_D4_OFFSET (PROBE_FIRST_FPREG_OFFSET + (4 * FPREG_SIZE))
#define PROBE_CPU_D5_OFFSET (PROBE_FIRST_FPREG_OFFSET + (5 * FPREG_SIZE))
#define PROBE_CPU_D6_OFFSET (PROBE_FIRST_FPREG_OFFSET + (6 * FPREG_SIZE))
#define PROBE_CPU_D7_OFFSET (PROBE_FIRST_FPREG_OFFSET + (7 * FPREG_SIZE))
#define PROBE_CPU_D8_OFFSET (PROBE_FIRST_FPREG_OFFSET + (8 * FPREG_SIZE))
#define PROBE_CPU_D9_OFFSET (PROBE_FIRST_FPREG_OFFSET + (9 * FPREG_SIZE))
#define PROBE_CPU_D10_OFFSET (PROBE_FIRST_FPREG_OFFSET + (10 * FPREG_SIZE))
#define PROBE_CPU_D11_OFFSET (PROBE_FIRST_FPREG_OFFSET + (11 * FPREG_SIZE))
#define PROBE_CPU_D12_OFFSET (PROBE_FIRST_FPREG_OFFSET + (12 * FPREG_SIZE))
#define PROBE_CPU_D13_OFFSET (PROBE_FIRST_FPREG_OFFSET + (13 * FPREG_SIZE))
#define PROBE_CPU_D14_OFFSET (PROBE_FIRST_FPREG_OFFSET + (14 * FPREG_SIZE))
#define PROBE_CPU_D15_OFFSET (PROBE_FIRST_FPREG_OFFSET + (15 * FPREG_SIZE))
#define PROBE_CPU_D16_OFFSET (PROBE_FIRST_FPREG_OFFSET + (16 * FPREG_SIZE))
#define PROBE_CPU_D17_OFFSET (PROBE_FIRST_FPREG_OFFSET + (17 * FPREG_SIZE))
#define PROBE_CPU_D18_OFFSET (PROBE_FIRST_FPREG_OFFSET + (18 * FPREG_SIZE))
#define PROBE_CPU_D19_OFFSET (PROBE_FIRST_FPREG_OFFSET + (19 * FPREG_SIZE))
#define PROBE_CPU_D20_OFFSET (PROBE_FIRST_FPREG_OFFSET + (20 * FPREG_SIZE))
#define PROBE_CPU_D21_OFFSET (PROBE_FIRST_FPREG_OFFSET + (21 * FPREG_SIZE))
#define PROBE_CPU_D22_OFFSET (PROBE_FIRST_FPREG_OFFSET + (22 * FPREG_SIZE))
#define PROBE_CPU_D23_OFFSET (PROBE_FIRST_FPREG_OFFSET + (23 * FPREG_SIZE))
#define PROBE_CPU_D24_OFFSET (PROBE_FIRST_FPREG_OFFSET + (24 * FPREG_SIZE))
#define PROBE_CPU_D25_OFFSET (PROBE_FIRST_FPREG_OFFSET + (25 * FPREG_SIZE))
#define PROBE_CPU_D26_OFFSET (PROBE_FIRST_FPREG_OFFSET + (26 * FPREG_SIZE))
#define PROBE_CPU_D27_OFFSET (PROBE_FIRST_FPREG_OFFSET + (27 * FPREG_SIZE))
#define PROBE_CPU_D28_OFFSET (PROBE_FIRST_FPREG_OFFSET + (28 * FPREG_SIZE))
#define PROBE_CPU_D29_OFFSET (PROBE_FIRST_FPREG_OFFSET + (29 * FPREG_SIZE))
#define PROBE_CPU_D30_OFFSET (PROBE_FIRST_FPREG_OFFSET + (30 * FPREG_SIZE))
#define PROBE_CPU_D31_OFFSET (PROBE_FIRST_FPREG_OFFSET + (31 * FPREG_SIZE))
#define PROBE_SIZE (PROBE_FIRST_FPREG_OFFSET + (32 * FPREG_SIZE))
// These ASSERTs remind you that if you change the layout of ProbeContext,
// you need to change ctiMasmProbeTrampoline offsets above to match.
#define PROBE_OFFSETOF(x) offsetof(struct MacroAssemblerARMv7::ProbeContext, x)
COMPILE_ASSERT(PROBE_OFFSETOF(probeFunction) == PROBE_PROBE_FUNCTION_OFFSET, ProbeContext_probeFunction_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(arg1) == PROBE_ARG1_OFFSET, ProbeContext_arg1_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(arg2) == PROBE_ARG2_OFFSET, ProbeContext_arg2_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r0) == PROBE_CPU_R0_OFFSET, ProbeContext_cpu_r0_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r1) == PROBE_CPU_R1_OFFSET, ProbeContext_cpu_r1_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r2) == PROBE_CPU_R2_OFFSET, ProbeContext_cpu_r2_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r3) == PROBE_CPU_R3_OFFSET, ProbeContext_cpu_r3_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r4) == PROBE_CPU_R4_OFFSET, ProbeContext_cpu_r4_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r5) == PROBE_CPU_R5_OFFSET, ProbeContext_cpu_r5_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r6) == PROBE_CPU_R6_OFFSET, ProbeContext_cpu_r6_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r7) == PROBE_CPU_R7_OFFSET, ProbeContext_cpu_r7_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r8) == PROBE_CPU_R8_OFFSET, ProbeContext_cpu_r8_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r9) == PROBE_CPU_R9_OFFSET, ProbeContext_cpu_r9_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r10) == PROBE_CPU_R10_OFFSET, ProbeContext_cpu_r10_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.r11) == PROBE_CPU_R11_OFFSET, ProbeContext_cpu_r11_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.ip) == PROBE_CPU_IP_OFFSET, ProbeContext_cpu_ip_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.sp) == PROBE_CPU_SP_OFFSET, ProbeContext_cpu_sp_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.lr) == PROBE_CPU_LR_OFFSET, ProbeContext_cpu_lr_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.pc) == PROBE_CPU_PC_OFFSET, ProbeContext_cpu_pc_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.apsr) == PROBE_CPU_APSR_OFFSET, ProbeContext_cpu_apsr_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.fpscr) == PROBE_CPU_FPSCR_OFFSET, ProbeContext_cpu_fpscr_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d0) == PROBE_CPU_D0_OFFSET, ProbeContext_cpu_d0_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d1) == PROBE_CPU_D1_OFFSET, ProbeContext_cpu_d1_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d2) == PROBE_CPU_D2_OFFSET, ProbeContext_cpu_d2_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d3) == PROBE_CPU_D3_OFFSET, ProbeContext_cpu_d3_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d4) == PROBE_CPU_D4_OFFSET, ProbeContext_cpu_d4_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d5) == PROBE_CPU_D5_OFFSET, ProbeContext_cpu_d5_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d6) == PROBE_CPU_D6_OFFSET, ProbeContext_cpu_d6_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d7) == PROBE_CPU_D7_OFFSET, ProbeContext_cpu_d7_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d8) == PROBE_CPU_D8_OFFSET, ProbeContext_cpu_d8_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d9) == PROBE_CPU_D9_OFFSET, ProbeContext_cpu_d9_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d10) == PROBE_CPU_D10_OFFSET, ProbeContext_cpu_d10_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d11) == PROBE_CPU_D11_OFFSET, ProbeContext_cpu_d11_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d12) == PROBE_CPU_D12_OFFSET, ProbeContext_cpu_d12_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d13) == PROBE_CPU_D13_OFFSET, ProbeContext_cpu_d13_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d14) == PROBE_CPU_D14_OFFSET, ProbeContext_cpu_d14_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d15) == PROBE_CPU_D15_OFFSET, ProbeContext_cpu_d15_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d16) == PROBE_CPU_D16_OFFSET, ProbeContext_cpu_d16_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d17) == PROBE_CPU_D17_OFFSET, ProbeContext_cpu_d17_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d18) == PROBE_CPU_D18_OFFSET, ProbeContext_cpu_d18_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d19) == PROBE_CPU_D19_OFFSET, ProbeContext_cpu_d19_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d20) == PROBE_CPU_D20_OFFSET, ProbeContext_cpu_d20_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d21) == PROBE_CPU_D21_OFFSET, ProbeContext_cpu_d21_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d22) == PROBE_CPU_D22_OFFSET, ProbeContext_cpu_d22_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d23) == PROBE_CPU_D23_OFFSET, ProbeContext_cpu_d23_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d24) == PROBE_CPU_D24_OFFSET, ProbeContext_cpu_d24_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d25) == PROBE_CPU_D25_OFFSET, ProbeContext_cpu_d25_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d26) == PROBE_CPU_D26_OFFSET, ProbeContext_cpu_d26_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d27) == PROBE_CPU_D27_OFFSET, ProbeContext_cpu_d27_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d28) == PROBE_CPU_D28_OFFSET, ProbeContext_cpu_d28_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d29) == PROBE_CPU_D29_OFFSET, ProbeContext_cpu_d29_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d30) == PROBE_CPU_D30_OFFSET, ProbeContext_cpu_d30_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(PROBE_OFFSETOF(cpu.d31) == PROBE_CPU_D31_OFFSET, ProbeContext_cpu_d31_offset_matches_ctiMasmProbeTrampoline);
COMPILE_ASSERT(sizeof(MacroAssemblerARMv7::ProbeContext) == PROBE_SIZE, ProbeContext_size_matches_ctiMasmProbeTrampoline);
#undef PROBE_OFFSETOF
asm (
".text" "\n"
".align 2" "\n"
".globl " SYMBOL_STRING(ctiMasmProbeTrampoline) "\n"
HIDE_SYMBOL(ctiMasmProbeTrampoline) "\n"
".thumb" "\n"
".thumb_func " THUMB_FUNC_PARAM(ctiMasmProbeTrampoline) "\n"
SYMBOL_STRING(ctiMasmProbeTrampoline) ":" "\n"
// MacroAssemblerARMv7::probe() has already generated code to store some values.
// The top of stack now looks like this:
// esp[0 * ptrSize]: probeFunction
// esp[1 * ptrSize]: arg1
// esp[2 * ptrSize]: arg2
// esp[3 * ptrSize]: saved r0
// esp[4 * ptrSize]: saved ip
// esp[5 * ptrSize]: saved lr
// esp[6 * ptrSize]: saved sp
"mov ip, sp" "\n"
"mov r0, sp" "\n"
"sub r0, r0, #" STRINGIZE_VALUE_OF(PROBE_SIZE) "\n"
// The ARM EABI specifies that the stack needs to be 16 byte aligned.
"bic r0, r0, #0xf" "\n"
"mov sp, r0" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_PC_OFFSET) "]" "\n"
"add lr, sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_R1_OFFSET) "\n"
"stmia lr, { r1-r11 }" "\n"
"mrs lr, APSR" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_APSR_OFFSET) "]" "\n"
"vmrs lr, FPSCR" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_FPSCR_OFFSET) "]" "\n"
"ldr lr, [ip, #0 * " STRINGIZE_VALUE_OF(PTR_SIZE) "]" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_PROBE_FUNCTION_OFFSET) "]" "\n"
"ldr lr, [ip, #1 * " STRINGIZE_VALUE_OF(PTR_SIZE) "]" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_ARG1_OFFSET) "]" "\n"
"ldr lr, [ip, #2 * " STRINGIZE_VALUE_OF(PTR_SIZE) "]" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_ARG2_OFFSET) "]" "\n"
"ldr lr, [ip, #3 * " STRINGIZE_VALUE_OF(PTR_SIZE) "]" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_R0_OFFSET) "]" "\n"
"ldr lr, [ip, #4 * " STRINGIZE_VALUE_OF(PTR_SIZE) "]" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_IP_OFFSET) "]" "\n"
"ldr lr, [ip, #5 * " STRINGIZE_VALUE_OF(PTR_SIZE) "]" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_LR_OFFSET) "]" "\n"
"ldr lr, [ip, #6 * " STRINGIZE_VALUE_OF(PTR_SIZE) "]" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_SP_OFFSET) "]" "\n"
"ldr lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_PC_OFFSET) "]" "\n"
"add ip, sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_D0_OFFSET) "\n"
"vstmia.64 ip, { d0-d31 }" "\n"
"mov fp, sp" "\n" // Save the ProbeContext*.
"ldr ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_PROBE_FUNCTION_OFFSET) "]" "\n"
"mov r0, sp" "\n" // the ProbeContext* arg.
"blx ip" "\n"
"mov sp, fp" "\n"
// To enable probes to modify register state, we copy all registers
// out of the ProbeContext before returning.
"add ip, sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_D31_OFFSET + FPREG_SIZE) "\n"
"vldmdb.64 ip!, { d0-d31 }" "\n"
"add ip, sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_R11_OFFSET + GPREG_SIZE) "\n"
"ldmdb ip, { r0-r11 }" "\n"
"ldr ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_FPSCR_OFFSET) "]" "\n"
"vmsr FPSCR, ip" "\n"
// There are 5 more registers left to restore: ip, sp, lr, pc, and apsr.
// There are 2 issues that complicate the restoration of these last few
// registers:
//
// 1. Normal ARM calling convention relies on moving lr to pc to return to
// the caller. In our case, the address to return to is specified by
// ProbeContext.cpu.pc. And at that moment, we won't have any available
// scratch registers to hold the return address (lr needs to hold
// ProbeContext.cpu.lr, not the return address).
//
// The solution is to store the return address on the stack and load the
// pc from there.
//
// 2. Issue 1 means we will need to write to the stack location at
// ProbeContext.cpu.sp - 4. But if the user probe function had modified
// the value of ProbeContext.cpu.sp to point in the range between
// &ProbeContext.cpu.ip thru &ProbeContext.cpu.aspr, then the action for
// Issue 1 may trash the values to be restored before we can restore
// them.
//
// The solution is to check if ProbeContext.cpu.sp contains a value in
// the undesirable range. If so, we copy the remaining ProbeContext
// register data to a safe range (at memory lower than where
// ProbeContext.cpu.sp points) first, and restore the remaining register
// from this new range.
"add ip, sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_APSR_OFFSET) "\n"
"ldr lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_SP_OFFSET) "]" "\n"
"cmp lr, ip" "\n"
"it gt" "\n"
"bgt " SYMBOL_STRING(ctiMasmProbeTrampolineEnd) "\n"
// We get here because the new expected stack pointer location is lower
// than where it's supposed to be. This means the safe range of stack
// memory where we'll be copying the remaining register restore values to
// might be in a region of memory below the sp i.e. unallocated stack
// memory. This, in turn, makes it vulnerable to interrupts potentially
// trashing the copied values. To prevent that, we must first allocate the
// needed stack memory by adjusting the sp before the copying.
"sub lr, lr, #(6 * " STRINGIZE_VALUE_OF(PTR_SIZE)
" + " STRINGIZE_VALUE_OF(PROBE_CPU_IP_OFFSET) ")" "\n"
"mov ip, sp" "\n"
"mov sp, lr" "\n"
"mov lr, ip" "\n"
"ldr ip, [lr, #" STRINGIZE_VALUE_OF(PROBE_CPU_IP_OFFSET) "]" "\n"
"str ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_IP_OFFSET) "]" "\n"
"ldr ip, [lr, #" STRINGIZE_VALUE_OF(PROBE_CPU_SP_OFFSET) "]" "\n"
"str ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_SP_OFFSET) "]" "\n"
"ldr ip, [lr, #" STRINGIZE_VALUE_OF(PROBE_CPU_LR_OFFSET) "]" "\n"
"str ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_LR_OFFSET) "]" "\n"
"ldr ip, [lr, #" STRINGIZE_VALUE_OF(PROBE_CPU_PC_OFFSET) "]" "\n"
"str ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_PC_OFFSET) "]" "\n"
"ldr ip, [lr, #" STRINGIZE_VALUE_OF(PROBE_CPU_APSR_OFFSET) "]" "\n"
"str ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_APSR_OFFSET) "]" "\n"
".thumb_func " THUMB_FUNC_PARAM(ctiMasmProbeTrampolineEnd) "\n"
SYMBOL_STRING(ctiMasmProbeTrampolineEnd) ":" "\n"
"ldr ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_PC_OFFSET) "]" "\n"
"ldr lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_SP_OFFSET) "]" "\n"
"sub lr, lr, #" STRINGIZE_VALUE_OF(PTR_SIZE) "\n"
"str ip, [lr]" "\n"
"str lr, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_SP_OFFSET) "]" "\n"
"ldr ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_APSR_OFFSET) "]" "\n"
"msr APSR, ip" "\n"
"ldr ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_LR_OFFSET) "]" "\n"
"mov lr, ip" "\n"
"ldr ip, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_IP_OFFSET) "]" "\n"
"ldr sp, [sp, #" STRINGIZE_VALUE_OF(PROBE_CPU_SP_OFFSET) "]" "\n"
"pop { pc }" "\n"
);
#endif // COMPILER(GCC_OR_CLANG)
void MacroAssemblerARMv7::probe(MacroAssemblerARMv7::ProbeFunction function, void* arg1, void* arg2)
{
push(RegisterID::lr);
push(RegisterID::lr);
add32(TrustedImm32(8), RegisterID::sp, RegisterID::lr);
store32(RegisterID::lr, ArmAddress(RegisterID::sp, 4));
push(RegisterID::ip);
push(RegisterID::r0);
// The following uses RegisterID::ip. So, they must come after we push ip above.
push(trustedImm32FromPtr(arg2));
push(trustedImm32FromPtr(arg1));
push(trustedImm32FromPtr(function));
move(trustedImm32FromPtr(ctiMasmProbeTrampoline), RegisterID::ip);
m_assembler.blx(RegisterID::ip);
}
#endif // ENABLE(MASM_PROBE)
} // namespace JSC
#endif // ENABLE(ASSEMBLER)
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