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#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "box64stack.h"
#include "box64context.h"
#include "elfloader.h"
#include "debug.h"
#include "emu/x64emu_private.h"
#include "emu/x64run_private.h"
#include "auxval.h"
EXPORTDYN
int CalcStackSize(box64context_t *context)
{
printf_log(LOG_DEBUG, "Calc stack size, based on %d elf(s)\n", context->elfsize);
context->stacksz = 8*1024*1024; context->stackalign=4;
for (int i=0; i<context->elfsize; ++i)
CalcStack(context->elfs[i], &context->stacksz, &context->stackalign);
if (posix_memalign((void**)&context->stack, context->stackalign, context->stacksz)) {
printf_log(LOG_NONE, "Cannot allocate aligned memory (0x%x/0x%x) for stack\n", context->stacksz, context->stackalign);
return 1;
}
memset(context->stack, 0, context->stacksz);
printf_log(LOG_DEBUG, "Stack is @%p size=0x%x align=0x%x\n", context->stack, context->stacksz, context->stackalign);
return 0;
}
uint16_t Pop16(x64emu_t *emu)
{
uint16_t* st = ((uint16_t*)(R_RSP));
R_RSP += 2;
return *st;
}
void Push16(x64emu_t *emu, uint16_t v)
{
R_RSP -= 2;
*((uint16_t*)R_RSP) = v;
}
uint32_t Pop32(x64emu_t *emu)
{
uint32_t* st = ((uint32_t*)(R_RSP));
R_RSP += 4;
return *st;
}
void Push32(x64emu_t *emu, uint32_t v)
{
R_RSP -= 4;
*((uint32_t*)R_RSP) = v;
}
uint64_t Pop64(x64emu_t *emu)
{
uint64_t* st = ((uint64_t*)(R_RSP));
R_RSP += 8;
return *st;
}
void Push64(x64emu_t *emu, uint64_t v)
{
R_RSP -= 8;
*((uint64_t*)R_RSP) = v;
}
void PushString(x64emu_t *emu, const char* s)
{
int sz = strlen(s) + 1;
// round to 4 bytes boundary
R_RSP -= sz;
memcpy((void*)R_RSP, s, sz);
}
EXPORTDYN
void SetupInitialStack(x64emu_t *emu)
{
// start with 0
Push(emu, 0);
// push program executed
PushString(emu, emu->context->argv[0]);
uintptr_t p_arg0 = R_RSP;
// push envs
uintptr_t p_envv[emu->context->envc];
for (int i=emu->context->envc-1; i>=0; --i) {
PushString(emu, emu->context->envv[i]);
p_envv[i] = R_RSP;
}
// push args, also, free the argv[] string and point to the one in the main stack
uintptr_t p_argv[emu->context->argc];
for (int i=emu->context->argc-1; i>=0; --i) {
PushString(emu, emu->context->argv[i]);
p_argv[i] = R_RSP;
free(emu->context->argv[i]);
emu->context->argv[i] = (char*)p_argv[i];
}
// align
uintptr_t tmp = (R_RSP)&~(emu->context->stackalign-1);
memset((void*)tmp, 0, R_RSP-tmp);
R_RSP=tmp;
// push some AuxVector stuffs
PushString(emu, "x86_64");
uintptr_t p_x86_64 = R_RSP;
uintptr_t p_random = real_getauxval(25);
if(!p_random) {
for (int i=0; i<4; ++i)
Push(emu, random());
p_random = R_RSP;
}
// align
tmp = (R_RSP)&~(emu->context->stackalign-1);
memset((void*)tmp, 0, R_RSP-tmp);
R_RSP=tmp;
// push the AuxVector themselves
Push(emu, 0); Push(emu, 0); //AT_NULL(0)=0
Push(emu, p_x86_64); Push(emu, 15); //AT_PLATFORM(15)=p_x86_64*
Push(emu, 0); Push(emu, 66); //AT_HWCAP2(26)=0
// Push HWCAP:
// FPU: 1<<0 ; VME: 1<<1 ; DE : 1<<2 ; PSE: 1<<3 ; TSC: 1<<4
// MSR: 1<<5 : PAE: 1<<6 : MCE: 1<<7 ; CX8: 1<<8 : APIC:1<<9
// SEP: 1<<11: MTRR:1<<12: PGE: 1<<13: MCA: 1<<14; CMOV:1<<15; FCMOV: 1<<16
// MMX: 1<<23:OSFXR:1<<24: XMM: 1<<25:XMM2: 1<<26;AMD3D:1<<31
Push(emu, (1<<0) | (1<<1) | (1<<2) | (1<<3) | (1<<4) | (1<<8) | (1<<15) | (1<<16) | (1<<23) | (1<<25) | (1<<26));
Push(emu, 16); //AT_HWCAP(16)=...
Push(emu, p_arg0); Push(emu, 31); //AT_EXECFN(31)=p_arg0
Push(emu, p_random); Push(emu, 25); //AT_RANDOM(25)=p_random
Push(emu, real_getauxval(23)); Push(emu, 23); //AT_SECURE(23)=0
Push(emu, real_getauxval(14)); Push(emu, 14); //AT_EGID(14)
Push(emu, real_getauxval(13)); Push(emu, 13); //AT_GID(13)
Push(emu, real_getauxval(12)); Push(emu, 12); //AT_EUID(12)
Push(emu, real_getauxval(11)); Push(emu, 11); //AT_UID(11)
Push(emu, box64_pagesize); Push(emu, 6); //AT_PAGESZ(6)
Push(emu, R_RIP); Push(emu, 9); //AT_ENTRY(9)=entrypoint
Push(emu, 0/*emu->context->vsyscall*/); Push(emu, 32); //AT_SYSINFO(32)=vsyscall
if(!emu->context->auxval_start) // store auxval start if needed
emu->context->auxval_start = (uintptr_t*)R_RSP;
// TODO: continue
// push nil / envs / nil / args / argc
Push(emu, 0);
for (int i=emu->context->envc-1; i>=0; --i)
Push(emu, p_envv[i]);
Push(emu, 0);
for (int i=emu->context->argc-1; i>=0; --i)
Push(emu, p_argv[i]);
Push(emu, emu->context->argc);
}
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