// #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *) 0)->MEMBER)
void pop_shack(TCGv_ptr cpu_env, TCGv next_eip){
//----------------------TCG operations
TCGv_ptr temp_shack_top = tcg_temp_new_ptr();
TCGv_ptr temp_shack_empty = tcg_temp_new_ptr();
TCGv_ptr temp_shack_top_next = tcg_temp_new_ptr();
TCGv_ptr temp_entry_ptr = tcg_temp_new_ptr();
TCGv_ptr temp_host_eip = tcg_temp_new_ptr();
TCGv temp_guest_eip = tcg_temp_local_new_i32();
TCGv temp_next_eip = tcg_temp_local_new_i32();
int eip_match_label = gen_new_label(); // create label
int empty_label = gen_new_label(); // create label
//load next_eip into temp_next_eip
tcg_gen_mov_i32(temp_next_eip, next_eip);
// load shack_top ptr into temp_shack_top
tcg_gen_ld_ptr(temp_shack_top, cpu_env, offsetof(CPUState, shack_top));
tcg_gen_ld_ptr(temp_shack_empty, cpu_env, offsetof(CPUState, shack));
//check if stack is empty
tcg_gen_brcond_ptr(TCG_COND_EQ, temp_shack_top, temp_shack_empty, empty_label);
// get (shack_top - 8)
tcg_gen_ld_ptr(temp_shack_top, cpu_env, offsetof(CPUState, shack_top));
tcg_gen_subi_tl(temp_shack_top_next, temp_shack_top, sizeof(uint64_t));
// get entry
tcg_gen_ld_ptr(temp_entry_ptr, temp_shack_top_next, 0);
// load entry.guest_eip
tcg_gen_ld_ptr(temp_guest_eip, temp_entry_ptr, offsetof(shack_hash_entry, guest_eip));
// branch to label
tcg_gen_brcond_ptr(TCG_COND_NE, temp_next_eip, temp_guest_eip, eip_match_label);
//reload all temps.
tcg_gen_ld_ptr(temp_shack_top, cpu_env, offsetof(CPUState, shack_top));
tcg_gen_subi_tl(temp_shack_top_next, temp_shack_top, sizeof(uint64_t));
tcg_gen_ld_ptr(temp_entry_ptr, temp_shack_top_next, 0);
// load entry.host_eip into temp_host_eip
tcg_gen_ld_ptr(temp_host_eip, temp_entry_ptr, offsetof(shack_hash_entry, host_eip));
// update shack_top
tcg_gen_st_ptr(temp_shack_top_next, cpu_env, offsetof(CPUState, shack_top));
// jump
*gen_opc_ptr++ = INDEX_op_jmp;
*gen_opparam_ptr++ = temp_host_eip;
// set label here
gen_set_label(eip_match_label);
// empty stack do nothing
gen_set_label(empty_label);
}
/*
* pop_shack()
* Pop next host eip from shadow stack.
*/
void pop_shack(TCGv_ptr cpu_env, TCGv next_eip)
{
// labels
int label_end = gen_new_label();
// prepare registers
TCGv_ptr temp_shack_start = tcg_temp_local_new_ptr(); // store shack start
TCGv_ptr temp_shack_top = tcg_temp_local_new_ptr(); // store shack top
TCGv eip_on_shack = tcg_temp_local_new();
TCGv_ptr host_slot_addr = tcg_temp_local_new();
TCGv_ptr host_addr = tcg_temp_new();
// load common values
tcg_gen_ld_ptr(temp_shack_start, cpu_env, offsetof(CPUState, shack));
tcg_gen_ld_ptr(temp_shack_top, cpu_env, offsetof(CPUState, shack_top));
// check if stack empty?
tcg_gen_brcond_ptr(TCG_COND_EQ,temp_shack_top,temp_shack_start,label_end);
// stack not empty, pop one
tcg_gen_subi_ptr(temp_shack_top, temp_shack_top, sizeof(uint64_t)); // decrease top
tcg_gen_st_ptr(temp_shack_top, cpu_env, offsetof(CPUState, shack_top)); // store back top
tcg_gen_ld_tl(eip_on_shack, temp_shack_top, 0); // get eip
// check if the same?
tcg_gen_brcond_ptr(TCG_COND_NE,tcg_const_tl(next_eip),eip_on_shack,label_end); // go to "end" if not the same
tcg_gen_ld_tl(host_slot_addr, temp_shack_top, sizeof(unsigned long)); // get slot addr
tcg_gen_ld_ptr(host_addr, host_slot_addr, 0) ; // get host addr
tcg_gen_brcond_ptr(TCG_COND_EQ,tcg_const_tl(0),host_addr,label_end); // go to "end" if addr is zero
// jump!
*gen_opc_ptr++ = INDEX_op_jmp;
*gen_opparam_ptr++ = GET_TCGV_I32(host_addr);
// label: end
gen_set_label(label_end);
tcg_temp_free(eip_on_shack);
tcg_temp_free_ptr(host_slot_addr);
tcg_temp_free_ptr(host_addr);
tcg_temp_free_ptr(temp_shack_top);
tcg_temp_free_ptr(temp_shack_start);
}
/*
* push_shack()
* Push next guest eip into shadow stack.
*/
void push_shack(CPUState *env, TCGv_ptr cpu_env, target_ulong next_eip)
{
// label
int label_do_push = gen_new_label();
// prepare registers
TCGv_ptr temp_shack_end = tcg_temp_local_new_ptr(); // store shack end
TCGv_ptr temp_shack_top = tcg_temp_local_new_ptr(); // store shack top
TCGv temp_next_eip = tcg_temp_local_new(); // store eip
// load common values
tcg_gen_ld_ptr(temp_shack_end, cpu_env, offsetof(CPUState, shack_end));
tcg_gen_ld_ptr(temp_shack_top, cpu_env, offsetof(CPUState, shack_top));
tcg_gen_mov_tl(temp_next_eip, tcg_const_tl(next_eip));
// check shack full?
tcg_gen_brcond_ptr(TCG_COND_NE,temp_shack_top,temp_shack_end,label_do_push); // if not full
// flush here
TCGv_ptr temp_shack_start = tcg_temp_new_ptr(); // store shack start
//tcg_en_st_tl(tcg_const_tl(0), cpu_env, offsetof(CPUState, shadow_ret_count)); // reset ret count
tcg_gen_ld_ptr(temp_shack_start, cpu_env, offsetof(CPUState, shack));
tcg_gen_mov_tl(temp_shack_top, temp_shack_start);
tcg_temp_free_ptr(temp_shack_start);
// call helper: flush the hash
gen_helper_shack_flush(cpu_env);
// end of flush
gen_set_label(label_do_push);
// do push here
// push guest eip
tcg_gen_st_ptr(temp_next_eip, temp_shack_top, 0); // store guest eip
tcg_gen_addi_ptr(temp_shack_top, temp_shack_top, sizeof(uint64_t)); // increase top
// call helper: check if we can fill the ret directly, or need to add hash-pair
gen_helper_shack_push(cpu_env, temp_next_eip);
// store back top
tcg_gen_st_ptr(temp_shack_top, cpu_env, offsetof(CPUState, shack_top));
// clean up
tcg_temp_free(temp_next_eip);
tcg_temp_free_ptr(temp_shack_top);
tcg_temp_free_ptr(temp_shack_end);
}