diff options
Diffstat (limited to 'x86_64-gen.c')
| -rw-r--r-- | x86_64-gen.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/x86_64-gen.c b/x86_64-gen.c index d5ed4f6..0083f8b 100644 --- a/x86_64-gen.c +++ b/x86_64-gen.c @@ -625,6 +625,90 @@ static void gcall_or_jmp(int is_jmp) } } +#if defined(CONFIG_TCC_BCHECK) +#ifndef TCC_TARGET_PE +static addr_t func_bound_offset; +static unsigned long func_bound_ind; +#endif + +static void gen_static_call(int v) +{ + Sym *sym = external_global_sym(v, &func_old_type, 0); + oad(0xe8, -4); + greloc(cur_text_section, sym, ind-4, R_X86_64_PC32); +} + +/* generate a bounded pointer addition */ +ST_FUNC void gen_bounded_ptr_add(void) +{ + /* save all temporary registers */ + save_regs(0); + + /* prepare fast x86_64 function call */ + gv(RC_RAX); + o(0xc68948); // mov %rax,%rsi ## second arg in %rsi, this must be size + vtop--; + + gv(RC_RAX); + o(0xc78948); // mov %rax,%rdi ## first arg in %rdi, this must be ptr + vtop--; + + /* do a fast function call */ + gen_static_call(TOK___bound_ptr_add); + + /* returned pointer is in rax */ + vtop++; + vtop->r = TREG_RAX | VT_BOUNDED; + + + /* relocation offset of the bounding function call point */ + vtop->c.ull = (cur_text_section->reloc->data_offset - sizeof(ElfW(Rela))); +} + +/* patch pointer addition in vtop so that pointer dereferencing is + also tested */ +ST_FUNC void gen_bounded_ptr_deref(void) +{ + addr_t func; + int size, align; + ElfW(Rela) *rel; + Sym *sym; + + size = 0; + /* XXX: put that code in generic part of tcc */ + if (!is_float(vtop->type.t)) { + if (vtop->r & VT_LVAL_BYTE) + size = 1; + else if (vtop->r & VT_LVAL_SHORT) + size = 2; + } + if (!size) + size = type_size(&vtop->type, &align); + switch(size) { + case 1: func = TOK___bound_ptr_indir1; break; + case 2: func = TOK___bound_ptr_indir2; break; + case 4: func = TOK___bound_ptr_indir4; break; + case 8: func = TOK___bound_ptr_indir8; break; + case 12: func = TOK___bound_ptr_indir12; break; + case 16: func = TOK___bound_ptr_indir16; break; + default: + tcc_error("unhandled size when dereferencing bounded pointer"); + func = 0; + break; + } + + sym = external_global_sym(func, &func_old_type, 0); + if (!sym->c) + put_extern_sym(sym, NULL, 0, 0); + + /* patch relocation */ + /* XXX: find a better solution ? */ + + rel = (ElfW(Rela) *)(cur_text_section->reloc->data + vtop->c.ull); + rel->r_info = ELF64_R_INFO(sym->c, ELF64_R_TYPE(rel->r_info)); +} +#endif + #ifdef TCC_TARGET_PE #define REGN 4 @@ -1520,6 +1604,17 @@ void gfunc_prolog(CType *func_type) sym_push(sym->v & ~SYM_FIELD, type, VT_LOCAL | VT_LVAL, param_addr); } + +#ifdef CONFIG_TCC_BCHECK + /* leave some room for bound checking code */ + if (tcc_state->do_bounds_check) { + func_bound_offset = lbounds_section->data_offset; + func_bound_ind = ind; + oad(0xb8, 0); /* lbound section pointer */ + o(0xc78948); /* mov %rax,%rdi ## first arg in %rdi, this must be ptr */ + oad(0xb8, 0); /* call to function */ + } +#endif } /* generate function epilog */ @@ -1527,6 +1622,37 @@ void gfunc_epilog(void) { int v, saved_ind; +#ifdef CONFIG_TCC_BCHECK + if (tcc_state->do_bounds_check + && func_bound_offset != lbounds_section->data_offset) + { + addr_t saved_ind; + addr_t *bounds_ptr; + Sym *sym_data; + + /* add end of table info */ + bounds_ptr = section_ptr_add(lbounds_section, sizeof(addr_t)); + *bounds_ptr = 0; + + /* generate bound local allocation */ + sym_data = get_sym_ref(&char_pointer_type, lbounds_section, + func_bound_offset, lbounds_section->data_offset); + saved_ind = ind; + ind = func_bound_ind; + greloc(cur_text_section, sym_data, ind + 1, R_386_32); + ind = ind + 5 + 3; + gen_static_call(TOK___bound_local_new); + ind = saved_ind; + + /* generate bound check local freeing */ + o(0x5250); /* save returned value, if any */ + greloc(cur_text_section, sym_data, ind + 1, R_386_32); + oad(0xb8, 0); /* mov xxx, %rax */ + o(0xc78948); /* mov %rax,%rdi ## first arg in %rdi, this must be ptr */ + gen_static_call(TOK___bound_local_delete); + o(0x585a); /* restore returned value, if any */ + } +#endif o(0xc9); /* leave */ if (func_ret_sub == 0) { o(0xc3); /* ret */ |