Cleanup new bound checking code

remove quadratic loops by not using side tables; address-taken can simply be a flag per local sym, and the lbounds section can be filled after symbols go out of scope at which point we know if the address was taken, so that there's no need to compress it again after the funcion is done.

Michael Matz committed 6 years ago

Commit 65f2fe31 parent 4a70b2b4 files · +47 −156Browse files

Unified · Split

4 files

i386-gen.c +2 −7
tcc.h +4 −8
tccgen.c +38 −127
x86_64-gen.c +3 −14

i386-gen.c+2−7

 static unsigned long func_sub_sp_offset;
 static int func_ret_sub;
 #ifdef CONFIG_TCC_BCHECK
+static addr_t func_bound_offset;
 static unsigned long func_bound_ind;
 #endif
     Sym *func_sym;
 #ifdef CONFIG_TCC_BCHECK
-    if (tcc_state->do_bounds_check) {
+    if (tcc_state->do_bounds_check)
-        save_temp_local (nb_args);
         gbound_args(nb_args);
-    }
 #endif
     args_size = 0;
     if (args_size && func_call != FUNC_STDCALL && func_call != FUNC_FASTCALLW)
         gadd_sp(args_size);
     vtop--;
-#ifdef CONFIG_TCC_BCHECK
-    if (tcc_state->do_bounds_check)
-        restore_temp_local ();
-#endif
 }
 #ifdef TCC_TARGET_PE

tcc.h+4−8

     dllexport   : 1,
     nodecorate  : 1,
     dllimport   : 1,
-    constructor : 1,
+    addrtaken   : 1,
-    destructor  : 1,
+    unused      : 3;
-    unused      : 2;
 };
 /* function attributes or temporary attributes for parsing */
 typedef struct AttributeDef {
     struct SymAttr a;
     struct FuncAttr f;
+    unsigned short constructor:1;
+    unsigned short destructor:1;
     struct Section *section;
     Sym *cleanup_func;
     int alias_target; /* token */
 ST_DATA int func_var; /* true if current function is variadic */
 ST_DATA int func_vc;
 ST_DATA const char *funcname;
-#ifdef CONFIG_TCC_BCHECK
-ST_DATA addr_t func_bound_offset;
-#endif
 ST_FUNC void tcc_debug_start(TCCState *s1);
 ST_FUNC void tcc_debug_end(TCCState *s1);
 #endif
 #ifdef CONFIG_TCC_BCHECK
 ST_FUNC void gbound_args(int nb_args);
-ST_FUNC void save_temp_local(int nb_args);
-ST_FUNC void restore_temp_local(void);
 #endif
 /* ------------ tccelf.c ------------ */

tccgen.c+38−127

@@ -111,16 +111,6 @@ ST_DATA struct temp_local_variable { · 110 unmodified lines
111	short align;	111	short align;
112	} arr_temp_local_vars[MAX_TEMP_LOCAL_VARIABLE_NUMBER];	112	} arr_temp_local_vars[MAX_TEMP_LOCAL_VARIABLE_NUMBER];
113	short nb_temp_local_vars;	113	short nb_temp_local_vars;
114	#ifdef CONFIG_TCC_BCHECK
115	static short call_nesting;
116	static char used_location[MAX_TEMP_LOCAL_VARIABLE_NUMBER];
117	static int nb_bound_local_param;
118	struct {
119	unsigned long data_offset;
120	int v;
121	} *bound_local_param;
122	ST_DATA addr_t func_bound_offset;
123	#endif
124		114
125	static struct scope {	115	static struct scope {
126	struct scope *prev;	116	struct scope *prev;
@@ -1502,11 +1492,7 @@ static int get_temp_local_var(int size,int align){ · 1375 unmodified lines
1502	found=0;	1492	found=0;
1503	for(i=0;i<nb_temp_local_vars;i++){	1493	for(i=0;i<nb_temp_local_vars;i++){
1504	temp_var=&arr_temp_local_vars[i];	1494	temp_var=&arr_temp_local_vars[i];
1505	if(temp_var->size<size\|\|align!=temp_var->align	1495	if(temp_var->size<size\|\|align!=temp_var->align){
1506	#ifdef CONFIG_TCC_BCHECK
1507	\|\| (tcc_state->do_bounds_check && used_location[i])
1508	#endif
1509	){
1510	continue;	1496	continue;
1511	}	1497	}
1512	/check if temp_var is free/	1498	/check if temp_var is free/
@@ -1607,50 +1593,36 @@ ST_FUNC void gbound_args(int nb_args) · 94 unmodified lines
1607	}	1593	}
1608	}	1594	}
1609		1595
1610	ST_FUNC void save_temp_local(int nb_args)	1596	/* Add bounds for local symbols from S to E (via ->prev) */
1611	{	1597	static void add_local_bounds(Sym s, Sym e)
1612	int i, j;	1598	{
1613		1599	for (; s != e; s = s->prev) {
1614	if (call_nesting++ == 0)	1600	if (!s->v \|\| (s->r & VT_VALMASK) != VT_LOCAL)
1615	for (i = 1; i <= nb_args; ++i)	1601	continue;
1616	for (j = 0; j < nb_temp_local_vars; j++)	1602	/* Add arrays/structs/unions because we always take address */
1617	if (vtop[1 - i].c.i == arr_temp_local_vars[j].location) {	1603	if ((s->type.t & VT_ARRAY)
1618	used_location[j] = 1;	1604	\|\| (s->type.t & VT_BTYPE) == VT_STRUCT
1619	break;	1605	\|\| s->a.addrtaken) {
1620	}	1606	/* add local bound info */
1621	}	1607	int align, size = type_size(&s->type, &align);
1622		1608	addr_t *bounds_ptr = section_ptr_add(lbounds_section,
1623	ST_FUNC void restore_temp_local()	1609	2 * sizeof(addr_t));
1624	{	1610	bounds_ptr[0] = s->c;
1625	if (--call_nesting == 0)	1611	bounds_ptr[1] = size;
1626	memset (used_location, 0, sizeof (used_location));	1612	}
		1613	}
1627	}	1614	}
		1615	#endif
1628		1616
1629	static void add_bound_param(CType *type, int size, int v, int c)	1617	/* Wrapper around sym_pop, that potentially also registers local bounds. */
		1618	static void pop_local_syms(Sym *ptop, Sym b, int keep)
1630	{	1619	{
1631	addr_t *bounds_ptr;	1620	#ifdef CONFIG_TCC_BCHECK
1632	/* Add arrays/structs/unions because we always take address */	1621	if (!keep && tcc_state->do_bounds_check)
1633	int taken = (type->t & VT_ARRAY)	1622	add_local_bounds(*ptop, b);
1634	\|\| (type->t & VT_BTYPE) == VT_STRUCT;
1635
1636	if (taken == 0) {
1637	/* Add parameter to check */
1638	nb_bound_local_param++;
1639	bound_local_param =
1640	tcc_realloc (bound_local_param,
1641	nb_bound_local_param *
1642	sizeof (*bound_local_param));
1643	bound_local_param[nb_bound_local_param-1].data_offset =
1644	lbounds_section->data_offset;
1645	bound_local_param[nb_bound_local_param-1].v = v;
1646	}
1647	/* add local bound info */
1648	bounds_ptr = section_ptr_add(lbounds_section,
1649	2 * sizeof(addr_t));
1650	bounds_ptr[0] = c;
1651	bounds_ptr[1] = taken ? size : ~size;
1652	}
1653	#endif	1623	#endif
		1624	sym_pop(ptop, b, keep);
		1625	}
1654		1626
1655	static void incr_bf_adr(int o)	1627	static void incr_bf_adr(int o)
1656	{	1628	{
@@ -3690,11 +3662,11 @@ redo: · 2033 unmodified lines
3690	}	3662	}
3691	case TOK_CONSTRUCTOR1:	3663	case TOK_CONSTRUCTOR1:
3692	case TOK_CONSTRUCTOR2:	3664	case TOK_CONSTRUCTOR2:
3693	ad->a.constructor = 1;	3665	ad->constructor = 1;
3694	break;	3666	break;
3695	case TOK_DESTRUCTOR1:	3667	case TOK_DESTRUCTOR1:
3696	case TOK_DESTRUCTOR2:	3668	case TOK_DESTRUCTOR2:
3697	ad->a.destructor = 1;	3669	ad->destructor = 1;
3698	break;	3670	break;
3699	case TOK_SECTION1:	3671	case TOK_SECTION1:
3700	case TOK_SECTION2:	3672	case TOK_SECTION2:
@@ -5138,23 +5110,8 @@ ST_FUNC void unary(void) · 1437 unmodified lines
5138	if ((vtop->type.t & VT_BTYPE) != VT_FUNC &&	5110	if ((vtop->type.t & VT_BTYPE) != VT_FUNC &&
5139	!(vtop->type.t & VT_ARRAY))	5111	!(vtop->type.t & VT_ARRAY))
5140	test_lvalue();	5112	test_lvalue();
5141	#ifdef CONFIG_TCC_BCHECK	5113	if (vtop->sym)
5142	if (tcc_state->do_bounds_check && vtop->sym) {	5114	vtop->sym->a.addrtaken = 1;
5143	int i;
5144
5145	/* Mark parameter as being used for address off */
5146	for (i = 0; i < nb_bound_local_param; i++) {
5147	if (bound_local_param[i].v == vtop->sym->v) {
5148	addr_t *bounds_ptr =
5149	(addr_t *) (lbounds_section->data +
5150	bound_local_param[i].data_offset);
5151	bounds_ptr[1] = ~bounds_ptr[1];
5152	bound_local_param[i].v = 0;
5153	break;
5154	}
5155	}
5156	}
5157	#endif
5158	mk_pointer(&vtop->type);	5115	mk_pointer(&vtop->type);
5159	gaddrof();	5116	gaddrof();
5160	break;	5117	break;
@@ -6454,7 +6411,7 @@ void prev_scope(struct scope *o, int is_expr) · 1293 unmodified lines
6454	tables, though. sym_pop will do that. */	6411	tables, though. sym_pop will do that. */
6455		6412
6456	/* pop locally defined symbols */	6413	/* pop locally defined symbols */
6457	sym_pop(&local_stack, o->lstk, is_expr);	6414	pop_local_syms(&local_stack, o->lstk, is_expr);
6458		6415
6459	cur_scope = o->prev;	6416	cur_scope = o->prev;
6460	--local_scope;	6417	--local_scope;
@@ -7426,17 +7383,13 @@ static void decl_initializer_alloc(CType type, AttributeDef ad, int r, · 965 unmodified lines
7426	Sym *sym = NULL;	7383	Sym *sym = NULL;
7427	int saved_nocode_wanted = nocode_wanted;	7384	int saved_nocode_wanted = nocode_wanted;
7428	#ifdef CONFIG_TCC_BCHECK	7385	#ifdef CONFIG_TCC_BCHECK
7429	int bcheck;	7386	int bcheck = tcc_state->do_bounds_check && !NODATA_WANTED;
7430	#endif	7387	#endif
7431		7388
7432	/* Always allocate static or global variables */	7389	/* Always allocate static or global variables */
7433	if (v && (r & VT_VALMASK) == VT_CONST)	7390	if (v && (r & VT_VALMASK) == VT_CONST)
7434	nocode_wanted \|= 0x80000000;	7391	nocode_wanted \|= 0x80000000;
7435		7392
7436	#ifdef CONFIG_TCC_BCHECK
7437	bcheck = tcc_state->do_bounds_check && !NODATA_WANTED;
7438	#endif
7439
7440	flexible_array = NULL;	7393	flexible_array = NULL;
7441	if ((type->t & VT_BTYPE) == VT_STRUCT) {	7394	if ((type->t & VT_BTYPE) == VT_STRUCT) {
7442	Sym *field = type->ref->next;	7395	Sym *field = type->ref->next;
@@ -7508,17 +7461,15 @@ static void decl_initializer_alloc(CType type, AttributeDef ad, int r, · 65 unmodified lines
7508	sec = NULL;	7461	sec = NULL;
7509	#ifdef CONFIG_TCC_BCHECK	7462	#ifdef CONFIG_TCC_BCHECK
7510	if (bcheck && v) {	7463	if (bcheck && v) {
7511	/* add padding between stack variables */	7464	/* add padding between stack variables for bound checking */
7512	loc--;	7465	loc--;
7513	}	7466	}
7514	#endif	7467	#endif
7515	loc = (loc - size) & -align;	7468	loc = (loc - size) & -align;
7516	addr = loc;	7469	addr = loc;
7517	#ifdef CONFIG_TCC_BCHECK	7470	#ifdef CONFIG_TCC_BCHECK
7518	/* handles bounds */
7519	if (bcheck && v) {	7471	if (bcheck && v) {
7520	add_bound_param (type, size, v, addr);	7472	/* add padding between stack variables for bound checking */
7521	/* add padding between stack variables */
7522	loc--;	7473	loc--;
7523	}	7474	}
7524	#endif	7475	#endif
@@ -7682,10 +7633,10 @@ static void gen_function(Sym sym, AttributeDef ad) · 157 unmodified lines
7682	/* NOTE: we patch the symbol size later */	7633	/* NOTE: we patch the symbol size later */
7683	put_extern_sym(sym, cur_text_section, ind, 0);	7634	put_extern_sym(sym, cur_text_section, ind, 0);
7684		7635
7685	if (ad && ad->a.constructor) {	7636	if (ad && ad->constructor) {
7686	add_init_array (tcc_state, sym);	7637	add_init_array (tcc_state, sym);
7687	}	7638	}
7688	if (ad && ad->a.destructor) {	7639	if (ad && ad->destructor) {
7689	add_fini_array (tcc_state, sym);	7640	add_fini_array (tcc_state, sym);
7690	}	7641	}
7691		7642
@@ -7698,56 +7649,16 @@ static void gen_function(Sym sym, AttributeDef ad) · 6 unmodified lines
7698	sym_push2(&local_stack, SYM_FIELD, 0, 0);	7649	sym_push2(&local_stack, SYM_FIELD, 0, 0);
7699	local_scope = 1; /* for function parameters */	7650	local_scope = 1; /* for function parameters */
7700	gfunc_prolog(sym);	7651	gfunc_prolog(sym);
7701	#ifdef CONFIG_TCC_BCHECK
7702	if (tcc_state->do_bounds_check
7703	&& sym->type.ref->f.func_type != FUNC_ELLIPSIS) {
7704	Sym *fpar;
7705
7706	/* Add function arguments in case & is used */
7707	for (fpar = sym->type.ref->next; fpar; fpar = fpar->next) {
7708	Sym *fsym = sym_find (fpar->v & ~SYM_FIELD);
7709
7710	if (fsym && (fsym->r & VT_VALMASK) == VT_LOCAL) {
7711	int align;
7712	int size = type_size(&fsym->type, &align);
7713
7714	if (size > 0)
7715	add_bound_param (&fsym->type, size, fsym->v, fsym->c);
7716	}
7717	}
7718	}
7719	#endif
7720	local_scope = 0;	7652	local_scope = 0;
7721	rsym = 0;	7653	rsym = 0;
7722	clear_temp_local_var_list();	7654	clear_temp_local_var_list();
7723	block(0);	7655	block(0);
7724	gsym(rsym);	7656	gsym(rsym);
7725	nocode_wanted = 0;	7657	nocode_wanted = 0;
7726	#ifdef CONFIG_TCC_BCHECK
7727	if (tcc_state->do_bounds_check) {
7728	addr_t o = func_bound_offset;
7729
7730	/* Remove parameters where address off is not used */
7731	while (o != lbounds_section->data_offset) {
7732	addr_t bounds_ptr = (addr_t ) (lbounds_section->data + o);
7733	if ((ssize_t) bounds_ptr[1] < 0) {
7734	lbounds_section->data_offset -= 2 * sizeof (addr_t);
7735	memmove(bounds_ptr, bounds_ptr + 2,
7736	lbounds_section->data_offset - o);
7737	}
7738	else {
7739	o += 2 * sizeof (addr_t);
7740	}
7741	}
7742	tcc_free (bound_local_param);
7743	nb_bound_local_param = 0;
7744	bound_local_param = NULL;
7745	}
7746	#endif
7747	gfunc_epilog();	7658	gfunc_epilog();
7748	cur_text_section->data_offset = ind;	7659	cur_text_section->data_offset = ind;
7749	/* reset local stack */	7660	/* reset local stack */
7750	sym_pop(&local_stack, NULL, 0);	7661	pop_local_syms(&local_stack, NULL, 0);
7751	local_scope = 0;	7662	local_scope = 0;
7752	label_pop(&global_label_stack, NULL, 0);	7663	label_pop(&global_label_stack, NULL, 0);
7753	sym_pop(&all_cleanups, NULL, 0);	7664	sym_pop(&all_cleanups, NULL, 0);

x86_64-gen.c+3−14

 }
 #if defined(CONFIG_TCC_BCHECK)
+static addr_t func_bound_offset;
 static unsigned long func_bound_ind;
 static void gen_bounds_call(int v)
     int arg;
 #ifdef CONFIG_TCC_BCHECK
-    if (tcc_state->do_bounds_check) {
+    if (tcc_state->do_bounds_check)
-        save_temp_local (nb_args);
         gbound_args(nb_args);
-    }
 #endif
     args_size = (nb_args < REGN ? REGN : nb_args) * PTR_SIZE;
     }
     vtop--;
-#ifdef CONFIG_TCC_BCHECK
-    if (tcc_state->do_bounds_check)
-        restore_temp_local ();
-#endif
 }
     char _onstack[nb_args ? nb_args : 1], *onstack = _onstack;
 #ifdef CONFIG_TCC_BCHECK
-    if (tcc_state->do_bounds_check) {
+    if (tcc_state->do_bounds_check)
-        save_temp_local (nb_args);
         gbound_args(nb_args);
-    }
 #endif
     /* calculate the number of integer/float register arguments, remember
     if (args_size)
         gadd_sp(args_size);
     vtop--;
-#ifdef CONFIG_TCC_BCHECK
-    if (tcc_state->do_bounds_check)
-        restore_temp_local ();
-#endif
 }
 #define FUNC_PROLOG_SIZE 11

Cleanup new bound checking code

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