1/* RTL manipulation functions exported by Pointer Bounds Checker. 2 Copyright (C) 2014-2015 Free Software Foundation, Inc. 3 Contributed by Ilya Enkovich (ilya.enkovich@intel.com) 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 3, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING3. If not see 19<http://www.gnu.org/licenses/>. */ 20 21#include "config.h" 22#include "system.h" 23#include "coretypes.h" 24#include "symtab.h" 25#include "hashtab.h" 26#include "hash-set.h" 27#include "vec.h" 28#include "machmode.h" 29#include "tm.h" 30#include "hard-reg-set.h" 31#include "input.h" 32#include "function.h" 33#include "rtl.h" 34#include "flags.h" 35#include "statistics.h" 36#include "double-int.h" 37#include "real.h" 38#include "fixed-value.h" 39#include "alias.h" 40#include "wide-int.h" 41#include "inchash.h" 42#include "tree.h" 43#include "insn-config.h" 44#include "expmed.h" 45#include "dojump.h" 46#include "explow.h" 47#include "calls.h" 48#include "emit-rtl.h" 49#include "varasm.h" 50#include "stmt.h" 51#include "expr.h" 52#include "target.h" 53#include "tree-ssa-alias.h" 54#include "internal-fn.h" 55#include "is-a.h" 56#include "predict.h" 57#include "basic-block.h" 58#include "fold-const.h" 59#include "gimple-expr.h" 60#include "gimple.h" 61#include "bitmap.h" 62#include "rtl-chkp.h" 63#include "tree-chkp.h" 64#include "hash-map.h" 65 66static hash_map<tree, rtx> *chkp_rtx_bounds_map; 67 68/* Get bounds rtx associated with NODE via 69 chkp_set_rtl_bounds call. */ 70rtx 71chkp_get_rtl_bounds (tree node) 72{ 73 rtx *slot; 74 75 if (!chkp_rtx_bounds_map) 76 return NULL_RTX; 77 78 slot = chkp_rtx_bounds_map->get (node); 79 return slot ? *slot : NULL_RTX; 80} 81 82/* Associate bounds rtx VAL with NODE. */ 83void 84chkp_set_rtl_bounds (tree node, rtx val) 85{ 86 if (!chkp_rtx_bounds_map) 87 chkp_rtx_bounds_map = new hash_map<tree, rtx>; 88 89 chkp_rtx_bounds_map->put (node, val); 90} 91 92/* Reset all bounds stored via chkp_set_rtl_bounds. */ 93void 94chkp_reset_rtl_bounds () 95{ 96 if (!chkp_rtx_bounds_map) 97 return; 98 99 delete chkp_rtx_bounds_map; 100 chkp_rtx_bounds_map = NULL; 101} 102 103/* Split SLOT identifying slot for function value or 104 argument into two parts SLOT_VAL and SLOT_BND. 105 First is the slot for regular value and the other one is 106 for bounds. */ 107void 108chkp_split_slot (rtx slot, rtx *slot_val, rtx *slot_bnd) 109{ 110 int i; 111 int val_num = 0; 112 int bnd_num = 0; 113 rtx *val_tmps; 114 rtx *bnd_tmps; 115 116 *slot_bnd = 0; 117 118 if (!slot 119 || GET_CODE (slot) != PARALLEL) 120 { 121 *slot_val = slot; 122 return; 123 } 124 125 val_tmps = XALLOCAVEC (rtx, XVECLEN (slot, 0)); 126 bnd_tmps = XALLOCAVEC (rtx, XVECLEN (slot, 0)); 127 128 for (i = 0; i < XVECLEN (slot, 0); i++) 129 { 130 rtx elem = XVECEXP (slot, 0, i); 131 rtx reg = GET_CODE (elem) == EXPR_LIST ? XEXP (elem, 0) : elem; 132 133 if (!reg) 134 continue; 135 136 if (POINTER_BOUNDS_MODE_P (GET_MODE (reg)) || CONST_INT_P (reg)) 137 bnd_tmps[bnd_num++] = elem; 138 else 139 val_tmps[val_num++] = elem; 140 } 141 142 gcc_assert (val_num); 143 144 if (!bnd_num) 145 { 146 *slot_val = slot; 147 return; 148 } 149 150 if ((GET_CODE (val_tmps[0]) == EXPR_LIST) || (val_num > 1)) 151 *slot_val = gen_rtx_PARALLEL (GET_MODE (slot), 152 gen_rtvec_v (val_num, val_tmps)); 153 else 154 *slot_val = val_tmps[0]; 155 156 if ((GET_CODE (bnd_tmps[0]) == EXPR_LIST) || (bnd_num > 1)) 157 *slot_bnd = gen_rtx_PARALLEL (VOIDmode, 158 gen_rtvec_v (bnd_num, bnd_tmps)); 159 else 160 *slot_bnd = bnd_tmps[0]; 161} 162 163/* Join previously splitted to VAL and BND rtx for function 164 value or argument and return it. */ 165rtx 166chkp_join_splitted_slot (rtx val, rtx bnd) 167{ 168 rtx res; 169 int i, n = 0; 170 171 if (!bnd) 172 return val; 173 174 if (GET_CODE (val) == PARALLEL) 175 n += XVECLEN (val, 0); 176 else 177 n++; 178 179 if (GET_CODE (bnd) == PARALLEL) 180 n += XVECLEN (bnd, 0); 181 else 182 n++; 183 184 res = gen_rtx_PARALLEL (GET_MODE (val), rtvec_alloc (n)); 185 186 n = 0; 187 188 if (GET_CODE (val) == PARALLEL) 189 for (i = 0; i < XVECLEN (val, 0); i++) 190 XVECEXP (res, 0, n++) = XVECEXP (val, 0, i); 191 else 192 XVECEXP (res, 0, n++) = val; 193 194 if (GET_CODE (bnd) == PARALLEL) 195 for (i = 0; i < XVECLEN (bnd, 0); i++) 196 XVECEXP (res, 0, n++) = XVECEXP (bnd, 0, i); 197 else 198 XVECEXP (res, 0, n++) = bnd; 199 200 return res; 201} 202 203/* If PAR is PARALLEL holding registers then transform 204 it into PARALLEL holding EXPR_LISTs of those regs 205 and zero constant (similar to how function value 206 on multiple registers looks like). */ 207void 208chkp_put_regs_to_expr_list (rtx par) 209{ 210 int n; 211 212 if (GET_CODE (par) != PARALLEL 213 || GET_CODE (XVECEXP (par, 0, 0)) == EXPR_LIST) 214 return; 215 216 for (n = 0; n < XVECLEN (par, 0); n++) 217 XVECEXP (par, 0, n) = gen_rtx_EXPR_LIST (VOIDmode, 218 XVECEXP (par, 0, n), 219 const0_rtx); 220} 221 222/* Search rtx PAR describing function return value for an 223 item related to value at offset OFFS and return it. 224 Return NULL if item was not found. */ 225rtx 226chkp_get_value_with_offs (rtx par, rtx offs) 227{ 228 int n; 229 230 gcc_assert (GET_CODE (par) == PARALLEL); 231 232 for (n = 0; n < XVECLEN (par, 0); n++) 233 { 234 rtx par_offs = XEXP (XVECEXP (par, 0, n), 1); 235 if (INTVAL (offs) == INTVAL (par_offs)) 236 return XEXP (XVECEXP (par, 0, n), 0); 237 } 238 239 return NULL; 240} 241 242/* Emit instructions to store BOUNDS for pointer VALUE 243 stored in MEM. 244 Function is used by expand to pass bounds for args 245 passed on stack. */ 246void 247chkp_emit_bounds_store (rtx bounds, rtx value, rtx mem) 248{ 249 gcc_assert (MEM_P (mem)); 250 251 if (REG_P (bounds) || CONST_INT_P (bounds)) 252 { 253 rtx ptr; 254 255 if (REG_P (value)) 256 ptr = value; 257 else 258 { 259 rtx slot = adjust_address (value, Pmode, 0); 260 ptr = gen_reg_rtx (Pmode); 261 emit_move_insn (ptr, slot); 262 } 263 264 if (CONST_INT_P (bounds)) 265 bounds = targetm.calls.load_bounds_for_arg (value, ptr, bounds); 266 267 targetm.calls.store_bounds_for_arg (ptr, mem, 268 bounds, NULL); 269 } 270 else 271 { 272 int i; 273 274 gcc_assert (GET_CODE (bounds) == PARALLEL); 275 gcc_assert (GET_CODE (value) == PARALLEL || MEM_P (value) || REG_P (value)); 276 277 for (i = 0; i < XVECLEN (bounds, 0); i++) 278 { 279 rtx reg = XEXP (XVECEXP (bounds, 0, i), 0); 280 rtx offs = XEXP (XVECEXP (bounds, 0, i), 1); 281 rtx slot = adjust_address (mem, Pmode, INTVAL (offs)); 282 rtx ptr; 283 284 if (GET_CODE (value) == PARALLEL) 285 ptr = chkp_get_value_with_offs (value, offs); 286 else if (MEM_P (value)) 287 { 288 rtx tmp = adjust_address (value, Pmode, INTVAL (offs)); 289 ptr = gen_reg_rtx (Pmode); 290 emit_move_insn (ptr, tmp); 291 } 292 else 293 ptr = gen_rtx_SUBREG (Pmode, value, INTVAL (offs)); 294 295 targetm.calls.store_bounds_for_arg (ptr, slot, reg, NULL); 296 } 297 } 298} 299 300/* Emit code to copy bounds for structure VALUE of type TYPE 301 copied to SLOT. */ 302void 303chkp_copy_bounds_for_stack_parm (rtx slot, rtx value, tree type) 304{ 305 bitmap have_bound; 306 bitmap_iterator bi; 307 unsigned i; 308 rtx tmp = NULL, bnd; 309 310 gcc_assert (TYPE_SIZE (type)); 311 gcc_assert (MEM_P (value)); 312 gcc_assert (MEM_P (slot)); 313 gcc_assert (RECORD_OR_UNION_TYPE_P (type)); 314 315 bitmap_obstack_initialize (NULL); 316 have_bound = BITMAP_ALLOC (NULL); 317 chkp_find_bound_slots (type, have_bound); 318 319 EXECUTE_IF_SET_IN_BITMAP (have_bound, 0, i, bi) 320 { 321 rtx ptr = adjust_address (value, Pmode, i * POINTER_SIZE / 8); 322 rtx to = adjust_address (slot, Pmode, i * POINTER_SIZE / 8); 323 324 if (!tmp) 325 tmp = gen_reg_rtx (Pmode); 326 327 emit_move_insn (tmp, ptr); 328 bnd = targetm.calls.load_bounds_for_arg (ptr, tmp, NULL); 329 targetm.calls.store_bounds_for_arg (tmp, to, bnd, NULL); 330 } 331 332 BITMAP_FREE (have_bound); 333 bitmap_obstack_release (NULL); 334} 335