1 /* Target-dependent code for X86-based targets. 2 3 Copyright (C) 2018-2020 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #include "defs.h" 21 #include "x86-tdep.h" 22 #include "symtab.h" 23 24 25 /* Check whether NAME is included in NAMES[LO] (inclusive) to NAMES[HI] 26 (exclusive). */ 27 28 static bool 29 x86_is_thunk_register_name (const char *name, const char **names, int lo, 30 int hi) 31 { 32 int reg; 33 for (reg = lo; reg < hi; ++reg) 34 if (strcmp (name, names[reg]) == 0) 35 return true; 36 37 return false; 38 } 39 40 /* See x86-tdep.h. */ 41 42 bool 43 x86_in_indirect_branch_thunk (CORE_ADDR pc, const char **register_names, 44 int lo, int hi) 45 { 46 struct bound_minimal_symbol bmfun = lookup_minimal_symbol_by_pc (pc); 47 if (bmfun.minsym == nullptr) 48 return false; 49 50 const char *name = bmfun.minsym->linkage_name (); 51 if (name == nullptr) 52 return false; 53 54 /* Check the indirect return thunk first. */ 55 if (strcmp (name, "__x86_return_thunk") == 0) 56 return true; 57 58 /* Then check a family of indirect call/jump thunks. */ 59 static const char thunk[] = "__x86_indirect_thunk"; 60 static const size_t length = sizeof (thunk) - 1; 61 if (strncmp (name, thunk, length) != 0) 62 return false; 63 64 /* If that's the complete name, we're in the memory thunk. */ 65 name += length; 66 if (*name == '\0') 67 return true; 68 69 /* Check for suffixes. */ 70 if (*name++ != '_') 71 return false; 72 73 if (x86_is_thunk_register_name (name, register_names, lo, hi)) 74 return true; 75 76 return false; 77 } 78