| 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 * const *names, |
| 30 | int lo, 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 * const *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 | } |