| /* Signal trampoline unwinder, for GDB the GNU Debugger. |
| |
| Copyright (C) 2004-2021 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "tramp-frame.h" |
| #include "frame-unwind.h" |
| #include "gdbcore.h" |
| #include "symtab.h" |
| #include "objfiles.h" |
| #include "target.h" |
| #include "trad-frame.h" |
| #include "frame-base.h" |
| |
| struct frame_data |
| { |
| const struct tramp_frame *tramp_frame; |
| }; |
| |
| struct tramp_frame_cache |
| { |
| CORE_ADDR func; |
| const struct tramp_frame *tramp_frame; |
| struct trad_frame_cache *trad_cache; |
| }; |
| |
| static struct trad_frame_cache * |
| tramp_frame_cache (struct frame_info *this_frame, |
| void **this_cache) |
| { |
| struct tramp_frame_cache *tramp_cache |
| = (struct tramp_frame_cache *) *this_cache; |
| |
| if (tramp_cache->trad_cache == NULL) |
| { |
| tramp_cache->trad_cache = trad_frame_cache_zalloc (this_frame); |
| tramp_cache->tramp_frame->init (tramp_cache->tramp_frame, |
| this_frame, |
| tramp_cache->trad_cache, |
| tramp_cache->func); |
| } |
| return tramp_cache->trad_cache; |
| } |
| |
| static void |
| tramp_frame_this_id (struct frame_info *this_frame, |
| void **this_cache, |
| struct frame_id *this_id) |
| { |
| struct trad_frame_cache *trad_cache |
| = tramp_frame_cache (this_frame, this_cache); |
| |
| trad_frame_get_id (trad_cache, this_id); |
| } |
| |
| static struct value * |
| tramp_frame_prev_register (struct frame_info *this_frame, |
| void **this_cache, |
| int prev_regnum) |
| { |
| struct trad_frame_cache *trad_cache |
| = tramp_frame_cache (this_frame, this_cache); |
| |
| return trad_frame_get_register (trad_cache, this_frame, prev_regnum); |
| } |
| |
| static CORE_ADDR |
| tramp_frame_start (const struct tramp_frame *tramp, |
| struct frame_info *this_frame, CORE_ADDR pc) |
| { |
| struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| int ti; |
| |
| /* Check if we can use this trampoline. */ |
| if (tramp->validate && !tramp->validate (tramp, this_frame, &pc)) |
| return 0; |
| |
| /* Search through the trampoline for one that matches the |
| instruction sequence around PC. */ |
| for (ti = 0; tramp->insn[ti].bytes != TRAMP_SENTINEL_INSN; ti++) |
| { |
| CORE_ADDR func = pc - tramp->insn_size * ti; |
| int i; |
| |
| for (i = 0; 1; i++) |
| { |
| gdb_byte buf[sizeof (tramp->insn[0])]; |
| ULONGEST insn; |
| size_t insn_size = tramp->insn_size; |
| |
| if (tramp->insn[i].bytes == TRAMP_SENTINEL_INSN) |
| return func; |
| if (!safe_frame_unwind_memory (this_frame, |
| func + i * insn_size, |
| {buf, insn_size})) |
| break; |
| insn = extract_unsigned_integer (buf, insn_size, byte_order); |
| if (tramp->insn[i].bytes != (insn & tramp->insn[i].mask)) |
| break; |
| } |
| } |
| /* Trampoline doesn't match. */ |
| return 0; |
| } |
| |
| static int |
| tramp_frame_sniffer (const struct frame_unwind *self, |
| struct frame_info *this_frame, |
| void **this_cache) |
| { |
| const struct tramp_frame *tramp = self->unwind_data->tramp_frame; |
| CORE_ADDR pc = get_frame_pc (this_frame); |
| CORE_ADDR func; |
| struct tramp_frame_cache *tramp_cache; |
| |
| /* tausq/2004-12-12: We used to assume if pc has a name or is in a valid |
| section, then this is not a trampoline. However, this assumption is |
| false on HPUX which has a signal trampoline that has a name; it can |
| also be false when using an alternative signal stack. */ |
| func = tramp_frame_start (tramp, this_frame, pc); |
| if (func == 0) |
| return 0; |
| tramp_cache = FRAME_OBSTACK_ZALLOC (struct tramp_frame_cache); |
| tramp_cache->func = func; |
| tramp_cache->tramp_frame = tramp; |
| (*this_cache) = tramp_cache; |
| return 1; |
| } |
| |
| void |
| tramp_frame_prepend_unwinder (struct gdbarch *gdbarch, |
| const struct tramp_frame *tramp_frame) |
| { |
| struct frame_data *data; |
| struct frame_unwind *unwinder; |
| int i; |
| |
| /* Check that the instruction sequence contains a sentinel. */ |
| for (i = 0; i < ARRAY_SIZE (tramp_frame->insn); i++) |
| { |
| if (tramp_frame->insn[i].bytes == TRAMP_SENTINEL_INSN) |
| break; |
| } |
| gdb_assert (i < ARRAY_SIZE (tramp_frame->insn)); |
| gdb_assert (tramp_frame->insn_size <= sizeof (tramp_frame->insn[0].bytes)); |
| |
| data = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_data); |
| unwinder = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind); |
| |
| data->tramp_frame = tramp_frame; |
| unwinder->type = tramp_frame->frame_type; |
| unwinder->unwind_data = data; |
| unwinder->sniffer = tramp_frame_sniffer; |
| unwinder->stop_reason = default_frame_unwind_stop_reason; |
| unwinder->this_id = tramp_frame_this_id; |
| unwinder->prev_register = tramp_frame_prev_register; |
| frame_unwind_prepend_unwinder (gdbarch, unwinder); |
| } |