| /* Target-dependent code for OpenBSD/alpha. |
| |
| Copyright (C) 2006-2012 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 "frame.h" |
| #include "gdbcore.h" |
| #include "osabi.h" |
| |
| #include "obsd-tdep.h" |
| #include "alpha-tdep.h" |
| #include "alphabsd-tdep.h" |
| #include "solib-svr4.h" |
| |
| /* Signal trampolines. */ |
| |
| /* The OpenBSD kernel maps the signal trampoline at some random |
| location in user space, which means that the traditional BSD way of |
| detecting it won't work. |
| |
| The signal trampoline will be mapped at an address that is page |
| aligned. We recognize the signal trampoline by looking for the |
| sigreturn system call. */ |
| |
| static const int alphaobsd_page_size = 8192; |
| |
| static LONGEST |
| alphaobsd_sigtramp_offset (struct gdbarch *gdbarch, CORE_ADDR pc) |
| { |
| return (pc & (alphaobsd_page_size - 1)); |
| } |
| |
| static int |
| alphaobsd_pc_in_sigtramp (struct gdbarch *gdbarch, |
| CORE_ADDR pc, const char *name) |
| { |
| CORE_ADDR start_pc = (pc & ~(alphaobsd_page_size - 1)); |
| unsigned insn; |
| |
| if (name) |
| return 0; |
| |
| /* Check for "". */ |
| insn = alpha_read_insn (gdbarch, start_pc + 5 * ALPHA_INSN_SIZE); |
| if (insn != 0x201f0067) |
| return 0; |
| |
| /* Check for "". */ |
| insn = alpha_read_insn (gdbarch, start_pc + 6 * ALPHA_INSN_SIZE); |
| if (insn != 0x00000083) |
| return 0; |
| |
| return 1; |
| } |
| |
| static CORE_ADDR |
| alphaobsd_sigcontext_addr (struct frame_info *this_frame) |
| { |
| struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| CORE_ADDR pc = get_frame_pc (this_frame); |
| |
| if (alphaobsd_sigtramp_offset (gdbarch, pc) < 3 * ALPHA_INSN_SIZE) |
| { |
| /* On entry, a pointer the `struct sigcontext' is passed in %a2. */ |
| return get_frame_register_unsigned (this_frame, ALPHA_A0_REGNUM + 2); |
| } |
| else if (alphaobsd_sigtramp_offset (gdbarch, pc) < 4 * ALPHA_INSN_SIZE) |
| { |
| /* It is stored on the stack Before calling the signal handler. */ |
| CORE_ADDR sp; |
| sp = get_frame_register_unsigned (this_frame, ALPHA_SP_REGNUM); |
| return get_frame_memory_unsigned (this_frame, sp, 8); |
| } |
| else |
| { |
| /* It is reloaded into %a0 for the sigreturn(2) call. */ |
| return get_frame_register_unsigned (this_frame, ALPHA_A0_REGNUM); |
| } |
| } |
| |
| |
| static void |
| alphaobsd_init_abi(struct gdbarch_info info, struct gdbarch *gdbarch) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| |
| /* Hook into the DWARF CFI frame unwinder. */ |
| alpha_dwarf2_init_abi (info, gdbarch); |
| |
| /* Hook into the MDEBUG frame unwinder. */ |
| alpha_mdebug_init_abi (info, gdbarch); |
| |
| /* OpenBSD/alpha 3.0 and earlier does not provide single step |
| support via ptrace(2); use software single-stepping for now. */ |
| set_gdbarch_software_single_step (gdbarch, alpha_software_single_step); |
| |
| /* OpenBSD/alpha has SVR4-style shared libraries. */ |
| set_solib_svr4_fetch_link_map_offsets |
| (gdbarch, svr4_lp64_fetch_link_map_offsets); |
| set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver); |
| |
| tdep->dynamic_sigtramp_offset = alphaobsd_sigtramp_offset; |
| tdep->pc_in_sigtramp = alphaobsd_pc_in_sigtramp; |
| tdep->sigcontext_addr = alphaobsd_sigcontext_addr; |
| |
| tdep->jb_pc = 2; |
| tdep->jb_elt_size = 8; |
| |
| set_gdbarch_regset_from_core_section |
| (gdbarch, alphanbsd_regset_from_core_section); |
| } |
| |
| |
| /* Provide a prototype to silence -Wmissing-prototypes. */ |
| void _initialize_alphaobsd_tdep (void); |
| |
| void |
| _initialize_alphaobsd_tdep (void) |
| { |
| gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_OPENBSD_ELF, |
| alphaobsd_init_abi); |
| } |