| /* Target-dependent code for OpenBSD/amd64. |
| |
| Copyright 2003, 2004, 2005 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 2 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, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "defs.h" |
| #include "frame.h" |
| #include "gdbcore.h" |
| #include "symtab.h" |
| #include "objfiles.h" |
| #include "osabi.h" |
| #include "regset.h" |
| #include "target.h" |
| |
| #include "gdb_assert.h" |
| #include "gdb_string.h" |
| |
| #include "amd64-tdep.h" |
| #include "i387-tdep.h" |
| #include "solib-svr4.h" |
| |
| /* Support for core dumps. */ |
| |
| static void |
| amd64obsd_supply_regset (const struct regset *regset, |
| struct regcache *regcache, int regnum, |
| const void *regs, size_t len) |
| { |
| const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); |
| |
| gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE); |
| |
| i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset); |
| amd64_supply_fxsave (regcache, regnum, |
| ((const gdb_byte *)regs) + tdep->sizeof_gregset); |
| } |
| |
| static const struct regset * |
| amd64obsd_regset_from_core_section (struct gdbarch *gdbarch, |
| const char *sect_name, size_t sect_size) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| |
| /* OpenBSD core dumps don't use seperate register sets for the |
| general-purpose and floating-point registers. */ |
| |
| if (strcmp (sect_name, ".reg") == 0 |
| && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE) |
| { |
| if (tdep->gregset == NULL) |
| tdep->gregset = regset_alloc (gdbarch, amd64obsd_supply_regset, NULL); |
| return tdep->gregset; |
| } |
| |
| return NULL; |
| } |
| |
| |
| /* Support for signal handlers. */ |
| |
| /* Default page size. */ |
| static const int amd64obsd_page_size = 4096; |
| |
| /* Return whether the frame preceding NEXT_FRAME corresponds to an |
| OpenBSD sigtramp routine. */ |
| |
| static int |
| amd64obsd_sigtramp_p (struct frame_info *next_frame) |
| { |
| CORE_ADDR pc = frame_pc_unwind (next_frame); |
| CORE_ADDR start_pc = (pc & ~(amd64obsd_page_size - 1)); |
| const gdb_byte sigreturn[] = |
| { |
| 0x48, 0xc7, 0xc0, |
| 0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */ |
| 0xcd, 0x80 /* int $0x80 */ |
| }; |
| size_t buflen = (sizeof sigreturn) + 1; |
| gdb_byte *buf; |
| char *name; |
| |
| /* If the function has a valid symbol name, it isn't a |
| trampoline. */ |
| find_pc_partial_function (pc, &name, NULL, NULL); |
| if (name != NULL) |
| return 0; |
| |
| /* If the function lives in a valid section (even without a starting |
| point) it isn't a trampoline. */ |
| if (find_pc_section (pc) != NULL) |
| return 0; |
| |
| /* If we can't read the instructions at START_PC, return zero. */ |
| buf = alloca ((sizeof sigreturn) + 1); |
| if (!safe_frame_unwind_memory (next_frame, start_pc + 6, buf, buflen)) |
| return 0; |
| |
| /* Check for sigreturn(2). Depending on how the assembler encoded |
| the `movq %rsp, %rdi' instruction, the code starts at offset 6 or |
| 7. */ |
| if (memcmp (buf, sigreturn, sizeof sigreturn) |
| && memcpy (buf + 1, sigreturn, sizeof sigreturn)) |
| return 0; |
| |
| return 1; |
| } |
| |
| /* Assuming NEXT_FRAME is for a frame following a BSD sigtramp |
| routine, return the address of the associated sigcontext structure. */ |
| |
| static CORE_ADDR |
| amd64obsd_sigcontext_addr (struct frame_info *next_frame) |
| { |
| CORE_ADDR pc = frame_pc_unwind (next_frame); |
| ULONGEST offset = (pc & (amd64obsd_page_size - 1)); |
| |
| /* The %rsp register points at `struct sigcontext' upon entry of a |
| signal trampoline. The relevant part of the trampoline is |
| |
| call *%rax |
| movq %rsp, %rdi |
| pushq %rdi |
| movq $SYS_sigreturn,%rax |
| int $0x80 |
| |
| (see /usr/src/sys/arch/amd64/amd64/locore.S). The `pushq' |
| instruction clobbers %rsp, but its value is saved in `%rdi'. */ |
| |
| if (offset > 5) |
| return frame_unwind_register_unsigned (next_frame, AMD64_RDI_REGNUM); |
| else |
| return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM); |
| } |
| |
| /* OpenBSD 3.5 or later. */ |
| |
| /* Mapping between the general-purpose registers in `struct reg' |
| format and GDB's register cache layout. */ |
| |
| /* From <machine/reg.h>. */ |
| int amd64obsd_r_reg_offset[] = |
| { |
| 14 * 8, /* %rax */ |
| 13 * 8, /* %rbx */ |
| 3 * 8, /* %rcx */ |
| 2 * 8, /* %rdx */ |
| 1 * 8, /* %rsi */ |
| 0 * 8, /* %rdi */ |
| 12 * 8, /* %rbp */ |
| 15 * 8, /* %rsp */ |
| 4 * 8, /* %r8 .. */ |
| 5 * 8, |
| 6 * 8, |
| 7 * 8, |
| 8 * 8, |
| 9 * 8, |
| 10 * 8, |
| 11 * 8, /* ... %r15 */ |
| 16 * 8, /* %rip */ |
| 17 * 8, /* %eflags */ |
| 18 * 8, /* %cs */ |
| 19 * 8, /* %ss */ |
| 20 * 8, /* %ds */ |
| 21 * 8, /* %es */ |
| 22 * 8, /* %fs */ |
| 23 * 8 /* %gs */ |
| }; |
| |
| /* From <machine/signal.h>. */ |
| static int amd64obsd_sc_reg_offset[] = |
| { |
| 14 * 8, /* %rax */ |
| 13 * 8, /* %rbx */ |
| 3 * 8, /* %rcx */ |
| 2 * 8, /* %rdx */ |
| 1 * 8, /* %rsi */ |
| 0 * 8, /* %rdi */ |
| 12 * 8, /* %rbp */ |
| 24 * 8, /* %rsp */ |
| 4 * 8, /* %r8 ... */ |
| 5 * 8, |
| 6 * 8, |
| 7 * 8, |
| 8 * 8, |
| 9 * 8, |
| 10 * 8, |
| 11 * 8, /* ... %r15 */ |
| 21 * 8, /* %rip */ |
| 23 * 8, /* %eflags */ |
| 22 * 8, /* %cs */ |
| 25 * 8, /* %ss */ |
| 18 * 8, /* %ds */ |
| 17 * 8, /* %es */ |
| 16 * 8, /* %fs */ |
| 15 * 8 /* %gs */ |
| }; |
| |
| static void |
| amd64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| |
| amd64_init_abi (info, gdbarch); |
| |
| /* Initialize general-purpose register set details. */ |
| tdep->gregset_reg_offset = amd64obsd_r_reg_offset; |
| tdep->gregset_num_regs = ARRAY_SIZE (amd64obsd_r_reg_offset); |
| tdep->sizeof_gregset = 24 * 8; |
| |
| set_gdbarch_regset_from_core_section (gdbarch, |
| amd64obsd_regset_from_core_section); |
| |
| tdep->jb_pc_offset = 7 * 8; |
| |
| tdep->sigtramp_p = amd64obsd_sigtramp_p; |
| tdep->sigcontext_addr = amd64obsd_sigcontext_addr; |
| tdep->sc_reg_offset = amd64obsd_sc_reg_offset; |
| tdep->sc_num_regs = ARRAY_SIZE (amd64obsd_sc_reg_offset); |
| |
| /* OpenBSD uses SVR4-style shared libraries. */ |
| set_solib_svr4_fetch_link_map_offsets |
| (gdbarch, svr4_lp64_fetch_link_map_offsets); |
| } |
| |
| |
| /* Provide a prototype to silence -Wmissing-prototypes. */ |
| void _initialize_amd64obsd_tdep (void); |
| |
| void |
| _initialize_amd64obsd_tdep (void) |
| { |
| /* The OpenBSD/amd64 native dependent code makes this assumption. */ |
| gdb_assert (ARRAY_SIZE (amd64obsd_r_reg_offset) == AMD64_NUM_GREGS); |
| |
| gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, |
| GDB_OSABI_OPENBSD_ELF, amd64obsd_init_abi); |
| |
| /* OpenBSD uses traditional (a.out) NetBSD-style core dumps. */ |
| gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, |
| GDB_OSABI_NETBSD_AOUT, amd64obsd_init_abi); |
| } |