diff options
Diffstat (limited to 'contrib/gdb/gdb/i386obsd-tdep.c')
| -rw-r--r-- | contrib/gdb/gdb/i386obsd-tdep.c | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/contrib/gdb/gdb/i386obsd-tdep.c b/contrib/gdb/gdb/i386obsd-tdep.c new file mode 100644 index 0000000..d8556ea --- /dev/null +++ b/contrib/gdb/gdb/i386obsd-tdep.c @@ -0,0 +1,277 @@ +/* Target-dependent code for OpenBSD/i386. + + Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002, + 2003, 2004 + 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 "arch-utils.h" +#include "gdbcore.h" +#include "regcache.h" +#include "regset.h" +#include "osabi.h" +#include "target.h" + +#include "gdb_assert.h" +#include "gdb_string.h" + +#include "i386-tdep.h" +#include "i387-tdep.h" +#include "solib-svr4.h" + +/* Support for signal handlers. */ + +/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page + in virtual memory. The randomness makes it somewhat tricky to + detect it, but fortunately we can rely on the fact that the start + of the sigtramp routine is page-aligned. By the way, the mapping + is read-only, so you cannot place a breakpoint in the signal + trampoline. */ + +/* Default page size. */ +static const int i386obsd_page_size = 4096; + +/* Return whether PC is in an OpenBSD sigtramp routine. */ + +static int +i386obsd_pc_in_sigtramp (CORE_ADDR pc, char *name) +{ + CORE_ADDR start_pc = (pc & ~(i386obsd_page_size - 1)); + const char sigreturn[] = + { + 0xb8, + 0x67, 0x00, 0x00, 0x00, /* movl $SYS_sigreturn, %eax */ + 0xcd, 0x80 /* int $0x80 */ + }; + char *buf; + + /* Avoid reading memory from the target if possible. If we're in a + named function, we're certainly not in a sigtramp routine + provided by the kernel. Take synthetic function names into + account though. */ + if (name && name[0] != '<') + return 0; + + /* If we can't read the instructions at START_PC, return zero. */ + buf = alloca (sizeof sigreturn); + if (target_read_memory (start_pc + 0x14, buf, sizeof sigreturn)) + return 0; + + /* Check for sigreturn(2). */ + if (memcmp (buf, sigreturn, sizeof sigreturn) == 0) + return 1; + + /* Check for a traditional BSD sigtramp routine. */ + return i386bsd_pc_in_sigtramp (pc, name); +} + +/* Return the start address of the sigtramp routine. */ + +static CORE_ADDR +i386obsd_sigtramp_start (CORE_ADDR pc) +{ + CORE_ADDR start_pc = (pc & ~(i386obsd_page_size - 1)); + + if (i386bsd_pc_in_sigtramp (pc, NULL)) + return i386bsd_sigtramp_start (pc); + + return start_pc; +} + +/* Return the end address of the sigtramp routine. */ + +static CORE_ADDR +i386obsd_sigtramp_end (CORE_ADDR pc) +{ + CORE_ADDR start_pc = (pc & ~(i386obsd_page_size - 1)); + + if (i386bsd_pc_in_sigtramp (pc, NULL)) + return i386bsd_sigtramp_end (pc); + + return start_pc + 0x22; +} + +/* Mapping between the general-purpose registers in `struct reg' + format and GDB's register cache layout. */ + +/* From <machine/reg.h>. */ +static int i386obsd_r_reg_offset[] = +{ + 0 * 4, /* %eax */ + 1 * 4, /* %ecx */ + 2 * 4, /* %edx */ + 3 * 4, /* %ebx */ + 4 * 4, /* %esp */ + 5 * 4, /* %ebp */ + 6 * 4, /* %esi */ + 7 * 4, /* %edi */ + 8 * 4, /* %eip */ + 9 * 4, /* %eflags */ + 10 * 4, /* %cs */ + 11 * 4, /* %ss */ + 12 * 4, /* %ds */ + 13 * 4, /* %es */ + 14 * 4, /* %fs */ + 15 * 4 /* %gs */ +}; + +static void +i386obsd_aout_supply_regset (const struct regset *regset, + struct regcache *regcache, int regnum, + const void *regs, size_t len) +{ + const struct gdbarch_tdep *tdep = regset->descr; + + gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE); + + i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset); + i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset); +} + +static const struct regset * +i386obsd_aout_regset_from_core_section (struct gdbarch *gdbarch, + const char *sect_name, + size_t sect_size) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* OpenBSD a.out 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_FSAVE) + { + if (tdep->gregset == NULL) + { + tdep->gregset = XMALLOC (struct regset); + tdep->gregset->descr = tdep; + tdep->gregset->supply_regset = i386obsd_aout_supply_regset; + } + return tdep->gregset; + } + + return NULL; +} + + +/* Sigtramp routine location for OpenBSD 3.1 and earlier releases. */ +CORE_ADDR i386obsd_sigtramp_start_addr = 0xbfbfdf20; +CORE_ADDR i386obsd_sigtramp_end_addr = 0xbfbfdff0; + +/* From <machine/signal.h>. */ +int i386obsd_sc_reg_offset[I386_NUM_GREGS] = +{ + 10 * 4, /* %eax */ + 9 * 4, /* %ecx */ + 8 * 4, /* %edx */ + 7 * 4, /* %ebx */ + 14 * 4, /* %esp */ + 6 * 4, /* %ebp */ + 5 * 4, /* %esi */ + 4 * 4, /* %edi */ + 11 * 4, /* %eip */ + 13 * 4, /* %eflags */ + 12 * 4, /* %cs */ + 15 * 4, /* %ss */ + 3 * 4, /* %ds */ + 2 * 4, /* %es */ + 1 * 4, /* %fs */ + 0 * 4 /* %gs */ +}; + +static void +i386obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* Obviously OpenBSD is BSD-based. */ + i386bsd_init_abi (info, gdbarch); + + /* OpenBSD has a different `struct reg'. */ + tdep->gregset_reg_offset = i386obsd_r_reg_offset; + tdep->gregset_num_regs = ARRAY_SIZE (i386obsd_r_reg_offset); + tdep->sizeof_gregset = 16 * 4; + + /* OpenBSD uses -freg-struct-return by default. */ + tdep->struct_return = reg_struct_return; + + /* OpenBSD uses a different memory layout. */ + tdep->sigtramp_start = i386obsd_sigtramp_start_addr; + tdep->sigtramp_end = i386obsd_sigtramp_end_addr; + set_gdbarch_pc_in_sigtramp (gdbarch, i386obsd_pc_in_sigtramp); + set_gdbarch_sigtramp_start (gdbarch, i386obsd_sigtramp_start); + set_gdbarch_sigtramp_end (gdbarch, i386obsd_sigtramp_end); + + /* OpenBSD has a `struct sigcontext' that's different from the + origional 4.3 BSD. */ + tdep->sc_reg_offset = i386obsd_sc_reg_offset; + tdep->sc_num_regs = ARRAY_SIZE (i386obsd_sc_reg_offset); +} + +/* OpenBSD a.out. */ + +static void +i386obsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + i386obsd_init_abi (info, gdbarch); + + /* OpenBSD a.out has a single register set. */ + set_gdbarch_regset_from_core_section + (gdbarch, i386obsd_aout_regset_from_core_section); +} + +/* OpenBSD ELF. */ + +static void +i386obsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* It's still OpenBSD. */ + i386obsd_init_abi (info, gdbarch); + + /* But ELF-based. */ + i386_elf_init_abi (info, gdbarch); + + /* OpenBSD ELF uses SVR4-style shared libraries. */ + set_gdbarch_in_solib_call_trampoline + (gdbarch, generic_in_solib_call_trampoline); + set_solib_svr4_fetch_link_map_offsets + (gdbarch, svr4_ilp32_fetch_link_map_offsets); +} + + +/* Provide a prototype to silence -Wmissing-prototypes. */ +void _initialize_i386obsd_tdep (void); + +void +_initialize_i386obsd_tdep (void) +{ + /* FIXME: kettenis/20021020: Since OpenBSD/i386 binaries are + indistingushable from NetBSD/i386 a.out binaries, building a GDB + that should support both these targets will probably not work as + expected. */ +#define GDB_OSABI_OPENBSD_AOUT GDB_OSABI_NETBSD_AOUT + + gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_OPENBSD_AOUT, + i386obsd_aout_init_abi); + gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_OPENBSD_ELF, + i386obsd_elf_init_abi); +} |
