NetBSD/gnu/dist/gdb6/gdb/i386nbsd-tdep.c

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/* Target-dependent code for NetBSD/i386.
Copyright (C) 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., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA. */
#include "defs.h"
#include "arch-utils.h"
#include "frame.h"
#include "gdbcore.h"
#include "regcache.h"
#include "regset.h"
#include "osabi.h"
#include "symtab.h"
#include "gdb_assert.h"
#include "gdb_string.h"
#include "i386-tdep.h"
#include "i387-tdep.h"
#include "nbsd-tdep.h"
#include "solib-svr4.h"
#include "elf-bfd.h" /* for header hack */
#include "trad-frame.h" /* signal trampoline/kernel frame support */
#include "frame-unwind.h" /* kernel frame support */
#include "tramp-frame.h" /* signal trampoline/kernel frame support
/* From <machine/reg.h>. */
static int i386nbsd_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
i386nbsd_aout_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_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 *
i386nbsd_aout_regset_from_core_section (struct gdbarch *gdbarch,
const char *sect_name,
size_t sect_size)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* NetBSD 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 =
regset_alloc (gdbarch, i386nbsd_aout_supply_regset, NULL);
return tdep->gregset;
}
return NULL;
}
/* From <machine/signal.h>. */
int i386nbsd_sc_reg_offset[] =
{
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 */
};
/* From <machine/mcontext.h>. */
int i386nbsd_mc_reg_offset[] =
{
11 * 4, /* %eax */
10 * 4, /* %ecx */
9 * 4, /* %edx */
8 * 4, /* %ebx */
7 * 4, /* %esp */
6 * 4, /* %ebp */
5 * 4, /* %esi */
4 * 4, /* %edi */
14 * 4, /* %eip */
16 * 4, /* %eflags */
15 * 4, /* %cs */
18 * 4, /* %ss */
3 * 4, /* %ds */
2 * 4, /* %es */
1 * 4, /* %fs */
0 * 4 /* %gs */
};
static void
i386nbsd_sigtramp_cache_init (const struct tramp_frame *,
struct frame_info *,
struct trad_frame_cache *,
CORE_ADDR);
static const struct tramp_frame i386nbsd_sigtramp_sc16 =
{
SIGTRAMP_FRAME,
1,
{
{ 0x8d, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x10, -1 },
/* leal 0x10(%esp), %eax */
{ 0x50, -1 }, /* pushl %eax */
{ 0x50, -1 }, /* pushl %eax */
{ 0xb8, -1 }, { 0x27, -1 }, {0x01, -1 }, {0x00, -1 }, {0x00, -1 },
/* movl $0x127, %eax # __sigreturn14 */
{ 0xcd, -1 }, { 0x80, -1},
/* int $0x80 */
{ 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
/* movl $0x1, %eax # exit */
{ 0xcd, -1 }, { 0x80, -1},
/* int $0x80 */
{ TRAMP_SENTINEL_INSN, -1 }
},
i386nbsd_sigtramp_cache_init
};
static const struct tramp_frame i386nbsd_sigtramp_sc2 =
{
SIGTRAMP_FRAME,
1,
{
{ 0x8d, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x0c, -1 },
/* leal 0x0c(%esp), %eax */
{ 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
/* movl %eax, 0x4(%esp) */
{ 0xb8, -1 }, { 0x27, -1 }, {0x01, -1 }, {0x00, -1 }, {0x00, -1 },
/* movl $0x127, %eax # __sigreturn14 */
{ 0xcd, -1 }, { 0x80, -1},
/* int $0x80 */
{ 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
/* movl %eax, 0x4(%esp) */
{ 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
/* movl $0x1, %eax */
{ 0xcd, -1 }, { 0x80, -1},
/* int $0x80 */
{ TRAMP_SENTINEL_INSN, -1 }
},
i386nbsd_sigtramp_cache_init
};
static const struct tramp_frame i386nbsd_sigtramp_si2 =
{
SIGTRAMP_FRAME,
1,
{
{ 0x8b, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x08, -1 },
/* movl 8(%esp),%eax */
{ 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
/* movl %eax, 0x4(%esp) */
{ 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
/* movl $0x134, %eax # setcontext */
{ 0xcd, -1 }, { 0x80, -1 },
/* int $0x80 */
{ 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
/* movl %eax, 0x4(%esp) */
{ 0xb8, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
/* movl $0x1, %eax */
{ 0xcd, -1 }, { 0x80, -1 },
/* int $0x80 */
{ TRAMP_SENTINEL_INSN, -1 }
},
i386nbsd_sigtramp_cache_init
};
static const struct tramp_frame i386nbsd_sigtramp_si31 =
{
SIGTRAMP_FRAME,
1,
{
{ 0x8d, -1 }, { 0x84, -1 }, { 0x24, -1 },
{ 0x8c, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
/* leal 0x8c(%esp), %eax */
{ 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
/* movl %eax, 0x4(%esp) */
{ 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
/* movl $0x134, %eax # setcontext */
{ 0xcd, -1 }, { 0x80, -1},
/* int $0x80 */
{ 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
/* movl %eax, 0x4(%esp) */
{ 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
/* movl $0x1, %eax */
{ 0xcd, -1 }, { 0x80, -1},
/* int $0x80 */
{ TRAMP_SENTINEL_INSN, -1 }
},
i386nbsd_sigtramp_cache_init
};
static const struct tramp_frame i386nbsd_sigtramp_si4 =
{
SIGTRAMP_FRAME,
1,
{
{ 0x8d, -1 }, { 0x84, -1 }, { 0x24, -1 },
{ 0x8c, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
/* leal 0x8c(%esp), %eax */
{ 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
/* movl %eax, 0x4(%esp) */
{ 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
/* movl $0x134, %eax # setcontext */
{ 0xcd, -1 }, { 0x80, -1},
/* int $0x80 */
{ 0xc7, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
{ 0xff, -1 }, { 0xff, -1 }, { 0xff, -1 }, { 0xff, -1 },
/* movl $0xffffffff,0x4(%esp) */
{ 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
/* movl $0x1, %eax */
{ 0xcd, -1 }, { 0x80, -1},
/* int $0x80 */
{ TRAMP_SENTINEL_INSN, -1 }
},
i386nbsd_sigtramp_cache_init
};
static void
i386nbsd_sigtramp_cache_init (const struct tramp_frame *self,
struct frame_info *next_frame,
struct trad_frame_cache *this_cache,
CORE_ADDR func)
{
struct gdbarch *gdbarch = get_frame_arch (next_frame);
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
CORE_ADDR sp = frame_unwind_register_unsigned (next_frame, I386_ESP_REGNUM);
CORE_ADDR base;
int *reg_offset;
int num_regs;
int i;
if (self == &i386nbsd_sigtramp_sc16 || self == &i386nbsd_sigtramp_sc2)
{
reg_offset = i386nbsd_sc_reg_offset;
num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
/* Read in the sigcontext address */
base = read_memory_unsigned_integer (sp + 8, 4);
}
else
{
reg_offset = i386nbsd_mc_reg_offset;
num_regs = ARRAY_SIZE (i386nbsd_mc_reg_offset);
/* Read in the ucontext address */
base = read_memory_unsigned_integer (sp + 8, 4);
/* offsetof(ucontext_t, uc_mcontext) == 36 */
base += 36;
}
for (i = 0; i < num_regs; i++)
if (reg_offset[i] != -1)
trad_frame_set_reg_addr (this_cache, i, base + reg_offset[i]);
/* Construct the frame ID using the function start. */
trad_frame_set_id (this_cache, frame_id_build (sp, func));
}
/* Kernel debugging support */
/* From <machine/frame.h>. Note that %esp and %ess are only saved in
a trap frame when entering the kernel from user space. */
static int i386nbsd_tf_reg_offset[] =
{
10 * 4, /* %eax */
9 * 4, /* %ecx */
8 * 4, /* %edx */
7 * 4, /* %ebx */
-1, /* %esp */
6 * 4, /* %ebp */
5 * 4, /* %esi */
4 * 4, /* %edi */
13 * 4, /* %eip */
15 * 4, /* %eflags */
14 * 4, /* %cs */
-1, /* %ss */
3 * 4, /* %ds */
2 * 4, /* %es */
1 * 4, /* %fs */
0 * 4 /* %gs */
};
static struct trad_frame_cache *
i386nbsd_trapframe_cache(struct frame_info *next_frame, void **this_cache)
{
struct trad_frame_cache *cache;
CORE_ADDR func, sp, addr, tmp;
ULONGEST cs;
char *name;
int i;
if (*this_cache)
return *this_cache;
cache = trad_frame_cache_zalloc (next_frame);
*this_cache = cache;
func = frame_func_unwind (next_frame);
sp = frame_unwind_register_unsigned (next_frame, I386_ESP_REGNUM);
find_pc_partial_function (func, &name, NULL, NULL);
if (name && strncmp (name, "Xintr", 5) == 0)
{
/* It's an interrupt frame. */
tmp = read_memory_unsigned_integer (sp + 4, 4);
if (tmp < 15)
{
/* Reasonable value for 'ppl': already on interrupt stack. */
addr = sp + 8;
}
else
{
/* Switch to previous stack. */
addr = tmp + 4;
}
}
else
{
/* It's a trap frame. */
addr = sp + 4;
}
for (i = 0; i < ARRAY_SIZE (i386nbsd_tf_reg_offset); i++)
if (i386nbsd_tf_reg_offset[i] != -1)
trad_frame_set_reg_addr (cache, i, addr + i386nbsd_tf_reg_offset[i]);
/* Read %cs from trap frame. */
addr += i386nbsd_tf_reg_offset[I386_CS_REGNUM];
cs = read_memory_unsigned_integer (addr, 4);
if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
{
/* Trap from user space; terminate backtrace. */
trad_frame_set_id (cache, null_frame_id);
}
else
{
/* Construct the frame ID using the function start. */
trad_frame_set_id (cache, frame_id_build (sp + 8, func));
}
return cache;
}
static void
i386nbsd_trapframe_this_id (struct frame_info *next_frame,
void **this_cache, struct frame_id *this_id)
{
struct trad_frame_cache *cache =
i386nbsd_trapframe_cache (next_frame, this_cache);
trad_frame_get_id (cache, this_id);
}
static void
i386nbsd_trapframe_prev_register (struct frame_info *next_frame,
void **this_cache, int regnum,
int *optimizedp, enum lval_type *lvalp,
CORE_ADDR *addrp, int *realnump,
gdb_byte *valuep)
{
struct trad_frame_cache *cache =
i386nbsd_trapframe_cache (next_frame, this_cache);
trad_frame_get_register (cache, next_frame, regnum,
optimizedp, lvalp, addrp, realnump, valuep);
}
static int
i386nbsd_trapframe_sniffer (const struct frame_unwind *self,
struct frame_info *next_frame,
void **this_prologue_cache)
{
ULONGEST cs;
char *name;
/* Check Current Privilege Level and bail out if we're not executing
in kernel space. */
cs = frame_unwind_register_unsigned (next_frame, I386_CS_REGNUM);
if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
return 0;
find_pc_partial_function (frame_pc_unwind (next_frame), &name, NULL, NULL);
return (name && ((strcmp (name, "alltraps") == 0)
|| (strcmp (name, "calltrap") == 0)
|| (strncmp (name, "Xtrap", 5) == 0)
|| (strcmp (name, "syscall1") == 0)
|| (strcmp (name, "Xsyscall") == 0)
|| (strncmp (name, "Xintr", 5) == 0)
|| (strncmp (name, "Xresume", 7) == 0)
|| (strncmp (name, "Xstray", 6) == 0)
|| (strncmp (name, "Xrecurse", 8) == 0)
|| (strncmp (name, "Xsoft", 5) == 0)
|| (strncmp (name, "Xdoreti", 5) == 0)));
}
const struct frame_unwind i386nbsd_trapframe_unwind = {
/* FIXME: kettenis/20051219: This really is more like an interrupt
frame, but SIGTRAMP_FRAME would print <signal handler called>,
which really is not what we want here. */
NORMAL_FRAME,
i386nbsd_trapframe_this_id,
i386nbsd_trapframe_prev_register,
NULL,
i386nbsd_trapframe_sniffer
};
static void
i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* Obviously NetBSD is BSD-based. */
i386bsd_init_abi (info, gdbarch);
/* NetBSD has a different `struct reg'. */
tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
tdep->sizeof_gregset = 16 * 4;
/* NetBSD uses -freg-struct-return by default. */
tdep->struct_return = reg_struct_return;
/* NetBSD uses tramp_frame sniffers for signal trampolines. */
tdep->sigcontext_addr= 0;
tdep->sigtramp_start = 0;
tdep->sigtramp_end = 0;
tdep->sigtramp_p = 0;
tdep->sc_reg_offset = 0;
tdep->sc_num_regs = 0;
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc16);
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc2);
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si2);
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si31);
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si4);
/* Unwind kernel trap frames correctly. */
frame_unwind_prepend_unwinder (gdbarch, &i386nbsd_trapframe_unwind);
}
/* NetBSD a.out. */
static void
i386nbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
i386nbsd_init_abi (info, gdbarch);
/* NetBSD a.out has a single register set. */
set_gdbarch_regset_from_core_section
(gdbarch, i386nbsd_aout_regset_from_core_section);
}
/* NetBSD ELF. */
static void
i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* It's still NetBSD. */
i386nbsd_init_abi (info, gdbarch);
/* But ELF-based. */
i386_elf_init_abi (info, gdbarch);
/* NetBSD ELF uses SVR4-style shared libraries. */
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_ilp32_fetch_link_map_offsets);
/* NetBSD ELF uses -fpcc-struct-return by default. */
tdep->struct_return = pcc_struct_return;
}
static enum gdb_osabi
i386nbsd_elf_osabi_sniffer (bfd *abfd)
{
if (strcmp (bfd_get_target (abfd), "elf32-i386") != 0)
return GDB_OSABI_UNKNOWN;
/* disgusting hack since kernels don't have a PT_NOTE section */
if ((unsigned long)elf_elfheader (abfd)->e_entry != (unsigned long)0xc0100000)
return GDB_OSABI_UNKNOWN;
return GDB_OSABI_NETBSD_ELF;
}
void
_initialize_i386nbsd_tdep (void)
{
gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_elf_flavour,
i386nbsd_elf_osabi_sniffer);
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT,
i386nbsdaout_init_abi);
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
i386nbsdelf_init_abi);
}