a28109e0ab
"bsd-uthread.h". (i386obsd_uthread_reg_offset): New variable. (I386OBSD_UTHREAD_ESP_OFFSET): New define. (i386obsd_supply_uthread, i386obsd_collect_uthread): New functions. (i386obsd_init_abi): Set supply_uthread and collect_uthread. * Makefile.in (i386obsd-tdep.o): Update dependencies. * config/i386/obsd.mt (TDEPFILES): Add bsd-uthread.o.
383 lines
11 KiB
C
383 lines
11 KiB
C
/* Target-dependent code for OpenBSD/i386.
|
||
|
||
Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002,
|
||
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 "arch-utils.h"
|
||
#include "frame.h"
|
||
#include "gdbcore.h"
|
||
#include "regcache.h"
|
||
#include "regset.h"
|
||
#include "symtab.h"
|
||
#include "objfiles.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"
|
||
#include "bsd-uthread.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 the frame preceding NEXT_FRAME corresponds to an
|
||
OpenBSD sigtramp routine. */
|
||
|
||
static int
|
||
i386obsd_sigtramp_p (struct frame_info *next_frame)
|
||
{
|
||
CORE_ADDR pc = frame_pc_unwind (next_frame);
|
||
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 */
|
||
};
|
||
size_t buflen = sizeof sigreturn;
|
||
char *name, *buf;
|
||
|
||
/* 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;
|
||
|
||
/* Allocate buffer. */
|
||
buf = alloca (buflen);
|
||
|
||
/* If we can't read the instructions at START_PC, return zero. */
|
||
if (!safe_frame_unwind_memory (next_frame, start_pc + 0x0a, buf, buflen))
|
||
return 0;
|
||
|
||
/* Check for sigreturn(2). */
|
||
if (memcmp (buf, sigreturn, buflen) == 0)
|
||
return 1;
|
||
|
||
/* If we can't read the instructions at START_PC, return zero. */
|
||
if (!safe_frame_unwind_memory (next_frame, start_pc + 0x14, buf, buflen))
|
||
return 0;
|
||
|
||
/* Check for sigreturn(2) (again). */
|
||
if (memcmp (buf, sigreturn, buflen) == 0)
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* 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 = 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 *
|
||
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 =
|
||
regset_alloc (gdbarch, i386obsd_aout_supply_regset, NULL);
|
||
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 */
|
||
};
|
||
|
||
/* From /usr/src/lib/libpthread/arch/i386/uthread_machdep.c. */
|
||
static int i386obsd_uthread_reg_offset[] =
|
||
{
|
||
11 * 4, /* %eax */
|
||
10 * 4, /* %ecx */
|
||
9 * 4, /* %edx */
|
||
8 * 4, /* %ebx */
|
||
-1, /* %esp */
|
||
6 * 4, /* %ebp */
|
||
5 * 4, /* %esi */
|
||
4 * 4, /* %edi */
|
||
12 * 4, /* %eip */
|
||
-1, /* %eflags */
|
||
13 * 4, /* %cs */
|
||
-1, /* %ss */
|
||
3 * 4, /* %ds */
|
||
2 * 4, /* %es */
|
||
1 * 4, /* %fs */
|
||
0 * 4 /* %gs */
|
||
};
|
||
|
||
/* Offset within the thread structure where we can find the saved
|
||
stack pointer (%esp). */
|
||
#define I386OBSD_UTHREAD_ESP_OFFSET 176
|
||
|
||
static void
|
||
i386obsd_supply_uthread (struct regcache *regcache,
|
||
int regnum, CORE_ADDR addr)
|
||
{
|
||
CORE_ADDR sp_addr = addr + I386OBSD_UTHREAD_ESP_OFFSET;
|
||
CORE_ADDR sp = 0;
|
||
char buf[4];
|
||
int i;
|
||
|
||
gdb_assert (regnum >= -1);
|
||
|
||
if (regnum == -1 || regnum == I386_ESP_REGNUM)
|
||
{
|
||
int offset;
|
||
|
||
/* Fetch stack pointer from thread structure. */
|
||
sp = read_memory_unsigned_integer (sp_addr, 4);
|
||
|
||
/* Adjust the stack pointer such that it looks as if we just
|
||
returned from _thread_machdep_switch. */
|
||
offset = i386obsd_uthread_reg_offset[I386_EIP_REGNUM] + 4;
|
||
store_unsigned_integer (buf, 4, sp + offset);
|
||
regcache_raw_supply (regcache, I386_ESP_REGNUM, buf);
|
||
}
|
||
|
||
for (i = 0; i < ARRAY_SIZE (i386obsd_uthread_reg_offset); i++)
|
||
{
|
||
if (i386obsd_uthread_reg_offset[i] != -1
|
||
&& (regnum == -1 || regnum == i))
|
||
{
|
||
/* Fetch stack pointer from thread structure (if we didn't
|
||
do so already). */
|
||
if (sp == 0)
|
||
sp = read_memory_unsigned_integer (sp_addr, 4);
|
||
|
||
/* Read the saved register from the stack frame. */
|
||
read_memory (sp + i386obsd_uthread_reg_offset[i], buf, 4);
|
||
regcache_raw_supply (regcache, i, buf);
|
||
}
|
||
}
|
||
|
||
}
|
||
|
||
static void
|
||
i386obsd_collect_uthread (const struct regcache *regcache,
|
||
int regnum, CORE_ADDR addr)
|
||
{
|
||
CORE_ADDR sp_addr = addr + I386OBSD_UTHREAD_ESP_OFFSET;
|
||
CORE_ADDR sp = 0;
|
||
char buf[4];
|
||
int i;
|
||
|
||
gdb_assert (regnum >= -1);
|
||
|
||
if (regnum == -1 || regnum == I386_ESP_REGNUM)
|
||
{
|
||
int offset;
|
||
|
||
/* Calculate the stack pointer (frame pointer) that will be
|
||
stored into the thread structure. */
|
||
offset = i386obsd_uthread_reg_offset[I386_EIP_REGNUM] + 4;
|
||
regcache_raw_collect (regcache, I386_ESP_REGNUM, buf);
|
||
sp = extract_unsigned_integer (buf, 4) - offset;
|
||
|
||
/* Store the stack pointer. */
|
||
write_memory_unsigned_integer (sp_addr, 4, sp);
|
||
|
||
/* The stack pointer was (potentially) modified. Make sure we
|
||
build a proper stack frame. */
|
||
regnum = -1;
|
||
}
|
||
|
||
for (i = 0; i < ARRAY_SIZE (i386obsd_uthread_reg_offset); i++)
|
||
{
|
||
if (i386obsd_uthread_reg_offset[i] != -1
|
||
&& (regnum == -1 || regnum == i))
|
||
{
|
||
/* Fetch stack pointer from thread structure (if we didn't
|
||
calculate it already). */
|
||
if (sp == 0)
|
||
sp = read_memory_unsigned_integer (sp_addr, 4);
|
||
|
||
/* Write the register into the stack frame. */
|
||
regcache_raw_collect (regcache, i, buf);
|
||
write_memory (sp + i386obsd_uthread_reg_offset[i], buf, 4);
|
||
}
|
||
}
|
||
}
|
||
|
||
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;
|
||
tdep->sigtramp_p = i386obsd_sigtramp_p;
|
||
|
||
/* OpenBSD has a `struct sigcontext' that's different from the
|
||
original 4.3 BSD. */
|
||
tdep->sc_reg_offset = i386obsd_sc_reg_offset;
|
||
tdep->sc_num_regs = ARRAY_SIZE (i386obsd_sc_reg_offset);
|
||
|
||
/* OpenBSD provides a user-level threads implementation. */
|
||
bsd_uthread_set_supply_uthread (gdbarch, i386obsd_supply_uthread);
|
||
bsd_uthread_set_collect_uthread (gdbarch, i386obsd_collect_uthread);
|
||
}
|
||
|
||
/* 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_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);
|
||
}
|