317 lines
8.7 KiB
C
317 lines
8.7 KiB
C
/* Target-dependent code for NetBSD/alpha.
|
||
|
||
Copyright (C) 2002-2013 Free Software Foundation, Inc.
|
||
|
||
Contributed by Wasabi Systems, 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 "regcache.h"
|
||
#include "regset.h"
|
||
#include "value.h"
|
||
|
||
#include "gdb_assert.h"
|
||
#include <string.h>
|
||
|
||
#include "alpha-tdep.h"
|
||
#include "alphabsd-tdep.h"
|
||
#include "nbsd-tdep.h"
|
||
#include "solib-svr4.h"
|
||
#include "target.h"
|
||
|
||
/* Core file support. */
|
||
|
||
/* Even though NetBSD/alpha used ELF since day one, it used the
|
||
traditional a.out-style core dump format before NetBSD 1.6. */
|
||
|
||
/* Sizeof `struct reg' in <machine/reg.h>. */
|
||
#define ALPHANBSD_SIZEOF_GREGS (32 * 8)
|
||
|
||
/* Sizeof `struct fpreg' in <machine/reg.h. */
|
||
#define ALPHANBSD_SIZEOF_FPREGS ((32 * 8) + 8)
|
||
|
||
/* Supply register REGNUM from the buffer specified by FPREGS and LEN
|
||
in the floating-point register set REGSET to register cache
|
||
REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
|
||
|
||
static void
|
||
alphanbsd_supply_fpregset (const struct regset *regset,
|
||
struct regcache *regcache,
|
||
int regnum, const void *fpregs, size_t len)
|
||
{
|
||
const gdb_byte *regs = fpregs;
|
||
int i;
|
||
|
||
gdb_assert (len >= ALPHANBSD_SIZEOF_FPREGS);
|
||
|
||
for (i = ALPHA_FP0_REGNUM; i < ALPHA_FP0_REGNUM + 31; i++)
|
||
{
|
||
if (regnum == i || regnum == -1)
|
||
regcache_raw_supply (regcache, i, regs + (i - ALPHA_FP0_REGNUM) * 8);
|
||
}
|
||
|
||
if (regnum == ALPHA_FPCR_REGNUM || regnum == -1)
|
||
regcache_raw_supply (regcache, ALPHA_FPCR_REGNUM, regs + 32 * 8);
|
||
}
|
||
|
||
/* Supply register REGNUM from the buffer specified by GREGS and LEN
|
||
in the general-purpose register set REGSET to register cache
|
||
REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
|
||
|
||
static void
|
||
alphanbsd_supply_gregset (const struct regset *regset,
|
||
struct regcache *regcache,
|
||
int regnum, const void *gregs, size_t len)
|
||
{
|
||
const gdb_byte *regs = gregs;
|
||
int i;
|
||
|
||
gdb_assert (len >= ALPHANBSD_SIZEOF_GREGS);
|
||
|
||
for (i = 0; i < ALPHA_ZERO_REGNUM; i++)
|
||
{
|
||
if (regnum == i || regnum == -1)
|
||
regcache_raw_supply (regcache, i, regs + i * 8);
|
||
}
|
||
|
||
if (regnum == ALPHA_PC_REGNUM || regnum == -1)
|
||
regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8);
|
||
}
|
||
|
||
/* Supply register REGNUM from the buffer specified by GREGS and LEN
|
||
in the general-purpose register set REGSET to register cache
|
||
REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
|
||
|
||
static void
|
||
alphanbsd_aout_supply_gregset (const struct regset *regset,
|
||
struct regcache *regcache,
|
||
int regnum, const void *gregs, size_t len)
|
||
{
|
||
const gdb_byte *regs = gregs;
|
||
int i;
|
||
|
||
/* Table to map a GDB register number to a trapframe register index. */
|
||
static const int regmap[] =
|
||
{
|
||
0, 1, 2, 3,
|
||
4, 5, 6, 7,
|
||
8, 9, 10, 11,
|
||
12, 13, 14, 15,
|
||
30, 31, 32, 16,
|
||
17, 18, 19, 20,
|
||
21, 22, 23, 24,
|
||
25, 29, 26
|
||
};
|
||
|
||
gdb_assert (len >= ALPHANBSD_SIZEOF_GREGS);
|
||
|
||
for (i = 0; i < ARRAY_SIZE(regmap); i++)
|
||
{
|
||
if (regnum == i || regnum == -1)
|
||
regcache_raw_supply (regcache, i, regs + regmap[i] * 8);
|
||
}
|
||
|
||
if (regnum == ALPHA_PC_REGNUM || regnum == -1)
|
||
regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8);
|
||
|
||
if (len >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS)
|
||
{
|
||
regs += ALPHANBSD_SIZEOF_GREGS;
|
||
len -= ALPHANBSD_SIZEOF_GREGS;
|
||
alphanbsd_supply_fpregset (regset, regcache, regnum, regs, len);
|
||
}
|
||
}
|
||
|
||
/* NetBSD/alpha register sets. */
|
||
|
||
static struct regset alphanbsd_gregset =
|
||
{
|
||
NULL,
|
||
alphanbsd_supply_gregset
|
||
};
|
||
|
||
static struct regset alphanbsd_fpregset =
|
||
{
|
||
NULL,
|
||
alphanbsd_supply_fpregset
|
||
};
|
||
|
||
static struct regset alphanbsd_aout_gregset =
|
||
{
|
||
NULL,
|
||
alphanbsd_aout_supply_gregset
|
||
};
|
||
|
||
/* Return the appropriate register set for the core section identified
|
||
by SECT_NAME and SECT_SIZE. */
|
||
|
||
const struct regset *
|
||
alphanbsd_regset_from_core_section (struct gdbarch *gdbarch,
|
||
const char *sect_name, size_t sect_size)
|
||
{
|
||
if (strcmp (sect_name, ".reg") == 0 && sect_size >= ALPHANBSD_SIZEOF_GREGS)
|
||
{
|
||
if (sect_size >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS)
|
||
return &alphanbsd_aout_gregset;
|
||
else
|
||
return &alphanbsd_gregset;
|
||
}
|
||
|
||
if (strcmp (sect_name, ".reg2") == 0 && sect_size >= ALPHANBSD_SIZEOF_FPREGS)
|
||
return &alphanbsd_fpregset;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
|
||
/* Signal trampolines. */
|
||
|
||
/* Under NetBSD/alpha, signal handler invocations can be identified by the
|
||
designated code sequence that is used to return from a signal handler.
|
||
In particular, the return address of a signal handler points to the
|
||
following code sequence:
|
||
|
||
ldq a0, 0(sp)
|
||
lda sp, 16(sp)
|
||
lda v0, 295(zero) # __sigreturn14
|
||
call_pal callsys
|
||
|
||
Each instruction has a unique encoding, so we simply attempt to match
|
||
the instruction the PC is pointing to with any of the above instructions.
|
||
If there is a hit, we know the offset to the start of the designated
|
||
sequence and can then check whether we really are executing in the
|
||
signal trampoline. If not, -1 is returned, otherwise the offset from the
|
||
start of the return sequence is returned. */
|
||
static const gdb_byte sigtramp_retcode[] =
|
||
{
|
||
0x00, 0x00, 0x1e, 0xa6, /* ldq a0, 0(sp) */
|
||
0x10, 0x00, 0xde, 0x23, /* lda sp, 16(sp) */
|
||
0x27, 0x01, 0x1f, 0x20, /* lda v0, 295(zero) */
|
||
0x83, 0x00, 0x00, 0x00, /* call_pal callsys */
|
||
};
|
||
#define RETCODE_NWORDS 4
|
||
#define RETCODE_SIZE (RETCODE_NWORDS * 4)
|
||
|
||
static LONGEST
|
||
alphanbsd_sigtramp_offset (struct gdbarch *gdbarch, CORE_ADDR pc)
|
||
{
|
||
gdb_byte ret[RETCODE_SIZE], w[4];
|
||
LONGEST off;
|
||
int i;
|
||
|
||
if (target_read_memory (pc, w, 4) != 0)
|
||
return -1;
|
||
|
||
for (i = 0; i < RETCODE_NWORDS; i++)
|
||
{
|
||
if (memcmp (w, sigtramp_retcode + (i * 4), 4) == 0)
|
||
break;
|
||
}
|
||
if (i == RETCODE_NWORDS)
|
||
return (-1);
|
||
|
||
off = i * 4;
|
||
pc -= off;
|
||
|
||
if (target_read_memory (pc, ret, sizeof (ret)) != 0)
|
||
return -1;
|
||
|
||
if (memcmp (ret, sigtramp_retcode, RETCODE_SIZE) == 0)
|
||
return off;
|
||
|
||
return -1;
|
||
}
|
||
|
||
static int
|
||
alphanbsd_pc_in_sigtramp (struct gdbarch *gdbarch,
|
||
CORE_ADDR pc, const char *func_name)
|
||
{
|
||
return (nbsd_pc_in_sigtramp (pc, func_name)
|
||
|| alphanbsd_sigtramp_offset (gdbarch, pc) >= 0);
|
||
}
|
||
|
||
static CORE_ADDR
|
||
alphanbsd_sigcontext_addr (struct frame_info *frame)
|
||
{
|
||
/* FIXME: This is not correct for all versions of NetBSD/alpha.
|
||
We will probably need to disassemble the trampoline to figure
|
||
out which trampoline frame type we have. */
|
||
if (!get_next_frame (frame))
|
||
return 0;
|
||
return get_frame_base (get_next_frame (frame));
|
||
}
|
||
|
||
|
||
static void
|
||
alphanbsd_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);
|
||
|
||
/* NetBSD/alpha does not provide single step support via ptrace(2); we
|
||
must use software single-stepping. */
|
||
set_gdbarch_software_single_step (gdbarch, alpha_software_single_step);
|
||
|
||
/* NetBSD/alpha has SVR4-style shared libraries. */
|
||
set_solib_svr4_fetch_link_map_offsets
|
||
(gdbarch, svr4_lp64_fetch_link_map_offsets);
|
||
|
||
tdep->dynamic_sigtramp_offset = alphanbsd_sigtramp_offset;
|
||
tdep->pc_in_sigtramp = alphanbsd_pc_in_sigtramp;
|
||
tdep->sigcontext_addr = alphanbsd_sigcontext_addr;
|
||
|
||
tdep->jb_pc = 2;
|
||
tdep->jb_elt_size = 8;
|
||
|
||
set_gdbarch_regset_from_core_section
|
||
(gdbarch, alphanbsd_regset_from_core_section);
|
||
}
|
||
|
||
|
||
static enum gdb_osabi
|
||
alphanbsd_core_osabi_sniffer (bfd *abfd)
|
||
{
|
||
if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
|
||
return GDB_OSABI_NETBSD_ELF;
|
||
|
||
return GDB_OSABI_UNKNOWN;
|
||
}
|
||
|
||
|
||
/* Provide a prototype to silence -Wmissing-prototypes. */
|
||
void _initialize_alphanbsd_tdep (void);
|
||
|
||
void
|
||
_initialize_alphanbsd_tdep (void)
|
||
{
|
||
/* BFD doesn't set a flavour for NetBSD style a.out core files. */
|
||
gdbarch_register_osabi_sniffer (bfd_arch_alpha, bfd_target_unknown_flavour,
|
||
alphanbsd_core_osabi_sniffer);
|
||
|
||
gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_NETBSD_ELF,
|
||
alphanbsd_init_abi);
|
||
}
|