230 lines
6.5 KiB
C
230 lines
6.5 KiB
C
/* Target-dependent code for OpenBSD/sparc64.
|
||
|
||
Copyright 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 "frame-unwind.h"
|
||
#include "osabi.h"
|
||
#include "regset.h"
|
||
#include "symtab.h"
|
||
#include "objfiles.h"
|
||
#include "solib-svr4.h"
|
||
#include "trad-frame.h"
|
||
|
||
#include "gdb_assert.h"
|
||
|
||
#include "sparc64-tdep.h"
|
||
|
||
/* OpenBSD uses the traditional NetBSD core file format, even for
|
||
ports that use ELF. The core files don't use multiple register
|
||
sets. Instead, the general-purpose and floating-point registers
|
||
are lumped together in a single section. Unlike on NetBSD, OpenBSD
|
||
uses a different layout for its general-purpose registers than the
|
||
layout used for ptrace(2). */
|
||
|
||
/* From <machine/reg.h>. */
|
||
const struct sparc_gregset sparc64obsd_core_gregset =
|
||
{
|
||
0 * 8, /* "tstate" */
|
||
1 * 8, /* %pc */
|
||
2 * 8, /* %npc */
|
||
3 * 8, /* %y */
|
||
-1, /* %fprs */
|
||
-1,
|
||
7 * 8, /* %g1 */
|
||
22 * 8, /* %l0 */
|
||
4 /* sizeof (%y) */
|
||
};
|
||
|
||
static void
|
||
sparc64obsd_supply_gregset (const struct regset *regset,
|
||
struct regcache *regcache,
|
||
int regnum, const void *gregs, size_t len)
|
||
{
|
||
const char *regs = gregs;
|
||
|
||
sparc64_supply_gregset (&sparc64obsd_core_gregset, regcache, regnum, regs);
|
||
sparc64_supply_fpregset (regcache, regnum, regs + 288);
|
||
}
|
||
|
||
|
||
/* Signal trampolines. */
|
||
|
||
/* 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. We recognize the
|
||
trampoline by looking for the code that invokes the sigreturn
|
||
system call. The offset where we can find that code varies from
|
||
release to release.
|
||
|
||
By the way, the mapping mentioned above is read-only, so you cannot
|
||
place a breakpoint in the signal trampoline. */
|
||
|
||
/* Default page size. */
|
||
static const int sparc64obsd_page_size = 8192;
|
||
|
||
/* Offset for sigreturn(2). */
|
||
static const int sparc64obsd_sigreturn_offset[] = {
|
||
0xf0, /* OpenBSD 3.8 */
|
||
0xec, /* OpenBSD 3.6 */
|
||
0xe8, /* OpenBSD 3.2 */
|
||
-1
|
||
};
|
||
|
||
static int
|
||
sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
|
||
{
|
||
CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1));
|
||
unsigned long insn;
|
||
const int *offset;
|
||
|
||
if (name)
|
||
return 0;
|
||
|
||
for (offset = sparc64obsd_sigreturn_offset; *offset != -1; offset++)
|
||
{
|
||
/* Check for "restore %g0, SYS_sigreturn, %g1". */
|
||
insn = sparc_fetch_instruction (start_pc + *offset);
|
||
if (insn != 0x83e82067)
|
||
continue;
|
||
|
||
/* Check for "t ST_SYSCALL". */
|
||
insn = sparc_fetch_instruction (start_pc + *offset + 8);
|
||
if (insn != 0x91d02000)
|
||
continue;
|
||
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
static struct sparc_frame_cache *
|
||
sparc64obsd_frame_cache (struct frame_info *next_frame, void **this_cache)
|
||
{
|
||
struct sparc_frame_cache *cache;
|
||
CORE_ADDR addr;
|
||
|
||
if (*this_cache)
|
||
return *this_cache;
|
||
|
||
cache = sparc_frame_cache (next_frame, this_cache);
|
||
gdb_assert (cache == *this_cache);
|
||
|
||
/* If we couldn't find the frame's function, we're probably dealing
|
||
with an on-stack signal trampoline. */
|
||
if (cache->pc == 0)
|
||
{
|
||
cache->pc = frame_pc_unwind (next_frame);
|
||
cache->pc &= ~(sparc64obsd_page_size - 1);
|
||
|
||
/* Since we couldn't find the frame's function, the cache was
|
||
initialized under the assumption that we're frameless. */
|
||
cache->frameless_p = 0;
|
||
addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM);
|
||
if (addr & 1)
|
||
addr += BIAS;
|
||
cache->base = addr;
|
||
}
|
||
|
||
/* We find the appropriate instance of `struct sigcontext' at a
|
||
fixed offset in the signal frame. */
|
||
addr = cache->base + 128 + 16;
|
||
cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, next_frame);
|
||
|
||
return cache;
|
||
}
|
||
|
||
static void
|
||
sparc64obsd_frame_this_id (struct frame_info *next_frame, void **this_cache,
|
||
struct frame_id *this_id)
|
||
{
|
||
struct sparc_frame_cache *cache =
|
||
sparc64obsd_frame_cache (next_frame, this_cache);
|
||
|
||
(*this_id) = frame_id_build (cache->base, cache->pc);
|
||
}
|
||
|
||
static void
|
||
sparc64obsd_frame_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 sparc_frame_cache *cache =
|
||
sparc64obsd_frame_cache (next_frame, this_cache);
|
||
|
||
trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
|
||
optimizedp, lvalp, addrp, realnump, valuep);
|
||
}
|
||
|
||
static const struct frame_unwind sparc64obsd_frame_unwind =
|
||
{
|
||
SIGTRAMP_FRAME,
|
||
sparc64obsd_frame_this_id,
|
||
sparc64obsd_frame_prev_register
|
||
};
|
||
|
||
static const struct frame_unwind *
|
||
sparc64obsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
|
||
{
|
||
CORE_ADDR pc = frame_pc_unwind (next_frame);
|
||
char *name;
|
||
|
||
find_pc_partial_function (pc, &name, NULL, NULL);
|
||
if (sparc64obsd_pc_in_sigtramp (pc, name))
|
||
return &sparc64obsd_frame_unwind;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
|
||
static void
|
||
sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
tdep->gregset = regset_alloc (gdbarch, sparc64obsd_supply_gregset, NULL);
|
||
tdep->sizeof_gregset = 832;
|
||
|
||
frame_unwind_append_sniffer (gdbarch, sparc64obsd_sigtramp_frame_sniffer);
|
||
|
||
sparc64_init_abi (info, gdbarch);
|
||
|
||
/* OpenBSD/sparc64 has SVR4-style shared libraries. */
|
||
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
|
||
set_solib_svr4_fetch_link_map_offsets
|
||
(gdbarch, svr4_lp64_fetch_link_map_offsets);
|
||
}
|
||
|
||
|
||
/* Provide a prototype to silence -Wmissing-prototypes. */
|
||
void _initialize_sparc64obsd_tdep (void);
|
||
|
||
void
|
||
_initialize_sparc64obsd_tdep (void)
|
||
{
|
||
gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
|
||
GDB_OSABI_OPENBSD_ELF, sparc64obsd_init_abi);
|
||
}
|