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/* Target-dependent code for OpenBSD/sparc64.
Copyright (C) 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., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, 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);
}
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