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/* Target-dependent code for GNU/Linux UltraSPARC.
Copyright 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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "frame.h"
#include "frame-unwind.h"
#include "gdbarch.h"
#include "osabi.h"
#include "solib-svr4.h"
#include "symtab.h"
#include "trad-frame.h"
#include "gdb_assert.h"
#include "gdb_string.h"
#include "sparc64-tdep.h"
/* The instruction sequence for RT signals is
mov __NR_rt_sigreturn, %g1 ! hex: 0x82102065
ta 0x6d ! hex: 0x91d0206d
The effect is to call the system call rt_sigreturn.
Note that 64-bit binaries only use this RT signal return method. */
#define LINUX64_RT_SIGTRAMP_INSN0 0x82102065
#define LINUX64_RT_SIGTRAMP_INSN1 0x91d0206d
/* If PC is in a sigtramp routine consisting of the instructions
LINUX64_RT_SIGTRAMP_INSN0 and LINUX64_RT_SIGTRAMP_INSN1, return
the address of the start of the routine. Otherwise, return 0. */
static CORE_ADDR
sparc64_linux_sigtramp_start (struct frame_info *next_frame)
{
CORE_ADDR pc = frame_pc_unwind (next_frame);
ULONGEST word0, word1;
unsigned char buf[8]; /* Two instructions. */
/* We only recognize a signal trampoline if PC is at the start of
one of the instructions. We optimize for finding the PC at the
start of the instruction sequence, as will be the case when the
trampoline is not the first frame on the stack. We assume that
in the case where the PC is not at the start of the instruction
sequence, there will be a few trailing readable bytes on the
stack. */
if (!safe_frame_unwind_memory (next_frame, pc, buf, sizeof buf))
return 0;
word0 = extract_unsigned_integer (buf, 4);
if (word0 != LINUX64_RT_SIGTRAMP_INSN0)
{
if (word0 != LINUX64_RT_SIGTRAMP_INSN1)
return 0;
pc -= 4;
if (!safe_frame_unwind_memory (next_frame, pc, buf, sizeof buf))
return 0;
word0 = extract_unsigned_integer (buf, 4);
}
word1 = extract_unsigned_integer (buf + 4, 4);
if (word0 != LINUX64_RT_SIGTRAMP_INSN0
|| word1 != LINUX64_RT_SIGTRAMP_INSN1)
return 0;
return pc;
}
static int
sparc64_linux_sigtramp_p (struct frame_info *next_frame)
{
CORE_ADDR pc = frame_pc_unwind (next_frame);
char *name;
find_pc_partial_function (pc, &name, NULL, NULL);
/* If we have NAME, we can optimize the search. The trampolines is
named __rt_sigreturn_stub. However, is isn't dynamically exported
from the shared C library, so the trampoline may appear to be part
of the preceding function. This should always be sigaction,
__sigaction, or __libc_sigaction (all aliases to the same function). */
if (name == NULL || strstr (name, "sigaction") != NULL)
return (sparc64_linux_sigtramp_start (next_frame) != 0);
return (strcmp ("__rt_sigreturn_stub", name) == 0);
}
static struct sparc_frame_cache *
sparc64_linux_sigtramp_frame_cache (struct frame_info *next_frame,
void **this_cache)
{
struct sparc_frame_cache *cache;
CORE_ADDR sigcontext_addr, addr;
int regnum;
if (*this_cache)
return *this_cache;
cache = sparc_frame_cache (next_frame, this_cache);
gdb_assert (cache == *this_cache);
regnum = SPARC_SP_REGNUM;
cache->base = frame_unwind_register_unsigned (next_frame, regnum);
if (cache->base & 1)
cache->base += BIAS;
regnum = SPARC_O1_REGNUM;
sigcontext_addr = frame_unwind_register_unsigned (next_frame, regnum);
/* If this is a RT signal trampoline, adjust SIGCONTEXT_ADDR
accordingly. */
addr = sparc64_linux_sigtramp_start (next_frame);
if (addr)
sigcontext_addr += 128;
else
addr = frame_func_unwind (next_frame);
cache->pc = addr;
cache->saved_regs = trad_frame_alloc_saved_regs (next_frame);
/* Offsets from <bits/sigcontext.h> */
/* Since %g0 is always zero, keep the identity encoding. */
for (addr = sigcontext_addr + 8, regnum = SPARC_G1_REGNUM;
regnum <= SPARC_O7_REGNUM; regnum++, addr += 8)
cache->saved_regs[regnum].addr = addr;
cache->saved_regs[SPARC64_STATE_REGNUM].addr = addr + 0;
cache->saved_regs[SPARC64_PC_REGNUM].addr = addr + 8;
cache->saved_regs[SPARC64_NPC_REGNUM].addr = addr + 16;
cache->saved_regs[SPARC64_Y_REGNUM].addr = addr + 24;
cache->saved_regs[SPARC64_FPRS_REGNUM].addr = addr + 28;
for (regnum = SPARC_L0_REGNUM, addr = cache->base;
regnum <= SPARC_I7_REGNUM; regnum++, addr += 8)
cache->saved_regs[regnum].addr = addr;
return cache;
}
static void
sparc64_linux_sigtramp_frame_this_id (struct frame_info *next_frame,
void **this_cache,
struct frame_id *this_id)
{
struct sparc_frame_cache *cache =
sparc64_linux_sigtramp_frame_cache (next_frame, this_cache);
(*this_id) = frame_id_build (cache->base, cache->pc);
}
static void
sparc64_linux_sigtramp_frame_prev_register (struct frame_info *next_frame,
void **this_cache,
int regnum, int *optimizedp,
enum lval_type *lvalp,
CORE_ADDR *addrp,
int *realnump, void *valuep)
{
struct sparc_frame_cache *cache =
sparc64_linux_sigtramp_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 sparc64_linux_sigtramp_frame_unwind =
{
SIGTRAMP_FRAME,
sparc64_linux_sigtramp_frame_this_id,
sparc64_linux_sigtramp_frame_prev_register
};
static const struct frame_unwind *
sparc64_linux_sigtramp_frame_sniffer (struct frame_info *next_frame)
{
if (sparc64_linux_sigtramp_p (next_frame))
return &sparc64_linux_sigtramp_frame_unwind;
return NULL;
}
static void
sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
frame_unwind_append_sniffer (gdbarch, sparc64_linux_sigtramp_frame_sniffer);
/* GNU/Linux is very similar to Solaris ... */
sparc64_sol2_init_abi (info, gdbarch);
/* ... but doesn't have kernel-assisted single-stepping support. */
set_gdbarch_software_single_step (gdbarch, sparc_software_single_step);
/* Enable TLS support. */
set_gdbarch_fetch_tls_load_module_address (gdbarch,
svr4_fetch_objfile_link_map);
}
/* Provide a prototype to silence -Wmissing-prototypes. */
extern void _initialize_sparc64_linux_tdep (void);
void
_initialize_sparc64_linux_tdep (void)
{
gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
GDB_OSABI_LINUX, sparc64_linux_init_abi);
}
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