290 lines
8.8 KiB
C
290 lines
8.8 KiB
C
/* Target-dependent code for GNU/Linux SPARC.
|
||
|
||
Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009
|
||
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 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 "dwarf2-frame.h"
|
||
#include "frame.h"
|
||
#include "frame-unwind.h"
|
||
#include "gdbtypes.h"
|
||
#include "regset.h"
|
||
#include "gdbarch.h"
|
||
#include "gdbcore.h"
|
||
#include "osabi.h"
|
||
#include "regcache.h"
|
||
#include "solib-svr4.h"
|
||
#include "symtab.h"
|
||
#include "trad-frame.h"
|
||
#include "tramp-frame.h"
|
||
|
||
#include "sparc-tdep.h"
|
||
|
||
/* Signal trampoline support. */
|
||
|
||
static void sparc32_linux_sigframe_init (const struct tramp_frame *self,
|
||
struct frame_info *this_frame,
|
||
struct trad_frame_cache *this_cache,
|
||
CORE_ADDR func);
|
||
|
||
/* GNU/Linux has two flavors of signals. Normal signal handlers, and
|
||
"realtime" (RT) signals. The RT signals can provide additional
|
||
information to the signal handler if the SA_SIGINFO flag is set
|
||
when establishing a signal handler using `sigaction'. It is not
|
||
unlikely that future versions of GNU/Linux will support SA_SIGINFO
|
||
for normal signals too. */
|
||
|
||
/* When the sparc Linux kernel calls a signal handler and the
|
||
SA_RESTORER flag isn't set, the return address points to a bit of
|
||
code on the stack. This code checks whether the PC appears to be
|
||
within this bit of code.
|
||
|
||
The instruction sequence for normal signals is encoded below.
|
||
Checking for the code sequence should be somewhat reliable, because
|
||
the effect is to call the system call sigreturn. This is unlikely
|
||
to occur anywhere other than a signal trampoline. */
|
||
|
||
static const struct tramp_frame sparc32_linux_sigframe =
|
||
{
|
||
SIGTRAMP_FRAME,
|
||
4,
|
||
{
|
||
{ 0x821020d8, -1 }, /* mov __NR_sugreturn, %g1 */
|
||
{ 0x91d02010, -1 }, /* ta 0x10 */
|
||
{ TRAMP_SENTINEL_INSN, -1 }
|
||
},
|
||
sparc32_linux_sigframe_init
|
||
};
|
||
|
||
/* The instruction sequence for RT signals is slightly different. The
|
||
effect is to call the system call rt_sigreturn. */
|
||
|
||
static const struct tramp_frame sparc32_linux_rt_sigframe =
|
||
{
|
||
SIGTRAMP_FRAME,
|
||
4,
|
||
{
|
||
{ 0x82102065, -1 }, /* mov __NR_rt_sigreturn, %g1 */
|
||
{ 0x91d02010, -1 }, /* ta 0x10 */
|
||
{ TRAMP_SENTINEL_INSN, -1 }
|
||
},
|
||
sparc32_linux_sigframe_init
|
||
};
|
||
|
||
static void
|
||
sparc32_linux_sigframe_init (const struct tramp_frame *self,
|
||
struct frame_info *this_frame,
|
||
struct trad_frame_cache *this_cache,
|
||
CORE_ADDR func)
|
||
{
|
||
CORE_ADDR base, addr, sp_addr;
|
||
int regnum;
|
||
|
||
base = get_frame_register_unsigned (this_frame, SPARC_O1_REGNUM);
|
||
if (self == &sparc32_linux_rt_sigframe)
|
||
base += 128;
|
||
|
||
/* Offsets from <bits/sigcontext.h>. */
|
||
|
||
trad_frame_set_reg_addr (this_cache, SPARC32_PSR_REGNUM, base + 0);
|
||
trad_frame_set_reg_addr (this_cache, SPARC32_PC_REGNUM, base + 4);
|
||
trad_frame_set_reg_addr (this_cache, SPARC32_NPC_REGNUM, base + 8);
|
||
trad_frame_set_reg_addr (this_cache, SPARC32_Y_REGNUM, base + 12);
|
||
|
||
/* Since %g0 is always zero, keep the identity encoding. */
|
||
addr = base + 20;
|
||
sp_addr = base + 16 + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 4);
|
||
for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
|
||
{
|
||
trad_frame_set_reg_addr (this_cache, regnum, addr);
|
||
addr += 4;
|
||
}
|
||
|
||
base = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
|
||
addr = get_frame_memory_unsigned (this_frame, sp_addr, 4);
|
||
|
||
for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
|
||
{
|
||
trad_frame_set_reg_addr (this_cache, regnum, addr);
|
||
addr += 4;
|
||
}
|
||
trad_frame_set_id (this_cache, frame_id_build (base, func));
|
||
}
|
||
|
||
/* Return the address of a system call's alternative return
|
||
address. */
|
||
|
||
static CORE_ADDR
|
||
sparc32_linux_step_trap (struct frame_info *frame, unsigned long insn)
|
||
{
|
||
if (insn == 0x91d02010)
|
||
{
|
||
ULONGEST sc_num = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);
|
||
|
||
/* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216 */
|
||
if (sc_num == 101 || sc_num == 216)
|
||
{
|
||
ULONGEST sp, pc_offset;
|
||
|
||
sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);
|
||
|
||
/* The kernel puts the sigreturn registers on the stack,
|
||
and this is where the signal unwinding state is take from
|
||
when returning from a signal.
|
||
|
||
For __NR_sigreturn, this register area sits 96 bytes from
|
||
the base of the stack. The saved PC sits 4 bytes into the
|
||
sigreturn register save area.
|
||
|
||
For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits
|
||
right before the sigreturn register save area. */
|
||
|
||
pc_offset = 96 + 4;
|
||
if (sc_num == 101)
|
||
pc_offset += 128;
|
||
|
||
return read_memory_unsigned_integer (sp + pc_offset, 4);
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
const struct sparc_gregset sparc32_linux_core_gregset =
|
||
{
|
||
32 * 4, /* %psr */
|
||
33 * 4, /* %pc */
|
||
34 * 4, /* %npc */
|
||
35 * 4, /* %y */
|
||
-1, /* %wim */
|
||
-1, /* %tbr */
|
||
1 * 4, /* %g1 */
|
||
16 * 4, /* %l0 */
|
||
4, /* y size */
|
||
};
|
||
|
||
|
||
static void
|
||
sparc32_linux_supply_core_gregset (const struct regset *regset,
|
||
struct regcache *regcache,
|
||
int regnum, const void *gregs, size_t len)
|
||
{
|
||
sparc32_supply_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
|
||
}
|
||
|
||
static void
|
||
sparc32_linux_collect_core_gregset (const struct regset *regset,
|
||
const struct regcache *regcache,
|
||
int regnum, void *gregs, size_t len)
|
||
{
|
||
sparc32_collect_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
|
||
}
|
||
|
||
static void
|
||
sparc32_linux_supply_core_fpregset (const struct regset *regset,
|
||
struct regcache *regcache,
|
||
int regnum, const void *fpregs, size_t len)
|
||
{
|
||
sparc32_supply_fpregset (regcache, regnum, fpregs);
|
||
}
|
||
|
||
static void
|
||
sparc32_linux_collect_core_fpregset (const struct regset *regset,
|
||
const struct regcache *regcache,
|
||
int regnum, void *fpregs, size_t len)
|
||
{
|
||
sparc32_collect_fpregset (regcache, regnum, fpregs);
|
||
}
|
||
|
||
/* Set the program counter for process PTID to PC. */
|
||
|
||
#define PSR_SYSCALL 0x00004000
|
||
|
||
static void
|
||
sparc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
|
||
ULONGEST psr;
|
||
|
||
regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
|
||
regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4);
|
||
|
||
/* Clear the "in syscall" bit to prevent the kernel from
|
||
messing with the PCs we just installed, if we happen to be
|
||
within an interrupted system call that the kernel wants to
|
||
restart.
|
||
|
||
Note that after we return from the dummy call, the PSR et al.
|
||
registers will be automatically restored, and the kernel
|
||
continues to restart the system call at this point. */
|
||
regcache_cooked_read_unsigned (regcache, SPARC32_PSR_REGNUM, &psr);
|
||
psr &= ~PSR_SYSCALL;
|
||
regcache_cooked_write_unsigned (regcache, SPARC32_PSR_REGNUM, psr);
|
||
}
|
||
|
||
|
||
|
||
static void
|
||
sparc32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
tdep->gregset = regset_alloc (gdbarch, sparc32_linux_supply_core_gregset,
|
||
sparc32_linux_collect_core_gregset);
|
||
tdep->sizeof_gregset = 152;
|
||
|
||
tdep->fpregset = regset_alloc (gdbarch, sparc32_linux_supply_core_fpregset,
|
||
sparc32_linux_collect_core_fpregset);
|
||
tdep->sizeof_fpregset = 396;
|
||
|
||
tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_sigframe);
|
||
tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_rt_sigframe);
|
||
|
||
/* GNU/Linux has SVR4-style shared libraries... */
|
||
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
|
||
set_solib_svr4_fetch_link_map_offsets
|
||
(gdbarch, svr4_ilp32_fetch_link_map_offsets);
|
||
|
||
/* ...which means that we need some special handling when doing
|
||
prologue analysis. */
|
||
tdep->plt_entry_size = 12;
|
||
|
||
/* Enable TLS support. */
|
||
set_gdbarch_fetch_tls_load_module_address (gdbarch,
|
||
svr4_fetch_objfile_link_map);
|
||
|
||
/* Make sure we can single-step over signal return system calls. */
|
||
tdep->step_trap = sparc32_linux_step_trap;
|
||
|
||
/* Hook in the DWARF CFI frame unwinder. */
|
||
dwarf2_append_unwinders (gdbarch);
|
||
|
||
set_gdbarch_write_pc (gdbarch, sparc_linux_write_pc);
|
||
}
|
||
|
||
/* Provide a prototype to silence -Wmissing-prototypes. */
|
||
extern void _initialize_sparc_linux_tdep (void);
|
||
|
||
void
|
||
_initialize_sparc_linux_tdep (void)
|
||
{
|
||
gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_LINUX,
|
||
sparc32_linux_init_abi);
|
||
}
|