mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-11-24 02:24:46 +08:00
441 lines
12 KiB
C
441 lines
12 KiB
C
/* Target-dependent code for GNU/Linux m32r.
|
||
|
||
Copyright (C) 2004-2014 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 "gdbcore.h"
|
||
#include "frame.h"
|
||
#include "value.h"
|
||
#include "regcache.h"
|
||
#include "inferior.h"
|
||
#include "osabi.h"
|
||
#include "reggroups.h"
|
||
#include "regset.h"
|
||
|
||
#include <string.h>
|
||
|
||
#include "glibc-tdep.h"
|
||
#include "solib-svr4.h"
|
||
#include "symtab.h"
|
||
|
||
#include "trad-frame.h"
|
||
#include "frame-unwind.h"
|
||
|
||
#include "m32r-tdep.h"
|
||
#include "linux-tdep.h"
|
||
|
||
|
||
|
||
/* Recognizing signal handler frames. */
|
||
|
||
/* 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 m32r 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 function returns whether the PC appears to
|
||
be within this bit of code.
|
||
|
||
The instruction sequence for normal signals is
|
||
ldi r7, #__NR_sigreturn
|
||
trap #2
|
||
or 0x67 0x77 0x10 0xf2.
|
||
|
||
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 in a signal trampoline.
|
||
|
||
It kind of sucks that we have to read memory from the process in
|
||
order to identify a signal trampoline, but there doesn't seem to be
|
||
any other way. Therefore we only do the memory reads if no
|
||
function name could be identified, which should be the case since
|
||
the code is on the stack.
|
||
|
||
Detection of signal trampolines for handlers that set the
|
||
SA_RESTORER flag is in general not possible. Unfortunately this is
|
||
what the GNU C Library has been doing for quite some time now.
|
||
However, as of version 2.1.2, the GNU C Library uses signal
|
||
trampolines (named __restore and __restore_rt) that are identical
|
||
to the ones used by the kernel. Therefore, these trampolines are
|
||
supported too. */
|
||
|
||
static const gdb_byte linux_sigtramp_code[] = {
|
||
0x67, 0x77, 0x10, 0xf2,
|
||
};
|
||
|
||
/* If PC is in a sigtramp routine, return the address of the start of
|
||
the routine. Otherwise, return 0. */
|
||
|
||
static CORE_ADDR
|
||
m32r_linux_sigtramp_start (CORE_ADDR pc, struct frame_info *this_frame)
|
||
{
|
||
gdb_byte buf[4];
|
||
|
||
/* 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 (pc % 2 != 0)
|
||
{
|
||
if (!safe_frame_unwind_memory (this_frame, pc, buf, 2))
|
||
return 0;
|
||
|
||
if (memcmp (buf, linux_sigtramp_code, 2) == 0)
|
||
pc -= 2;
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
if (!safe_frame_unwind_memory (this_frame, pc, buf, 4))
|
||
return 0;
|
||
|
||
if (memcmp (buf, linux_sigtramp_code, 4) != 0)
|
||
return 0;
|
||
|
||
return pc;
|
||
}
|
||
|
||
/* This function does the same for RT signals. Here the instruction
|
||
sequence is
|
||
ldi r7, #__NR_rt_sigreturn
|
||
trap #2
|
||
or 0x97 0xf0 0x00 0xad 0x10 0xf2 0xf0 0x00.
|
||
|
||
The effect is to call the system call rt_sigreturn. */
|
||
|
||
static const gdb_byte linux_rt_sigtramp_code[] = {
|
||
0x97, 0xf0, 0x00, 0xad, 0x10, 0xf2, 0xf0, 0x00,
|
||
};
|
||
|
||
/* If PC is in a RT sigtramp routine, return the address of the start
|
||
of the routine. Otherwise, return 0. */
|
||
|
||
static CORE_ADDR
|
||
m32r_linux_rt_sigtramp_start (CORE_ADDR pc, struct frame_info *this_frame)
|
||
{
|
||
gdb_byte buf[4];
|
||
|
||
/* 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 (pc % 2 != 0)
|
||
return 0;
|
||
|
||
if (!safe_frame_unwind_memory (this_frame, pc, buf, 4))
|
||
return 0;
|
||
|
||
if (memcmp (buf, linux_rt_sigtramp_code, 4) == 0)
|
||
{
|
||
if (!safe_frame_unwind_memory (this_frame, pc + 4, buf, 4))
|
||
return 0;
|
||
|
||
if (memcmp (buf, linux_rt_sigtramp_code + 4, 4) == 0)
|
||
return pc;
|
||
}
|
||
else if (memcmp (buf, linux_rt_sigtramp_code + 4, 4) == 0)
|
||
{
|
||
if (!safe_frame_unwind_memory (this_frame, pc - 4, buf, 4))
|
||
return 0;
|
||
|
||
if (memcmp (buf, linux_rt_sigtramp_code, 4) == 0)
|
||
return pc - 4;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
static int
|
||
m32r_linux_pc_in_sigtramp (CORE_ADDR pc, const char *name,
|
||
struct frame_info *this_frame)
|
||
{
|
||
/* If we have NAME, we can optimize the search. The trampolines are
|
||
named __restore and __restore_rt. However, they aren'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 (m32r_linux_sigtramp_start (pc, this_frame) != 0
|
||
|| m32r_linux_rt_sigtramp_start (pc, this_frame) != 0);
|
||
|
||
return (strcmp ("__restore", name) == 0
|
||
|| strcmp ("__restore_rt", name) == 0);
|
||
}
|
||
|
||
/* From <asm/sigcontext.h>. */
|
||
static int m32r_linux_sc_reg_offset[] = {
|
||
4 * 4, /* r0 */
|
||
5 * 4, /* r1 */
|
||
6 * 4, /* r2 */
|
||
7 * 4, /* r3 */
|
||
0 * 4, /* r4 */
|
||
1 * 4, /* r5 */
|
||
2 * 4, /* r6 */
|
||
8 * 4, /* r7 */
|
||
9 * 4, /* r8 */
|
||
10 * 4, /* r9 */
|
||
11 * 4, /* r10 */
|
||
12 * 4, /* r11 */
|
||
13 * 4, /* r12 */
|
||
21 * 4, /* fp */
|
||
22 * 4, /* lr */
|
||
-1 * 4, /* sp */
|
||
16 * 4, /* psw */
|
||
-1 * 4, /* cbr */
|
||
23 * 4, /* spi */
|
||
20 * 4, /* spu */
|
||
19 * 4, /* bpc */
|
||
17 * 4, /* pc */
|
||
15 * 4, /* accl */
|
||
14 * 4 /* acch */
|
||
};
|
||
|
||
struct m32r_frame_cache
|
||
{
|
||
CORE_ADDR base, pc;
|
||
struct trad_frame_saved_reg *saved_regs;
|
||
};
|
||
|
||
static struct m32r_frame_cache *
|
||
m32r_linux_sigtramp_frame_cache (struct frame_info *this_frame,
|
||
void **this_cache)
|
||
{
|
||
struct m32r_frame_cache *cache;
|
||
CORE_ADDR sigcontext_addr, addr;
|
||
int regnum;
|
||
|
||
if ((*this_cache) != NULL)
|
||
return (*this_cache);
|
||
cache = FRAME_OBSTACK_ZALLOC (struct m32r_frame_cache);
|
||
(*this_cache) = cache;
|
||
cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
|
||
|
||
cache->base = get_frame_register_unsigned (this_frame, M32R_SP_REGNUM);
|
||
sigcontext_addr = cache->base + 4;
|
||
|
||
cache->pc = get_frame_pc (this_frame);
|
||
addr = m32r_linux_sigtramp_start (cache->pc, this_frame);
|
||
if (addr == 0)
|
||
{
|
||
/* If this is a RT signal trampoline, adjust SIGCONTEXT_ADDR
|
||
accordingly. */
|
||
addr = m32r_linux_rt_sigtramp_start (cache->pc, this_frame);
|
||
if (addr)
|
||
sigcontext_addr += 128;
|
||
else
|
||
addr = get_frame_func (this_frame);
|
||
}
|
||
cache->pc = addr;
|
||
|
||
cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
|
||
|
||
for (regnum = 0; regnum < sizeof (m32r_linux_sc_reg_offset) / 4; regnum++)
|
||
{
|
||
if (m32r_linux_sc_reg_offset[regnum] >= 0)
|
||
cache->saved_regs[regnum].addr =
|
||
sigcontext_addr + m32r_linux_sc_reg_offset[regnum];
|
||
}
|
||
|
||
return cache;
|
||
}
|
||
|
||
static void
|
||
m32r_linux_sigtramp_frame_this_id (struct frame_info *this_frame,
|
||
void **this_cache,
|
||
struct frame_id *this_id)
|
||
{
|
||
struct m32r_frame_cache *cache =
|
||
m32r_linux_sigtramp_frame_cache (this_frame, this_cache);
|
||
|
||
(*this_id) = frame_id_build (cache->base, cache->pc);
|
||
}
|
||
|
||
static struct value *
|
||
m32r_linux_sigtramp_frame_prev_register (struct frame_info *this_frame,
|
||
void **this_cache, int regnum)
|
||
{
|
||
struct m32r_frame_cache *cache =
|
||
m32r_linux_sigtramp_frame_cache (this_frame, this_cache);
|
||
|
||
return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
|
||
}
|
||
|
||
static int
|
||
m32r_linux_sigtramp_frame_sniffer (const struct frame_unwind *self,
|
||
struct frame_info *this_frame,
|
||
void **this_cache)
|
||
{
|
||
CORE_ADDR pc = get_frame_pc (this_frame);
|
||
const char *name;
|
||
|
||
find_pc_partial_function (pc, &name, NULL, NULL);
|
||
if (m32r_linux_pc_in_sigtramp (pc, name, this_frame))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
static const struct frame_unwind m32r_linux_sigtramp_frame_unwind = {
|
||
SIGTRAMP_FRAME,
|
||
default_frame_unwind_stop_reason,
|
||
m32r_linux_sigtramp_frame_this_id,
|
||
m32r_linux_sigtramp_frame_prev_register,
|
||
NULL,
|
||
m32r_linux_sigtramp_frame_sniffer
|
||
};
|
||
|
||
/* Mapping between the registers in `struct pt_regs'
|
||
format and GDB's register array layout. */
|
||
|
||
static int m32r_pt_regs_offset[] = {
|
||
4 * 4, /* r0 */
|
||
4 * 5, /* r1 */
|
||
4 * 6, /* r2 */
|
||
4 * 7, /* r3 */
|
||
4 * 0, /* r4 */
|
||
4 * 1, /* r5 */
|
||
4 * 2, /* r6 */
|
||
4 * 8, /* r7 */
|
||
4 * 9, /* r8 */
|
||
4 * 10, /* r9 */
|
||
4 * 11, /* r10 */
|
||
4 * 12, /* r11 */
|
||
4 * 13, /* r12 */
|
||
4 * 24, /* fp */
|
||
4 * 25, /* lr */
|
||
4 * 23, /* sp */
|
||
4 * 19, /* psw */
|
||
4 * 19, /* cbr */
|
||
4 * 26, /* spi */
|
||
4 * 23, /* spu */
|
||
4 * 22, /* bpc */
|
||
4 * 20, /* pc */
|
||
4 * 16, /* accl */
|
||
4 * 15 /* acch */
|
||
};
|
||
|
||
#define PSW_OFFSET (4 * 19)
|
||
#define BBPSW_OFFSET (4 * 21)
|
||
#define SPU_OFFSET (4 * 23)
|
||
#define SPI_OFFSET (4 * 26)
|
||
|
||
static void
|
||
m32r_linux_supply_gregset (const struct regset *regset,
|
||
struct regcache *regcache, int regnum,
|
||
const void *gregs, size_t size)
|
||
{
|
||
const char *regs = gregs;
|
||
unsigned long psw, bbpsw;
|
||
int i;
|
||
|
||
psw = *((unsigned long *) (regs + PSW_OFFSET));
|
||
bbpsw = *((unsigned long *) (regs + BBPSW_OFFSET));
|
||
|
||
for (i = 0; i < sizeof (m32r_pt_regs_offset) / 4; i++)
|
||
{
|
||
if (regnum != -1 && regnum != i)
|
||
continue;
|
||
|
||
switch (i)
|
||
{
|
||
case PSW_REGNUM:
|
||
*((unsigned long *) (regs + m32r_pt_regs_offset[i])) =
|
||
((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
|
||
break;
|
||
case CBR_REGNUM:
|
||
*((unsigned long *) (regs + m32r_pt_regs_offset[i])) =
|
||
((psw >> 8) & 1);
|
||
break;
|
||
case M32R_SP_REGNUM:
|
||
if (psw & 0x8000)
|
||
*((unsigned long *) (regs + m32r_pt_regs_offset[i])) =
|
||
*((unsigned long *) (regs + SPU_OFFSET));
|
||
else
|
||
*((unsigned long *) (regs + m32r_pt_regs_offset[i])) =
|
||
*((unsigned long *) (regs + SPI_OFFSET));
|
||
break;
|
||
}
|
||
|
||
regcache_raw_supply (regcache, i,
|
||
regs + m32r_pt_regs_offset[i]);
|
||
}
|
||
}
|
||
|
||
static struct regset m32r_linux_gregset = {
|
||
NULL, m32r_linux_supply_gregset
|
||
};
|
||
|
||
static const struct regset *
|
||
m32r_linux_regset_from_core_section (struct gdbarch *core_arch,
|
||
const char *sect_name, size_t sect_size)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (core_arch);
|
||
if (strcmp (sect_name, ".reg") == 0)
|
||
return &m32r_linux_gregset;
|
||
return NULL;
|
||
}
|
||
|
||
static void
|
||
m32r_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
linux_init_abi (info, gdbarch);
|
||
|
||
/* Since EVB register is not available for native debug, we reduce
|
||
the number of registers. */
|
||
set_gdbarch_num_regs (gdbarch, M32R_NUM_REGS - 1);
|
||
|
||
frame_unwind_append_unwinder (gdbarch, &m32r_linux_sigtramp_frame_unwind);
|
||
|
||
/* GNU/Linux uses 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);
|
||
|
||
/* Core file support. */
|
||
set_gdbarch_regset_from_core_section
|
||
(gdbarch, m32r_linux_regset_from_core_section);
|
||
|
||
/* 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_m32r_linux_tdep (void);
|
||
|
||
void
|
||
_initialize_m32r_linux_tdep (void)
|
||
{
|
||
gdbarch_register_osabi (bfd_arch_m32r, 0, GDB_OSABI_LINUX,
|
||
m32r_linux_init_abi);
|
||
}
|