/* GNU/Linux/MIPS specific low level interface, for the remote server for GDB.
Copyright (C) 1995-2015 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 . */
#include "server.h"
#include "linux-low.h"
#include
#include
#include "nat/mips-linux-watch.h"
#include "gdb_proc_service.h"
/* Defined in auto-generated file mips-linux.c. */
void init_registers_mips_linux (void);
extern const struct target_desc *tdesc_mips_linux;
/* Defined in auto-generated file mips-dsp-linux.c. */
void init_registers_mips_dsp_linux (void);
extern const struct target_desc *tdesc_mips_dsp_linux;
/* Defined in auto-generated file mips64-linux.c. */
void init_registers_mips64_linux (void);
extern const struct target_desc *tdesc_mips64_linux;
/* Defined in auto-generated file mips64-dsp-linux.c. */
void init_registers_mips64_dsp_linux (void);
extern const struct target_desc *tdesc_mips64_dsp_linux;
#ifdef __mips64
#define tdesc_mips_linux tdesc_mips64_linux
#define tdesc_mips_dsp_linux tdesc_mips64_dsp_linux
#endif
#ifndef PTRACE_GET_THREAD_AREA
#define PTRACE_GET_THREAD_AREA 25
#endif
#ifdef HAVE_SYS_REG_H
#include
#endif
#define mips_num_regs 73
#define mips_dsp_num_regs 80
#include
#ifndef DSP_BASE
#define DSP_BASE 71
#define DSP_CONTROL 77
#endif
union mips_register
{
unsigned char buf[8];
/* Deliberately signed, for proper sign extension. */
int reg32;
long long reg64;
};
/* Return the ptrace ``address'' of register REGNO. */
#define mips_base_regs \
-1, 1, 2, 3, 4, 5, 6, 7, \
8, 9, 10, 11, 12, 13, 14, 15, \
16, 17, 18, 19, 20, 21, 22, 23, \
24, 25, 26, 27, 28, 29, 30, 31, \
\
-1, MMLO, MMHI, BADVADDR, CAUSE, PC, \
\
FPR_BASE, FPR_BASE + 1, FPR_BASE + 2, FPR_BASE + 3, \
FPR_BASE + 4, FPR_BASE + 5, FPR_BASE + 6, FPR_BASE + 7, \
FPR_BASE + 8, FPR_BASE + 9, FPR_BASE + 10, FPR_BASE + 11, \
FPR_BASE + 12, FPR_BASE + 13, FPR_BASE + 14, FPR_BASE + 15, \
FPR_BASE + 16, FPR_BASE + 17, FPR_BASE + 18, FPR_BASE + 19, \
FPR_BASE + 20, FPR_BASE + 21, FPR_BASE + 22, FPR_BASE + 23, \
FPR_BASE + 24, FPR_BASE + 25, FPR_BASE + 26, FPR_BASE + 27, \
FPR_BASE + 28, FPR_BASE + 29, FPR_BASE + 30, FPR_BASE + 31, \
FPC_CSR, FPC_EIR
#define mips_dsp_regs \
DSP_BASE, DSP_BASE + 1, DSP_BASE + 2, DSP_BASE + 3, \
DSP_BASE + 4, DSP_BASE + 5, \
DSP_CONTROL
static int mips_regmap[mips_num_regs] = {
mips_base_regs,
0
};
static int mips_dsp_regmap[mips_dsp_num_regs] = {
mips_base_regs,
mips_dsp_regs,
0
};
/* DSP registers are not in any regset and can only be accessed
individually. */
static unsigned char mips_dsp_regset_bitmap[(mips_dsp_num_regs + 7) / 8] = {
0xfe, 0xff, 0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0xff, 0x80
};
static int have_dsp = -1;
/* Try peeking at an arbitrarily chosen DSP register and pick the available
user register set accordingly. */
static const struct target_desc *
mips_read_description (void)
{
if (have_dsp < 0)
{
int pid = lwpid_of (current_thread);
errno = 0;
ptrace (PTRACE_PEEKUSER, pid, DSP_CONTROL, 0);
switch (errno)
{
case 0:
have_dsp = 1;
break;
case EIO:
have_dsp = 0;
break;
default:
perror_with_name ("ptrace");
break;
}
}
return have_dsp ? tdesc_mips_dsp_linux : tdesc_mips_linux;
}
static void
mips_arch_setup (void)
{
current_process ()->tdesc = mips_read_description ();
}
static struct usrregs_info *
get_usrregs_info (void)
{
const struct regs_info *regs_info = the_low_target.regs_info ();
return regs_info->usrregs;
}
/* Per-process arch-specific data we want to keep. */
struct arch_process_info
{
/* -1 if the kernel and/or CPU do not support watch registers.
1 if watch_readback is valid and we can read style, num_valid
and the masks.
0 if we need to read the watch_readback. */
int watch_readback_valid;
/* Cached watch register read values. */
struct pt_watch_regs watch_readback;
/* Current watchpoint requests for this process. */
struct mips_watchpoint *current_watches;
/* The current set of watch register values for writing the
registers. */
struct pt_watch_regs watch_mirror;
};
/* Per-thread arch-specific data we want to keep. */
struct arch_lwp_info
{
/* Non-zero if our copy differs from what's recorded in the thread. */
int watch_registers_changed;
};
/* From mips-linux-nat.c. */
/* Pseudo registers can not be read. ptrace does not provide a way to
read (or set) PS_REGNUM, and there's no point in reading or setting
ZERO_REGNUM. We also can not set BADVADDR, CAUSE, or FCRIR via
ptrace(). */
static int
mips_cannot_fetch_register (int regno)
{
const struct target_desc *tdesc;
if (get_usrregs_info ()->regmap[regno] == -1)
return 1;
tdesc = current_process ()->tdesc;
if (find_regno (tdesc, "r0") == regno)
return 1;
return 0;
}
static int
mips_cannot_store_register (int regno)
{
const struct target_desc *tdesc;
if (get_usrregs_info ()->regmap[regno] == -1)
return 1;
tdesc = current_process ()->tdesc;
if (find_regno (tdesc, "r0") == regno)
return 1;
if (find_regno (tdesc, "cause") == regno)
return 1;
if (find_regno (tdesc, "badvaddr") == regno)
return 1;
if (find_regno (tdesc, "fir") == regno)
return 1;
return 0;
}
static CORE_ADDR
mips_get_pc (struct regcache *regcache)
{
union mips_register pc;
collect_register_by_name (regcache, "pc", pc.buf);
return register_size (regcache->tdesc, 0) == 4 ? pc.reg32 : pc.reg64;
}
static void
mips_set_pc (struct regcache *regcache, CORE_ADDR pc)
{
union mips_register newpc;
if (register_size (regcache->tdesc, 0) == 4)
newpc.reg32 = pc;
else
newpc.reg64 = pc;
supply_register_by_name (regcache, "pc", newpc.buf);
}
/* Correct in either endianness. */
static const unsigned int mips_breakpoint = 0x0005000d;
#define mips_breakpoint_len 4
/* We only place breakpoints in empty marker functions, and thread locking
is outside of the function. So rather than importing software single-step,
we can just run until exit. */
static CORE_ADDR
mips_reinsert_addr (void)
{
struct regcache *regcache = get_thread_regcache (current_thread, 1);
union mips_register ra;
collect_register_by_name (regcache, "r31", ra.buf);
return register_size (regcache->tdesc, 0) == 4 ? ra.reg32 : ra.reg64;
}
static int
mips_breakpoint_at (CORE_ADDR where)
{
unsigned int insn;
(*the_target->read_memory) (where, (unsigned char *) &insn, 4);
if (insn == mips_breakpoint)
return 1;
/* If necessary, recognize more trap instructions here. GDB only uses the
one. */
return 0;
}
/* Mark the watch registers of lwp, represented by ENTRY, as changed,
if the lwp's process id is *PID_P. */
static int
update_watch_registers_callback (struct inferior_list_entry *entry,
void *pid_p)
{
struct thread_info *thread = (struct thread_info *) entry;
struct lwp_info *lwp = get_thread_lwp (thread);
int pid = *(int *) pid_p;
/* Only update the threads of this process. */
if (pid_of (thread) == pid)
{
/* The actual update is done later just before resuming the lwp,
we just mark that the registers need updating. */
lwp->arch_private->watch_registers_changed = 1;
/* If the lwp isn't stopped, force it to momentarily pause, so
we can update its watch registers. */
if (!lwp->stopped)
linux_stop_lwp (lwp);
}
return 0;
}
/* This is the implementation of linux_target_ops method
new_process. */
static struct arch_process_info *
mips_linux_new_process (void)
{
struct arch_process_info *info = xcalloc (1, sizeof (*info));
return info;
}
/* This is the implementation of linux_target_ops method new_thread.
Mark the watch registers as changed, so the threads' copies will
be updated. */
static struct arch_lwp_info *
mips_linux_new_thread (void)
{
struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
info->watch_registers_changed = 1;
return info;
}
/* This is the implementation of linux_target_ops method
prepare_to_resume. If the watch regs have changed, update the
thread's copies. */
static void
mips_linux_prepare_to_resume (struct lwp_info *lwp)
{
ptid_t ptid = ptid_of (get_lwp_thread (lwp));
struct process_info *proc = find_process_pid (ptid_get_pid (ptid));
struct arch_process_info *private = proc->private->arch_private;
if (lwp->arch_private->watch_registers_changed)
{
/* Only update the watch registers if we have set or unset a
watchpoint already. */
if (mips_linux_watch_get_num_valid (&private->watch_mirror) > 0)
{
/* Write the mirrored watch register values. */
int tid = ptid_get_lwp (ptid);
if (-1 == ptrace (PTRACE_SET_WATCH_REGS, tid,
&private->watch_mirror))
perror_with_name ("Couldn't write watch register");
}
lwp->arch_private->watch_registers_changed = 0;
}
}
static int
mips_supports_z_point_type (char z_type)
{
switch (z_type)
{
case Z_PACKET_WRITE_WP:
case Z_PACKET_READ_WP:
case Z_PACKET_ACCESS_WP:
return 1;
default:
return 0;
}
}
/* This is the implementation of linux_target_ops method
insert_point. */
static int
mips_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
int len, struct raw_breakpoint *bp)
{
struct process_info *proc = current_process ();
struct arch_process_info *private = proc->private->arch_private;
struct pt_watch_regs regs;
struct mips_watchpoint *new_watch;
struct mips_watchpoint **pw;
int pid;
long lwpid;
enum target_hw_bp_type watch_type;
uint32_t irw;
lwpid = lwpid_of (current_thread);
if (!mips_linux_read_watch_registers (lwpid,
&private->watch_readback,
&private->watch_readback_valid,
0))
return -1;
if (len <= 0)
return -1;
regs = private->watch_readback;
/* Add the current watches. */
mips_linux_watch_populate_regs (private->current_watches, ®s);
/* Now try to add the new watch. */
watch_type = raw_bkpt_type_to_target_hw_bp_type (type);
irw = mips_linux_watch_type_to_irw (watch_type);
if (!mips_linux_watch_try_one_watch (®s, addr, len, irw))
return -1;
/* It fit. Stick it on the end of the list. */
new_watch = xmalloc (sizeof (struct mips_watchpoint));
new_watch->addr = addr;
new_watch->len = len;
new_watch->type = watch_type;
new_watch->next = NULL;
pw = &private->current_watches;
while (*pw != NULL)
pw = &(*pw)->next;
*pw = new_watch;
private->watch_mirror = regs;
/* Only update the threads of this process. */
pid = pid_of (proc);
find_inferior (&all_threads, update_watch_registers_callback, &pid);
return 0;
}
/* This is the implementation of linux_target_ops method
remove_point. */
static int
mips_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
int len, struct raw_breakpoint *bp)
{
struct process_info *proc = current_process ();
struct arch_process_info *private = proc->private->arch_private;
int deleted_one;
int pid;
enum target_hw_bp_type watch_type;
struct mips_watchpoint **pw;
struct mips_watchpoint *w;
/* Search for a known watch that matches. Then unlink and free it. */
watch_type = raw_bkpt_type_to_target_hw_bp_type (type);
deleted_one = 0;
pw = &private->current_watches;
while ((w = *pw))
{
if (w->addr == addr && w->len == len && w->type == watch_type)
{
*pw = w->next;
free (w);
deleted_one = 1;
break;
}
pw = &(w->next);
}
if (!deleted_one)
return -1; /* We don't know about it, fail doing nothing. */
/* At this point watch_readback is known to be valid because we
could not have added the watch without reading it. */
gdb_assert (private->watch_readback_valid == 1);
private->watch_mirror = private->watch_readback;
mips_linux_watch_populate_regs (private->current_watches,
&private->watch_mirror);
/* Only update the threads of this process. */
pid = pid_of (proc);
find_inferior (&all_threads, update_watch_registers_callback, &pid);
return 0;
}
/* This is the implementation of linux_target_ops method
stopped_by_watchpoint. The watchhi R and W bits indicate
the watch register triggered. */
static int
mips_stopped_by_watchpoint (void)
{
struct process_info *proc = current_process ();
struct arch_process_info *private = proc->private->arch_private;
int n;
int num_valid;
long lwpid = lwpid_of (current_thread);
if (!mips_linux_read_watch_registers (lwpid,
&private->watch_readback,
&private->watch_readback_valid,
1))
return 0;
num_valid = mips_linux_watch_get_num_valid (&private->watch_readback);
for (n = 0; n < MAX_DEBUG_REGISTER && n < num_valid; n++)
if (mips_linux_watch_get_watchhi (&private->watch_readback, n)
& (R_MASK | W_MASK))
return 1;
return 0;
}
/* This is the implementation of linux_target_ops method
stopped_data_address. */
static CORE_ADDR
mips_stopped_data_address (void)
{
struct process_info *proc = current_process ();
struct arch_process_info *private = proc->private->arch_private;
int n;
int num_valid;
long lwpid = lwpid_of (current_thread);
/* On MIPS we don't know the low order 3 bits of the data address.
GDB does not support remote targets that can't report the
watchpoint address. So, make our best guess; return the starting
address of a watchpoint request which overlaps the one that
triggered. */
if (!mips_linux_read_watch_registers (lwpid,
&private->watch_readback,
&private->watch_readback_valid,
0))
return 0;
num_valid = mips_linux_watch_get_num_valid (&private->watch_readback);
for (n = 0; n < MAX_DEBUG_REGISTER && n < num_valid; n++)
if (mips_linux_watch_get_watchhi (&private->watch_readback, n)
& (R_MASK | W_MASK))
{
CORE_ADDR t_low, t_hi;
int t_irw;
struct mips_watchpoint *watch;
t_low = mips_linux_watch_get_watchlo (&private->watch_readback, n);
t_irw = t_low & IRW_MASK;
t_hi = (mips_linux_watch_get_watchhi (&private->watch_readback, n)
| IRW_MASK);
t_low &= ~(CORE_ADDR)t_hi;
for (watch = private->current_watches;
watch != NULL;
watch = watch->next)
{
CORE_ADDR addr = watch->addr;
CORE_ADDR last_byte = addr + watch->len - 1;
if ((t_irw & mips_linux_watch_type_to_irw (watch->type)) == 0)
{
/* Different type. */
continue;
}
/* Check for overlap of even a single byte. */
if (last_byte >= t_low && addr <= t_low + t_hi)
return addr;
}
}
/* Shouldn't happen. */
return 0;
}
/* Fetch the thread-local storage pointer for libthread_db. */
ps_err_e
ps_get_thread_area (const struct ps_prochandle *ph,
lwpid_t lwpid, int idx, void **base)
{
if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
return PS_ERR;
/* IDX is the bias from the thread pointer to the beginning of the
thread descriptor. It has to be subtracted due to implementation
quirks in libthread_db. */
*base = (void *) ((char *)*base - idx);
return PS_OK;
}
#ifdef HAVE_PTRACE_GETREGS
static void
mips_collect_register (struct regcache *regcache,
int use_64bit, int regno, union mips_register *reg)
{
union mips_register tmp_reg;
if (use_64bit)
{
collect_register (regcache, regno, &tmp_reg.reg64);
*reg = tmp_reg;
}
else
{
collect_register (regcache, regno, &tmp_reg.reg32);
reg->reg64 = tmp_reg.reg32;
}
}
static void
mips_supply_register (struct regcache *regcache,
int use_64bit, int regno, const union mips_register *reg)
{
int offset = 0;
/* For big-endian 32-bit targets, ignore the high four bytes of each
eight-byte slot. */
if (__BYTE_ORDER == __BIG_ENDIAN && !use_64bit)
offset = 4;
supply_register (regcache, regno, reg->buf + offset);
}
static void
mips_collect_register_32bit (struct regcache *regcache,
int use_64bit, int regno, unsigned char *buf)
{
union mips_register tmp_reg;
int reg32;
mips_collect_register (regcache, use_64bit, regno, &tmp_reg);
reg32 = tmp_reg.reg64;
memcpy (buf, ®32, 4);
}
static void
mips_supply_register_32bit (struct regcache *regcache,
int use_64bit, int regno, const unsigned char *buf)
{
union mips_register tmp_reg;
int reg32;
memcpy (®32, buf, 4);
tmp_reg.reg64 = reg32;
mips_supply_register (regcache, use_64bit, regno, &tmp_reg);
}
static void
mips_fill_gregset (struct regcache *regcache, void *buf)
{
union mips_register *regset = buf;
int i, use_64bit;
const struct target_desc *tdesc = regcache->tdesc;
use_64bit = (register_size (tdesc, 0) == 8);
for (i = 1; i < 32; i++)
mips_collect_register (regcache, use_64bit, i, regset + i);
mips_collect_register (regcache, use_64bit,
find_regno (tdesc, "lo"), regset + 32);
mips_collect_register (regcache, use_64bit,
find_regno (tdesc, "hi"), regset + 33);
mips_collect_register (regcache, use_64bit,
find_regno (tdesc, "pc"), regset + 34);
mips_collect_register (regcache, use_64bit,
find_regno (tdesc, "badvaddr"), regset + 35);
mips_collect_register (regcache, use_64bit,
find_regno (tdesc, "status"), regset + 36);
mips_collect_register (regcache, use_64bit,
find_regno (tdesc, "cause"), regset + 37);
mips_collect_register (regcache, use_64bit,
find_regno (tdesc, "restart"), regset + 0);
}
static void
mips_store_gregset (struct regcache *regcache, const void *buf)
{
const union mips_register *regset = buf;
int i, use_64bit;
use_64bit = (register_size (regcache->tdesc, 0) == 8);
for (i = 0; i < 32; i++)
mips_supply_register (regcache, use_64bit, i, regset + i);
mips_supply_register (regcache, use_64bit,
find_regno (regcache->tdesc, "lo"), regset + 32);
mips_supply_register (regcache, use_64bit,
find_regno (regcache->tdesc, "hi"), regset + 33);
mips_supply_register (regcache, use_64bit,
find_regno (regcache->tdesc, "pc"), regset + 34);
mips_supply_register (regcache, use_64bit,
find_regno (regcache->tdesc, "badvaddr"), regset + 35);
mips_supply_register (regcache, use_64bit,
find_regno (regcache->tdesc, "status"), regset + 36);
mips_supply_register (regcache, use_64bit,
find_regno (regcache->tdesc, "cause"), regset + 37);
mips_supply_register (regcache, use_64bit,
find_regno (regcache->tdesc, "restart"), regset + 0);
}
static void
mips_fill_fpregset (struct regcache *regcache, void *buf)
{
union mips_register *regset = buf;
int i, use_64bit, first_fp, big_endian;
use_64bit = (register_size (regcache->tdesc, 0) == 8);
first_fp = find_regno (regcache->tdesc, "f0");
big_endian = (__BYTE_ORDER == __BIG_ENDIAN);
/* See GDB for a discussion of this peculiar layout. */
for (i = 0; i < 32; i++)
if (use_64bit)
collect_register (regcache, first_fp + i, regset[i].buf);
else
collect_register (regcache, first_fp + i,
regset[i & ~1].buf + 4 * (big_endian != (i & 1)));
mips_collect_register_32bit (regcache, use_64bit,
find_regno (regcache->tdesc, "fcsr"), regset[32].buf);
mips_collect_register_32bit (regcache, use_64bit,
find_regno (regcache->tdesc, "fir"),
regset[32].buf + 4);
}
static void
mips_store_fpregset (struct regcache *regcache, const void *buf)
{
const union mips_register *regset = buf;
int i, use_64bit, first_fp, big_endian;
use_64bit = (register_size (regcache->tdesc, 0) == 8);
first_fp = find_regno (regcache->tdesc, "f0");
big_endian = (__BYTE_ORDER == __BIG_ENDIAN);
/* See GDB for a discussion of this peculiar layout. */
for (i = 0; i < 32; i++)
if (use_64bit)
supply_register (regcache, first_fp + i, regset[i].buf);
else
supply_register (regcache, first_fp + i,
regset[i & ~1].buf + 4 * (big_endian != (i & 1)));
mips_supply_register_32bit (regcache, use_64bit,
find_regno (regcache->tdesc, "fcsr"),
regset[32].buf);
mips_supply_register_32bit (regcache, use_64bit,
find_regno (regcache->tdesc, "fir"),
regset[32].buf + 4);
}
#endif /* HAVE_PTRACE_GETREGS */
static struct regset_info mips_regsets[] = {
#ifdef HAVE_PTRACE_GETREGS
{ PTRACE_GETREGS, PTRACE_SETREGS, 0, 38 * 8, GENERAL_REGS,
mips_fill_gregset, mips_store_gregset },
{ PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, 33 * 8, FP_REGS,
mips_fill_fpregset, mips_store_fpregset },
#endif /* HAVE_PTRACE_GETREGS */
{ 0, 0, 0, -1, -1, NULL, NULL }
};
static struct regsets_info mips_regsets_info =
{
mips_regsets, /* regsets */
0, /* num_regsets */
NULL, /* disabled_regsets */
};
static struct usrregs_info mips_dsp_usrregs_info =
{
mips_dsp_num_regs,
mips_dsp_regmap,
};
static struct usrregs_info mips_usrregs_info =
{
mips_num_regs,
mips_regmap,
};
static struct regs_info dsp_regs_info =
{
mips_dsp_regset_bitmap,
&mips_dsp_usrregs_info,
&mips_regsets_info
};
static struct regs_info regs_info =
{
NULL, /* regset_bitmap */
&mips_usrregs_info,
&mips_regsets_info
};
static const struct regs_info *
mips_regs_info (void)
{
if (have_dsp)
return &dsp_regs_info;
else
return ®s_info;
}
struct linux_target_ops the_low_target = {
mips_arch_setup,
mips_regs_info,
mips_cannot_fetch_register,
mips_cannot_store_register,
NULL, /* fetch_register */
mips_get_pc,
mips_set_pc,
(const unsigned char *) &mips_breakpoint,
mips_breakpoint_len,
mips_reinsert_addr,
0,
mips_breakpoint_at,
mips_supports_z_point_type,
mips_insert_point,
mips_remove_point,
mips_stopped_by_watchpoint,
mips_stopped_data_address,
NULL,
NULL,
NULL, /* siginfo_fixup */
mips_linux_new_process,
mips_linux_new_thread,
mips_linux_prepare_to_resume
};
void
initialize_low_arch (void)
{
/* Initialize the Linux target descriptions. */
init_registers_mips_linux ();
init_registers_mips_dsp_linux ();
init_registers_mips64_linux ();
init_registers_mips64_dsp_linux ();
initialize_regsets_info (&mips_regsets_info);
}