binutils-gdb/gdb/common/mips-linux-watch.c

350 lines
8.9 KiB
C

/* Copyright (C) 2009-2014 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 <sys/ptrace.h>
#include "mips-linux-watch.h"
#include "gdb_assert.h"
/* Assuming usable watch registers REGS, return the irw_mask of
register N. */
uint32_t
mips_linux_watch_get_irw_mask (struct pt_watch_regs *regs, int n)
{
switch (regs->style)
{
case pt_watch_style_mips32:
return regs->mips32.watch_masks[n] & IRW_MASK;
case pt_watch_style_mips64:
return regs->mips64.watch_masks[n] & IRW_MASK;
default:
internal_error (__FILE__, __LINE__,
_("Unrecognized watch register style"));
}
}
/* Assuming usable watch registers REGS, return the reg_mask of
register N. */
static uint32_t
get_reg_mask (struct pt_watch_regs *regs, int n)
{
switch (regs->style)
{
case pt_watch_style_mips32:
return regs->mips32.watch_masks[n] & ~IRW_MASK;
case pt_watch_style_mips64:
return regs->mips64.watch_masks[n] & ~IRW_MASK;
default:
internal_error (__FILE__, __LINE__,
_("Unrecognized watch register style"));
}
}
/* Assuming usable watch registers REGS, return the num_valid. */
uint32_t
mips_linux_watch_get_num_valid (struct pt_watch_regs *regs)
{
switch (regs->style)
{
case pt_watch_style_mips32:
return regs->mips32.num_valid;
case pt_watch_style_mips64:
return regs->mips64.num_valid;
default:
internal_error (__FILE__, __LINE__,
_("Unrecognized watch register style"));
}
}
/* Assuming usable watch registers REGS, return the watchlo of
register N. */
CORE_ADDR
mips_linux_watch_get_watchlo (struct pt_watch_regs *regs, int n)
{
switch (regs->style)
{
case pt_watch_style_mips32:
return regs->mips32.watchlo[n];
case pt_watch_style_mips64:
return regs->mips64.watchlo[n];
default:
internal_error (__FILE__, __LINE__,
_("Unrecognized watch register style"));
}
}
/* Assuming usable watch registers REGS, set watchlo of register N to
VALUE. */
void
mips_linux_watch_set_watchlo (struct pt_watch_regs *regs, int n,
CORE_ADDR value)
{
switch (regs->style)
{
case pt_watch_style_mips32:
/* The cast will never throw away bits as 64 bit addresses can
never be used on a 32 bit kernel. */
regs->mips32.watchlo[n] = (uint32_t) value;
break;
case pt_watch_style_mips64:
regs->mips64.watchlo[n] = value;
break;
default:
internal_error (__FILE__, __LINE__,
_("Unrecognized watch register style"));
}
}
/* Assuming usable watch registers REGS, return the watchhi of
register N. */
uint32_t
mips_linux_watch_get_watchhi (struct pt_watch_regs *regs, int n)
{
switch (regs->style)
{
case pt_watch_style_mips32:
return regs->mips32.watchhi[n];
case pt_watch_style_mips64:
return regs->mips64.watchhi[n];
default:
internal_error (__FILE__, __LINE__,
_("Unrecognized watch register style"));
}
}
/* Assuming usable watch registers REGS, set watchhi of register N to
VALUE. */
void
mips_linux_watch_set_watchhi (struct pt_watch_regs *regs, int n,
uint16_t value)
{
switch (regs->style)
{
case pt_watch_style_mips32:
regs->mips32.watchhi[n] = value;
break;
case pt_watch_style_mips64:
regs->mips64.watchhi[n] = value;
break;
default:
internal_error (__FILE__, __LINE__,
_("Unrecognized watch register style"));
}
}
/* Read the watch registers of process LWPID and store it in
WATCH_READBACK. Save true to *WATCH_READBACK_VALID if watch
registers are valid. Return 1 if watch registers are usable.
Cached information is used unless FORCE is true. */
int
mips_linux_read_watch_registers (long lwpid,
struct pt_watch_regs *watch_readback,
int *watch_readback_valid, int force)
{
if (force || *watch_readback_valid == 0)
{
if (ptrace (PTRACE_GET_WATCH_REGS, lwpid, watch_readback) == -1)
{
*watch_readback_valid = -1;
return 0;
}
switch (watch_readback->style)
{
case pt_watch_style_mips32:
if (watch_readback->mips32.num_valid == 0)
{
*watch_readback_valid = -1;
return 0;
}
break;
case pt_watch_style_mips64:
if (watch_readback->mips64.num_valid == 0)
{
*watch_readback_valid = -1;
return 0;
}
break;
default:
*watch_readback_valid = -1;
return 0;
}
/* Watch registers appear to be usable. */
*watch_readback_valid = 1;
}
return (*watch_readback_valid == 1) ? 1 : 0;
}
/* Convert GDB's TYPE to an IRW mask. */
uint32_t
mips_linux_watch_type_to_irw (int type)
{
switch (type)
{
case hw_write:
return W_MASK;
case hw_read:
return R_MASK;
case hw_access:
return (W_MASK | R_MASK);
default:
return 0;
}
}
/* Set any low order bits in MASK that are not set. */
static CORE_ADDR
fill_mask (CORE_ADDR mask)
{
CORE_ADDR f = 1;
while (f && f < mask)
{
mask |= f;
f <<= 1;
}
return mask;
}
/* Try to add a single watch to the specified registers REGS. The
address of added watch is ADDR, the length is LEN, and the mask
is IRW. Return 1 on success, 0 on failure. */
int
mips_linux_watch_try_one_watch (struct pt_watch_regs *regs,
CORE_ADDR addr, int len, uint32_t irw)
{
CORE_ADDR base_addr, last_byte, break_addr, segment_len;
CORE_ADDR mask_bits, t_low;
uint16_t t_hi;
int i, free_watches;
struct pt_watch_regs regs_copy;
if (len <= 0)
return 0;
last_byte = addr + len - 1;
mask_bits = fill_mask (addr ^ last_byte) | IRW_MASK;
base_addr = addr & ~mask_bits;
/* Check to see if it is covered by current registers. */
for (i = 0; i < mips_linux_watch_get_num_valid (regs); i++)
{
t_low = mips_linux_watch_get_watchlo (regs, i);
if (t_low != 0 && irw == ((uint32_t) t_low & irw))
{
t_hi = mips_linux_watch_get_watchhi (regs, i) | IRW_MASK;
t_low &= ~(CORE_ADDR) t_hi;
if (addr >= t_low && last_byte <= (t_low + t_hi))
return 1;
}
}
/* Try to find an empty register. */
free_watches = 0;
for (i = 0; i < mips_linux_watch_get_num_valid (regs); i++)
{
t_low = mips_linux_watch_get_watchlo (regs, i);
if (t_low == 0
&& irw == (mips_linux_watch_get_irw_mask (regs, i) & irw))
{
if (mask_bits <= (get_reg_mask (regs, i) | IRW_MASK))
{
/* It fits, we'll take it. */
mips_linux_watch_set_watchlo (regs, i, base_addr | irw);
mips_linux_watch_set_watchhi (regs, i, mask_bits & ~IRW_MASK);
return 1;
}
else
{
/* It doesn't fit, but has the proper IRW capabilities. */
free_watches++;
}
}
}
if (free_watches > 1)
{
/* Try to split it across several registers. */
regs_copy = *regs;
for (i = 0; i < mips_linux_watch_get_num_valid (&regs_copy); i++)
{
t_low = mips_linux_watch_get_watchlo (&regs_copy, i);
t_hi = get_reg_mask (&regs_copy, i) | IRW_MASK;
if (t_low == 0 && irw == (t_hi & irw))
{
t_low = addr & ~(CORE_ADDR) t_hi;
break_addr = t_low + t_hi + 1;
if (break_addr >= addr + len)
segment_len = len;
else
segment_len = break_addr - addr;
mask_bits = fill_mask (addr ^ (addr + segment_len - 1));
mips_linux_watch_set_watchlo (&regs_copy, i,
(addr & ~mask_bits) | irw);
mips_linux_watch_set_watchhi (&regs_copy, i,
mask_bits & ~IRW_MASK);
if (break_addr >= addr + len)
{
*regs = regs_copy;
return 1;
}
len = addr + len - break_addr;
addr = break_addr;
}
}
}
/* It didn't fit anywhere, we failed. */
return 0;
}
/* Fill in the watch registers REGS with the currently cached
watches CURRENT_WATCHES. */
void
mips_linux_watch_populate_regs (struct mips_watchpoint *current_watches,
struct pt_watch_regs *regs)
{
struct mips_watchpoint *w;
int i;
/* Clear them out. */
for (i = 0; i < mips_linux_watch_get_num_valid (regs); i++)
{
mips_linux_watch_set_watchlo (regs, i, 0);
mips_linux_watch_set_watchhi (regs, i, 0);
}
w = current_watches;
while (w)
{
uint32_t irw = mips_linux_watch_type_to_irw (w->type);
i = mips_linux_watch_try_one_watch (regs, w->addr, w->len, irw);
/* They must all fit, because we previously calculated that they
would. */
gdb_assert (i);
w = w->next;
}
}