binutils-gdb/gdb/nat/aarch64-linux-hw-point.h
John Baldwin 4bd817e71e nat: Split out platform-independent aarch64 debug register support.
Move non-Linux-specific support for hardware break/watchpoints from
nat/aarch64-linux-hw-point.c to nat/aarch64-hw-point.c.  Changes
beyond a simple split of the code are:

- aarch64_linux_region_ok_for_watchpoint and
  aarch64_linux_any_set_debug_regs_state renamed to drop linux_ as
  they are not platform specific.

- Platforms must implement the aarch64_notify_debug_reg_change
  function which is invoked from the platform-independent code when a
  debug register changes for a given debug register state.  This does
  not use the indirection of a 'low' structure as is done for x86.

- The handling for kernel_supports_any_contiguous_range is not
  pristine.  For non-Linux it is simply defined to true.  Some uses of
  this could perhaps be implemented as new 'low' routines for the
  various places that check it instead?

- Pass down ptid into aarch64_handle_breakpoint and
  aarch64_handle_watchpoint rather than using current_lwp_ptid which
  is only defined on Linux.  In addition, pass the ptid on to
  aarch64_notify_debug_reg_change instead of the unused state
  argument.
2022-03-22 12:05:43 -07:00

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4.0 KiB
C

/* Copyright (C) 2009-2022 Free Software Foundation, Inc.
Contributed by ARM Ltd.
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/>. */
#ifndef NAT_AARCH64_LINUX_HW_POINT_H
#define NAT_AARCH64_LINUX_HW_POINT_H
#include "gdbsupport/break-common.h" /* For enum target_hw_bp_type. */
#include "nat/aarch64-hw-point.h"
/* ptrace hardware breakpoint resource info is formatted as follows:
31 24 16 8 0
+---------------+--------------+---------------+---------------+
| RESERVED | RESERVED | DEBUG_ARCH | NUM_SLOTS |
+---------------+--------------+---------------+---------------+ */
/* Macros to extract fields from the hardware debug information word. */
#define AARCH64_DEBUG_NUM_SLOTS(x) ((x) & 0xff)
#define AARCH64_DEBUG_ARCH(x) (((x) >> 8) & 0xff)
/* Each bit of a variable of this type is used to indicate whether a
hardware breakpoint or watchpoint setting has been changed since
the last update.
Bit N corresponds to the Nth hardware breakpoint or watchpoint
setting which is managed in aarch64_debug_reg_state, where N is
valid between 0 and the total number of the hardware breakpoint or
watchpoint debug registers minus 1.
When bit N is 1, the corresponding breakpoint or watchpoint setting
has changed, and therefore the corresponding hardware debug
register needs to be updated via the ptrace interface.
In the per-thread arch-specific data area, we define two such
variables for per-thread hardware breakpoint and watchpoint
settings respectively.
This type is part of the mechanism which helps reduce the number of
ptrace calls to the kernel, i.e. avoid asking the kernel to write
to the debug registers with unchanged values. */
typedef ULONGEST dr_changed_t;
/* Set each of the lower M bits of X to 1; assert X is wide enough. */
#define DR_MARK_ALL_CHANGED(x, m) \
do \
{ \
gdb_assert (sizeof ((x)) * 8 >= (m)); \
(x) = (((dr_changed_t)1 << (m)) - 1); \
} while (0)
#define DR_MARK_N_CHANGED(x, n) \
do \
{ \
(x) |= ((dr_changed_t)1 << (n)); \
} while (0)
#define DR_CLEAR_CHANGED(x) \
do \
{ \
(x) = 0; \
} while (0)
#define DR_HAS_CHANGED(x) ((x) != 0)
#define DR_N_HAS_CHANGED(x, n) ((x) & ((dr_changed_t)1 << (n)))
/* Per-thread arch-specific data we want to keep. */
struct arch_lwp_info
{
/* When bit N is 1, it indicates the Nth hardware breakpoint or
watchpoint register pair needs to be updated when the thread is
resumed; see aarch64_linux_prepare_to_resume. */
dr_changed_t dr_changed_bp;
dr_changed_t dr_changed_wp;
};
/* True if this kernel does not have the bug described by PR
external/20207 (Linux >= 4.10). A fixed kernel supports any
contiguous range of bits in 8-bit byte DR_CONTROL_MASK. A buggy
kernel supports only 0x01, 0x03, 0x0f and 0xff. We start by
assuming the bug is fixed, and then detect the bug at
PTRACE_SETREGSET time. */
extern bool kernel_supports_any_contiguous_range;
void aarch64_linux_set_debug_regs (struct aarch64_debug_reg_state *state,
int tid, int watchpoint);
void aarch64_linux_get_debug_reg_capacity (int tid);
struct aarch64_debug_reg_state *aarch64_get_debug_reg_state (pid_t pid);
#endif /* NAT_AARCH64_LINUX_HW_POINT_H */