/* Native-dependent code for the i386.
- Copyright (C) 2001, 2004, 2005, 2007, 2008, 2009, 2010, 2011
- Free Software Foundation, Inc.
+ Copyright (C) 2001-2014 Free Software Foundation, Inc.
This file is part of GDB.
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 "i386-nat.h"
#include "defs.h"
+#include "i386-nat.h"
#include "breakpoint.h"
#include "command.h"
#include "gdbcmd.h"
#include "target.h"
#include "gdb_assert.h"
+#include "inferior.h"
/* Support for hardware watchpoints and breakpoints using the i386
debug registers.
The functions below implement debug registers sharing by reference
counts, and allow to watch regions up to 16 bytes long. */
-struct i386_dr_low_type i386_dr_low;
+/* Whether or not to print the mirrored debug registers. */
+static int debug_hw_points;
+/* Function used for printing mirrored debug registers. */
+#define debug_printf(fmt, args...) \
+ fprintf_unfiltered (gdb_stdlog, fmt, ##args);
-/* Support for 8-byte wide hw watchpoints. */
-#define TARGET_HAS_DR_LEN_8 (i386_dr_low.debug_register_length == 8)
+/* Low-level function vector. */
+struct i386_dr_low_type i386_dr_low;
-/* Debug registers' indices. */
-#define DR_NADDR 4 /* The number of debug address registers. */
-#define DR_STATUS 6 /* Index of debug status register (DR6). */
-#define DR_CONTROL 7 /* Index of debug control register (DR7). */
+/* Support for 8-byte wide hw watchpoints. */
+#define TARGET_HAS_DR_LEN_8 (i386_get_debug_register_length () == 8)
/* DR7 Debug Control register fields. */
Currently, all watchpoint are locally enabled. If you need to
enable them globally, read the comment which pertains to this in
- i386_insert_aligned_watchpoint below. */
+ i386_dr_insert_aligned_watchpoint below. */
#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit. */
#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit. */
#define DR_ENABLE_SIZE 2 /* Two enable bits per debug register. */
later processors do that automatically. We set these flags for
backwards compatibility. */
#define DR_LOCAL_SLOWDOWN (0x100)
-#define DR_GLOBAL_SLOWDOWN (0x200)
+#define DR_GLOBAL_SLOWDOWN (0x200)
/* Fields reserved by Intel. This includes the GD (General Detect
Enable) flag, which causes a debug exception to be generated when a
/* The I'th debug register is vacant if its Local and Global Enable
bits are reset in the Debug Control register. */
-#define I386_DR_VACANT(i) \
- ((dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
+#define I386_DR_VACANT(state, i) \
+ (((state)->dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
/* Locally enable the break/watchpoint in the I'th debug register. */
-#define I386_DR_LOCAL_ENABLE(i) \
- dr_control_mirror |= (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i)))
+#define I386_DR_LOCAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
/* Globally enable the break/watchpoint in the I'th debug register. */
-#define I386_DR_GLOBAL_ENABLE(i) \
- dr_control_mirror |= (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i)))
+#define I386_DR_GLOBAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
/* Disable the break/watchpoint in the I'th debug register. */
-#define I386_DR_DISABLE(i) \
- dr_control_mirror &= ~(3 << (DR_ENABLE_SIZE * (i)))
+#define I386_DR_DISABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror &= \
+ ~(3 << (DR_ENABLE_SIZE * (i))); \
+ } while (0)
/* Set in DR7 the RW and LEN fields for the I'th debug register. */
-#define I386_DR_SET_RW_LEN(i,rwlen) \
+#define I386_DR_SET_RW_LEN(state, i, rwlen) \
do { \
- dr_control_mirror &= ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
- dr_control_mirror |= ((rwlen) << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
+ (state)->dr_control_mirror &= \
+ ~(0x0f << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))); \
+ (state)->dr_control_mirror |= \
+ ((rwlen) << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))); \
} while (0)
/* Get from DR7 the RW and LEN fields for the I'th debug register. */
-#define I386_DR_GET_RW_LEN(i) \
- ((dr_control_mirror >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
-
-/* Mask that this I'th watchpoint has triggered. */
-#define I386_DR_WATCH_MASK(i) (1 << (i))
+#define I386_DR_GET_RW_LEN(dr7, i) \
+ (((dr7) \
+ >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
/* Did the watchpoint whose address is in the I'th register break? */
-#define I386_DR_WATCH_HIT(i) (dr_status_mirror & I386_DR_WATCH_MASK (i))
+#define I386_DR_WATCH_HIT(dr6, i) ((dr6) & (1 << (i)))
-/* A macro to loop over all debug registers. */
-#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
+/* Per-process data. We don't bind this to a per-inferior registry
+ because of targets like x86 GNU/Linux that need to keep track of
+ processes that aren't bound to any inferior (e.g., fork children,
+ checkpoints). */
-/* Mirror the inferior's DRi registers. We keep the status and
- control registers separated because they don't hold addresses. */
-static CORE_ADDR dr_mirror[DR_NADDR];
-static unsigned long dr_status_mirror, dr_control_mirror;
+struct i386_process_info
+{
+ /* Linked list. */
+ struct i386_process_info *next;
-/* Reference counts for each debug register. */
-static int dr_ref_count[DR_NADDR];
+ /* The process identifier. */
+ pid_t pid;
-/* Whether or not to print the mirrored debug registers. */
-static int maint_show_dr;
+ /* Copy of i386 hardware debug registers. */
+ struct i386_debug_reg_state state;
+};
-/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
-typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
+static struct i386_process_info *i386_process_list = NULL;
-/* Internal functions. */
+/* Find process data for process PID. */
-/* Return the value of a 4-bit field for DR7 suitable for watching a
- region of LEN bytes for accesses of type TYPE. LEN is assumed to
- have the value of 1, 2, or 4. */
-static unsigned i386_length_and_rw_bits (int len, enum target_hw_bp_type type);
+static struct i386_process_info *
+i386_find_process_pid (pid_t pid)
+{
+ struct i386_process_info *proc;
-/* Insert a watchpoint at address ADDR, which is assumed to be aligned
- according to the length of the region to watch. LEN_RW_BITS is the
- value of the bit-field from DR7 which describes the length and
- access type of the region to be watched by this watchpoint. Return
- 0 on success, -1 on failure. */
-static int i386_insert_aligned_watchpoint (CORE_ADDR addr,
- unsigned len_rw_bits);
+ for (proc = i386_process_list; proc; proc = proc->next)
+ if (proc->pid == pid)
+ return proc;
-/* Remove a watchpoint at address ADDR, which is assumed to be aligned
- according to the length of the region to watch. LEN_RW_BITS is the
- value of the bits from DR7 which describes the length and access
- type of the region watched by this watchpoint. Return 0 on
- success, -1 on failure. */
-static int i386_remove_aligned_watchpoint (CORE_ADDR addr,
- unsigned len_rw_bits);
+ return NULL;
+}
-/* Insert or remove a (possibly non-aligned) watchpoint, or count the
- number of debug registers required to watch a region at address
- ADDR whose length is LEN for accesses of type TYPE. Return 0 on
- successful insertion or removal, a positive number when queried
- about the number of registers, or -1 on failure. If WHAT is not a
- valid value, bombs through internal_error. */
-static int i386_handle_nonaligned_watchpoint (i386_wp_op_t what,
- CORE_ADDR addr, int len,
- enum target_hw_bp_type type);
+/* Add process data for process PID. Returns newly allocated info
+ object. */
+
+static struct i386_process_info *
+i386_add_process (pid_t pid)
+{
+ struct i386_process_info *proc;
+
+ proc = xcalloc (1, sizeof (*proc));
+ proc->pid = pid;
+
+ proc->next = i386_process_list;
+ i386_process_list = proc;
+
+ return proc;
+}
+
+/* Get data specific info for process PID, creating it if necessary.
+ Never returns NULL. */
+
+static struct i386_process_info *
+i386_process_info_get (pid_t pid)
+{
+ struct i386_process_info *proc;
+
+ proc = i386_find_process_pid (pid);
+ if (proc == NULL)
+ proc = i386_add_process (pid);
+
+ return proc;
+}
+
+/* Get debug registers state for process PID. */
+
+struct i386_debug_reg_state *
+i386_debug_reg_state (pid_t pid)
+{
+ return &i386_process_info_get (pid)->state;
+}
+
+/* See declaration in i386-nat.h. */
+
+void
+i386_forget_process (pid_t pid)
+{
+ struct i386_process_info *proc, **proc_link;
+
+ proc = i386_process_list;
+ proc_link = &i386_process_list;
+
+ while (proc != NULL)
+ {
+ if (proc->pid == pid)
+ {
+ *proc_link = proc->next;
+
+ xfree (proc);
+ return;
+ }
+
+ proc_link = &proc->next;
+ proc = *proc_link;
+ }
+}
+
+/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
+typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
/* Implementation. */
void
i386_cleanup_dregs (void)
{
- int i;
-
- ALL_DEBUG_REGISTERS(i)
- {
- dr_mirror[i] = 0;
- dr_ref_count[i] = 0;
- }
- dr_control_mirror = 0;
- dr_status_mirror = 0;
+ /* Starting from scratch has the same effect. */
+ i386_forget_process (ptid_get_pid (inferior_ptid));
}
-/* Print the values of the mirrored debug registers. This is called
- when maint_show_dr is non-zero. To set that up, type "maint
- show-debug-regs" at GDB's prompt. */
+/* Print the values of the mirrored debug registers. */
-static void
-i386_show_dr (const char *func, CORE_ADDR addr,
+void
+i386_dr_show (struct i386_debug_reg_state *state,
+ const char *func, CORE_ADDR addr,
int len, enum target_hw_bp_type type)
{
- int addr_size = gdbarch_addr_bit (target_gdbarch) / 8;
int i;
- puts_unfiltered (func);
+ debug_printf ("%s", func);
if (addr || len)
- printf_unfiltered (" (addr=%lx, len=%d, type=%s)",
- /* This code is for ia32, so casting CORE_ADDR
- to unsigned long should be okay. */
- (unsigned long)addr, len,
- type == hw_write ? "data-write"
- : (type == hw_read ? "data-read"
- : (type == hw_access ? "data-read/write"
- : (type == hw_execute ? "instruction-execute"
- /* FIXME: if/when I/O read/write
- watchpoints are supported, add them
- here. */
- : "??unknown??"))));
- puts_unfiltered (":\n");
- printf_unfiltered ("\tCONTROL (DR7): %s STATUS (DR6): %s\n",
- phex (dr_control_mirror, 8), phex (dr_status_mirror, 8));
- ALL_DEBUG_REGISTERS(i)
+ debug_printf (" (addr=%s, len=%d, type=%s)",
+ phex (addr, 8), len,
+ type == hw_write ? "data-write"
+ : (type == hw_read ? "data-read"
+ : (type == hw_access ? "data-read/write"
+ : (type == hw_execute ? "instruction-execute"
+ /* FIXME: if/when I/O read/write
+ watchpoints are supported, add them
+ here. */
+ : "??unknown??"))));
+ debug_printf (":\n");
+ debug_printf ("\tCONTROL (DR7): %s STATUS (DR6): %s\n",
+ phex (state->dr_control_mirror, 8),
+ phex (state->dr_status_mirror, 8));
+ ALL_DEBUG_REGISTERS (i)
{
- printf_unfiltered ("\
+ debug_printf ("\
\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
- i, phex (dr_mirror[i], addr_size), dr_ref_count[i],
- i+1, phex (dr_mirror[i+1], addr_size), dr_ref_count[i+1]);
+ i, phex (state->dr_mirror[i],
+ i386_get_debug_register_length ()),
+ state->dr_ref_count[i],
+ i + 1, phex (state->dr_mirror[i + 1],
+ i386_get_debug_register_length ()),
+ state->dr_ref_count[i + 1]);
i++;
}
}
region of LEN bytes for accesses of type TYPE. LEN is assumed to
have the value of 1, 2, or 4. */
-static unsigned
-i386_length_and_rw_bits (int len, enum target_hw_bp_type type)
+unsigned
+i386_dr_length_and_rw_bits (int len, enum target_hw_bp_type type)
{
unsigned rw;
break;
case hw_read:
internal_error (__FILE__, __LINE__,
- _("The i386 doesn't support data-read watchpoints.\n"));
+ _("The i386 doesn't support "
+ "data-read watchpoints.\n"));
case hw_access:
rw = DR_RW_READ;
break;
#endif
default:
internal_error (__FILE__, __LINE__, _("\
-Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n"),
+Invalid hardware breakpoint type %d in i386_dr_length_and_rw_bits.\n"),
(int) type);
}
case 8:
if (TARGET_HAS_DR_LEN_8)
return (DR_LEN_8 | rw);
+ /* ELSE FALL THROUGH */
default:
internal_error (__FILE__, __LINE__, _("\
-Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n"), len);
+Invalid hardware breakpoint length %d in i386_dr_length_and_rw_bits.\n"), len);
}
}
type of the region to be watched by this watchpoint. Return 0 on
success, -1 on failure. */
-static int
-i386_insert_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
+int
+i386_dr_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
{
int i;
- if (!i386_dr_low.set_addr || !i386_dr_low.set_control)
+ if (!i386_dr_low_can_set_addr () || !i386_dr_low_can_set_control ())
return -1;
/* First, look for an occupied debug register with the same address
and the same RW and LEN definitions. If we find one, we can
reuse it for this watchpoint as well (and save a register). */
- ALL_DEBUG_REGISTERS(i)
+ ALL_DEBUG_REGISTERS (i)
{
- if (!I386_DR_VACANT (i)
- && dr_mirror[i] == addr
- && I386_DR_GET_RW_LEN (i) == len_rw_bits)
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state->dr_control_mirror, i) == len_rw_bits)
{
- dr_ref_count[i]++;
+ state->dr_ref_count[i]++;
return 0;
}
}
/* Next, look for a vacant debug register. */
- ALL_DEBUG_REGISTERS(i)
+ ALL_DEBUG_REGISTERS (i)
{
- if (I386_DR_VACANT (i))
+ if (I386_DR_VACANT (state, i))
break;
}
/* Now set up the register I to watch our region. */
/* Record the info in our local mirrored array. */
- dr_mirror[i] = addr;
- dr_ref_count[i] = 1;
- I386_DR_SET_RW_LEN (i, len_rw_bits);
+ state->dr_mirror[i] = addr;
+ state->dr_ref_count[i] = 1;
+ I386_DR_SET_RW_LEN (state, i, len_rw_bits);
/* Note: we only enable the watchpoint locally, i.e. in the current
task. Currently, no i386 target allows or supports global
watchpoints; however, if any target would want that in the
to enable watchpoints globally or locally, and the code below
should use global or local enable and slow-down flags as
appropriate. */
- I386_DR_LOCAL_ENABLE (i);
- dr_control_mirror |= DR_LOCAL_SLOWDOWN;
- dr_control_mirror &= I386_DR_CONTROL_MASK;
-
- /* Finally, actually pass the info to the inferior. */
- i386_dr_low.set_addr (i, addr);
- i386_dr_low.set_control (dr_control_mirror);
-
- /* Only a sanity check for leftover bits (set possibly only by inferior). */
- if (i386_dr_low.unset_status)
- i386_dr_low.unset_status (I386_DR_WATCH_MASK (i));
+ I386_DR_LOCAL_ENABLE (state, i);
+ state->dr_control_mirror |= DR_LOCAL_SLOWDOWN;
+ state->dr_control_mirror &= I386_DR_CONTROL_MASK;
return 0;
}
type of the region watched by this watchpoint. Return 0 on
success, -1 on failure. */
-static int
-i386_remove_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
+int
+i386_dr_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
{
int i, retval = -1;
- ALL_DEBUG_REGISTERS(i)
+ ALL_DEBUG_REGISTERS (i)
{
- if (!I386_DR_VACANT (i)
- && dr_mirror[i] == addr
- && I386_DR_GET_RW_LEN (i) == len_rw_bits)
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state->dr_control_mirror, i) == len_rw_bits)
{
- if (--dr_ref_count[i] == 0) /* no longer in use? */
+ if (--state->dr_ref_count[i] == 0) /* No longer in use? */
{
/* Reset our mirror. */
- dr_mirror[i] = 0;
- I386_DR_DISABLE (i);
- /* Reset it in the inferior. */
- i386_dr_low.set_control (dr_control_mirror);
- if (i386_dr_low.reset_addr)
- i386_dr_low.reset_addr (i);
+ state->dr_mirror[i] = 0;
+ I386_DR_DISABLE (state, i);
}
retval = 0;
}
valid value, bombs through internal_error. */
static int
-i386_handle_nonaligned_watchpoint (i386_wp_op_t what, CORE_ADDR addr, int len,
+i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
+ i386_wp_op_t what, CORE_ADDR addr, int len,
enum target_hw_bp_type type)
{
- int retval = 0, status = 0;
+ int retval = 0;
int max_wp_len = TARGET_HAS_DR_LEN_8 ? 8 : 4;
- static int size_try_array[8][8] =
+ static const int size_try_array[8][8] =
{
{1, 1, 1, 1, 1, 1, 1, 1}, /* Trying size one. */
{2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size two. */
}
else
{
- unsigned len_rw = i386_length_and_rw_bits (size, type);
+ unsigned len_rw = i386_dr_length_and_rw_bits (size, type);
if (what == WP_INSERT)
- status = i386_insert_aligned_watchpoint (addr, len_rw);
+ retval = i386_dr_insert_aligned_watchpoint (state, addr, len_rw);
else if (what == WP_REMOVE)
- status = i386_remove_aligned_watchpoint (addr, len_rw);
+ retval = i386_dr_remove_aligned_watchpoint (state, addr, len_rw);
else
internal_error (__FILE__, __LINE__, _("\
Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n"),
- (int)what);
- /* We keep the loop going even after a failure, because some
- of the other aligned watchpoints might still succeed
- (e.g. if they watch addresses that are already watched,
- in which case we just increment the reference counts of
- occupied debug registers). If we break out of the loop
- too early, we could cause those addresses watched by
- other watchpoints to be disabled when breakpoint.c reacts
- to our failure to insert this watchpoint and tries to
- remove it. */
- if (status)
- retval = status;
+ (int) what);
+ if (retval)
+ break;
}
addr += size;
return retval;
}
+/* Update the inferior debug registers state, in STATE, with the
+ new debug registers state, in NEW_STATE. */
+
+void
+i386_dr_update_inferior_debug_regs (struct i386_debug_reg_state *state,
+ struct i386_debug_reg_state *new_state)
+{
+ int i;
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (I386_DR_VACANT (new_state, i) != I386_DR_VACANT (state, i))
+ i386_dr_low_set_addr (new_state, i);
+ else
+ gdb_assert (new_state->dr_mirror[i] == state->dr_mirror[i]);
+ }
+
+ if (new_state->dr_control_mirror != state->dr_control_mirror)
+ i386_dr_low_set_control (new_state);
+
+ *state = *new_state;
+}
+
/* Insert a watchpoint to watch a memory region which starts at
address ADDR and whose length is LEN bytes. Watch memory accesses
of the type TYPE. Return 0 on success, -1 on failure. */
static int
-i386_insert_watchpoint (CORE_ADDR addr, int len, int type,
+i386_insert_watchpoint (struct target_ops *self,
+ CORE_ADDR addr, int len, int type,
struct expression *cond)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
int retval;
+ /* Work on a local copy of the debug registers, and on success,
+ commit the change back to the inferior. */
+ struct i386_debug_reg_state local_state = *state;
if (type == hw_read)
return 1; /* unsupported */
- if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ if (((len != 1 && len != 2 && len != 4)
+ && !(TARGET_HAS_DR_LEN_8 && len == 8))
|| addr % len != 0)
- retval = i386_handle_nonaligned_watchpoint (WP_INSERT, addr, len, type);
+ {
+ retval = i386_handle_nonaligned_watchpoint (&local_state,
+ WP_INSERT,
+ addr, len, type);
+ }
else
{
- unsigned len_rw = i386_length_and_rw_bits (len, type);
+ unsigned len_rw = i386_dr_length_and_rw_bits (len, type);
- retval = i386_insert_aligned_watchpoint (addr, len_rw);
+ retval = i386_dr_insert_aligned_watchpoint (&local_state,
+ addr, len_rw);
}
- if (maint_show_dr)
- i386_show_dr ("insert_watchpoint", addr, len, type);
+ if (retval == 0)
+ i386_dr_update_inferior_debug_regs (state, &local_state);
+
+ if (debug_hw_points)
+ i386_dr_show (state, "insert_watchpoint", addr, len, type);
return retval;
}
address ADDR, whose length is LEN bytes, and for accesses of the
type TYPE. Return 0 on success, -1 on failure. */
static int
-i386_remove_watchpoint (CORE_ADDR addr, int len, int type,
+i386_remove_watchpoint (struct target_ops *self,
+ CORE_ADDR addr, int len, int type,
struct expression *cond)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
int retval;
+ /* Work on a local copy of the debug registers, and on success,
+ commit the change back to the inferior. */
+ struct i386_debug_reg_state local_state = *state;
- if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ if (((len != 1 && len != 2 && len != 4)
+ && !(TARGET_HAS_DR_LEN_8 && len == 8))
|| addr % len != 0)
- retval = i386_handle_nonaligned_watchpoint (WP_REMOVE, addr, len, type);
+ {
+ retval = i386_handle_nonaligned_watchpoint (&local_state,
+ WP_REMOVE,
+ addr, len, type);
+ }
else
{
- unsigned len_rw = i386_length_and_rw_bits (len, type);
+ unsigned len_rw = i386_dr_length_and_rw_bits (len, type);
- retval = i386_remove_aligned_watchpoint (addr, len_rw);
+ retval = i386_dr_remove_aligned_watchpoint (&local_state,
+ addr, len_rw);
}
- if (maint_show_dr)
- i386_show_dr ("remove_watchpoint", addr, len, type);
+ if (retval == 0)
+ i386_dr_update_inferior_debug_regs (state, &local_state);
+
+ if (debug_hw_points)
+ i386_dr_show (state, "remove_watchpoint", addr, len, type);
return retval;
}
address ADDR and whose length is LEN bytes. */
static int
-i386_region_ok_for_watchpoint (CORE_ADDR addr, int len)
+i386_region_ok_for_watchpoint (struct target_ops *self,
+ CORE_ADDR addr, int len)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
int nregs;
/* Compute how many aligned watchpoints we would need to cover this
region. */
- nregs = i386_handle_nonaligned_watchpoint (WP_COUNT, addr, len, hw_write);
+ nregs = i386_handle_nonaligned_watchpoint (state, WP_COUNT,
+ addr, len, hw_write);
return nregs <= DR_NADDR ? 1 : 0;
}
-/* If the inferior has some watchpoint that triggered, set the
- address associated with that watchpoint and return non-zero.
+/* If the inferior has some break/watchpoint that triggered, set the
+ address associated with that break/watchpoint and return non-zero.
Otherwise, return zero. */
static int
i386_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
CORE_ADDR addr = 0;
int i;
int rc = 0;
+ /* The current thread's DR_STATUS. We always need to read this to
+ check whether some watchpoint caused the trap. */
+ unsigned status;
+ /* We need DR_CONTROL as well, but only iff DR_STATUS indicates a
+ data breakpoint trap. Only fetch it when necessary, to avoid an
+ unnecessary extra syscall when no watchpoint triggered. */
+ int control_p = 0;
+ unsigned control = 0;
+
+ /* In non-stop/async, threads can be running while we change the
+ global dr_mirror (and friends). Say, we set a watchpoint, and
+ let threads resume. Now, say you delete the watchpoint, or
+ add/remove watchpoints such that dr_mirror changes while threads
+ are running. On targets that support non-stop,
+ inserting/deleting watchpoints updates the global dr_mirror only.
+ It does not update the real thread's debug registers; that's only
+ done prior to resume. Instead, if threads are running when the
+ mirror changes, a temporary and transparent stop on all threads
+ is forced so they can get their copy of the debug registers
+ updated on re-resume. Now, say, a thread hit a watchpoint before
+ having been updated with the new dr_mirror contents, and we
+ haven't yet handled the corresponding SIGTRAP. If we trusted
+ dr_mirror below, we'd mistake the real trapped address (from the
+ last time we had updated debug registers in the thread) with
+ whatever was currently in dr_mirror. So to fix this, dr_mirror
+ always represents intention, what we _want_ threads to have in
+ debug registers. To get at the address and cause of the trap, we
+ need to read the state the thread still has in its debug
+ registers.
+
+ In sum, always get the current debug register values the current
+ thread has, instead of trusting the global mirror. If the thread
+ was running when we last changed watchpoints, the mirror no
+ longer represents what was set in this thread's debug
+ registers. */
+ status = i386_dr_low_get_status ();
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (!I386_DR_WATCH_HIT (status, i))
+ continue;
- dr_status_mirror = i386_dr_low.get_status ();
+ if (!control_p)
+ {
+ control = i386_dr_low_get_control ();
+ control_p = 1;
+ }
- ALL_DEBUG_REGISTERS(i)
- {
- if (I386_DR_WATCH_HIT (i)
- /* This second condition makes sure DRi is set up for a data
- watchpoint, not a hardware breakpoint. The reason is
- that GDB doesn't call the target_stopped_data_address
- method except for data watchpoints. In other words, I'm
- being paranoiac. */
- && I386_DR_GET_RW_LEN (i) != 0
- /* This third condition makes sure DRi is not vacant, this
- avoids false positives in windows-nat.c. */
- && !I386_DR_VACANT (i))
+ /* This second condition makes sure DRi is set up for a data
+ watchpoint, not a hardware breakpoint. The reason is that
+ GDB doesn't call the target_stopped_data_address method
+ except for data watchpoints. In other words, I'm being
+ paranoiac. */
+ if (I386_DR_GET_RW_LEN (control, i) != 0)
{
- addr = dr_mirror[i];
+ addr = i386_dr_low_get_addr (i);
rc = 1;
- if (maint_show_dr)
- i386_show_dr ("watchpoint_hit", addr, -1, hw_write);
+ if (debug_hw_points)
+ i386_dr_show (state, "watchpoint_hit", addr, -1, hw_write);
}
}
- if (maint_show_dr && addr == 0)
- i386_show_dr ("stopped_data_addr", 0, 0, hw_write);
+
+ if (debug_hw_points && addr == 0)
+ i386_dr_show (state, "stopped_data_addr", 0, 0, hw_write);
if (rc)
*addr_p = addr;
return rc;
}
+/* Return non-zero if the inferior has some watchpoint that triggered.
+ Otherwise return zero. */
+
static int
-i386_stopped_by_watchpoint (void)
+i386_stopped_by_watchpoint (struct target_ops *ops)
{
CORE_ADDR addr = 0;
- return i386_stopped_data_address (¤t_target, &addr);
+ return i386_stopped_data_address (ops, &addr);
}
/* Insert a hardware-assisted breakpoint at BP_TGT->placed_address.
Return 0 on success, EBUSY on failure. */
static int
-i386_insert_hw_breakpoint (struct gdbarch *gdbarch,
+i386_insert_hw_breakpoint (struct target_ops *self, struct gdbarch *gdbarch,
struct bp_target_info *bp_tgt)
{
- unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
+ unsigned len_rw = i386_dr_length_and_rw_bits (1, hw_execute);
CORE_ADDR addr = bp_tgt->placed_address;
- int retval = i386_insert_aligned_watchpoint (addr, len_rw) ? EBUSY : 0;
+ /* Work on a local copy of the debug registers, and on success,
+ commit the change back to the inferior. */
+ struct i386_debug_reg_state local_state = *state;
+ int retval = i386_dr_insert_aligned_watchpoint (&local_state,
+ addr,
+ len_rw) ? EBUSY : 0;
+
+ if (retval == 0)
+ i386_dr_update_inferior_debug_regs (state, &local_state);
- if (maint_show_dr)
- i386_show_dr ("insert_hwbp", addr, 1, hw_execute);
+ if (debug_hw_points)
+ i386_dr_show (state, "insert_hwbp", addr, 1, hw_execute);
return retval;
}
Return 0 on success, -1 on failure. */
static int
-i386_remove_hw_breakpoint (struct gdbarch *gdbarch,
+i386_remove_hw_breakpoint (struct target_ops *self, struct gdbarch *gdbarch,
struct bp_target_info *bp_tgt)
{
- unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
+ unsigned len_rw = i386_dr_length_and_rw_bits (1, hw_execute);
CORE_ADDR addr = bp_tgt->placed_address;
- int retval = i386_remove_aligned_watchpoint (addr, len_rw);
+ /* Work on a local copy of the debug registers, and on success,
+ commit the change back to the inferior. */
+ struct i386_debug_reg_state local_state = *state;
+ int retval = i386_dr_remove_aligned_watchpoint (&local_state,
+ addr, len_rw);
+
+ if (retval == 0)
+ i386_dr_update_inferior_debug_regs (state, &local_state);
- if (maint_show_dr)
- i386_show_dr ("remove_hwbp", addr, 1, hw_execute);
+ if (debug_hw_points)
+ i386_dr_show (state, "remove_hwbp", addr, 1, hw_execute);
return retval;
}
sharing implemented via reference counts in i386-nat.c. */
static int
-i386_can_use_hw_breakpoint (int type, int cnt, int othertype)
+i386_can_use_hw_breakpoint (struct target_ops *self,
+ int type, int cnt, int othertype)
{
return 1;
}
/* A maintenance command to enable printing the internal DRi mirror
variables. */
add_setshow_boolean_cmd ("show-debug-regs", class_maintenance,
- &maint_show_dr, _("\
+ &debug_hw_points, _("\
Set whether to show variables that mirror the x86 debug registers."), _("\
Show whether to show variables that mirror the x86 debug registers."), _("\
Use \"on\" to enable, \"off\" to disable.\n\
projects / deliverable / binutils-gdb.git / blobdiff