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-rw-r--r--gdb/i386-nat.c281
1 files changed, 183 insertions, 98 deletions
diff --git a/gdb/i386-nat.c b/gdb/i386-nat.c
index 7e6814e..4c6c4e9 100644
--- a/gdb/i386-nat.c
+++ b/gdb/i386-nat.c
@@ -111,45 +111,88 @@ struct i386_dr_low_type i386_dr_low;
/* 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)
+#define I386_DR_GET_RW_LEN(dr7, i) \
+ (((dr7) \
+ >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
/* Mask that this I'th watchpoint has triggered. */
#define I386_DR_WATCH_MASK(i) (1 << (i))
/* 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++)
-/* 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;
+
+/* Global state needed to track h/w watchpoints. */
+
+struct i386_debug_reg_state
+{
+ /* Mirror the inferior's DRi registers. We keep the status and
+ control registers separated because they don't hold addresses.
+ Note that since we can change these mirrors while threads are
+ running, we never trust them to explain a cause of a trap.
+ For that, we need to peek directly in the inferior registers. */
+ CORE_ADDR dr_mirror[DR_NADDR];
+ unsigned dr_status_mirror, dr_control_mirror;
+
+ /* Reference counts for each debug register. */
+ int dr_ref_count[DR_NADDR];
+};
+
+/* Clear the reference counts and forget everything we knew about the
+ debug registers. */
+
+static void
+i386_init_dregs (struct i386_debug_reg_state *state)
+{
+ int i;
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ state->dr_mirror[i] = 0;
+ state->dr_ref_count[i] = 0;
+ }
+ state->dr_control_mirror = 0;
+ state->dr_status_mirror = 0;
+}
+
+static struct i386_debug_reg_state dr_mirror;
/* Reference counts for each debug register. */
static int dr_ref_count[DR_NADDR];
@@ -172,7 +215,8 @@ static unsigned i386_length_and_rw_bits (int len, enum target_hw_bp_type type);
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,
+static int i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr,
unsigned len_rw_bits);
/* Remove a watchpoint at address ADDR, which is assumed to be aligned
@@ -180,7 +224,8 @@ static int i386_insert_aligned_watchpoint (CORE_ADDR addr,
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,
+static int i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr,
unsigned len_rw_bits);
/* Insert or remove a (possibly non-aligned) watchpoint, or count the
@@ -189,7 +234,8 @@ static int i386_remove_aligned_watchpoint (CORE_ADDR addr,
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,
+static int 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);
@@ -201,15 +247,7 @@ static int i386_handle_nonaligned_watchpoint (i386_wp_op_t what,
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;
+ i386_init_dregs (&dr_mirror);
}
/* Print the values of the mirrored debug registers. This is called
@@ -217,7 +255,8 @@ i386_cleanup_dregs (void)
show-debug-regs" at GDB's prompt. */
static void
-i386_show_dr (const char *func, CORE_ADDR addr,
+i386_show_dr (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;
@@ -239,13 +278,16 @@ i386_show_dr (const char *func, CORE_ADDR addr,
: "??unknown??"))));
puts_unfiltered (":\n");
printf_unfiltered ("\tCONTROL (DR7): %s STATUS (DR6): %s\n",
- phex (dr_control_mirror, 8), phex (dr_status_mirror, 8));
+ phex (state->dr_control_mirror, 8),
+ phex (state->dr_status_mirror, 8));
ALL_DEBUG_REGISTERS(i)
{
printf_unfiltered ("\
\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], addr_size),
+ state->dr_ref_count[i],
+ i + 1, phex (state->dr_mirror[i + 1], addr_size),
+ state->dr_ref_count[i+1]);
i++;
}
}
@@ -311,7 +353,8 @@ Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n"), len);
success, -1 on failure. */
static int
-i386_insert_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
+i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
{
int i;
@@ -323,11 +366,11 @@ i386_insert_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
reuse it for this watchpoint as well (and save a register). */
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;
}
}
@@ -335,7 +378,7 @@ i386_insert_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
/* Next, look for a vacant debug register. */
ALL_DEBUG_REGISTERS(i)
{
- if (I386_DR_VACANT (i))
+ if (I386_DR_VACANT (state, i))
break;
}
@@ -346,9 +389,9 @@ i386_insert_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
/* 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
@@ -356,17 +399,9 @@ i386_insert_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
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;
}
@@ -378,25 +413,22 @@ i386_insert_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
success, -1 on failure. */
static int
-i386_remove_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
+i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
{
int i, retval = -1;
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;
}
@@ -413,10 +445,11 @@ i386_remove_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
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] =
@@ -454,24 +487,15 @@ i386_handle_nonaligned_watchpoint (i386_wp_op_t what, CORE_ADDR addr, int len,
unsigned len_rw = i386_length_and_rw_bits (size, type);
if (what == WP_INSERT)
- status = i386_insert_aligned_watchpoint (addr, len_rw);
+ retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
else if (what == WP_REMOVE)
- status = i386_remove_aligned_watchpoint (addr, len_rw);
+ retval = i386_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;
+ if (retval)
+ break;
}
addr += size;
@@ -481,6 +505,43 @@ Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n"),
return retval;
}
+/* Update the inferior's debug registers with the new debug registers
+ state, in NEW_STATE, and then update our local mirror to match. */
+
+static void
+i386_update_inferior_debug_regs (struct i386_debug_reg_state *new_state)
+{
+ int i;
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (I386_DR_VACANT (new_state, i) != I386_DR_VACANT (&dr_mirror, i))
+ {
+ if (!I386_DR_VACANT (new_state, i))
+ {
+ i386_dr_low.set_addr (i, new_state->dr_mirror[i]);
+
+ /* 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));
+ }
+ else
+ {
+ if (i386_dr_low.reset_addr)
+ i386_dr_low.reset_addr (i);
+ }
+ }
+ else
+ gdb_assert (new_state->dr_mirror[i] == dr_mirror.dr_mirror[i]);
+ }
+
+ if (new_state->dr_control_mirror != dr_mirror.dr_control_mirror)
+ i386_dr_low.set_control (new_state->dr_control_mirror);
+
+ dr_mirror = *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. */
@@ -490,22 +551,30 @@ i386_insert_watchpoint (CORE_ADDR addr, int len, int type,
struct expression *cond)
{
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 = dr_mirror;
if (type == hw_read)
return 1; /* unsupported */
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);
- retval = i386_insert_aligned_watchpoint (addr, len_rw);
+ retval = i386_insert_aligned_watchpoint (&local_state,
+ addr, len_rw);
}
+ if (retval == 0)
+ i386_update_inferior_debug_regs (&local_state);
+
if (maint_show_dr)
- i386_show_dr ("insert_watchpoint", addr, len, type);
+ i386_show_dr (&dr_mirror, "insert_watchpoint", addr, len, type);
return retval;
}
@@ -518,19 +587,27 @@ i386_remove_watchpoint (CORE_ADDR addr, int len, int type,
struct expression *cond)
{
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 = dr_mirror;
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);
- retval = i386_remove_aligned_watchpoint (addr, len_rw);
+ retval = i386_remove_aligned_watchpoint (&local_state,
+ addr, len_rw);
}
+ if (retval == 0)
+ i386_update_inferior_debug_regs (&local_state);
+
if (maint_show_dr)
- i386_show_dr ("remove_watchpoint", addr, len, type);
+ i386_show_dr (&dr_mirror, "remove_watchpoint", addr, len, type);
return retval;
}
@@ -545,7 +622,8 @@ i386_region_ok_for_watchpoint (CORE_ADDR addr, int len)
/* 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 (&dr_mirror,
+ WP_COUNT, addr, len, hw_write);
return nregs <= DR_NADDR ? 1 : 0;
}
@@ -559,30 +637,35 @@ i386_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
CORE_ADDR addr = 0;
int i;
int rc = 0;
+ unsigned status;
+ unsigned control;
+ struct i386_debug_reg_state *state = &dr_mirror;
- dr_status_mirror = i386_dr_low.get_status ();
+ dr_mirror.dr_status_mirror = i386_dr_low.get_status ();
+ status = dr_mirror.dr_status_mirror;
+ control = dr_mirror.dr_control_mirror;
ALL_DEBUG_REGISTERS(i)
{
- if (I386_DR_WATCH_HIT (i)
+ if (I386_DR_WATCH_HIT (status, 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
+ && I386_DR_GET_RW_LEN (control, i) != 0
/* This third condition makes sure DRi is not vacant, this
avoids false positives in windows-nat.c. */
- && !I386_DR_VACANT (i))
+ && !I386_DR_VACANT (state, i))
{
- addr = dr_mirror[i];
+ addr = state->dr_mirror[i];
rc = 1;
if (maint_show_dr)
- i386_show_dr ("watchpoint_hit", addr, -1, hw_write);
+ i386_show_dr (&dr_mirror, "watchpoint_hit", addr, -1, hw_write);
}
}
if (maint_show_dr && addr == 0)
- i386_show_dr ("stopped_data_addr", 0, 0, hw_write);
+ i386_show_dr (&dr_mirror, "stopped_data_addr", 0, 0, hw_write);
if (rc)
*addr_p = addr;
@@ -604,10 +687,11 @@ i386_insert_hw_breakpoint (struct gdbarch *gdbarch,
{
unsigned len_rw = i386_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;
+ int retval = i386_insert_aligned_watchpoint (&dr_mirror,
+ addr, len_rw) ? EBUSY : 0;
if (maint_show_dr)
- i386_show_dr ("insert_hwbp", addr, 1, hw_execute);
+ i386_show_dr (&dr_mirror, "insert_hwbp", addr, 1, hw_execute);
return retval;
}
@@ -621,10 +705,11 @@ i386_remove_hw_breakpoint (struct gdbarch *gdbarch,
{
unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
CORE_ADDR addr = bp_tgt->placed_address;
- int retval = i386_remove_aligned_watchpoint (addr, len_rw);
+ int retval = i386_remove_aligned_watchpoint (&dr_mirror,
+ addr, len_rw);
if (maint_show_dr)
- i386_show_dr ("remove_hwbp", addr, 1, hw_execute);
+ i386_show_dr (&dr_mirror, "remove_hwbp", addr, 1, hw_execute);
return retval;
}