}
}
+/* Assuming that B is a watchpoint: returns true if the current thread
+ and its running state are safe to evaluate or update watchpoint B.
+ Watchpoints on local expressions need to be evaluated in the
+ context of the thread that was current when the watchpoint was
+ created, and, that thread needs to be stopped to be able to select
+ the correct frame context. Watchpoints on global expressions can
+ be evaluated on any thread, and in any state. It is presently left
+ to the target allowing memory accesses when threads are
+ running. */
+
+static int
+watchpoint_in_thread_scope (struct breakpoint *b)
+{
+ return (ptid_equal (b->watchpoint_thread, null_ptid)
+ || (ptid_equal (inferior_ptid, b->watchpoint_thread)
+ && !is_executing (inferior_ptid)));
+}
+
/* Assuming that B is a watchpoint:
- Reparse watchpoint expression, if REPARSE is non-zero
- Evaluate expression and store the result in B->val
- Update the list of values that must be watched in B->loc.
If the watchpoint disposition is disp_del_at_next_stop, then do nothing.
- If this is local watchpoint that is out of scope, delete it. */
+ If this is local watchpoint that is out of scope, delete it.
+
+ Even with `set breakpoint always-inserted on' the watchpoints are removed
+ + inserted on each stop here. Normal breakpoints must never be removed
+ because they might be missed by a running thread when debugging in non-stop
+ mode. On the other hand, hardware watchpoints (is_hardware_watchpoint;
+ processed here) are specific to each LWP since they are stored in each LWP's
+ hardware debug registers. Therefore, such LWP must be stopped first in
+ order to be able to modify its hardware watchpoints.
+
+ Hardware watchpoints must be reset exactly once after being presented to the
+ user. It cannot be done sooner, because it would reset the data used to
+ present the watchpoint hit to the user. And it must not be done later
+ because it could display the same single watchpoint hit during multiple GDB
+ stops. Note that the latter is relevant only to the hardware watchpoint
+ types bp_read_watchpoint and bp_access_watchpoint. False hit by
+ bp_hardware_watchpoint is not user-visible - its hit is suppressed if the
+ memory content has not changed.
+
+ The following constraints influence the location where we can reset hardware
+ watchpoints:
+
+ * target_stopped_by_watchpoint and target_stopped_data_address are called
+ several times when GDB stops.
+
+ [linux]
+ * Multiple hardware watchpoints can be hit at the same time, causing GDB to
+ stop. GDB only presents one hardware watchpoint hit at a time as the
+ reason for stopping, and all the other hits are presented later, one after
+ the other, each time the user requests the execution to be resumed.
+ Execution is not resumed for the threads still having pending hit event
+ stored in LWP_INFO->STATUS. While the watchpoint is already removed from
+ the inferior on the first stop the thread hit event is kept being reported
+ from its cached value by linux_nat_stopped_data_address until the real
+ thread resume happens after the watchpoint gets presented and thus its
+ LWP_INFO->STATUS gets reset.
+
+ Therefore the hardware watchpoint hit can get safely reset on the watchpoint
+ removal from inferior. */
+
static void
update_watchpoint (struct breakpoint *b, int reparse)
{
int within_current_scope;
struct frame_id saved_frame_id;
struct bp_location *loc;
+ int frame_saved;
bpstat bs;
- struct program_space *frame_pspace;
+
+ /* If this is a local watchpoint, we only want to check if the
+ watchpoint frame is in scope if the current thread is the thread
+ that was used to create the watchpoint. */
+ if (!watchpoint_in_thread_scope (b))
+ return;
/* We don't free locations. They are stored in bp_location array and
update_global_locations will eventually delete them and remove
if (b->disposition == disp_del_at_next_stop)
return;
- /* Save the current frame's ID so we can restore it after
- evaluating the watchpoint expression on its own frame. */
- /* FIXME drow/2003-09-09: It would be nice if evaluate_expression
- took a frame parameter, so that we didn't have to change the
- selected frame. */
- saved_frame_id = get_frame_id (get_selected_frame (NULL));
+ frame_saved = 0;
/* Determine if the watchpoint is within scope. */
if (b->exp_valid_block == NULL)
else
{
struct frame_info *fi;
+
+ /* Save the current frame's ID so we can restore it after
+ evaluating the watchpoint expression on its own frame. */
+ /* FIXME drow/2003-09-09: It would be nice if evaluate_expression
+ took a frame parameter, so that we didn't have to change the
+ selected frame. */
+ frame_saved = 1;
+ saved_frame_id = get_frame_id (get_selected_frame (NULL));
+
fi = frame_find_by_id (b->watchpoint_frame);
within_current_scope = (fi != NULL);
if (within_current_scope)
select_frame (fi);
}
- frame_pspace = get_frame_program_space (get_selected_frame (NULL));
-
if (within_current_scope && reparse)
{
char *s;
don't try to insert watchpoint. We don't automatically delete
such watchpoint, though, since failure to parse expression
is different from out-of-scope watchpoint. */
- if (within_current_scope && b->exp)
+ if ( !target_has_execution)
+ {
+ /* Without execution, memory can't change. No use to try and
+ set watchpoint locations. The watchpoint will be reset when
+ the target gains execution, through breakpoint_re_set. */
+ }
+ else if (within_current_scope && b->exp)
{
struct value *val_chain, *v, *result, *next;
+ struct program_space *frame_pspace;
fetch_watchpoint_value (b->exp, &v, &result, &val_chain);
}
}
+ frame_pspace = get_frame_program_space (get_selected_frame (NULL));
+
/* Look at each value on the value chain. */
for (v = val_chain; v; v = next)
{
}
/* Restore the selected frame. */
- select_frame (frame_find_by_id (saved_frame_id));
+ if (frame_saved)
+ select_frame (frame_find_by_id (saved_frame_id));
}
if (!bpt->enabled || bpt->shlib_disabled || bpt->duplicate)
return 0;
+ /* This is set for example, when we're attached to the parent of a
+ vfork, and have detached from the child. The child is running
+ free, and we expect it to do an exec or exit, at which point the
+ OS makes the parent schedulable again (and the target reports
+ that the vfork is done). Until the child is done with the shared
+ memory region, do not insert breakpoints in the parent, otherwise
+ the child could still trip on the parent's breakpoints. Since
+ the parent is blocked anyway, it won't miss any breakpoint. */
+ if (bpt->pspace->breakpoints_not_allowed)
+ return 0;
+
/* Tracepoints are inserted by the target at a time of its choosing,
not by us. */
if (bpt->owner->type == bp_tracepoint)
&& ptid_equal (inferior_ptid, null_ptid))
continue;
- if (!ptid_equal (inferior_ptid, null_ptid))
- {
- struct inferior *inf = current_inferior ();
- if (inf->waiting_for_vfork_done)
- {
- /* This is set when we're attached to the parent of the
- vfork, and have detached from the child. The child
- is running free, and we expect it to do an exec or
- exit, at which point the OS makes the parent
- schedulable again (and the target reports that the
- vfork is done). Until the child is done with the
- shared memory region, do not insert breakpoints in
- parent, otherwise the child could still trip on the
- parent's breakpoints. Since the parent is blocked
- anyway, it won't miss any breakpoint. */
- continue;
- }
- }
-
val = insert_bp_location (b, tmp_error_stream,
&disabled_breaks,
&hw_breakpoint_error);
continue;
for (loc = bpt->loc; loc; loc = loc->next)
- if (!loc->inserted)
+ if (!loc->inserted && should_be_inserted (loc))
{
some_failed = 1;
break;
return 0;
}
+int
+hardware_watchpoint_inserted_in_range (struct address_space *aspace,
+ CORE_ADDR addr, ULONGEST len)
+{
+ struct breakpoint *bpt;
+
+ ALL_BREAKPOINTS (bpt)
+ {
+ struct bp_location *loc;
+
+ if (bpt->type != bp_hardware_watchpoint
+ && bpt->type != bp_access_watchpoint)
+ continue;
+
+ if (!breakpoint_enabled (bpt))
+ continue;
+
+ for (loc = bpt->loc; loc; loc = loc->next)
+ if (loc->pspace->aspace == aspace && loc->inserted)
+ {
+ CORE_ADDR l, h;
+
+ /* Check for intersection. */
+ l = max (loc->address, addr);
+ h = min (loc->address + loc->length, addr + len);
+ if (l < h)
+ return 1;
+ }
+ }
+ return 0;
+}
+
/* breakpoint_thread_match (PC, PTID) returns true if the breakpoint at
PC is valid for process/thread PTID. */
#define BP_TEMPFLAG 1
#define BP_HARDWAREFLAG 2
-/* Check watchpoint condition. */
+/* Evaluate watchpoint condition expression and check if its value changed.
+
+ P should be a pointer to struct bpstat, but is defined as a void *
+ in order for this function to be usable with catch_errors. */
static int
watchpoint_check (void *p)
b = bs->breakpoint_at->owner;
+ /* If this is a local watchpoint, we only want to check if the
+ watchpoint frame is in scope if the current thread is the thread
+ that was used to create the watchpoint. */
+ if (!watchpoint_in_thread_scope (b))
+ return WP_VALUE_NOT_CHANGED;
+
if (b->exp_valid_block == NULL)
within_current_scope = 1;
else
struct value *new_val;
fetch_watchpoint_value (b->exp, &new_val, NULL, NULL);
+
+ /* We use value_equal_contents instead of value_equal because the latter
+ coerces an array to a pointer, thus comparing just the address of the
+ array instead of its contents. This is not what we want. */
if ((b->val != NULL) != (new_val != NULL)
- || (b->val != NULL && !value_equal (b->val, new_val)))
+ || (b->val != NULL && !value_equal_contents (b->val, new_val)))
{
if (new_val != NULL)
{
{
struct breakpoint *b = bl->owner;
+ /* By definition, the inferior does not report stops at
+ tracepoints. */
+ if (b->type == bp_tracepoint)
+ return 0;
+
if (b->type != bp_watchpoint
&& b->type != bp_hardware_watchpoint
&& b->type != bp_read_watchpoint
/* Pointer to the last thing in the chain currently. */
bpstat bs = root_bs;
int ix;
- int need_remove_insert, update_locations = 0;
+ int need_remove_insert;
- ALL_BP_LOCATIONS (bl, blp_tmp)
- {
- b = bl->owner;
- gdb_assert (b);
- if (!breakpoint_enabled (b) && b->enable_state != bp_permanent)
- continue;
+ /* ALL_BP_LOCATIONS iteration would break across
+ update_global_location_list possibly executed by
+ bpstat_check_breakpoint_conditions's inferior call. */
- /* For hardware watchpoints, we look only at the first location.
- The watchpoint_check function will work on entire expression,
- not the individual locations. For read watchopints, the
- watchpoints_triggered function have checked all locations
- alrea
- */
- if (b->type == bp_hardware_watchpoint && bl != b->loc)
- continue;
+ ALL_BREAKPOINTS (b)
+ {
+ if (!breakpoint_enabled (b) && b->enable_state != bp_permanent)
+ continue;
- if (!bpstat_check_location (bl, aspace, bp_addr))
- continue;
+ for (bl = b->loc; bl != NULL; bl = bl->next)
+ {
+ /* For hardware watchpoints, we look only at the first location.
+ The watchpoint_check function will work on entire expression,
+ not the individual locations. For read watchopints, the
+ watchpoints_triggered function have checked all locations
+ already. */
+ if (b->type == bp_hardware_watchpoint && bl != b->loc)
+ break;
- /* Come here if it's a watchpoint, or if the break address matches */
+ if (bl->shlib_disabled)
+ continue;
- bs = bpstat_alloc (bl, bs); /* Alloc a bpstat to explain stop */
+ if (!bpstat_check_location (bl, aspace, bp_addr))
+ continue;
- /* Assume we stop. Should we find watchpoint that is not actually
- triggered, or if condition of breakpoint is false, we'll reset
- 'stop' to 0. */
- bs->stop = 1;
- bs->print = 1;
+ /* Come here if it's a watchpoint, or if the break address matches */
- bpstat_check_watchpoint (bs);
- if (!bs->stop)
- continue;
+ bs = bpstat_alloc (bl, bs); /* Alloc a bpstat to explain stop */
- if (b->type == bp_thread_event || b->type == bp_overlay_event
- || b->type == bp_longjmp_master)
- /* We do not stop for these. */
- bs->stop = 0;
- else
- bpstat_check_breakpoint_conditions (bs, ptid);
-
- if (bs->stop)
- {
- if (b->enable_state != bp_disabled)
- ++(b->hit_count);
+ /* Assume we stop. Should we find watchpoint that is not actually
+ triggered, or if condition of breakpoint is false, we'll reset
+ 'stop' to 0. */
+ bs->stop = 1;
+ bs->print = 1;
- /* We will stop here */
- if (b->disposition == disp_disable)
- {
- if (b->enable_state != bp_permanent)
- b->enable_state = bp_disabled;
- update_locations = 1;
- }
- if (b->silent)
- bs->print = 0;
- bs->commands = b->commands;
- if (bs->commands
- && (strcmp ("silent", bs->commands->line) == 0
- || (xdb_commands && strcmp ("Q", bs->commands->line) == 0)))
- {
- bs->commands = bs->commands->next;
- bs->print = 0;
- }
- bs->commands = copy_command_lines (bs->commands);
- }
+ bpstat_check_watchpoint (bs);
+ if (!bs->stop)
+ continue;
- /* Print nothing for this entry if we dont stop or if we dont print. */
- if (bs->stop == 0 || bs->print == 0)
- bs->print_it = print_it_noop;
- }
+ if (b->type == bp_thread_event || b->type == bp_overlay_event
+ || b->type == bp_longjmp_master)
+ /* We do not stop for these. */
+ bs->stop = 0;
+ else
+ bpstat_check_breakpoint_conditions (bs, ptid);
+
+ if (bs->stop)
+ {
+ ++(b->hit_count);
- /* Delay this call which would break the ALL_BP_LOCATIONS iteration above. */
- if (update_locations)
- update_global_location_list (0);
+ /* We will stop here */
+ if (b->disposition == disp_disable)
+ {
+ if (b->enable_state != bp_permanent)
+ b->enable_state = bp_disabled;
+ update_global_location_list (0);
+ }
+ if (b->silent)
+ bs->print = 0;
+ bs->commands = b->commands;
+ if (bs->commands
+ && (strcmp ("silent", bs->commands->line) == 0
+ || (xdb_commands && strcmp ("Q",
+ bs->commands->line) == 0)))
+ {
+ bs->commands = bs->commands->next;
+ bs->print = 0;
+ }
+ bs->commands = copy_command_lines (bs->commands);
+ }
+
+ /* Print nothing for this entry if we dont stop or dont print. */
+ if (bs->stop == 0 || bs->print == 0)
+ bs->print_it = print_it_noop;
+ }
+ }
for (ix = 0; VEC_iterate (bp_location_p, moribund_locations, ix, loc); ++ix)
{
for (bs = root_bs->next; bs != NULL; bs = bs->next)
if (!bs->stop
&& bs->breakpoint_at->owner
- && (bs->breakpoint_at->owner->type == bp_hardware_watchpoint
- || bs->breakpoint_at->owner->type == bp_read_watchpoint
- || bs->breakpoint_at->owner->type == bp_access_watchpoint))
+ && is_hardware_watchpoint (bs->breakpoint_at->owner))
{
- /* remove/insert can invalidate bs->breakpoint_at, if this
- location is no longer used by the watchpoint. Prevent
- further code from trying to use it. */
+ update_watchpoint (bs->breakpoint_at->owner, 0 /* don't reparse. */);
+ /* Updating watchpoints invalidates bs->breakpoint_at.
+ Prevent further code from trying to use it. */
bs->breakpoint_at = NULL;
need_remove_insert = 1;
}
if (need_remove_insert)
- {
- remove_breakpoints ();
- insert_breakpoints ();
- }
+ update_global_location_list (1);
return root_bs->next;
}
return 0;
}
+int
+bpstat_causes_stop (bpstat bs)
+{
+ for (; bs != NULL; bs = bs->next)
+ if (bs->stop)
+ return 1;
+
+ return 0;
+}
+
\f
+/* Print the LOC location out of the list of B->LOC locations. */
+
static void print_breakpoint_location (struct breakpoint *b,
struct bp_location *loc,
char *wrap_indent,
{
struct cleanup *old_chain = save_current_program_space ();
+ if (loc != NULL && loc->shlib_disabled)
+ loc = NULL;
+
if (loc != NULL)
set_current_program_space (loc->pspace);
- if (b->source_file)
+ if (b->source_file && loc)
{
struct symbol *sym
= find_pc_sect_function (loc->address, loc->section);
ui_out_field_int (uiout, "line", b->line_number);
}
- else if (!b->loc)
+ else if (loc)
{
- ui_out_field_string (uiout, "pending", b->addr_string);
- }
- else
- {
- print_address_symbolic (loc->address, stb->stream, demangle, "");
+ print_address_symbolic (loc->gdbarch, loc->address, stb->stream,
+ demangle, "");
ui_out_field_stream (uiout, "at", stb);
}
+ else
+ ui_out_field_string (uiout, "pending", b->addr_string);
do_cleanups (old_chain);
}
for (loc = b->loc; loc; loc = loc->next)
{
- int addr_bit = gdbarch_addr_bit (b->gdbarch);
+ int addr_bit = gdbarch_addr_bit (loc->gdbarch);
if (addr_bit > print_address_bits)
print_address_bits = addr_bit;
}
these types to be a duplicate of an actual breakpoint at address zero:
bp_watchpoint
- bp_hardware_watchpoint
- bp_read_watchpoint
- bp_access_watchpoint
- bp_catchpoint */
+ bp_catchpoint
+
+*/
static int
breakpoint_address_is_meaningful (struct breakpoint *bpt)
{
enum bptype type = bpt->type;
- return (type != bp_watchpoint
- && type != bp_hardware_watchpoint
- && type != bp_read_watchpoint
- && type != bp_access_watchpoint
- && type != bp_catchpoint);
+ return (type != bp_watchpoint && type != bp_catchpoint);
+}
+
+/* Assuming LOC1 and LOC2's owners are hardware watchpoints, returns
+ true if LOC1 and LOC2 represent the same watchpoint location. */
+
+static int
+watchpoint_locations_match (struct bp_location *loc1, struct bp_location *loc2)
+{
+ return (loc1->owner->type == loc2->owner->type
+ && loc1->pspace->aspace == loc2->pspace->aspace
+ && loc1->address == loc2->address
+ && loc1->length == loc2->length);
}
/* Returns true if {ASPACE1,ADDR1} and {ASPACE2,ADDR2} represent the
&& addr1 == addr2);
}
+/* Assuming LOC1 and LOC2's types' have meaningful target addresses
+ (breakpoint_address_is_meaningful), returns true if LOC1 and LOC2
+ represent the same location. */
+
+static int
+breakpoint_locations_match (struct bp_location *loc1, struct bp_location *loc2)
+{
+ int hw_point1 = is_hardware_watchpoint (loc1->owner);
+ int hw_point2 = is_hardware_watchpoint (loc2->owner);
+
+ if (hw_point1 != hw_point2)
+ return 0;
+ else if (hw_point1)
+ return watchpoint_locations_match (loc1, loc2);
+ else
+ return breakpoint_address_match (loc1->pspace->aspace, loc1->address,
+ loc2->pspace->aspace, loc2->address);
+}
+
static void
breakpoint_adjustment_warning (CORE_ADDR from_addr, CORE_ADDR to_addr,
int bnum, int have_bnum)
if (expanded.nelts == 1)
{
- /* We had one sal, we got one sal. Without futher
- processing, just return the original sal. */
+ /* We had one sal, we got one sal. Return that sal, adjusting it
+ past the function prologue if necessary. */
xfree (expanded.sals);
expanded.nelts = 1;
expanded.sals = xmalloc (sizeof (struct symtab_and_line));
sal.pc = original_pc;
expanded.sals[0] = sal;
+ skip_prologue_sal (&expanded.sals[0]);
do_cleanups (old_chain);
return expanded;
}
if (tok == tmptok)
error (_("Junk after task keyword."));
if (!valid_task_id (*task))
- error (_("Unknown task %d\n"), *task);
+ error (_("Unknown task %d."), *task);
}
else
error (_("Junk at end of arguments."));
{
struct gdbarch *gdbarch = get_current_arch ();
struct breakpoint *b, *scope_breakpoint = NULL;
- struct symtab_and_line sal;
struct expression *exp;
struct block *exp_valid_block;
struct value *val, *mark;
int toklen;
char *cond_start = NULL;
char *cond_end = NULL;
- struct expression *cond = NULL;
int i, other_type_used, target_resources_ok = 0;
enum bptype bp_type;
int mem_cnt = 0;
int thread = -1;
- init_sal (&sal); /* initialize to zeroes */
-
/* Make sure that we actually have parameters to parse. */
if (arg != NULL && arg[0] != '\0')
{
}
}
- sal.pspace = current_program_space;
-
/* Parse the rest of the arguments. */
innermost_block = NULL;
exp_start = arg;
toklen = end_tok - tok;
if (toklen >= 1 && strncmp (tok, "if", toklen) == 0)
{
+ struct expression *cond;
+
tok = cond_start = end_tok + 1;
cond = parse_exp_1 (&tok, 0, 0);
+ xfree (cond);
cond_end = tok;
}
if (*tok)
}
/* Now set up the breakpoint. */
- b = set_raw_breakpoint (gdbarch, sal, bp_type);
+ b = set_raw_breakpoint_without_location (NULL, bp_type);
set_breakpoint_count (breakpoint_count + 1);
b->number = breakpoint_count;
b->thread = thread;
b->exp_string = savestring (exp_start, exp_end - exp_start);
b->val = val;
b->val_valid = 1;
- b->loc->cond = cond;
if (cond_start)
b->cond_string = savestring (cond_start, cond_end - cond_start);
else
b->cond_string = 0;
if (frame)
- b->watchpoint_frame = get_frame_id (frame);
+ {
+ b->watchpoint_frame = get_frame_id (frame);
+ b->watchpoint_thread = inferior_ptid;
+ }
else
- b->watchpoint_frame = null_frame_id;
+ {
+ b->watchpoint_frame = null_frame_id;
+ b->watchpoint_thread = null_ptid;
+ }
if (scope_breakpoint != NULL)
{
}
value_free_to_mark (mark);
+
+ /* Finally update the new watchpoint. This creates the locations
+ that should be inserted. */
+ update_watchpoint (b, 1);
+
mention (b);
update_global_location_list (1);
}
/* Check if the user provided a syscall name or a number. */
syscall_number = (int) strtol (cur_name, &endptr, 0);
if (*endptr == '\0')
- {
- get_syscall_by_number (syscall_number, &s);
-
- if (s.name == NULL)
- /* We can issue just a warning, but still create the catchpoint.
- This is because, even not knowing the syscall name that
- this number represents, we can still try to catch the syscall
- number. */
- warning (_("The number '%d' does not represent a known syscall."),
- syscall_number);
- }
+ get_syscall_by_number (syscall_number, &s);
else
{
/* We have a name. Let's check if it's valid and convert it
}
}
-/* A comparison function for bp_location A and B being interfaced to qsort.
+/* A comparison function for bp_location AP and BP being interfaced to qsort.
Sort elements primarily by their ADDRESS (no matter what does
breakpoint_address_is_meaningful say for its OWNER), secondarily by ordering
first bp_permanent OWNERed elements and terciarily just ensuring the array
is sorted stable way despite qsort being an instable algorithm. */
static int
-bp_location_compare (struct bp_location *a, struct bp_location *b)
+bp_location_compare (const void *ap, const void *bp)
{
+ struct bp_location *a = *(void **) ap;
+ struct bp_location *b = *(void **) bp;
int a_perm = a->owner->enable_state == bp_permanent;
int b_perm = b->owner->enable_state == bp_permanent;
return (a > b) - (a < b);
}
-/* Interface bp_location_compare as the COMPAR parameter of qsort function. */
-
-static int
-bp_location_compare_for_qsort (const void *ap, const void *bp)
-{
- struct bp_location *a = *(void **) ap;
- struct bp_location *b = *(void **) bp;
-
- return bp_location_compare (a, b);
-}
-
/* Set bp_location_placed_address_before_address_max and
bp_location_shadow_len_after_address_max according to the current content of
the bp_location array. */
struct bp_location **locp, *loc;
struct cleanup *cleanups;
- /* The first bp_location being the only one non-DUPLICATE for the current run
- of the same ADDRESS. */
- struct bp_location *loc_first;
+ /* Used in the duplicates detection below. When iterating over all
+ bp_locations, points to the first bp_location of a given address.
+ Breakpoints and watchpoints of different types are never
+ duplicates of each other. Keep one pointer for each type of
+ breakpoint/watchpoint, so we only need to loop over all locations
+ once. */
+ struct bp_location *bp_loc_first; /* breakpoint */
+ struct bp_location *wp_loc_first; /* hardware watchpoint */
+ struct bp_location *awp_loc_first; /* access watchpoint */
+ struct bp_location *rwp_loc_first; /* read watchpoint */
/* Saved former bp_location array which we compare against the newly built
bp_location from the current state of ALL_BREAKPOINTS. */
for (loc = b->loc; loc; loc = loc->next)
*locp++ = loc;
qsort (bp_location, bp_location_count, sizeof (*bp_location),
- bp_location_compare_for_qsort);
+ bp_location_compare);
bp_location_target_extensions_update ();
old_locp++)
{
struct bp_location *old_loc = *old_locp;
+ struct bp_location **loc2p;
/* Tells if 'old_loc' is found amoung the new locations. If not, we
have to free it. */
- int found_object;
+ int found_object = 0;
/* Tells if the location should remain inserted in the target. */
int keep_in_target = 0;
int removed = 0;
/* Skip LOCP entries which will definitely never be needed. Stop either
at or being the one matching OLD_LOC. */
while (locp < bp_location + bp_location_count
- && bp_location_compare (*locp, old_loc) < 0)
+ && (*locp)->address < old_loc->address)
locp++;
- found_object = locp < bp_location + bp_location_count && *locp == old_loc;
+
+ for (loc2p = locp;
+ (loc2p < bp_location + bp_location_count
+ && (*loc2p)->address == old_loc->address);
+ loc2p++)
+ {
+ if (*loc2p == old_loc)
+ {
+ found_object = 1;
+ break;
+ }
+ }
/* If this location is no longer present, and inserted, look if there's
maybe a new location at the same address. If so, mark that one
if (breakpoint_address_is_meaningful (old_loc->owner))
{
- struct bp_location **loc2p;
-
for (loc2p = locp;
- loc2p < bp_location + bp_location_count
- && breakpoint_address_match ((*loc2p)->pspace->aspace,
- (*loc2p)->address,
- old_loc->pspace->aspace,
- old_loc->address);
+ (loc2p < bp_location + bp_location_count
+ && (*loc2p)->address == old_loc->address);
loc2p++)
{
struct bp_location *loc2 = *loc2p;
- /* For the sake of should_be_inserted.
- Duplicates check below will fix up this later. */
- loc2->duplicate = 0;
- if (loc2 != old_loc && should_be_inserted (loc2))
- {
- loc2->inserted = 1;
- loc2->target_info = old_loc->target_info;
- keep_in_target = 1;
- break;
+ if (breakpoint_locations_match (loc2, old_loc))
+ {
+ /* For the sake of should_be_inserted.
+ Duplicates check below will fix up this later. */
+ loc2->duplicate = 0;
+ if (loc2 != old_loc && should_be_inserted (loc2))
+ {
+ loc2->inserted = 1;
+ loc2->target_info = old_loc->target_info;
+ keep_in_target = 1;
+ break;
+ }
}
}
}
if (!found_object)
{
- if (removed && non_stop)
+ if (removed && non_stop
+ && breakpoint_address_is_meaningful (old_loc->owner)
+ && !is_hardware_watchpoint (old_loc->owner))
{
- /* This location was removed from the targets. In non-stop mode,
- a race condition is possible where we've removed a breakpoint,
- but stop events for that breakpoint are already queued and will
- arrive later. To suppress spurious SIGTRAPs reported to user,
- we keep this breakpoint location for a bit, and will retire it
- after we see 3 * thread_count events.
- The theory here is that reporting of events should,
- "on the average", be fair, so after that many event we'll see
- events from all threads that have anything of interest, and no
- longer need to keep this breakpoint. This is just a
- heuristic, but if it's wrong, we'll report unexpected SIGTRAP,
- which is usability issue, but not a correctness problem. */
+ /* This location was removed from the target. In
+ non-stop mode, a race condition is possible where
+ we've removed a breakpoint, but stop events for that
+ breakpoint are already queued and will arrive later.
+ We apply an heuristic to be able to distinguish such
+ SIGTRAPs from other random SIGTRAPs: we keep this
+ breakpoint location for a bit, and will retire it
+ after we see some number of events. The theory here
+ is that reporting of events should, "on the average",
+ be fair, so after a while we'll see events from all
+ threads that have anything of interest, and no longer
+ need to keep this breakpoint location around. We
+ don't hold locations forever so to reduce chances of
+ mistaking a non-breakpoint SIGTRAP for a breakpoint
+ SIGTRAP.
+
+ The heuristic failing can be disastrous on
+ decr_pc_after_break targets.
+
+ On decr_pc_after_break targets, like e.g., x86-linux,
+ if we fail to recognize a late breakpoint SIGTRAP,
+ because events_till_retirement has reached 0 too
+ soon, we'll fail to do the PC adjustment, and report
+ a random SIGTRAP to the user. When the user resumes
+ the inferior, it will most likely immediately crash
+ with SIGILL/SIGBUS/SEGSEGV, or worse, get silently
+ corrupted, because of being resumed e.g., in the
+ middle of a multi-byte instruction, or skipped a
+ one-byte instruction. This was actually seen happen
+ on native x86-linux, and should be less rare on
+ targets that do not support new thread events, like
+ remote, due to the heuristic depending on
+ thread_count.
+
+ Mistaking a random SIGTRAP for a breakpoint trap
+ causes similar symptoms (PC adjustment applied when
+ it shouldn't), but then again, playing with SIGTRAPs
+ behind the debugger's back is asking for trouble.
+
+ Since hardware watchpoint traps are always
+ distinguishable from other traps, so we don't need to
+ apply keep hardware watchpoint moribund locations
+ around. We simply always ignore hardware watchpoint
+ traps we can no longer explain. */
+
old_loc->events_till_retirement = 3 * (thread_count () + 1);
old_loc->owner = NULL;
}
}
- /* Rescan breakpoints at the same address and section,
- marking the first one as "first" and any others as "duplicates".
- This is so that the bpt instruction is only inserted once.
- If we have a permanent breakpoint at the same place as BPT, make
- that one the official one, and the rest as duplicates. Permanent
- breakpoints are sorted first for the same address. */
+ /* Rescan breakpoints at the same address and section, marking the
+ first one as "first" and any others as "duplicates". This is so
+ that the bpt instruction is only inserted once. If we have a
+ permanent breakpoint at the same place as BPT, make that one the
+ official one, and the rest as duplicates. Permanent breakpoints
+ are sorted first for the same address.
- loc_first = NULL;
+ Do the same for hardware watchpoints, but also considering the
+ watchpoint's type (regular/access/read) and length. */
+
+ bp_loc_first = NULL;
+ wp_loc_first = NULL;
+ awp_loc_first = NULL;
+ rwp_loc_first = NULL;
ALL_BP_LOCATIONS (loc, locp)
{
struct breakpoint *b = loc->owner;
+ struct bp_location **loc_first_p;
if (b->enable_state == bp_disabled
|| b->enable_state == bp_call_disabled
_("allegedly permanent breakpoint is not "
"actually inserted"));
- if (loc_first == NULL
- || (overlay_debugging && loc->section != loc_first->section)
- || !breakpoint_address_match (loc->pspace->aspace, loc->address,
- loc_first->pspace->aspace,
- loc_first->address))
+ if (b->type == bp_hardware_watchpoint)
+ loc_first_p = &wp_loc_first;
+ else if (b->type == bp_read_watchpoint)
+ loc_first_p = &rwp_loc_first;
+ else if (b->type == bp_access_watchpoint)
+ loc_first_p = &awp_loc_first;
+ else
+ loc_first_p = &bp_loc_first;
+
+ if (*loc_first_p == NULL
+ || (overlay_debugging && loc->section != (*loc_first_p)->section)
+ || !breakpoint_locations_match (loc, *loc_first_p))
{
- loc_first = loc;
+ *loc_first_p = loc;
loc->duplicate = 0;
continue;
}
loc->duplicate = 1;
- if (loc_first->owner->enable_state == bp_permanent && loc->inserted
- && b->enable_state != bp_permanent)
+ if ((*loc_first_p)->owner->enable_state == bp_permanent && loc->inserted
+ && b->enable_state != bp_permanent)
internal_error (__FILE__, __LINE__,
_("another breakpoint was inserted on top of "
"a permanent breakpoint"));
{
}
+/* Invalidate last known value of any hardware watchpoint if
+ the memory which that value represents has been written to by
+ GDB itself. */
+
+static void
+invalidate_bp_value_on_memory_change (CORE_ADDR addr, int len,
+ const bfd_byte *data)
+{
+ struct breakpoint *bp;
+
+ ALL_BREAKPOINTS (bp)
+ if (bp->enable_state == bp_enabled
+ && bp->type == bp_hardware_watchpoint
+ && bp->val_valid && bp->val)
+ {
+ struct bp_location *loc;
+
+ for (loc = bp->loc; loc != NULL; loc = loc->next)
+ if (loc->loc_type == bp_loc_hardware_watchpoint
+ && loc->address + loc->length > addr
+ && addr + len > loc->address)
+ {
+ value_free (bp->val);
+ bp->val = NULL;
+ bp->val_valid = 0;
+ }
+ }
+}
+
/* Use default_breakpoint_'s, or nothing if they aren't valid. */
struct symtabs_and_lines
observer_attach_solib_unloaded (disable_breakpoints_in_unloaded_shlib);
observer_attach_inferior_exit (clear_syscall_counts);
+ observer_attach_memory_changed (invalidate_bp_value_on_memory_change);
breakpoint_chain = 0;
/* Don't bother to call set_breakpoint_count. $bpnum isn't useful
Convenience variable \"$bpnum\" contains the number of the last\n\
breakpoint set."));
+ add_info_alias ("b", "breakpoints", 1);
+
if (xdb_commands)
add_com ("lb", class_breakpoint, breakpoints_info, _("\
Status of user-settable breakpoints, or breakpoint number NUMBER.\n\
projects / deliverable / binutils-gdb.git / blobdiff