Force to insert software single step breakpoint
GDB doesn't insert software single step breakpoint if the instruction
branches to itself, so that the program can't stop after command "si".
(gdb) b 32
Breakpoint 2 at 0x8680: file git/gdb/testsuite/gdb.base/branch-to-self.c, line 32.
(gdb) c
Continuing.
Breakpoint 2, main () at gdb/git/gdb/testsuite/gdb.base/branch-to-self.c:32
32 asm (".Lhere: " BRANCH_INSN " .Lhere"); /* loop-line */
(gdb) si
infrun: clear_proceed_status_thread (Thread 3991.3991)
infrun: proceed (addr=0xffffffff, signal=GDB_SIGNAL_DEFAULT)
infrun: step-over queue now empty
infrun: resuming [Thread 3991.3991] for step-over
infrun: skipping breakpoint: stepping past insn at: 0x8680
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Sending packet: $Z0,8678,4#f3...Packet received: OK
infrun: skipping breakpoint: stepping past insn at: 0x8680
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Sending packet: $Z0,b6fe86c8,4#82...Packet received: OK
infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=1, current thread [Thread 3991.3991] at 0x868
breakpoint.c:should_be_inserted thinks the breakpoint shouldn't be
inserted, which is wrong. This patch restrict the condition that
only skip the non-single-step breakpoints if they are inserted at
the place we are stepping over, however we don't want to skip
single-step breakpoint if its thread is the thread we are stepping
over, so in this patch, I add a thread num in 'struct step_over_info'
to record the thread we're stepping over.
gdb:
2016-04-25 Yao Qi <yao.qi@linaro.org>
* breakpoint.c (should_be_inserted): Return 0 if the location's
owner is not single step breakpoint or single step breakpoint's
thread isn't the thread which is stepping past a breakpoint.
* gdbarch.sh (software_single_step): Update comments.
* gdbarch.h: Regenerated.
* infrun.c (struct step_over_info) <thread>: New field.
(set_step_over_info): New argument 'thread'. Callers updated.
(clear_step_over_info): Set field thread to -1.
(thread_is_stepping_over_breakpoint): New function.
* infrun.h (thread_is_stepping_over_breakpoint): Declaration.
This commit is contained in:
Yao Qi
parent
101ae4cd31
commit
21edc42f4e
@ -1,3 +1,16 @@
|
||||
2016-04-25 Yao Qi <yao.qi@linaro.org>
|
||||
|
||||
* breakpoint.c (should_be_inserted): Return 0 if the location's
|
||||
owner is not single step breakpoint or single step breakpoint's
|
||||
thread isn't the thread which is stepping past a breakpoint.
|
||||
* gdbarch.sh (software_single_step): Update comments.
|
||||
* gdbarch.h: Regenerated.
|
||||
* infrun.c (struct step_over_info) <thread>: New field.
|
||||
(set_step_over_info): New argument 'thread'. Callers updated.
|
||||
(clear_step_over_info): Set field thread to -1.
|
||||
(thread_is_stepping_over_breakpoint): New function.
|
||||
* infrun.h (thread_is_stepping_over_breakpoint): Declaration.
|
||||
|
||||
2016-04-22 Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>
|
||||
|
||||
* ppc-linux-nat.c (ppc_linux_read_description): Use PPC_FEATURE_HAS_VSX
|
||||
|
||||
@ -2219,11 +2219,22 @@ should_be_inserted (struct bp_location *bl)
|
||||
return 0;
|
||||
|
||||
/* Don't insert a breakpoint if we're trying to step past its
|
||||
location. */
|
||||
location, except if the breakpoint is a single-step breakpoint,
|
||||
and the breakpoint's thread is the thread which is stepping past
|
||||
a breakpoint. */
|
||||
if ((bl->loc_type == bp_loc_software_breakpoint
|
||||
|| bl->loc_type == bp_loc_hardware_breakpoint)
|
||||
&& stepping_past_instruction_at (bl->pspace->aspace,
|
||||
bl->address))
|
||||
bl->address)
|
||||
/* The single-step breakpoint may be inserted at the location
|
||||
we're trying to step if the instruction branches to itself.
|
||||
However, the instruction won't be executed at all and it may
|
||||
break the semantics of the instruction, for example, the
|
||||
instruction is a conditional branch or updates some flags.
|
||||
We can't fix it unless GDB is able to emulate the instruction
|
||||
or switch to displaced stepping. */
|
||||
&& !(bl->owner->type == bp_single_step
|
||||
&& thread_is_stepping_over_breakpoint (bl->owner->thread)))
|
||||
{
|
||||
if (debug_infrun)
|
||||
{
|
||||
|
||||
@ -650,7 +650,12 @@ extern void set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch, gdbarch_addr_
|
||||
target can single step. If not, then implement single step using breakpoints.
|
||||
|
||||
A return value of 1 means that the software_single_step breakpoints
|
||||
were inserted; 0 means they were not. */
|
||||
were inserted; 0 means they were not. Multiple breakpoints may be
|
||||
inserted for some instructions such as conditional branch. However,
|
||||
each implementation must always evaluate the condition and only put
|
||||
the breakpoint at the branch destination if the condition is true, so
|
||||
that we ensure forward progress when stepping past a conditional
|
||||
branch to self. */
|
||||
|
||||
extern int gdbarch_software_single_step_p (struct gdbarch *gdbarch);
|
||||
|
||||
|
||||
@ -609,7 +609,12 @@ m:CORE_ADDR:addr_bits_remove:CORE_ADDR addr:addr::core_addr_identity::0
|
||||
# target can single step. If not, then implement single step using breakpoints.
|
||||
#
|
||||
# A return value of 1 means that the software_single_step breakpoints
|
||||
# were inserted; 0 means they were not.
|
||||
# were inserted; 0 means they were not. Multiple breakpoints may be
|
||||
# inserted for some instructions such as conditional branch. However,
|
||||
# each implementation must always evaluate the condition and only put
|
||||
# the breakpoint at the branch destination if the condition is true, so
|
||||
# that we ensure forward progress when stepping past a conditional
|
||||
# branch to self.
|
||||
F:int:software_single_step:struct frame_info *frame:frame
|
||||
|
||||
# Return non-zero if the processor is executing a delay slot and a
|
||||
|
||||
24
gdb/infrun.c
24
gdb/infrun.c
@ -1296,6 +1296,9 @@ struct step_over_info
|
||||
/* The instruction being stepped over triggers a nonsteppable
|
||||
watchpoint. If true, we'll skip inserting watchpoints. */
|
||||
int nonsteppable_watchpoint_p;
|
||||
|
||||
/* The thread's global number. */
|
||||
int thread;
|
||||
};
|
||||
|
||||
/* The step-over info of the location that is being stepped over.
|
||||
@ -1329,11 +1332,13 @@ static struct step_over_info step_over_info;
|
||||
|
||||
static void
|
||||
set_step_over_info (struct address_space *aspace, CORE_ADDR address,
|
||||
int nonsteppable_watchpoint_p)
|
||||
int nonsteppable_watchpoint_p,
|
||||
int thread)
|
||||
{
|
||||
step_over_info.aspace = aspace;
|
||||
step_over_info.address = address;
|
||||
step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
|
||||
step_over_info.thread = thread;
|
||||
}
|
||||
|
||||
/* Called when we're not longer stepping over a breakpoint / an
|
||||
@ -1348,6 +1353,7 @@ clear_step_over_info (void)
|
||||
step_over_info.aspace = NULL;
|
||||
step_over_info.address = 0;
|
||||
step_over_info.nonsteppable_watchpoint_p = 0;
|
||||
step_over_info.thread = -1;
|
||||
}
|
||||
|
||||
/* See infrun.h. */
|
||||
@ -1364,6 +1370,15 @@ stepping_past_instruction_at (struct address_space *aspace,
|
||||
|
||||
/* See infrun.h. */
|
||||
|
||||
int
|
||||
thread_is_stepping_over_breakpoint (int thread)
|
||||
{
|
||||
return (step_over_info.thread != -1
|
||||
&& thread == step_over_info.thread);
|
||||
}
|
||||
|
||||
/* See infrun.h. */
|
||||
|
||||
int
|
||||
stepping_past_nonsteppable_watchpoint (void)
|
||||
{
|
||||
@ -2579,7 +2594,7 @@ resume (enum gdb_signal sig)
|
||||
stop_all_threads ();
|
||||
|
||||
set_step_over_info (get_regcache_aspace (regcache),
|
||||
regcache_read_pc (regcache), 0);
|
||||
regcache_read_pc (regcache), 0, tp->global_num);
|
||||
|
||||
step = maybe_software_singlestep (gdbarch, pc);
|
||||
|
||||
@ -7750,10 +7765,11 @@ keep_going_pass_signal (struct execution_control_state *ecs)
|
||||
&& (remove_wps || !use_displaced_stepping (ecs->event_thread)))
|
||||
{
|
||||
set_step_over_info (get_regcache_aspace (regcache),
|
||||
regcache_read_pc (regcache), remove_wps);
|
||||
regcache_read_pc (regcache), remove_wps,
|
||||
ecs->event_thread->global_num);
|
||||
}
|
||||
else if (remove_wps)
|
||||
set_step_over_info (NULL, 0, remove_wps);
|
||||
set_step_over_info (NULL, 0, remove_wps, -1);
|
||||
|
||||
/* If we now need to do an in-line step-over, we need to stop
|
||||
all other threads. Note this must be done before
|
||||
|
||||
@ -133,6 +133,10 @@ extern void insert_step_resume_breakpoint_at_sal (struct gdbarch *,
|
||||
extern int stepping_past_instruction_at (struct address_space *aspace,
|
||||
CORE_ADDR address);
|
||||
|
||||
/* Returns true if thread whose thread number is THREAD is stepping
|
||||
over a breakpoint. */
|
||||
extern int thread_is_stepping_over_breakpoint (int thread);
|
||||
|
||||
/* Returns true if we're trying to step past an instruction that
|
||||
triggers a non-steppable watchpoint. */
|
||||
extern int stepping_past_nonsteppable_watchpoint (void);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user