diff options
Diffstat (limited to 'gdb/infrun.c')
| -rw-r--r-- | gdb/infrun.c | 70 |
1 files changed, 69 insertions, 1 deletions
diff --git a/gdb/infrun.c b/gdb/infrun.c index abfeeee..8d3a9bf 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -3468,6 +3468,18 @@ adjust_pc_after_break (struct execution_control_state *ecs) if (execution_direction == EXEC_REVERSE) return; + /* If the target can tell whether the thread hit a SW breakpoint, + trust it. Targets that can tell also adjust the PC + themselves. */ + if (target_supports_stopped_by_sw_breakpoint ()) + return; + + /* Note that relying on whether a breakpoint is planted in memory to + determine this can fail. E.g,. the breakpoint could have been + removed since. Or the thread could have been told to step an + instruction the size of a breakpoint instruction, and only + _after_ was a breakpoint inserted at its address. */ + /* If this target does not decrement the PC after breakpoints, then we have nothing to do. */ regcache = get_thread_regcache (ecs->ptid); @@ -3483,6 +3495,11 @@ adjust_pc_after_break (struct execution_control_state *ecs) breakpoint would be. */ breakpoint_pc = regcache_read_pc (regcache) - decr_pc; + /* If the target can't tell whether a software breakpoint triggered, + fallback to figuring it out based on breakpoints we think were + inserted in the target, and on whether the thread was stepped or + continued. */ + /* Check whether there actually is a software breakpoint inserted at that location. @@ -3490,7 +3507,10 @@ adjust_pc_after_break (struct execution_control_state *ecs) removed a breakpoint, but stop events for that breakpoint were already queued and arrive later. To suppress those spurious SIGTRAPs, we keep a list of such breakpoint locations for a bit, - and retire them after a number of stop events are reported. */ + and retire them after a number of stop events are reported. Note + this is an heuristic and can thus get confused. The real fix is + to get the "stopped by SW BP and needs adjustment" info out of + the target/kernel (and thus never reach here; see above). */ if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc) || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc))) { @@ -4505,6 +4525,54 @@ handle_signal_stop (struct execution_control_state *ecs) = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat, ecs->event_thread->suspend.stop_signal); + /* Maybe this was a trap for a software breakpoint that has since + been removed. */ + if (random_signal && target_stopped_by_sw_breakpoint ()) + { + if (program_breakpoint_here_p (gdbarch, stop_pc)) + { + struct regcache *regcache; + int decr_pc; + + /* Re-adjust PC to what the program would see if GDB was not + debugging it. */ + regcache = get_thread_regcache (ecs->event_thread->ptid); + decr_pc = target_decr_pc_after_break (gdbarch); + if (decr_pc != 0) + { + struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL); + + if (record_full_is_used ()) + record_full_gdb_operation_disable_set (); + + regcache_write_pc (regcache, stop_pc + decr_pc); + + do_cleanups (old_cleanups); + } + } + else + { + /* A delayed software breakpoint event. Ignore the trap. */ + if (debug_infrun) + fprintf_unfiltered (gdb_stdlog, + "infrun: delayed software breakpoint " + "trap, ignoring\n"); + random_signal = 0; + } + } + + /* Maybe this was a trap for a hardware breakpoint/watchpoint that + has since been removed. */ + if (random_signal && target_stopped_by_hw_breakpoint ()) + { + /* A delayed hardware breakpoint event. Ignore the trap. */ + if (debug_infrun) + fprintf_unfiltered (gdb_stdlog, + "infrun: delayed hardware breakpoint/watchpoint " + "trap, ignoring\n"); + random_signal = 0; + } + /* If not, perhaps stepping/nexting can. */ if (random_signal) random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |