From c8edd8b484eaa59ae60a2b3c89f5772b98aefad1 Mon Sep 17 00:00:00 2001 From: Joel Brobecker Date: Sat, 17 Aug 2002 06:12:52 +0000 Subject: [PATCH] * alpha-osf1-tdep.c (alpha_osf1_init_abi): Unfortunately, procfs appears to be broken when debugging on multi-processor machines. So enable software single stepping in order to avoid using the procfs interface to do next/step operations, using internal breakpoints instead. * infrun.c (handle_inferior_event): Readjust the stop_pc by DECR_PC_AFTER_BREAK when hitting a single step breakpoint, to make this pc address equal to the value it would have if the system stepping capability was used. Also set a new flag used to ensure that we don't readjust the PC one more time later. * breakpoint.c (bpstat_stop_status): Do not adjust the PC address by DECR_PC_AFTER_BREAK when software single step is in use for this architecture, as this has already been taken care of in handle_inferior_event(). --- gdb/ChangeLog | 19 +++++++++++++++++++ gdb/alpha-osf1-tdep.c | 4 ++++ gdb/breakpoint.c | 3 +-- gdb/infrun.c | 23 +++++++++++++++++++---- 4 files changed, 43 insertions(+), 6 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index e819fd690fa..d1f03f93477 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,22 @@ +2002-08-16 Joel Brobecker + + * alpha-osf1-tdep.c (alpha_osf1_init_abi): Unfortunately, + procfs appears to be broken when debugging on multi-processor + machines. So enable software single stepping in order to avoid + using the procfs interface to do next/step operations, using + internal breakpoints instead. + + * infrun.c (handle_inferior_event): Readjust the stop_pc by + DECR_PC_AFTER_BREAK when hitting a single step breakpoint, to + make this pc address equal to the value it would have if the + system stepping capability was used. Also set a new flag used + to ensure that we don't readjust the PC one more time later. + + * breakpoint.c (bpstat_stop_status): Do not adjust the PC + address by DECR_PC_AFTER_BREAK when software single step is + in use for this architecture, as this has already been taken + care of in handle_inferior_event(). + 2002-08-16 Joel Brobecker * infrun.c (handle_inferior_event): Minor reformatting, to make diff --git a/gdb/alpha-osf1-tdep.c b/gdb/alpha-osf1-tdep.c index 12320519ae8..ece5e2694f2 100644 --- a/gdb/alpha-osf1-tdep.c +++ b/gdb/alpha-osf1-tdep.c @@ -58,6 +58,10 @@ alpha_osf1_init_abi (struct gdbarch_info info, struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); set_gdbarch_pc_in_sigtramp (gdbarch, alpha_osf1_pc_in_sigtramp); + /* The next/step support via procfs on OSF1 is broken when running + on multi-processor machines. We need to use software single stepping + instead. */ + set_gdbarch_software_single_step (gdbarch, alpha_software_single_step); tdep->skip_sigtramp_frame = alpha_osf1_skip_sigtramp_frame; tdep->sigcontext_addr = alpha_osf1_sigcontext_addr; diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index 86e700eeac7..283539061ca 100644 --- a/gdb/breakpoint.c +++ b/gdb/breakpoint.c @@ -2429,8 +2429,7 @@ bpstat_stop_status (CORE_ADDR *pc, int not_a_sw_breakpoint) trace/singlestep trap event, we would not want to subtract DECR_PC_AFTER_BREAK from the PC. */ - bp_addr = *pc - (not_a_sw_breakpoint && !SOFTWARE_SINGLE_STEP_P () ? - 0 : DECR_PC_AFTER_BREAK); + bp_addr = *pc - (not_a_sw_breakpoint ? 0 : DECR_PC_AFTER_BREAK); ALL_BREAKPOINTS_SAFE (b, temp) { diff --git a/gdb/infrun.c b/gdb/infrun.c index 8375b6937c1..98867cc9a46 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -1408,6 +1408,7 @@ handle_inferior_event (struct execution_control_state *ecs) { CORE_ADDR tmp; int stepped_after_stopped_by_watchpoint; + int sw_single_step_trap_p = 0; /* Cache the last pid/waitstatus. */ target_last_wait_ptid = ecs->ptid; @@ -1888,6 +1889,18 @@ handle_inferior_event (struct execution_control_state *ecs) } else if (SOFTWARE_SINGLE_STEP_P () && singlestep_breakpoints_inserted_p) { + /* Readjust the stop_pc as it is off by DECR_PC_AFTER_BREAK + compared to the value it would have if the system stepping + capability was used. This allows the rest of the code in + this function to use this address without having to worry + whether software single step is in use or not. */ + if (DECR_PC_AFTER_BREAK) + { + stop_pc -= DECR_PC_AFTER_BREAK; + write_pc_pid (stop_pc, ecs->ptid); + } + + sw_single_step_trap_p = 1; ecs->random_signal = 0; } } @@ -2111,14 +2124,16 @@ handle_inferior_event (struct execution_control_state *ecs) (&stop_pc, /* Pass TRUE if our reason for stopping is something other than hitting a breakpoint. We do this by checking that + either we detected earlier a software single step trap or 1) stepping is going on and 2) we didn't hit a breakpoint in a signal handler without an intervening stop in sigtramp, which is detected by a new stack pointer value below any usual function calling stack adjustments. */ - (currently_stepping (ecs) - && prev_pc != stop_pc - DECR_PC_AFTER_BREAK - && !(step_range_end - && INNER_THAN (read_sp (), (step_sp - 16))))); + sw_single_step_trap_p + || (currently_stepping (ecs) + && prev_pc != stop_pc - DECR_PC_AFTER_BREAK + && !(step_range_end + && INNER_THAN (read_sp (), (step_sp - 16))))); /* Following in case break condition called a function. */ stop_print_frame = 1; -- 2.30.2