From 2bf6fb9d85394f90abb3e21ee037a732b6e4c983 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Tue, 24 Mar 2015 18:31:51 +0000 Subject: [PATCH] Debug output tweaks in the Linux target backends This adds/tweaks a few debug logs I found useful recently. gdb/gdbserver/ChangeLog: 2015-03-24 Pedro Alves * linux-low.c (check_stopped_by_breakpoint): Tweak debug log output. Also dump TRAP_TRACE. (linux_low_filter_event): In debug output, distinguish a resume_stop SIGSTOP from a delayed SIGSTOP. gdb/ChangeLog: 2015-03-24 Pedro Alves * linux-nat.c (linux_nat_resume): Output debug logs before trying to resume the event lwp. Use the lwp's ptid instead of the passed in (maybe wildcard) ptid. (stop_wait_callback): Tweak debug log output. (check_stopped_by_breakpoint): Tweak debug log output. Also dump TRAP_TRACE. (linux_nat_filter_event): In debug output, distinguish a resume_stop SIGSTOP from a delayed SIGSTOP. Output debug logs before trying to resume the lwp. --- gdb/ChangeLog | 12 ++++++++++ gdb/gdbserver/ChangeLog | 7 ++++++ gdb/gdbserver/linux-low.c | 30 ++++++++++++++++++++---- gdb/linux-nat.c | 49 ++++++++++++++++++++++----------------- 4 files changed, 73 insertions(+), 25 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 43dda5596a9..fc65c603c62 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2015-03-24 Pedro Alves + + * linux-nat.c (linux_nat_resume): Output debug logs before trying + to resume the event lwp. Use the lwp's ptid instead of the passed + in (maybe wildcard) ptid. + (stop_wait_callback): Tweak debug log output. + (check_stopped_by_breakpoint): Tweak debug log output. Also dump + TRAP_TRACE. + (linux_nat_filter_event): In debug output, distinguish a + resume_stop SIGSTOP from a delayed SIGSTOP. Output debug logs + before trying to resume the lwp. + 2015-03-24 Joel Brobecker * gdbtypes.h (struct dynamic_prop_list) : Remove diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index d9bc729789b..396abcb6f14 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,10 @@ +2015-03-24 Pedro Alves + + * linux-low.c (check_stopped_by_breakpoint): Tweak debug log + output. Also dump TRAP_TRACE. + (linux_low_filter_event): In debug output, distinguish a + resume_stop SIGSTOP from a delayed SIGSTOP. + 2015-03-24 Gary Benson * linux-x86-low.c (x86_linux_new_thread): Moved to diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index 4743f7b96dd..e4c54202e74 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -562,7 +562,7 @@ check_stopped_by_breakpoint (struct lwp_info *lwp) { struct thread_info *thr = get_lwp_thread (lwp); - debug_printf ("CSBB: Push back software breakpoint for %s\n", + debug_printf ("CSBB: %s stopped by software breakpoint\n", target_pid_to_str (ptid_of (thr))); } @@ -585,8 +585,8 @@ check_stopped_by_breakpoint (struct lwp_info *lwp) { struct thread_info *thr = get_lwp_thread (lwp); - debug_printf ("CSBB: Push back hardware " - "breakpoint/watchpoint for %s\n", + debug_printf ("CSBB: %s stopped by hardware " + "breakpoint/watchpoint\n", target_pid_to_str (ptid_of (thr))); } @@ -595,6 +595,16 @@ check_stopped_by_breakpoint (struct lwp_info *lwp) current_thread = saved_thread; return 1; } + else if (siginfo.si_code == TRAP_TRACE) + { + if (debug_threads) + { + struct thread_info *thr = get_lwp_thread (lwp); + + debug_printf ("CSBB: %s stopped by trace\n", + target_pid_to_str (ptid_of (thr))); + } + } } } #else @@ -2059,16 +2069,28 @@ linux_low_filter_event (int lwpid, int wstat) { /* We want to report the stop to the core. Treat the SIGSTOP as a normal event. */ + if (debug_threads) + debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n", + target_pid_to_str (ptid_of (thread))); } else if (stopping_threads != NOT_STOPPING_THREADS) { /* Stopping threads. We don't want this SIGSTOP to end up pending. */ + if (debug_threads) + debug_printf ("LLW: SIGSTOP caught for %s " + "while stopping threads.\n", + target_pid_to_str (ptid_of (thread))); return NULL; } else { - /* Filter out the event. */ + /* This is a delayed SIGSTOP. Filter out the event. */ + if (debug_threads) + debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", + child->stepping ? "step" : "continue", + target_pid_to_str (ptid_of (thread))); + linux_resume_one_lwp (child, child->stepping, 0, NULL); return NULL; } diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index 803bdf6b1e2..660dc8f80f1 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -1799,16 +1799,16 @@ linux_nat_resume (struct target_ops *ops, if (resume_many) iterate_over_lwps (ptid, linux_nat_resume_callback, lp); - linux_resume_one_lwp (lp, step, signo); - if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, "LLR: %s %s, %s (resume event thread)\n", step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", - target_pid_to_str (ptid), + target_pid_to_str (lp->ptid), (signo != GDB_SIGNAL_0 ? strsignal (gdb_signal_to_host (signo)) : "0")); + linux_resume_one_lwp (lp, step, signo); + if (target_can_async_p ()) target_async (inferior_event_handler, 0); } @@ -2618,7 +2618,7 @@ stop_wait_callback (struct lwp_info *lp, void *data) if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, - "SWC: Delayed SIGSTOP caught for %s.\n", + "SWC: Expected SIGSTOP caught for %s.\n", target_pid_to_str (lp->ptid)); /* Reset SIGNALLED only after the stop_wait_callback call @@ -2795,8 +2795,8 @@ check_stopped_by_breakpoint (struct lwp_info *lp) { if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, - "CSBB: Push back software " - "breakpoint for %s\n", + "CSBB: %s stopped by software " + "breakpoint\n", target_pid_to_str (lp->ptid)); /* Back up the PC if necessary. */ @@ -2811,14 +2811,21 @@ check_stopped_by_breakpoint (struct lwp_info *lp) { if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, - "CSBB: Push back hardware " - "breakpoint/watchpoint for %s\n", + "CSBB: %s stopped by hardware " + "breakpoint/watchpoint\n", target_pid_to_str (lp->ptid)); lp->stop_pc = pc; lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; return 1; } + else if (siginfo.si_code == TRAP_TRACE) + { + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "CSBB: %s stopped by trace\n", + target_pid_to_str (lp->ptid)); + } } } #else @@ -2830,7 +2837,7 @@ check_stopped_by_breakpoint (struct lwp_info *lp) breakpoint instruction. */ if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, - "CB: Push back software breakpoint for %s\n", + "CSBB: %s stopped by software breakpoint\n", target_pid_to_str (lp->ptid)); /* Back up the PC if necessary. */ @@ -2846,7 +2853,7 @@ check_stopped_by_breakpoint (struct lwp_info *lp) { if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, - "CB: Push back hardware breakpoint for %s\n", + "CSBB: stopped by hardware breakpoint %s\n", target_pid_to_str (lp->ptid)); lp->stop_pc = pc; @@ -3206,28 +3213,28 @@ linux_nat_filter_event (int lwpid, int status) if (lp->signalled && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) { - if (debug_linux_nat) - fprintf_unfiltered (gdb_stdlog, - "LLW: Delayed SIGSTOP caught for %s.\n", - target_pid_to_str (lp->ptid)); - lp->signalled = 0; - if (lp->last_resume_kind != resume_stop) + if (lp->last_resume_kind == resume_stop) { - /* This is a delayed SIGSTOP. */ + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "LLW: resume_stop SIGSTOP caught for %s.\n", + target_pid_to_str (lp->ptid)); + } + else + { + /* This is a delayed SIGSTOP. Filter out the event. */ - linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, - "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", + "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", target_pid_to_str (lp->ptid)); + linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); gdb_assert (lp->resumed); - - /* Discard the event. */ return NULL; } } -- 2.30.2