diff options
| -rw-r--r-- | gdb/ChangeLog | 31 | ||||
| -rw-r--r-- | gdb/breakpoint.c | 106 | ||||
| -rw-r--r-- | gdb/breakpoint.h | 19 | ||||
| -rw-r--r-- | gdb/dummy-frame.c | 51 | ||||
| -rw-r--r-- | gdb/dummy-frame.h | 2 | ||||
| -rw-r--r-- | gdb/gdbthread.h | 4 | ||||
| -rw-r--r-- | gdb/infcall.c | 13 | ||||
| -rw-r--r-- | gdb/infrun.c | 22 | ||||
| -rw-r--r-- | gdb/testsuite/ChangeLog | 8 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.base/call-signal-resume.exp | 12 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.base/stale-infcall.c | 63 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.base/stale-infcall.exp | 57 |
12 files changed, 367 insertions, 21 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 86c5093..ee6dfc3 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,34 @@ +2012-06-18 Jan Kratochvil <jan.kratochvil@redhat.com> + + Remove stale dummy frames. + * breakpoint.c: Include dummy-frame.h. + (longjmp_breakpoint_ops): New variable. + (update_breakpoints_after_exec, breakpoint_init_inferior): Delete also + bp_longjmp_call_dummy. + (bpstat_what, bptype_string, print_one_breakpoint_location) + (init_bp_location): Support bp_longjmp_call_dummy. + (set_longjmp_breakpoint): Use longjmp_breakpoint_ops. Comment why. + (set_longjmp_breakpoint_for_call_dummy) + (check_longjmp_breakpoint_for_call_dummy, longjmp_bkpt_dtor): New + functions. + (initialize_breakpoint_ops): Initialize longjmp_breakpoint_ops. + * breakpoint.h (enum bptype): New item bp_longjmp_call_dummy. Delete + FIXME comment and extend the other comment for bp_call_dummy. + (set_longjmp_breakpoint_for_call_dummy) + (check_longjmp_breakpoint_for_call_dummy): New declarations. + * dummy-frame.c: Include gdbthread.h. + (pop_dummy_frame_bpt): New function. + (pop_dummy_frame): Call pop_dummy_frame_bpt. + (dummy_frame_discard): New function. + (cleanup_dummy_frames): Update the comment about longjmps. + * dummy-frame.h (dummy_frame_discard): New declaration. + * gdbthread.h (struct thread_info): Extend initiating_frame comment. + * infcall.c (call_function_by_hand): New variable longjmp_b. Call + set_longjmp_breakpoint_for_call_dummy. Chain its breakpoints with BPT. + * infrun.c (handle_inferior_event) <BPSTAT_WHAT_CLEAR_LONGJMP_RESUME>: + Add case 4 comment. Call check_longjmp_breakpoint_for_call_dummy and + keep_going if IS_LONGJMP and there is no other reason to stop. + 2012-06-18 Greta Yorsh <Greta.Yorsh@arm.com> * remote-sim.c (sim_command_completer): Initialize diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index 82265cc..12ab271 100644 --- a/gdb/breakpoint.c +++ b/gdb/breakpoint.c @@ -68,6 +68,7 @@ #include "skip.h" #include "gdb_regex.h" #include "ax-gdb.h" +#include "dummy-frame.h" /* readline include files */ #include "readline/readline.h" @@ -287,6 +288,9 @@ static struct breakpoint_ops internal_breakpoint_ops; /* Momentary breakpoints class type. */ static struct breakpoint_ops momentary_breakpoint_ops; +/* Momentary breakpoints for bp_longjmp and bp_exception class type. */ +static struct breakpoint_ops longjmp_breakpoint_ops; + /* The breakpoint_ops structure to be used in regular user created breakpoints. */ struct breakpoint_ops bkpt_breakpoint_ops; @@ -3204,6 +3208,7 @@ update_breakpoints_after_exec (void) /* Longjmp and longjmp-resume breakpoints are also meaningless after an exec. */ if (b->type == bp_longjmp || b->type == bp_longjmp_resume + || b->type == bp_longjmp_call_dummy || b->type == bp_exception || b->type == bp_exception_resume) { delete_breakpoint (b); @@ -3495,6 +3500,7 @@ breakpoint_init_inferior (enum inf_context context) switch (b->type) { case bp_call_dummy: + case bp_longjmp_call_dummy: /* If the call dummy breakpoint is at the entry point it will cause problems when the inferior is rerun, so we better get @@ -5154,9 +5160,10 @@ bpstat_what (bpstat bs_head) } break; case bp_longjmp: + case bp_longjmp_call_dummy: case bp_exception: this_action = BPSTAT_WHAT_SET_LONGJMP_RESUME; - retval.is_longjmp = bptype == bp_longjmp; + retval.is_longjmp = bptype != bp_exception; break; case bp_longjmp_resume: case bp_exception_resume: @@ -5489,6 +5496,7 @@ bptype_string (enum bptype type) {bp_access_watchpoint, "acc watchpoint"}, {bp_longjmp, "longjmp"}, {bp_longjmp_resume, "longjmp resume"}, + {bp_longjmp_call_dummy, "longjmp for call dummy"}, {bp_exception, "exception"}, {bp_exception_resume, "exception resume"}, {bp_step_resume, "step resume"}, @@ -5631,6 +5639,7 @@ print_one_breakpoint_location (struct breakpoint *b, case bp_finish: case bp_longjmp: case bp_longjmp_resume: + case bp_longjmp_call_dummy: case bp_exception: case bp_exception_resume: case bp_step_resume: @@ -6494,6 +6503,7 @@ init_bp_location (struct bp_location *loc, const struct bp_location_ops *ops, case bp_finish: case bp_longjmp: case bp_longjmp_resume: + case bp_longjmp_call_dummy: case bp_exception: case bp_exception_resume: case bp_step_resume: @@ -6797,8 +6807,10 @@ set_longjmp_breakpoint (struct thread_info *tp, struct frame_id frame) enum bptype type = b->type == bp_longjmp_master ? bp_longjmp : bp_exception; struct breakpoint *clone; + /* longjmp_breakpoint_ops ensures INITIATING_FRAME is cleared again + after their removal. */ clone = momentary_breakpoint_from_master (b, type, - &momentary_breakpoint_ops); + &longjmp_breakpoint_ops); clone->thread = thread; } @@ -6832,6 +6844,75 @@ delete_longjmp_breakpoint_at_next_stop (int thread) } } +/* Place breakpoints of type bp_longjmp_call_dummy to catch longjmp for + INFERIOR_PTID thread. Chain them all by RELATED_BREAKPOINT and return + pointer to any of them. Return NULL if this system cannot place longjmp + breakpoints. */ + +struct breakpoint * +set_longjmp_breakpoint_for_call_dummy (void) +{ + struct breakpoint *b, *retval = NULL; + + ALL_BREAKPOINTS (b) + if (b->pspace == current_program_space && b->type == bp_longjmp_master) + { + struct breakpoint *new_b; + + new_b = momentary_breakpoint_from_master (b, bp_longjmp_call_dummy, + &momentary_breakpoint_ops); + new_b->thread = pid_to_thread_id (inferior_ptid); + + /* Link NEW_B into the chain of RETVAL breakpoints. */ + + gdb_assert (new_b->related_breakpoint == new_b); + if (retval == NULL) + retval = new_b; + new_b->related_breakpoint = retval; + while (retval->related_breakpoint != new_b->related_breakpoint) + retval = retval->related_breakpoint; + retval->related_breakpoint = new_b; + } + + return retval; +} + +/* Verify all existing dummy frames and their associated breakpoints for + THREAD. Remove those which can no longer be found in the current frame + stack. + + You should call this function only at places where it is safe to currently + unwind the whole stack. Failed stack unwind would discard live dummy + frames. */ + +void +check_longjmp_breakpoint_for_call_dummy (int thread) +{ + struct breakpoint *b, *b_tmp; + + ALL_BREAKPOINTS_SAFE (b, b_tmp) + if (b->type == bp_longjmp_call_dummy && b->thread == thread) + { + struct breakpoint *dummy_b = b->related_breakpoint; + + while (dummy_b != b && dummy_b->type != bp_call_dummy) + dummy_b = dummy_b->related_breakpoint; + if (dummy_b->type != bp_call_dummy + || frame_find_by_id (dummy_b->frame_id) != NULL) + continue; + + dummy_frame_discard (dummy_b->frame_id); + + while (b->related_breakpoint != b) + { + if (b_tmp == b->related_breakpoint) + b_tmp = b->related_breakpoint->next; + delete_breakpoint (b->related_breakpoint); + } + delete_breakpoint (b); + } +} + void enable_overlay_breakpoints (void) { @@ -12821,6 +12902,22 @@ momentary_bkpt_print_mention (struct breakpoint *b) /* Nothing to mention. These breakpoints are internal. */ } +/* Ensure INITIATING_FRAME is cleared when no such breakpoint exists. + + It gets cleared already on the removal of the first one of such placed + breakpoints. This is OK as they get all removed altogether. */ + +static void +longjmp_bkpt_dtor (struct breakpoint *self) +{ + struct thread_info *tp = find_thread_id (self->thread); + + if (tp) + tp->initiating_frame = null_frame_id; + + momentary_breakpoint_ops.dtor (self); +} + /* Specific methods for probe breakpoints. */ static int @@ -15409,6 +15506,11 @@ initialize_breakpoint_ops (void) ops->print_it = momentary_bkpt_print_it; ops->print_mention = momentary_bkpt_print_mention; + /* Momentary breakpoints for bp_longjmp and bp_exception. */ + ops = &longjmp_breakpoint_ops; + *ops = momentary_breakpoint_ops; + ops->dtor = longjmp_bkpt_dtor; + /* Probe breakpoints. */ ops = &bkpt_probe_breakpoint_ops; *ops = bkpt_breakpoint_ops; diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h index 2ad80d6..68a9688 100644 --- a/gdb/breakpoint.h +++ b/gdb/breakpoint.h @@ -65,6 +65,12 @@ enum bptype bp_longjmp, /* secret breakpoint to find longjmp() */ bp_longjmp_resume, /* secret breakpoint to escape longjmp() */ + /* Breakpoint placed to the same location(s) like bp_longjmp but used to + protect against stale DUMMY_FRAME. Multiple bp_longjmp_call_dummy and + one bp_call_dummy are chained together by related_breakpoint for each + DUMMY_FRAME. */ + bp_longjmp_call_dummy, + /* An internal breakpoint that is installed on the unwinder's debug hook. */ bp_exception, @@ -94,14 +100,8 @@ enum bptype 3) It can never be disabled. */ bp_watchpoint_scope, - /* The breakpoint at the end of a call dummy. */ - /* FIXME: What if the function we are calling longjmp()s out of - the call, or the user gets out with the "return" command? We - currently have no way of cleaning up the breakpoint in these - (obscure) situations. (Probably can solve this by noticing - longjmp, "return", etc., it's similar to noticing when a - watchpoint on a local variable goes out of scope (with hardware - support for watchpoints)). */ + /* The breakpoint at the end of a call dummy. See bp_longjmp_call_dummy it + is chained with by related_breakpoint. */ bp_call_dummy, /* A breakpoint set on std::terminate, that is used to catch @@ -1287,6 +1287,9 @@ extern void delete_longjmp_breakpoint (int thread); /* Mark all longjmp breakpoints from THREAD for later deletion. */ extern void delete_longjmp_breakpoint_at_next_stop (int thread); +extern struct breakpoint *set_longjmp_breakpoint_for_call_dummy (void); +extern void check_longjmp_breakpoint_for_call_dummy (int thread); + extern void enable_overlay_breakpoints (void); extern void disable_overlay_breakpoints (void); diff --git a/gdb/dummy-frame.c b/gdb/dummy-frame.c index 4a42a76..b8a8c86 100644 --- a/gdb/dummy-frame.c +++ b/gdb/dummy-frame.c @@ -29,6 +29,7 @@ #include "gdbcmd.h" #include "gdb_string.h" #include "observer.h" +#include "gdbthread.h" /* Dummy frame. This saves the processor state just prior to setting up the inferior function call. Older targets save the registers @@ -108,19 +109,44 @@ remove_dummy_frame (struct dummy_frame **dummy_ptr) xfree (dummy); } +/* Delete any breakpoint B which is a momentary breakpoint for return from + inferior call matching DUMMY_VOIDP. */ + +static int +pop_dummy_frame_bpt (struct breakpoint *b, void *dummy_voidp) +{ + struct dummy_frame *dummy = dummy_voidp; + + if (b->thread == pid_to_thread_id (inferior_ptid) + && b->disposition == disp_del && frame_id_eq (b->frame_id, dummy->id)) + { + while (b->related_breakpoint != b) + delete_breakpoint (b->related_breakpoint); + + delete_breakpoint (b); + + /* Stop the traversal. */ + return 1; + } + + /* Continue the traversal. */ + return 0; +} + /* Pop *DUMMY_PTR, restoring program state to that before the frame was created. */ static void pop_dummy_frame (struct dummy_frame **dummy_ptr) { - struct dummy_frame *dummy; + struct dummy_frame *dummy = *dummy_ptr; + + restore_infcall_suspend_state (dummy->caller_state); - restore_infcall_suspend_state ((*dummy_ptr)->caller_state); + iterate_over_breakpoints (pop_dummy_frame_bpt, dummy); /* restore_infcall_control_state frees inf_state, all that remains is to pop *dummy_ptr. */ - dummy = *dummy_ptr; *dummy_ptr = dummy->next; xfree (dummy); @@ -166,9 +192,22 @@ dummy_frame_pop (struct frame_id dummy_id) pop_dummy_frame (dp); } -/* There may be stale dummy frames, perhaps left over from when a longjump took - us out of a function that was called by the debugger. Clean them up at - least once whenever we start a new inferior. */ +/* Drop dummy frame DUMMY_ID. Do nothing if it is not found. Do not restore + its state into inferior, just free its memory. */ + +void +dummy_frame_discard (struct frame_id dummy_id) +{ + struct dummy_frame **dp; + + dp = lookup_dummy_frame (dummy_id); + if (dp) + remove_dummy_frame (dp); +} + +/* There may be stale dummy frames, perhaps left over from when an uncaught + longjmp took us out of a function that was called by the debugger. Clean + them up at least once whenever we start a new inferior. */ static void cleanup_dummy_frames (struct target_ops *target, int from_tty) diff --git a/gdb/dummy-frame.h b/gdb/dummy-frame.h index a921e92..1b3979d 100644 --- a/gdb/dummy-frame.h +++ b/gdb/dummy-frame.h @@ -52,6 +52,8 @@ extern void dummy_frame_push (struct infcall_suspend_state *caller_state, extern void dummy_frame_pop (struct frame_id dummy_id); +extern void dummy_frame_discard (struct frame_id dummy_id); + /* If the PC falls in a dummy frame, return a dummy frame unwinder. */ diff --git a/gdb/gdbthread.h b/gdb/gdbthread.h index 2512357..7cd66b6 100644 --- a/gdb/gdbthread.h +++ b/gdb/gdbthread.h @@ -216,7 +216,9 @@ struct thread_info int stop_requested; /* The initiating frame of a nexting operation, used for deciding - which exceptions to intercept. */ + which exceptions to intercept. If it is null_frame_id no + bp_longjmp or bp_exception but longjmp has been caught just for + bp_longjmp_call_dummy. */ struct frame_id initiating_frame; /* Private data used by the target vector implementation. */ diff --git a/gdb/infcall.c b/gdb/infcall.c index 20a2c2b..51cd118 100644 --- a/gdb/infcall.c +++ b/gdb/infcall.c @@ -744,7 +744,7 @@ call_function_by_hand (struct value *function, int nargs, struct value **args) inferior. That way it breaks when it returns. */ { - struct breakpoint *bpt; + struct breakpoint *bpt, *longjmp_b; struct symtab_and_line sal; init_sal (&sal); /* initialize to zeroes */ @@ -760,6 +760,17 @@ call_function_by_hand (struct value *function, int nargs, struct value **args) frame = NULL; bpt->disposition = disp_del; + gdb_assert (bpt->related_breakpoint == bpt); + + longjmp_b = set_longjmp_breakpoint_for_call_dummy (); + if (longjmp_b) + { + /* Link BPT into the chain of LONGJMP_B. */ + bpt->related_breakpoint = longjmp_b; + while (longjmp_b->related_breakpoint != bpt->related_breakpoint) + longjmp_b = longjmp_b->related_breakpoint; + longjmp_b->related_breakpoint = bpt; + } } /* Create a breakpoint in std::terminate. diff --git a/gdb/infrun.c b/gdb/infrun.c index 95a3ae9..53db335 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -4445,18 +4445,34 @@ process_event_stop_test: 3. The initiating frame exists and is different from the current frame. This means the exception or longjmp has been caught beneath the initiating frame, so keep - going. */ + going. + + 4. longjmp breakpoint has been placed just to protect + against stale dummy frames and user is not interested in + stopping around longjmps. */ if (debug_infrun) fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n"); - init_frame = frame_find_by_id (ecs->event_thread->initiating_frame); - gdb_assert (ecs->event_thread->control.exception_resume_breakpoint != NULL); delete_exception_resume_breakpoint (ecs->event_thread); + if (what.is_longjmp) + { + check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num); + + if (!frame_id_p (ecs->event_thread->initiating_frame)) + { + /* Case 4. */ + keep_going (ecs); + return; + } + } + + init_frame = frame_find_by_id (ecs->event_thread->initiating_frame); + if (init_frame) { struct frame_id current_id diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 2b55c3e..be5f0f6 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2012-06-18 Jan Kratochvil <jan.kratochvil@redhat.com> + + Remove stale dummy frames. + * gdb.base/call-signal-resume.exp (maintenance print dummy-frames) + (maintenance info breakpoints): New tests. + * gdb.base/stale-infcall.c: New file. + * gdb.base/stale-infcall.exp: New file. + 2012-06-17 Jan Kratochvil <jan.kratochvil@redhat.com> * gdb.arch/amd64-entry-value-param.S: New file. diff --git a/gdb/testsuite/gdb.base/call-signal-resume.exp b/gdb/testsuite/gdb.base/call-signal-resume.exp index d383f5c..2baa3f6 100644 --- a/gdb/testsuite/gdb.base/call-signal-resume.exp +++ b/gdb/testsuite/gdb.base/call-signal-resume.exp @@ -101,6 +101,18 @@ gdb_test "frame $frame_number" ".*" gdb_test_no_output "set confirm off" gdb_test "return" "" +# Verify there are no remains of the dummy frame. +gdb_test_no_output "maintenance print dummy-frames" +set test "maintenance info breakpoints" +gdb_test_multiple $test $test { + -re " call dummy .*\r\n$gdb_prompt $" { + fail $test + } + -re "\r\n$gdb_prompt $" { + pass $test + } +} + # Resume execution, the program should continue without any signal. gdb_test "break stop_two" "Breakpoint \[0-9\]* at .*" diff --git a/gdb/testsuite/gdb.base/stale-infcall.c b/gdb/testsuite/gdb.base/stale-infcall.c new file mode 100644 index 0000000..1f5169a --- /dev/null +++ b/gdb/testsuite/gdb.base/stale-infcall.c @@ -0,0 +1,63 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2012 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include <setjmp.h> +#include <string.h> +#include <stdlib.h> + +#define BUFSIZE 0x1000 + +static jmp_buf jmp; + +void +infcall (void) +{ + longjmp (jmp, 1); +} + +static void +run1 (void) +{ + char buf[BUFSIZE / 2]; + int dummy = 0; + + dummy++; /* break-run1 */ +} + +static char buf_zero[BUFSIZE]; + +static void +run2 (void) +{ + char buf[BUFSIZE]; + + memset (buf, 0, sizeof (buf)); + + if (memcmp (buf, buf_zero, sizeof (buf)) != 0) /* break-run2 */ + abort (); /* break-fail */ +} + +int +main () +{ + if (setjmp (jmp) == 0) + run1 (); + else + run2 (); + + return 0; /* break-exit */ +} diff --git a/gdb/testsuite/gdb.base/stale-infcall.exp b/gdb/testsuite/gdb.base/stale-infcall.exp new file mode 100644 index 0000000..bb22339 --- /dev/null +++ b/gdb/testsuite/gdb.base/stale-infcall.exp @@ -0,0 +1,57 @@ +# Copyright (C) 2012 Free Software Foundation # Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + +set testfile stale-infcall +set srcfile ${testfile}.c +if { [prepare_for_testing $testfile.exp $testfile $srcfile] } { + return -1 +} + +if ![runto_main] { + return -1 +} + +gdb_breakpoint [gdb_get_line_number "break-run1"] +gdb_breakpoint [gdb_get_line_number "break-run2"] +gdb_breakpoint [gdb_get_line_number "break-exit"] +gdb_breakpoint [gdb_get_line_number "break-fail"] + +gdb_continue_to_breakpoint "break-run1" ".* break-run1 .*" + +gdb_test "print infcall ()" " break-run2 .*The program being debugged stopped while in a function called from GDB\\..*When the function is done executing, GDB will silently stop\\." + +set test "stack corrupted" +gdb_test_multiple "continue" $test { + -re " break-exit .*\r\n$gdb_prompt $" { + pass $test + } + -re " break-fail .*\r\n$gdb_prompt $" { + fail $test + } +} + +gdb_test "bt" "#0 \[^\r\n\]* main \[^\r\n\]*" + +# Verify there are no remains of the dummy frame. +gdb_test_no_output "maintenance print dummy-frames" +set test "maintenance info breakpoints" +gdb_test_multiple $test $test { + -re " call dummy .*\r\n$gdb_prompt $" { + fail $test + } + -re "\r\n$gdb_prompt $" { + pass $test + } +} |