| /* Everything about syscall catchpoints, for GDB. |
| |
| Copyright (C) 2009-2016 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| 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 "defs.h" |
| #include <ctype.h> |
| #include "breakpoint.h" |
| #include "gdbcmd.h" |
| #include "inferior.h" |
| #include "cli/cli-utils.h" |
| #include "annotate.h" |
| #include "mi/mi-common.h" |
| #include "valprint.h" |
| #include "arch-utils.h" |
| #include "observer.h" |
| #include "xml-syscall.h" |
| |
| /* An instance of this type is used to represent a syscall catchpoint. |
| It includes a "struct breakpoint" as a kind of base class; users |
| downcast to "struct breakpoint *" when needed. A breakpoint is |
| really of this type iff its ops pointer points to |
| CATCH_SYSCALL_BREAKPOINT_OPS. */ |
| |
| struct syscall_catchpoint |
| { |
| /* The base class. */ |
| struct breakpoint base; |
| |
| /* Syscall numbers used for the 'catch syscall' feature. If no |
| syscall has been specified for filtering, its value is NULL. |
| Otherwise, it holds a list of all syscalls to be caught. The |
| list elements are allocated with xmalloc. */ |
| VEC(int) *syscalls_to_be_caught; |
| }; |
| |
| /* Implement the "dtor" breakpoint_ops method for syscall |
| catchpoints. */ |
| |
| static void |
| dtor_catch_syscall (struct breakpoint *b) |
| { |
| struct syscall_catchpoint *c = (struct syscall_catchpoint *) b; |
| |
| VEC_free (int, c->syscalls_to_be_caught); |
| |
| base_breakpoint_ops.dtor (b); |
| } |
| |
| static const struct inferior_data *catch_syscall_inferior_data = NULL; |
| |
| struct catch_syscall_inferior_data |
| { |
| /* We keep a count of the number of times the user has requested a |
| particular syscall to be tracked, and pass this information to the |
| target. This lets capable targets implement filtering directly. */ |
| |
| /* Number of times that "any" syscall is requested. */ |
| int any_syscall_count; |
| |
| /* Count of each system call. */ |
| VEC(int) *syscalls_counts; |
| |
| /* This counts all syscall catch requests, so we can readily determine |
| if any catching is necessary. */ |
| int total_syscalls_count; |
| }; |
| |
| static struct catch_syscall_inferior_data* |
| get_catch_syscall_inferior_data (struct inferior *inf) |
| { |
| struct catch_syscall_inferior_data *inf_data; |
| |
| inf_data = ((struct catch_syscall_inferior_data *) |
| inferior_data (inf, catch_syscall_inferior_data)); |
| if (inf_data == NULL) |
| { |
| inf_data = XCNEW (struct catch_syscall_inferior_data); |
| set_inferior_data (inf, catch_syscall_inferior_data, inf_data); |
| } |
| |
| return inf_data; |
| } |
| |
| static void |
| catch_syscall_inferior_data_cleanup (struct inferior *inf, void *arg) |
| { |
| xfree (arg); |
| } |
| |
| |
| /* Implement the "insert" breakpoint_ops method for syscall |
| catchpoints. */ |
| |
| static int |
| insert_catch_syscall (struct bp_location *bl) |
| { |
| struct syscall_catchpoint *c = (struct syscall_catchpoint *) bl->owner; |
| struct inferior *inf = current_inferior (); |
| struct catch_syscall_inferior_data *inf_data |
| = get_catch_syscall_inferior_data (inf); |
| |
| ++inf_data->total_syscalls_count; |
| if (!c->syscalls_to_be_caught) |
| ++inf_data->any_syscall_count; |
| else |
| { |
| int i, iter; |
| |
| for (i = 0; |
| VEC_iterate (int, c->syscalls_to_be_caught, i, iter); |
| i++) |
| { |
| int elem; |
| |
| if (iter >= VEC_length (int, inf_data->syscalls_counts)) |
| { |
| int old_size = VEC_length (int, inf_data->syscalls_counts); |
| uintptr_t vec_addr_offset |
| = old_size * ((uintptr_t) sizeof (int)); |
| uintptr_t vec_addr; |
| VEC_safe_grow (int, inf_data->syscalls_counts, iter + 1); |
| vec_addr = ((uintptr_t) VEC_address (int, |
| inf_data->syscalls_counts) |
| + vec_addr_offset); |
| memset ((void *) vec_addr, 0, |
| (iter + 1 - old_size) * sizeof (int)); |
| } |
| elem = VEC_index (int, inf_data->syscalls_counts, iter); |
| VEC_replace (int, inf_data->syscalls_counts, iter, ++elem); |
| } |
| } |
| |
| return target_set_syscall_catchpoint (ptid_get_pid (inferior_ptid), |
| inf_data->total_syscalls_count != 0, |
| inf_data->any_syscall_count, |
| VEC_length (int, |
| inf_data->syscalls_counts), |
| VEC_address (int, |
| inf_data->syscalls_counts)); |
| } |
| |
| /* Implement the "remove" breakpoint_ops method for syscall |
| catchpoints. */ |
| |
| static int |
| remove_catch_syscall (struct bp_location *bl) |
| { |
| struct syscall_catchpoint *c = (struct syscall_catchpoint *) bl->owner; |
| struct inferior *inf = current_inferior (); |
| struct catch_syscall_inferior_data *inf_data |
| = get_catch_syscall_inferior_data (inf); |
| |
| --inf_data->total_syscalls_count; |
| if (!c->syscalls_to_be_caught) |
| --inf_data->any_syscall_count; |
| else |
| { |
| int i, iter; |
| |
| for (i = 0; |
| VEC_iterate (int, c->syscalls_to_be_caught, i, iter); |
| i++) |
| { |
| int elem; |
| if (iter >= VEC_length (int, inf_data->syscalls_counts)) |
| /* Shouldn't happen. */ |
| continue; |
| elem = VEC_index (int, inf_data->syscalls_counts, iter); |
| VEC_replace (int, inf_data->syscalls_counts, iter, --elem); |
| } |
| } |
| |
| return target_set_syscall_catchpoint (ptid_get_pid (inferior_ptid), |
| inf_data->total_syscalls_count != 0, |
| inf_data->any_syscall_count, |
| VEC_length (int, |
| inf_data->syscalls_counts), |
| VEC_address (int, |
| inf_data->syscalls_counts)); |
| } |
| |
| /* Implement the "breakpoint_hit" breakpoint_ops method for syscall |
| catchpoints. */ |
| |
| static int |
| breakpoint_hit_catch_syscall (const struct bp_location *bl, |
| struct address_space *aspace, CORE_ADDR bp_addr, |
| const struct target_waitstatus *ws) |
| { |
| /* We must check if we are catching specific syscalls in this |
| breakpoint. If we are, then we must guarantee that the called |
| syscall is the same syscall we are catching. */ |
| int syscall_number = 0; |
| const struct syscall_catchpoint *c |
| = (const struct syscall_catchpoint *) bl->owner; |
| |
| if (ws->kind != TARGET_WAITKIND_SYSCALL_ENTRY |
| && ws->kind != TARGET_WAITKIND_SYSCALL_RETURN) |
| return 0; |
| |
| syscall_number = ws->value.syscall_number; |
| |
| /* Now, checking if the syscall is the same. */ |
| if (c->syscalls_to_be_caught) |
| { |
| int i, iter; |
| |
| for (i = 0; |
| VEC_iterate (int, c->syscalls_to_be_caught, i, iter); |
| i++) |
| if (syscall_number == iter) |
| return 1; |
| |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* Implement the "print_it" breakpoint_ops method for syscall |
| catchpoints. */ |
| |
| static enum print_stop_action |
| print_it_catch_syscall (bpstat bs) |
| { |
| struct ui_out *uiout = current_uiout; |
| struct breakpoint *b = bs->breakpoint_at; |
| /* These are needed because we want to know in which state a |
| syscall is. It can be in the TARGET_WAITKIND_SYSCALL_ENTRY |
| or TARGET_WAITKIND_SYSCALL_RETURN, and depending on it we |
| must print "called syscall" or "returned from syscall". */ |
| ptid_t ptid; |
| struct target_waitstatus last; |
| struct syscall s; |
| struct gdbarch *gdbarch = bs->bp_location_at->gdbarch; |
| |
| get_last_target_status (&ptid, &last); |
| |
| get_syscall_by_number (gdbarch, last.value.syscall_number, &s); |
| |
| annotate_catchpoint (b->number); |
| maybe_print_thread_hit_breakpoint (uiout); |
| |
| if (b->disposition == disp_del) |
| ui_out_text (uiout, "Temporary catchpoint "); |
| else |
| ui_out_text (uiout, "Catchpoint "); |
| if (ui_out_is_mi_like_p (uiout)) |
| { |
| ui_out_field_string (uiout, "reason", |
| async_reason_lookup (last.kind == TARGET_WAITKIND_SYSCALL_ENTRY |
| ? EXEC_ASYNC_SYSCALL_ENTRY |
| : EXEC_ASYNC_SYSCALL_RETURN)); |
| ui_out_field_string (uiout, "disp", bpdisp_text (b->disposition)); |
| } |
| ui_out_field_int (uiout, "bkptno", b->number); |
| |
| if (last.kind == TARGET_WAITKIND_SYSCALL_ENTRY) |
| ui_out_text (uiout, " (call to syscall "); |
| else |
| ui_out_text (uiout, " (returned from syscall "); |
| |
| if (s.name == NULL || ui_out_is_mi_like_p (uiout)) |
| ui_out_field_int (uiout, "syscall-number", last.value.syscall_number); |
| if (s.name != NULL) |
| ui_out_field_string (uiout, "syscall-name", s.name); |
| |
| ui_out_text (uiout, "), "); |
| |
| return PRINT_SRC_AND_LOC; |
| } |
| |
| /* Implement the "print_one" breakpoint_ops method for syscall |
| catchpoints. */ |
| |
| static void |
| print_one_catch_syscall (struct breakpoint *b, |
| struct bp_location **last_loc) |
| { |
| struct syscall_catchpoint *c = (struct syscall_catchpoint *) b; |
| struct value_print_options opts; |
| struct ui_out *uiout = current_uiout; |
| struct gdbarch *gdbarch = b->loc->gdbarch; |
| |
| get_user_print_options (&opts); |
| /* Field 4, the address, is omitted (which makes the columns not |
| line up too nicely with the headers, but the effect is relatively |
| readable). */ |
| if (opts.addressprint) |
| ui_out_field_skip (uiout, "addr"); |
| annotate_field (5); |
| |
| if (c->syscalls_to_be_caught |
| && VEC_length (int, c->syscalls_to_be_caught) > 1) |
| ui_out_text (uiout, "syscalls \""); |
| else |
| ui_out_text (uiout, "syscall \""); |
| |
| if (c->syscalls_to_be_caught) |
| { |
| int i, iter; |
| char *text = xstrprintf ("%s", ""); |
| |
| for (i = 0; |
| VEC_iterate (int, c->syscalls_to_be_caught, i, iter); |
| i++) |
| { |
| char *x = text; |
| struct syscall s; |
| get_syscall_by_number (gdbarch, iter, &s); |
| |
| if (s.name != NULL) |
| text = xstrprintf ("%s%s, ", text, s.name); |
| else |
| text = xstrprintf ("%s%d, ", text, iter); |
| |
| /* We have to xfree the last 'text' (now stored at 'x') |
| because xstrprintf dynamically allocates new space for it |
| on every call. */ |
| xfree (x); |
| } |
| /* Remove the last comma. */ |
| text[strlen (text) - 2] = '\0'; |
| ui_out_field_string (uiout, "what", text); |
| } |
| else |
| ui_out_field_string (uiout, "what", "<any syscall>"); |
| ui_out_text (uiout, "\" "); |
| |
| if (ui_out_is_mi_like_p (uiout)) |
| ui_out_field_string (uiout, "catch-type", "syscall"); |
| } |
| |
| /* Implement the "print_mention" breakpoint_ops method for syscall |
| catchpoints. */ |
| |
| static void |
| print_mention_catch_syscall (struct breakpoint *b) |
| { |
| struct syscall_catchpoint *c = (struct syscall_catchpoint *) b; |
| struct gdbarch *gdbarch = b->loc->gdbarch; |
| |
| if (c->syscalls_to_be_caught) |
| { |
| int i, iter; |
| |
| if (VEC_length (int, c->syscalls_to_be_caught) > 1) |
| printf_filtered (_("Catchpoint %d (syscalls"), b->number); |
| else |
| printf_filtered (_("Catchpoint %d (syscall"), b->number); |
| |
| for (i = 0; |
| VEC_iterate (int, c->syscalls_to_be_caught, i, iter); |
| i++) |
| { |
| struct syscall s; |
| get_syscall_by_number (gdbarch, iter, &s); |
| |
| if (s.name) |
| printf_filtered (" '%s' [%d]", s.name, s.number); |
| else |
| printf_filtered (" %d", s.number); |
| } |
| printf_filtered (")"); |
| } |
| else |
| printf_filtered (_("Catchpoint %d (any syscall)"), |
| b->number); |
| } |
| |
| /* Implement the "print_recreate" breakpoint_ops method for syscall |
| catchpoints. */ |
| |
| static void |
| print_recreate_catch_syscall (struct breakpoint *b, struct ui_file *fp) |
| { |
| struct syscall_catchpoint *c = (struct syscall_catchpoint *) b; |
| struct gdbarch *gdbarch = b->loc->gdbarch; |
| |
| fprintf_unfiltered (fp, "catch syscall"); |
| |
| if (c->syscalls_to_be_caught) |
| { |
| int i, iter; |
| |
| for (i = 0; |
| VEC_iterate (int, c->syscalls_to_be_caught, i, iter); |
| i++) |
| { |
| struct syscall s; |
| |
| get_syscall_by_number (gdbarch, iter, &s); |
| if (s.name) |
| fprintf_unfiltered (fp, " %s", s.name); |
| else |
| fprintf_unfiltered (fp, " %d", s.number); |
| } |
| } |
| print_recreate_thread (b, fp); |
| } |
| |
| /* The breakpoint_ops structure to be used in syscall catchpoints. */ |
| |
| static struct breakpoint_ops catch_syscall_breakpoint_ops; |
| |
| /* Returns non-zero if 'b' is a syscall catchpoint. */ |
| |
| static int |
| syscall_catchpoint_p (struct breakpoint *b) |
| { |
| return (b->ops == &catch_syscall_breakpoint_ops); |
| } |
| |
| static void |
| create_syscall_event_catchpoint (int tempflag, VEC(int) *filter, |
| const struct breakpoint_ops *ops) |
| { |
| struct syscall_catchpoint *c; |
| struct gdbarch *gdbarch = get_current_arch (); |
| |
| c = XNEW (struct syscall_catchpoint); |
| init_catchpoint (&c->base, gdbarch, tempflag, NULL, ops); |
| c->syscalls_to_be_caught = filter; |
| |
| install_breakpoint (0, &c->base, 1); |
| } |
| |
| /* Splits the argument using space as delimiter. Returns an xmalloc'd |
| filter list, or NULL if no filtering is required. */ |
| static VEC(int) * |
| catch_syscall_split_args (char *arg) |
| { |
| VEC(int) *result = NULL; |
| struct cleanup *cleanup = make_cleanup (VEC_cleanup (int), &result); |
| struct gdbarch *gdbarch = target_gdbarch (); |
| |
| while (*arg != '\0') |
| { |
| int i, syscall_number; |
| char *endptr; |
| char cur_name[128]; |
| struct syscall s; |
| |
| /* Skip whitespace. */ |
| arg = skip_spaces (arg); |
| |
| for (i = 0; i < 127 && arg[i] && !isspace (arg[i]); ++i) |
| cur_name[i] = arg[i]; |
| cur_name[i] = '\0'; |
| arg += i; |
| |
| /* Check if the user provided a syscall name or a number. */ |
| syscall_number = (int) strtol (cur_name, &endptr, 0); |
| if (*endptr == '\0') |
| get_syscall_by_number (gdbarch, syscall_number, &s); |
| else |
| { |
| /* We have a name. Let's check if it's valid and convert it |
| to a number. */ |
| get_syscall_by_name (gdbarch, cur_name, &s); |
| |
| if (s.number == UNKNOWN_SYSCALL) |
| /* Here we have to issue an error instead of a warning, |
| because GDB cannot do anything useful if there's no |
| syscall number to be caught. */ |
| error (_("Unknown syscall name '%s'."), cur_name); |
| } |
| |
| /* Ok, it's valid. */ |
| VEC_safe_push (int, result, s.number); |
| } |
| |
| discard_cleanups (cleanup); |
| return result; |
| } |
| |
| /* Implement the "catch syscall" command. */ |
| |
| static void |
| catch_syscall_command_1 (char *arg, int from_tty, |
| struct cmd_list_element *command) |
| { |
| int tempflag; |
| VEC(int) *filter; |
| struct syscall s; |
| struct gdbarch *gdbarch = get_current_arch (); |
| |
| /* Checking if the feature if supported. */ |
| if (gdbarch_get_syscall_number_p (gdbarch) == 0) |
| error (_("The feature 'catch syscall' is not supported on \ |
| this architecture yet.")); |
| |
| tempflag = get_cmd_context (command) == CATCH_TEMPORARY; |
| |
| arg = skip_spaces (arg); |
| |
| /* We need to do this first "dummy" translation in order |
| to get the syscall XML file loaded or, most important, |
| to display a warning to the user if there's no XML file |
| for his/her architecture. */ |
| get_syscall_by_number (gdbarch, 0, &s); |
| |
| /* The allowed syntax is: |
| catch syscall |
| catch syscall <name | number> [<name | number> ... <name | number>] |
| |
| Let's check if there's a syscall name. */ |
| |
| if (arg != NULL) |
| filter = catch_syscall_split_args (arg); |
| else |
| filter = NULL; |
| |
| create_syscall_event_catchpoint (tempflag, filter, |
| &catch_syscall_breakpoint_ops); |
| } |
| |
| |
| /* Returns 0 if 'bp' is NOT a syscall catchpoint, |
| non-zero otherwise. */ |
| static int |
| is_syscall_catchpoint_enabled (struct breakpoint *bp) |
| { |
| if (syscall_catchpoint_p (bp) |
| && bp->enable_state != bp_disabled |
| && bp->enable_state != bp_call_disabled) |
| return 1; |
| else |
| return 0; |
| } |
| |
| int |
| catch_syscall_enabled (void) |
| { |
| struct catch_syscall_inferior_data *inf_data |
| = get_catch_syscall_inferior_data (current_inferior ()); |
| |
| return inf_data->total_syscalls_count != 0; |
| } |
| |
| /* Helper function for catching_syscall_number. If B is a syscall |
| catchpoint for SYSCALL_NUMBER, return 1 (which will make |
| 'breakpoint_find_if' return). Otherwise, return 0. */ |
| |
| static int |
| catching_syscall_number_1 (struct breakpoint *b, |
| void *data) |
| { |
| int syscall_number = (int) (uintptr_t) data; |
| |
| if (is_syscall_catchpoint_enabled (b)) |
| { |
| struct syscall_catchpoint *c = (struct syscall_catchpoint *) b; |
| |
| if (c->syscalls_to_be_caught) |
| { |
| int i, iter; |
| for (i = 0; |
| VEC_iterate (int, c->syscalls_to_be_caught, i, iter); |
| i++) |
| if (syscall_number == iter) |
| return 1; |
| } |
| else |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| int |
| catching_syscall_number (int syscall_number) |
| { |
| struct breakpoint *b = breakpoint_find_if (catching_syscall_number_1, |
| (void *) (uintptr_t) syscall_number); |
| |
| return b != NULL; |
| } |
| |
| /* Complete syscall names. Used by "catch syscall". */ |
| static VEC (char_ptr) * |
| catch_syscall_completer (struct cmd_list_element *cmd, |
| const char *text, const char *word) |
| { |
| const char **list = get_syscall_names (get_current_arch ()); |
| VEC (char_ptr) *retlist |
| = (list == NULL) ? NULL : complete_on_enum (list, word, word); |
| |
| xfree (list); |
| return retlist; |
| } |
| |
| static void |
| clear_syscall_counts (struct inferior *inf) |
| { |
| struct catch_syscall_inferior_data *inf_data |
| = get_catch_syscall_inferior_data (inf); |
| |
| inf_data->total_syscalls_count = 0; |
| inf_data->any_syscall_count = 0; |
| VEC_free (int, inf_data->syscalls_counts); |
| } |
| |
| static void |
| initialize_syscall_catchpoint_ops (void) |
| { |
| struct breakpoint_ops *ops; |
| |
| initialize_breakpoint_ops (); |
| |
| /* Syscall catchpoints. */ |
| ops = &catch_syscall_breakpoint_ops; |
| *ops = base_breakpoint_ops; |
| ops->dtor = dtor_catch_syscall; |
| ops->insert_location = insert_catch_syscall; |
| ops->remove_location = remove_catch_syscall; |
| ops->breakpoint_hit = breakpoint_hit_catch_syscall; |
| ops->print_it = print_it_catch_syscall; |
| ops->print_one = print_one_catch_syscall; |
| ops->print_mention = print_mention_catch_syscall; |
| ops->print_recreate = print_recreate_catch_syscall; |
| } |
| |
| initialize_file_ftype _initialize_break_catch_syscall; |
| |
| void |
| _initialize_break_catch_syscall (void) |
| { |
| initialize_syscall_catchpoint_ops (); |
| |
| observer_attach_inferior_exit (clear_syscall_counts); |
| catch_syscall_inferior_data |
| = register_inferior_data_with_cleanup (NULL, |
| catch_syscall_inferior_data_cleanup); |
| |
| add_catch_command ("syscall", _("\ |
| Catch system calls by their names and/or numbers.\n\ |
| Arguments say which system calls to catch. If no arguments\n\ |
| are given, every system call will be caught.\n\ |
| Arguments, if given, should be one or more system call names\n\ |
| (if your system supports that), or system call numbers."), |
| catch_syscall_command_1, |
| catch_syscall_completer, |
| CATCH_PERMANENT, |
| CATCH_TEMPORARY); |
| } |