| /* Everything about syscall catchpoints, for GDB. |
| |
| Copyright (C) 2009-2021 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 "observable.h" |
| #include "xml-syscall.h" |
| #include "cli/cli-style.h" |
| #include "cli/cli-decode.h" |
| |
| /* An instance of this type is used to represent a syscall catchpoint. |
| A breakpoint is really of this type iff its ops pointer points to |
| CATCH_SYSCALL_BREAKPOINT_OPS. */ |
| |
| struct syscall_catchpoint : public breakpoint |
| { |
| /* Syscall numbers used for the 'catch syscall' feature. If no |
| syscall has been specified for filtering, it is empty. |
| Otherwise, it holds a list of all syscalls to be caught. */ |
| std::vector<int> syscalls_to_be_caught; |
| }; |
| |
| 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. */ |
| std::vector<int> syscalls_counts; |
| |
| /* This counts all syscall catch requests, so we can readily determine |
| if any catching is necessary. */ |
| int total_syscalls_count; |
| }; |
| |
| static const struct inferior_key<struct catch_syscall_inferior_data> |
| catch_syscall_inferior_data; |
| |
| static struct catch_syscall_inferior_data * |
| get_catch_syscall_inferior_data (struct inferior *inf) |
| { |
| struct catch_syscall_inferior_data *inf_data; |
| |
| inf_data = catch_syscall_inferior_data.get (inf); |
| if (inf_data == NULL) |
| inf_data = catch_syscall_inferior_data.emplace (inf); |
| |
| return inf_data; |
| } |
| |
| /* 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.empty ()) |
| ++inf_data->any_syscall_count; |
| else |
| { |
| for (int iter : c->syscalls_to_be_caught) |
| { |
| if (iter >= inf_data->syscalls_counts.size ()) |
| inf_data->syscalls_counts.resize (iter + 1); |
| ++inf_data->syscalls_counts[iter]; |
| } |
| } |
| |
| return target_set_syscall_catchpoint (inferior_ptid.pid (), |
| inf_data->total_syscalls_count != 0, |
| inf_data->any_syscall_count, |
| inf_data->syscalls_counts); |
| } |
| |
| /* Implement the "remove" breakpoint_ops method for syscall |
| catchpoints. */ |
| |
| static int |
| remove_catch_syscall (struct bp_location *bl, enum remove_bp_reason reason) |
| { |
| 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.empty ()) |
| --inf_data->any_syscall_count; |
| else |
| { |
| for (int iter : c->syscalls_to_be_caught) |
| { |
| if (iter >= inf_data->syscalls_counts.size ()) |
| /* Shouldn't happen. */ |
| continue; |
| --inf_data->syscalls_counts[iter]; |
| } |
| } |
| |
| return target_set_syscall_catchpoint (inferior_ptid.pid (), |
| inf_data->total_syscalls_count != 0, |
| inf_data->any_syscall_count, |
| 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, |
| const 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.empty ()) |
| { |
| for (int iter : c->syscalls_to_be_caught) |
| 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". */ |
| struct target_waitstatus last; |
| struct syscall s; |
| struct gdbarch *gdbarch = bs->bp_location_at->gdbarch; |
| |
| get_last_target_status (nullptr, nullptr, &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) |
| uiout->text ("Temporary catchpoint "); |
| else |
| uiout->text ("Catchpoint "); |
| if (uiout->is_mi_like_p ()) |
| { |
| uiout->field_string ("reason", |
| async_reason_lookup (last.kind == TARGET_WAITKIND_SYSCALL_ENTRY |
| ? EXEC_ASYNC_SYSCALL_ENTRY |
| : EXEC_ASYNC_SYSCALL_RETURN)); |
| uiout->field_string ("disp", bpdisp_text (b->disposition)); |
| } |
| uiout->field_signed ("bkptno", b->number); |
| |
| if (last.kind == TARGET_WAITKIND_SYSCALL_ENTRY) |
| uiout->text (" (call to syscall "); |
| else |
| uiout->text (" (returned from syscall "); |
| |
| if (s.name == NULL || uiout->is_mi_like_p ()) |
| uiout->field_signed ("syscall-number", last.value.syscall_number); |
| if (s.name != NULL) |
| uiout->field_string ("syscall-name", s.name); |
| |
| uiout->text ("), "); |
| |
| 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) |
| uiout->field_skip ("addr"); |
| annotate_field (5); |
| |
| if (c->syscalls_to_be_caught.size () > 1) |
| uiout->text ("syscalls \""); |
| else |
| uiout->text ("syscall \""); |
| |
| if (!c->syscalls_to_be_caught.empty ()) |
| { |
| char *text = xstrprintf ("%s", ""); |
| |
| for (int iter : c->syscalls_to_be_caught) |
| { |
| char *previous_text = 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 previous_text because xstrprintf dynamically |
| allocates new space for text on every call. */ |
| xfree (previous_text); |
| } |
| /* Remove the last comma. */ |
| text[strlen (text) - 2] = '\0'; |
| uiout->field_string ("what", text); |
| /* xfree last text. */ |
| xfree (text); |
| } |
| else |
| uiout->field_string ("what", "<any syscall>", metadata_style.style ()); |
| uiout->text ("\" "); |
| |
| if (uiout->is_mi_like_p ()) |
| uiout->field_string ("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.empty ()) |
| { |
| if (c->syscalls_to_be_caught.size () > 1) |
| printf_filtered (_("Catchpoint %d (syscalls"), b->number); |
| else |
| printf_filtered (_("Catchpoint %d (syscall"), b->number); |
| |
| for (int iter : c->syscalls_to_be_caught) |
| { |
| struct syscall s; |
| get_syscall_by_number (gdbarch, iter, &s); |
| |
| if (s.name != NULL) |
| 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"); |
| |
| for (int iter : c->syscalls_to_be_caught) |
| { |
| struct syscall s; |
| |
| get_syscall_by_number (gdbarch, iter, &s); |
| if (s.name != NULL) |
| 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, std::vector<int> &&filter, |
| const struct breakpoint_ops *ops) |
| { |
| struct gdbarch *gdbarch = get_current_arch (); |
| |
| std::unique_ptr<syscall_catchpoint> c (new syscall_catchpoint ()); |
| init_catchpoint (c.get (), gdbarch, tempflag, NULL, ops); |
| c->syscalls_to_be_caught = std::move (filter); |
| |
| install_breakpoint (0, std::move (c), 1); |
| } |
| |
| /* Splits the argument using space as delimiter. */ |
| |
| static std::vector<int> |
| catch_syscall_split_args (const char *arg) |
| { |
| std::vector<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, group, or a number. */ |
| syscall_number = (int) strtol (cur_name, &endptr, 0); |
| if (*endptr == '\0') |
| { |
| if (syscall_number < 0) |
| error (_("Unknown syscall number '%d'."), syscall_number); |
| get_syscall_by_number (gdbarch, syscall_number, &s); |
| result.push_back (s.number); |
| } |
| else if (startswith (cur_name, "g:") |
| || startswith (cur_name, "group:")) |
| { |
| /* We have a syscall group. Let's expand it into a syscall |
| list before inserting. */ |
| const char *group_name; |
| |
| /* Skip over "g:" and "group:" prefix strings. */ |
| group_name = strchr (cur_name, ':') + 1; |
| |
| if (!get_syscalls_by_group (gdbarch, group_name, &result)) |
| error (_("Unknown syscall group '%s'."), group_name); |
| } |
| else |
| { |
| /* We have a name. Let's check if it's valid and fetch a |
| list of matching numbers. */ |
| if (!get_syscalls_by_name (gdbarch, cur_name, &result)) |
| /* 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); |
| } |
| } |
| |
| return result; |
| } |
| |
| /* Implement the "catch syscall" command. */ |
| |
| static void |
| catch_syscall_command_1 (const char *arg, int from_tty, |
| struct cmd_list_element *command) |
| { |
| int tempflag; |
| std::vector<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 = command->context () == 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); |
| |
| create_syscall_event_catchpoint (tempflag, std::move (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. return true if B is a syscall |
| catchpoint for SYSCALL_NUMBER, else false. */ |
| |
| static bool |
| catching_syscall_number_1 (struct breakpoint *b, int syscall_number) |
| { |
| |
| if (is_syscall_catchpoint_enabled (b)) |
| { |
| struct syscall_catchpoint *c = (struct syscall_catchpoint *) b; |
| |
| if (!c->syscalls_to_be_caught.empty ()) |
| { |
| for (int iter : c->syscalls_to_be_caught) |
| if (syscall_number == iter) |
| return true; |
| } |
| else |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool |
| catching_syscall_number (int syscall_number) |
| { |
| for (breakpoint *b : all_breakpoints ()) |
| if (catching_syscall_number_1 (b, syscall_number)) |
| return true; |
| |
| return false; |
| } |
| |
| /* Complete syscall names. Used by "catch syscall". */ |
| |
| static void |
| catch_syscall_completer (struct cmd_list_element *cmd, |
| completion_tracker &tracker, |
| const char *text, const char *word) |
| { |
| struct gdbarch *gdbarch = get_current_arch (); |
| gdb::unique_xmalloc_ptr<const char *> group_list; |
| const char *prefix; |
| |
| /* Completion considers ':' to be a word separator, so we use this to |
| verify whether the previous word was a group prefix. If so, we |
| build the completion list using group names only. */ |
| for (prefix = word; prefix != text && prefix[-1] != ' '; prefix--) |
| ; |
| |
| if (startswith (prefix, "g:") || startswith (prefix, "group:")) |
| { |
| /* Perform completion inside 'group:' namespace only. */ |
| group_list.reset (get_syscall_group_names (gdbarch)); |
| if (group_list != NULL) |
| complete_on_enum (tracker, group_list.get (), word, word); |
| } |
| else |
| { |
| /* Complete with both, syscall names and groups. */ |
| gdb::unique_xmalloc_ptr<const char *> syscall_list |
| (get_syscall_names (gdbarch)); |
| group_list.reset (get_syscall_group_names (gdbarch)); |
| |
| const char **group_ptr = group_list.get (); |
| |
| /* Hold on to strings while we're using them. */ |
| std::vector<std::string> holders; |
| |
| /* Append "group:" prefix to syscall groups. */ |
| for (int i = 0; group_ptr[i] != NULL; i++) |
| holders.push_back (string_printf ("group:%s", group_ptr[i])); |
| |
| for (int i = 0; group_ptr[i] != NULL; i++) |
| group_ptr[i] = holders[i].c_str (); |
| |
| if (syscall_list != NULL) |
| complete_on_enum (tracker, syscall_list.get (), word, word); |
| if (group_list != NULL) |
| complete_on_enum (tracker, group_ptr, word, word); |
| } |
| } |
| |
| 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; |
| inf_data->syscalls_counts.clear (); |
| } |
| |
| 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->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; |
| } |
| |
| void _initialize_break_catch_syscall (); |
| void |
| _initialize_break_catch_syscall () |
| { |
| initialize_syscall_catchpoint_ops (); |
| |
| gdb::observers::inferior_exit.attach (clear_syscall_counts, |
| "break-catch-syscall"); |
| |
| add_catch_command ("syscall", _("\ |
| Catch system calls by their names, groups and/or numbers.\n\ |
| Arguments say which system calls to catch. If no arguments are given,\n\ |
| every system call will be caught. Arguments, if given, should be one\n\ |
| or more system call names (if your system supports that), system call\n\ |
| groups or system call numbers."), |
| catch_syscall_command_1, |
| catch_syscall_completer, |
| CATCH_PERMANENT, |
| CATCH_TEMPORARY); |
| } |