634 lines
18 KiB
C
634 lines
18 KiB
C
/* Everything about syscall catchpoints, for GDB.
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Copyright (C) 2009-2018 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include <ctype.h>
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#include "breakpoint.h"
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#include "gdbcmd.h"
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#include "inferior.h"
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#include "cli/cli-utils.h"
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#include "annotate.h"
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#include "mi/mi-common.h"
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#include "valprint.h"
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#include "arch-utils.h"
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#include "observable.h"
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#include "xml-syscall.h"
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/* An instance of this type is used to represent a syscall catchpoint.
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A breakpoint is really of this type iff its ops pointer points to
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CATCH_SYSCALL_BREAKPOINT_OPS. */
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struct syscall_catchpoint : public breakpoint
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{
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/* Syscall numbers used for the 'catch syscall' feature. If no
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syscall has been specified for filtering, it is empty.
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Otherwise, it holds a list of all syscalls to be caught. */
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std::vector<int> syscalls_to_be_caught;
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};
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static const struct inferior_data *catch_syscall_inferior_data = NULL;
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struct catch_syscall_inferior_data
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{
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/* We keep a count of the number of times the user has requested a
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particular syscall to be tracked, and pass this information to the
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target. This lets capable targets implement filtering directly. */
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/* Number of times that "any" syscall is requested. */
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int any_syscall_count;
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/* Count of each system call. */
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std::vector<int> syscalls_counts;
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/* This counts all syscall catch requests, so we can readily determine
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if any catching is necessary. */
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int total_syscalls_count;
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};
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static struct catch_syscall_inferior_data *
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get_catch_syscall_inferior_data (struct inferior *inf)
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{
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struct catch_syscall_inferior_data *inf_data;
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inf_data = ((struct catch_syscall_inferior_data *)
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inferior_data (inf, catch_syscall_inferior_data));
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if (inf_data == NULL)
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{
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inf_data = new struct catch_syscall_inferior_data ();
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set_inferior_data (inf, catch_syscall_inferior_data, inf_data);
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}
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return inf_data;
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}
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static void
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catch_syscall_inferior_data_cleanup (struct inferior *inf, void *arg)
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{
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struct catch_syscall_inferior_data *inf_data
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= (struct catch_syscall_inferior_data *) arg;
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delete inf_data;
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}
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/* Implement the "insert" breakpoint_ops method for syscall
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catchpoints. */
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static int
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insert_catch_syscall (struct bp_location *bl)
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{
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struct syscall_catchpoint *c = (struct syscall_catchpoint *) bl->owner;
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struct inferior *inf = current_inferior ();
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struct catch_syscall_inferior_data *inf_data
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= get_catch_syscall_inferior_data (inf);
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++inf_data->total_syscalls_count;
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if (c->syscalls_to_be_caught.empty ())
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++inf_data->any_syscall_count;
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else
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{
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for (int iter : c->syscalls_to_be_caught)
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{
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if (iter >= inf_data->syscalls_counts.size ())
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inf_data->syscalls_counts.resize (iter + 1);
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++inf_data->syscalls_counts[iter];
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}
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}
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return target_set_syscall_catchpoint (inferior_ptid.pid (),
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inf_data->total_syscalls_count != 0,
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inf_data->any_syscall_count,
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inf_data->syscalls_counts);
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}
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/* Implement the "remove" breakpoint_ops method for syscall
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catchpoints. */
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static int
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remove_catch_syscall (struct bp_location *bl, enum remove_bp_reason reason)
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{
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struct syscall_catchpoint *c = (struct syscall_catchpoint *) bl->owner;
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struct inferior *inf = current_inferior ();
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struct catch_syscall_inferior_data *inf_data
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= get_catch_syscall_inferior_data (inf);
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--inf_data->total_syscalls_count;
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if (c->syscalls_to_be_caught.empty ())
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--inf_data->any_syscall_count;
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else
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{
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for (int iter : c->syscalls_to_be_caught)
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{
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if (iter >= inf_data->syscalls_counts.size ())
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/* Shouldn't happen. */
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continue;
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--inf_data->syscalls_counts[iter];
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}
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}
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return target_set_syscall_catchpoint (inferior_ptid.pid (),
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inf_data->total_syscalls_count != 0,
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inf_data->any_syscall_count,
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inf_data->syscalls_counts);
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}
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/* Implement the "breakpoint_hit" breakpoint_ops method for syscall
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catchpoints. */
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static int
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breakpoint_hit_catch_syscall (const struct bp_location *bl,
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const address_space *aspace, CORE_ADDR bp_addr,
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const struct target_waitstatus *ws)
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{
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/* We must check if we are catching specific syscalls in this
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breakpoint. If we are, then we must guarantee that the called
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syscall is the same syscall we are catching. */
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int syscall_number = 0;
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const struct syscall_catchpoint *c
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= (const struct syscall_catchpoint *) bl->owner;
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if (ws->kind != TARGET_WAITKIND_SYSCALL_ENTRY
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&& ws->kind != TARGET_WAITKIND_SYSCALL_RETURN)
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return 0;
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syscall_number = ws->value.syscall_number;
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/* Now, checking if the syscall is the same. */
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if (!c->syscalls_to_be_caught.empty ())
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{
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for (int iter : c->syscalls_to_be_caught)
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if (syscall_number == iter)
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return 1;
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return 0;
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}
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return 1;
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}
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/* Implement the "print_it" breakpoint_ops method for syscall
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catchpoints. */
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static enum print_stop_action
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print_it_catch_syscall (bpstat bs)
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{
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struct ui_out *uiout = current_uiout;
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struct breakpoint *b = bs->breakpoint_at;
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/* These are needed because we want to know in which state a
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syscall is. It can be in the TARGET_WAITKIND_SYSCALL_ENTRY
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or TARGET_WAITKIND_SYSCALL_RETURN, and depending on it we
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must print "called syscall" or "returned from syscall". */
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ptid_t ptid;
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struct target_waitstatus last;
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struct syscall s;
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struct gdbarch *gdbarch = bs->bp_location_at->gdbarch;
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get_last_target_status (&ptid, &last);
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get_syscall_by_number (gdbarch, last.value.syscall_number, &s);
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annotate_catchpoint (b->number);
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maybe_print_thread_hit_breakpoint (uiout);
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if (b->disposition == disp_del)
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uiout->text ("Temporary catchpoint ");
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else
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uiout->text ("Catchpoint ");
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if (uiout->is_mi_like_p ())
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{
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uiout->field_string ("reason",
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async_reason_lookup (last.kind == TARGET_WAITKIND_SYSCALL_ENTRY
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? EXEC_ASYNC_SYSCALL_ENTRY
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: EXEC_ASYNC_SYSCALL_RETURN));
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uiout->field_string ("disp", bpdisp_text (b->disposition));
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}
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uiout->field_int ("bkptno", b->number);
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if (last.kind == TARGET_WAITKIND_SYSCALL_ENTRY)
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uiout->text (" (call to syscall ");
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else
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uiout->text (" (returned from syscall ");
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if (s.name == NULL || uiout->is_mi_like_p ())
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uiout->field_int ("syscall-number", last.value.syscall_number);
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if (s.name != NULL)
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uiout->field_string ("syscall-name", s.name);
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uiout->text ("), ");
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return PRINT_SRC_AND_LOC;
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}
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/* Implement the "print_one" breakpoint_ops method for syscall
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catchpoints. */
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static void
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print_one_catch_syscall (struct breakpoint *b,
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struct bp_location **last_loc)
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{
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struct syscall_catchpoint *c = (struct syscall_catchpoint *) b;
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struct value_print_options opts;
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struct ui_out *uiout = current_uiout;
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struct gdbarch *gdbarch = b->loc->gdbarch;
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get_user_print_options (&opts);
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/* Field 4, the address, is omitted (which makes the columns not
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line up too nicely with the headers, but the effect is relatively
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readable). */
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if (opts.addressprint)
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uiout->field_skip ("addr");
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annotate_field (5);
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if (c->syscalls_to_be_caught.size () > 1)
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uiout->text ("syscalls \"");
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else
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uiout->text ("syscall \"");
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if (!c->syscalls_to_be_caught.empty ())
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{
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char *text = xstrprintf ("%s", "");
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for (int iter : c->syscalls_to_be_caught)
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{
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char *x = text;
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struct syscall s;
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get_syscall_by_number (gdbarch, iter, &s);
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if (s.name != NULL)
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text = xstrprintf ("%s%s, ", text, s.name);
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else
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text = xstrprintf ("%s%d, ", text, iter);
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/* We have to xfree the last 'text' (now stored at 'x')
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because xstrprintf dynamically allocates new space for it
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on every call. */
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xfree (x);
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}
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/* Remove the last comma. */
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text[strlen (text) - 2] = '\0';
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uiout->field_string ("what", text);
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}
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else
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uiout->field_string ("what", "<any syscall>");
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uiout->text ("\" ");
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if (uiout->is_mi_like_p ())
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uiout->field_string ("catch-type", "syscall");
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}
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/* Implement the "print_mention" breakpoint_ops method for syscall
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catchpoints. */
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static void
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print_mention_catch_syscall (struct breakpoint *b)
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{
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struct syscall_catchpoint *c = (struct syscall_catchpoint *) b;
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struct gdbarch *gdbarch = b->loc->gdbarch;
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if (!c->syscalls_to_be_caught.empty ())
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{
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if (c->syscalls_to_be_caught.size () > 1)
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printf_filtered (_("Catchpoint %d (syscalls"), b->number);
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else
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printf_filtered (_("Catchpoint %d (syscall"), b->number);
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for (int iter : c->syscalls_to_be_caught)
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{
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struct syscall s;
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get_syscall_by_number (gdbarch, iter, &s);
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if (s.name != NULL)
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printf_filtered (" '%s' [%d]", s.name, s.number);
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else
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printf_filtered (" %d", s.number);
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}
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printf_filtered (")");
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}
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else
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printf_filtered (_("Catchpoint %d (any syscall)"),
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b->number);
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}
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/* Implement the "print_recreate" breakpoint_ops method for syscall
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catchpoints. */
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static void
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print_recreate_catch_syscall (struct breakpoint *b, struct ui_file *fp)
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{
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struct syscall_catchpoint *c = (struct syscall_catchpoint *) b;
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struct gdbarch *gdbarch = b->loc->gdbarch;
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fprintf_unfiltered (fp, "catch syscall");
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for (int iter : c->syscalls_to_be_caught)
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{
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struct syscall s;
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get_syscall_by_number (gdbarch, iter, &s);
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if (s.name != NULL)
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fprintf_unfiltered (fp, " %s", s.name);
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else
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fprintf_unfiltered (fp, " %d", s.number);
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}
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print_recreate_thread (b, fp);
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}
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/* The breakpoint_ops structure to be used in syscall catchpoints. */
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static struct breakpoint_ops catch_syscall_breakpoint_ops;
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/* Returns non-zero if 'b' is a syscall catchpoint. */
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static int
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syscall_catchpoint_p (struct breakpoint *b)
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{
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return (b->ops == &catch_syscall_breakpoint_ops);
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}
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static void
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create_syscall_event_catchpoint (int tempflag, std::vector<int> &&filter,
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const struct breakpoint_ops *ops)
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{
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struct gdbarch *gdbarch = get_current_arch ();
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std::unique_ptr<syscall_catchpoint> c (new syscall_catchpoint ());
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init_catchpoint (c.get (), gdbarch, tempflag, NULL, ops);
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c->syscalls_to_be_caught = std::move (filter);
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install_breakpoint (0, std::move (c), 1);
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}
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/* Splits the argument using space as delimiter. */
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static std::vector<int>
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catch_syscall_split_args (const char *arg)
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{
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std::vector<int> result;
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struct gdbarch *gdbarch = target_gdbarch ();
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while (*arg != '\0')
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{
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int i, syscall_number;
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char *endptr;
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char cur_name[128];
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struct syscall s;
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/* Skip whitespace. */
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arg = skip_spaces (arg);
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for (i = 0; i < 127 && arg[i] && !isspace (arg[i]); ++i)
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cur_name[i] = arg[i];
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cur_name[i] = '\0';
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arg += i;
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/* Check if the user provided a syscall name, group, or a number. */
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syscall_number = (int) strtol (cur_name, &endptr, 0);
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if (*endptr == '\0')
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{
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get_syscall_by_number (gdbarch, syscall_number, &s);
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result.push_back (s.number);
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}
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else if (startswith (cur_name, "g:")
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|| startswith (cur_name, "group:"))
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{
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/* We have a syscall group. Let's expand it into a syscall
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list before inserting. */
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const char *group_name;
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/* Skip over "g:" and "group:" prefix strings. */
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group_name = strchr (cur_name, ':') + 1;
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if (!get_syscalls_by_group (gdbarch, group_name, &result))
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error (_("Unknown syscall group '%s'."), group_name);
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}
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else
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{
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/* We have a name. Let's check if it's valid and fetch a
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list of matching numbers. */
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if (!get_syscalls_by_name (gdbarch, cur_name, &result))
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/* Here we have to issue an error instead of a warning,
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because GDB cannot do anything useful if there's no
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syscall number to be caught. */
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error (_("Unknown syscall name '%s'."), cur_name);
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}
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}
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return result;
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}
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/* Implement the "catch syscall" command. */
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static void
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catch_syscall_command_1 (const char *arg, int from_tty,
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struct cmd_list_element *command)
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{
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int tempflag;
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std::vector<int> filter;
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struct syscall s;
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struct gdbarch *gdbarch = get_current_arch ();
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/* Checking if the feature if supported. */
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if (gdbarch_get_syscall_number_p (gdbarch) == 0)
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error (_("The feature 'catch syscall' is not supported on \
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this architecture yet."));
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tempflag = get_cmd_context (command) == CATCH_TEMPORARY;
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arg = skip_spaces (arg);
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/* We need to do this first "dummy" translation in order
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to get the syscall XML file loaded or, most important,
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to display a warning to the user if there's no XML file
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for his/her architecture. */
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get_syscall_by_number (gdbarch, 0, &s);
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/* The allowed syntax is:
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catch syscall
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catch syscall <name | number> [<name | number> ... <name | number>]
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Let's check if there's a syscall name. */
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if (arg != NULL)
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filter = catch_syscall_split_args (arg);
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create_syscall_event_catchpoint (tempflag, std::move (filter),
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&catch_syscall_breakpoint_ops);
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}
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/* Returns 0 if 'bp' is NOT a syscall catchpoint,
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non-zero otherwise. */
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static int
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is_syscall_catchpoint_enabled (struct breakpoint *bp)
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{
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if (syscall_catchpoint_p (bp)
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&& bp->enable_state != bp_disabled
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&& bp->enable_state != bp_call_disabled)
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return 1;
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else
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return 0;
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}
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int
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catch_syscall_enabled (void)
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{
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struct catch_syscall_inferior_data *inf_data
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= get_catch_syscall_inferior_data (current_inferior ());
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return inf_data->total_syscalls_count != 0;
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}
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/* Helper function for catching_syscall_number. If B is a syscall
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catchpoint for SYSCALL_NUMBER, return 1 (which will make
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'breakpoint_find_if' return). Otherwise, return 0. */
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static int
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catching_syscall_number_1 (struct breakpoint *b,
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void *data)
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{
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int syscall_number = (int) (uintptr_t) data;
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if (is_syscall_catchpoint_enabled (b))
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{
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struct syscall_catchpoint *c = (struct syscall_catchpoint *) b;
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if (!c->syscalls_to_be_caught.empty ())
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{
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for (int iter : c->syscalls_to_be_caught)
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if (syscall_number == iter)
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return 1;
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}
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else
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return 1;
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}
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return 0;
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}
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int
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catching_syscall_number (int syscall_number)
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{
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struct breakpoint *b = breakpoint_find_if (catching_syscall_number_1,
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(void *) (uintptr_t) syscall_number);
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return b != NULL;
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}
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|
|
|
/* 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_syscall_catchpoint_ops ();
|
|
|
|
gdb::observers::inferior_exit.attach (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, 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);
|
|
}
|