breakpoint.h revision 622581f4db4ae4ef8932984a4d1c4935ca7f61ef
1/* 2 * This file is part of ltrace. 3 * Copyright (C) 2012 Petr Machata, Red Hat Inc. 4 * Copyright (C) 2009 Juan Cespedes 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of the 9 * License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, but 12 * WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 19 * 02110-1301 USA 20 */ 21 22#ifndef BREAKPOINT_H 23#define BREAKPOINT_H 24 25/* XXX This is currently a very weak abstraction. We would like to 26 * much expand this to allow things like breakpoints on SDT probes and 27 * such. 28 * 29 * In particular, we would like to add a tracepoint abstraction. 30 * Tracepoint is a traceable feature--e.g. an exact address, a DWARF 31 * symbol, an ELF symbol, a PLT entry, or an SDT probe. Tracepoints 32 * are named and the user can configure which of them he wants to 33 * enable. Realized tracepoints enable breakpoints, which are a 34 * low-level realization of high-level tracepoint. 35 * 36 * Service breakpoints like the handling of dlopen would be a 37 * low-level breakpoint, likely without tracepoint attached. 38 * 39 * So that's for sometimes. 40 */ 41 42#include "sysdep.h" 43#include "library.h" 44 45struct Process; 46struct breakpoint; 47 48struct bp_callbacks { 49 void (*on_hit)(struct breakpoint *bp, struct Process *proc); 50 void (*on_continue)(struct breakpoint *bp, struct Process *proc); 51}; 52 53struct breakpoint { 54 struct bp_callbacks *cbs; 55 struct library_symbol *libsym; 56 void *addr; 57 unsigned char orig_value[BREAKPOINT_LENGTH]; 58 int enabled; 59 struct arch_breakpoint_data arch; 60}; 61 62/* Call on-hit handler of BP, if any is set. */ 63void breakpoint_on_hit(struct breakpoint *bp, struct Process *proc); 64 65/* Call on-continue handler of BP. If none is set, call 66 * continue_after_breakpoint. */ 67void breakpoint_on_continue(struct breakpoint *bp, struct Process *proc); 68 69/* Initialize a breakpoint structure. That doesn't actually realize 70 * the breakpoint. The breakpoint is initially assumed to be 71 * disabled. orig_value has to be set separately. CBS may be 72 * NULL. */ 73int breakpoint_init(struct breakpoint *bp, struct Process *proc, 74 target_address_t addr, struct library_symbol *libsym); 75 76/* Make a clone of breakpoint BP into the area of memory pointed to by 77 * RETP. The original breakpoint was assigned to process OLD_PROC, 78 * the cloned breakpoint will be attached to process NEW_PROC. 79 * Returns 0 on success or a negative value on failure. */ 80int breakpoint_clone(struct breakpoint *retp, struct Process *new_proc, 81 struct breakpoint *bp, struct Process *old_proc); 82 83/* Set callbacks. If CBS is non-NULL, then BP->cbs shall be NULL. */ 84void breakpoint_set_callbacks(struct breakpoint *bp, struct bp_callbacks *cbs); 85 86/* Destroy a breakpoint structure. */ 87void breakpoint_destroy(struct breakpoint *bp); 88 89/* Call enable_breakpoint the first time it's called. Returns 0 on 90 * success and a negative value on failure. */ 91int breakpoint_turn_on(struct breakpoint *bp, struct Process *proc); 92 93/* Call disable_breakpoint when turned off the same number of times 94 * that it was turned on. Returns 0 on success and a negative value 95 * on failure. */ 96int breakpoint_turn_off(struct breakpoint *bp, struct Process *proc); 97 98/* Utility function that does what typically needs to be done when a 99 * breakpoint is to be inserted. It checks whether there is another 100 * breakpoint in PROC->LEADER for given ADDR. If not, it allocates 101 * memory for a new breakpoint on the heap, initializes it, and calls 102 * PROC_ADD_BREAKPOINT to add the newly-created breakpoint. For newly 103 * added as well as preexisting breakpoints, it then calls 104 * BREAKPOINT_TURN_ON. If anything fails, it cleans up and returns 105 * NULL. Otherwise it returns the breakpoint for ADDR. */ 106struct breakpoint *insert_breakpoint(struct Process *proc, void *addr, 107 struct library_symbol *libsym); 108 109/* Name of a symbol associated with BP. May be NULL. */ 110const char *breakpoint_name(const struct breakpoint *bp); 111 112/* A library that this breakpoint comes from. May be NULL. */ 113struct library *breakpoint_library(const struct breakpoint *bp); 114 115/* Again, this seems to be several interfaces rolled into one: 116 * - breakpoint_disable 117 * - proc_remove_breakpoint 118 * - breakpoint_destroy 119 * XXX */ 120void delete_breakpoint(struct Process *proc, void *addr); 121 122/* XXX some of the following belongs to proc.h/proc.c. */ 123struct breakpoint *address2bpstruct(struct Process *proc, void *addr); 124void enable_all_breakpoints(struct Process *proc); 125void disable_all_breakpoints(struct Process *proc); 126int breakpoints_init(struct Process *proc); 127 128#endif /* BREAKPOINT_H */ 129