Imported Upstream version 0.7.2upstream/0.7.2

1 files changed, 138 insertions, 0 deletions

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+/*
+ * This file is part of ltrace.
+ * Copyright (C) 2012 Petr Machata, Red Hat Inc.
+ * Copyright (C) 2009 Juan Cespedes
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef BREAKPOINT_H
+#define BREAKPOINT_H
+
+/* XXX This is currently a very weak abstraction.  We would like to
+ * much expand this to allow things like breakpoints on SDT probes and
+ * such.
+ *
+ * In particular, we would like to add a tracepoint abstraction.
+ * Tracepoint is a traceable feature--e.g. an exact address, a DWARF
+ * symbol, an ELF symbol, a PLT entry, or an SDT probe.  Tracepoints
+ * are named and the user can configure which of them he wants to
+ * enable.  Realized tracepoints enable breakpoints, which are a
+ * low-level realization of high-level tracepoint.
+ *
+ * Service breakpoints like the handling of dlopen would be a
+ * low-level breakpoint, likely without tracepoint attached.
+ *
+ * So that's for sometimes.
+ */
+
+#include "sysdep.h"
+#include "library.h"
+
+struct Process;
+struct breakpoint;
+
+struct bp_callbacks {
+	void (*on_hit)(struct breakpoint *bp, struct Process *proc);
+	void (*on_continue)(struct breakpoint *bp, struct Process *proc);
+	void (*on_retract)(struct breakpoint *bp, struct Process *proc);
+};
+
+struct breakpoint {
+	struct bp_callbacks *cbs;
+	struct library_symbol *libsym;
+	void *addr;
+	unsigned char orig_value[BREAKPOINT_LENGTH];
+	int enabled;
+	struct arch_breakpoint_data arch;
+};
+
+/* Call on-hit handler of BP, if any is set.  */
+void breakpoint_on_hit(struct breakpoint *bp, struct Process *proc);
+
+/* Call on-continue handler of BP.  If none is set, call
+ * continue_after_breakpoint.  */
+void breakpoint_on_continue(struct breakpoint *bp, struct Process *proc);
+
+/* Call on-retract handler of BP, if any is set.  This should be
+ * called before the breakpoints are destroyed.  The reason for a
+ * separate interface is that breakpoint_destroy has to be callable
+ * without PROC.  ON_DISABLE might be useful as well, but that would
+ * be called every time we disable the breakpoint, which is too often
+ * (a breakpoint has to be disabled every time that we need to execute
+ * the instruction underneath it).  */
+void breakpoint_on_retract(struct breakpoint *bp, struct Process *proc);
+
+/* Initialize a breakpoint structure.  That doesn't actually realize
+ * the breakpoint.  The breakpoint is initially assumed to be
+ * disabled.  orig_value has to be set separately.  CBS may be
+ * NULL.  */
+int breakpoint_init(struct breakpoint *bp, struct Process *proc,
+		    arch_addr_t addr, struct library_symbol *libsym);
+
+/* Make a clone of breakpoint BP into the area of memory pointed to by
+ * RETP.  The original breakpoint was assigned to process OLD_PROC,
+ * the cloned breakpoint will be attached to process NEW_PROC.
+ * Returns 0 on success or a negative value on failure.  */
+int breakpoint_clone(struct breakpoint *retp, struct Process *new_proc,
+		     struct breakpoint *bp, struct Process *old_proc);
+
+/* Set callbacks.  If CBS is non-NULL, then BP->cbs shall be NULL.  */
+void breakpoint_set_callbacks(struct breakpoint *bp, struct bp_callbacks *cbs);
+
+/* Destroy a breakpoint structure.   */
+void breakpoint_destroy(struct breakpoint *bp);
+
+/* Call enable_breakpoint the first time it's called.  Returns 0 on
+ * success and a negative value on failure.  */
+int breakpoint_turn_on(struct breakpoint *bp, struct Process *proc);
+
+/* Call disable_breakpoint when turned off the same number of times
+ * that it was turned on.  Returns 0 on success and a negative value
+ * on failure.  */
+int breakpoint_turn_off(struct breakpoint *bp, struct Process *proc);
+
+/* Utility function that does what typically needs to be done when a
+ * breakpoint is to be inserted.  It checks whether there is another
+ * breakpoint in PROC->LEADER for given ADDR.  If not, it allocates
+ * memory for a new breakpoint on the heap, initializes it, and calls
+ * PROC_ADD_BREAKPOINT to add the newly-created breakpoint.  For newly
+ * added as well as preexisting breakpoints, it then calls
+ * BREAKPOINT_TURN_ON.  If anything fails, it cleans up and returns
+ * NULL.  Otherwise it returns the breakpoint for ADDR.  */
+struct breakpoint *insert_breakpoint(struct Process *proc, void *addr,
+				     struct library_symbol *libsym);
+
+/* Name of a symbol associated with BP.  May be NULL.  */
+const char *breakpoint_name(const struct breakpoint *bp);
+
+/* A library that this breakpoint comes from.  May be NULL.  */
+struct library *breakpoint_library(const struct breakpoint *bp);
+
+/* Again, this seems to be several interfaces rolled into one:
+ *  - breakpoint_disable
+ *  - proc_remove_breakpoint
+ *  - breakpoint_destroy
+ * XXX */
+void delete_breakpoint(struct Process *proc, void *addr);
+
+/* XXX some of the following belongs to proc.h/proc.c.  */
+struct breakpoint *address2bpstruct(struct Process *proc, void *addr);
+void enable_all_breakpoints(struct Process *proc);
+void disable_all_breakpoints(struct Process *proc);
+int breakpoints_init(struct Process *proc);
+
+#endif /* BREAKPOINT_H */