proc.h revision ef7fa37f2d0b949b5afb1f326187e4f023d86c25 
1/*
2 * This file is part of ltrace.
3 * Copyright (C) 2010,2011,2012 Petr Machata, Red Hat Inc.
4 * Copyright (C) 2010 Joe Damato
5 * Copyright (C) 1998,2001,2008,2009 Juan Cespedes
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of the
10 * License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA
21 */
22
23#ifndef _PROC_H_
24#define _PROC_H_
25
26#if defined(HAVE_LIBUNWIND)
27# include <libunwind.h>
28#endif /* defined(HAVE_LIBUNWIND) */
29
30#include "ltrace.h"
31#include "dict.h"
32
33struct library;
34
35/* XXX Move this somewhere where it makes sense.  When the mess in
36 * common.h is disentangled, that would actually be a good place for
37 * this.  */
38enum callback_status {
39	CBS_STOP, /* The iteration should stop.  */
40	CBS_CONT, /* The iteration should continue.  */
41	CBS_FAIL, /* There was an error.  The iteration should stop
42		   * and return error.  */
43};
44
45struct event_handler {
46	/* Event handler that overrides the default one.  Should
47	 * return NULL if the event was handled, otherwise the
48	 * returned event is passed to the default handler.  */
49	Event *(*on_event)(struct event_handler *self, Event *event);
50
51	/* Called when the event handler removal is requested.  */
52	void (*destroy)(struct event_handler *self);
53};
54
55enum process_state {
56	STATE_ATTACHED = 0,
57	STATE_BEING_CREATED,
58	STATE_IGNORED  /* ignore this process (it's a fork and no -f was used) */
59};
60
61struct callstack_element {
62	union {
63		int syscall;
64		struct library_symbol * libfunc;
65	} c_un;
66	int is_syscall;
67	void * return_addr;
68	struct timeval time_spent;
69	void * arch_ptr;
70};
71
72/* XXX We should get rid of this.  */
73#define MAX_CALLDEPTH 64
74
75/* XXX We would rather have this all organized a little differently,
76 * have Process for the whole group and Task for what's there for
77 * per-thread stuff.  But for now this is the less invasive way of
78 * structuring it.  */
79typedef struct Process Process;
80struct Process {
81	enum process_state state;
82	Process * parent;         /* needed by STATE_BEING_CREATED */
83	char * filename;
84	pid_t pid;
85
86	/* Dictionary of breakpoints (which is a mapping
87	 * address->breakpoint).  This is NULL for non-leader
88	 * processes.  */
89	Dict * breakpoints;
90
91	int mask_32bit;           /* 1 if 64-bit ltrace is tracing 32-bit process */
92	unsigned int personality;
93	int tracesysgood;         /* signal indicating a PTRACE_SYSCALL trap */
94
95	int callstack_depth;
96	struct callstack_element callstack[MAX_CALLDEPTH];
97	struct library *libraries;
98
99	/* Arch-dependent: */
100	void * debug;	/* arch-dep process debug struct */
101	long debug_state; /* arch-dep debug state */
102	void * instruction_pointer;
103	void * stack_pointer;      /* To get return addr, args... */
104	void * return_addr;
105	void * arch_ptr;
106	short e_machine;
107#ifdef __arm__
108	int thumb_mode;           /* ARM execution mode: 0: ARM, 1: Thumb */
109#endif
110
111#if defined(HAVE_LIBUNWIND)
112	/* libunwind address space */
113	unw_addr_space_t unwind_as;
114	void *unwind_priv;
115#endif /* defined(HAVE_LIBUNWIND) */
116
117	/* Set in leader.  */
118	struct event_handler *event_handler;
119
120	/**
121	 * Process chaining.
122	 **/
123	Process * next;
124
125	/* LEADER points to the leader thread of the POSIX.1 process.
126	   If X->LEADER == X, then X is the leader thread and the
127	   Process structures chained by NEXT represent other threads,
128	   up until, but not including, the next leader thread.
129	   LEADER may be NULL after the leader has already exited.  In
130	   that case this process is waiting to be collected.  */
131	Process * leader;
132};
133
134int process_init(struct Process *proc,
135		 const char *filename, pid_t pid, int enable_breakpoints);
136
137Process * open_program(const char *filename, pid_t pid, int enable_breakpoints);
138void open_pid(pid_t pid);
139Process * pid2proc(pid_t pid);
140
141/* Clone the contents of PROC into the memory referenced by RETP.
142 * Returns 0 on success or a negative value on failure.  */
143int process_clone(struct Process *retp, struct Process *proc, pid_t pid);
144
145/* Iterate through the processes that ltrace currently traces.  CB is
146 * called for each process.  Tasks are considered to be processes for
147 * the purpose of this iterator.
148 *
149 * Notes on this iteration interface: The iteration starts after the
150 * process designated by START_AFTER, or at the first process if
151 * START_AFTER is NULL.  DATA is passed verbatim to CB.  If CB returns
152 * CBS_STOP, the iteration stops and the current iterator is returned.
153 * That iterator can then be used to restart the iteration.  NULL is
154 * returned when iteration ends.
155 *
156 * There's no provision for returning error states.  Errors need to be
157 * signaled to the caller via DATA, together with any other data that
158 * the callback needs.  */
159Process *each_process(Process *start_after,
160		      enum callback_status (*cb)(struct Process *proc,
161						 void *data),
162		      void *data);
163
164/* Iterate through list of tasks of given process PROC.  Restarts are
165 * supported via START_AFTER (see each_process for details of
166 * iteration interface).  */
167Process *each_task(struct Process *proc, struct Process *start_after,
168		   enum callback_status (*cb)(struct Process *proc,
169					      void *data),
170		   void *data);
171
172void add_process(Process *proc);
173void change_process_leader(Process *proc, Process *leader);
174void remove_process(Process *proc);
175void install_event_handler(Process *proc, struct event_handler *handler);
176void destroy_event_handler(Process *proc);
177
178/* Add a library LIB to the list of PROC's libraries.  */
179void proc_add_library(struct Process *proc, struct library *lib);
180
181/* Remove LIB from list of PROC's libraries.  Returns 0 if the library
182 * was found and unlinked, otherwise returns a negative value.  */
183int proc_remove_library(struct Process *proc, struct library *lib);
184
185/* Iterate through the libraries of PROC.  See each_process for
186 * detailed description of the iteration interface.  */
187struct library *proc_each_library(struct Process *proc, struct library *start,
188				  enum callback_status (*cb)(struct Process *p,
189							     struct library *l,
190							     void *data),
191				  void *data);
192
193
194#endif /* _PROC_H_ */
195