proc.h revision 165b566a50b2bd560af3bd9649e456915397066b
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#include "config.h"
27
28#include <sys/time.h>
29
30#if defined(HAVE_LIBUNWIND)
31# include <libunwind.h>
32#endif /* defined(HAVE_LIBUNWIND) */
33
34#include "ltrace.h"
35#include "dict.h"
36#include "sysdep.h"
37#include "callback.h"
38
39struct library;
40struct breakpoint;
41
42struct event_handler {
43	/* Event handler that overrides the default one.  Should
44	 * return NULL if the event was handled, otherwise the
45	 * returned event is passed to the default handler.  */
46	Event *(*on_event)(struct event_handler *self, Event *event);
47
48	/* Called when the event handler removal is requested.  */
49	void (*destroy)(struct event_handler *self);
50};
51
52enum process_state {
53	STATE_ATTACHED = 0,
54	STATE_BEING_CREATED,
55	STATE_IGNORED  /* ignore this process (it's a fork and no -f was used) */
56};
57
58struct output_state {
59	size_t params_left;
60	int need_delim;
61};
62
63struct callstack_element {
64	union {
65		int syscall;
66		struct library_symbol * libfunc;
67	} c_un;
68	int is_syscall;
69	void * return_addr;
70	struct timeval time_spent;
71	struct fetch_context *fetch_context;
72	struct value_dict *arguments;
73	struct output_state out;
74};
75
76/* XXX We should get rid of this.  */
77#define MAX_CALLDEPTH 64
78
79/* XXX We would rather have this all organized a little differently,
80 * have Process for the whole group and Task for what's there for
81 * per-thread stuff.  But for now this is the less invasive way of
82 * structuring it.  */
83typedef struct Process Process;
84struct Process {
85	enum process_state state;
86	Process * parent;         /* needed by STATE_BEING_CREATED */
87	char * filename;
88	pid_t pid;
89
90	/* Dictionary of breakpoints (which is a mapping
91	 * address->breakpoint).  This is NULL for non-leader
92	 * processes.  XXX note that we store addresses (keys) by
93	 * value.  That assumes that arch_addr_t fits in host
94	 * pointer.  */
95	Dict * breakpoints;
96
97	int mask_32bit;           /* 1 if 64-bit ltrace is tracing 32-bit process */
98	unsigned int personality;
99	int tracesysgood;         /* signal indicating a PTRACE_SYSCALL trap */
100
101	size_t callstack_depth;
102	struct callstack_element callstack[MAX_CALLDEPTH];
103
104	/* Linked list of libraries in backwards order of mapping.
105	 * The last element is the executed binary itself.  */
106	struct library *libraries;
107
108	/* Arch-dependent: */
109	void * instruction_pointer;
110	void * stack_pointer;      /* To get return addr, args... */
111	void * return_addr;
112	void * arch_ptr;
113
114	/* XXX We would like to replace this with a pointer to ABI
115	 * object that would provide the relevant services, instead of
116	 * checking the necessary flags in the back end ad
117	 * nauseam.  */
118	short e_machine;
119	char e_class;
120
121	/* XXX this shoudl go to ARM's arch_process_data.  */
122#ifdef __arm__
123	int thumb_mode;           /* ARM execution mode: 0: ARM, 1: Thumb */
124#endif
125
126#if defined(HAVE_LIBUNWIND)
127	/* libunwind address space */
128	unw_addr_space_t unwind_as;
129	void *unwind_priv;
130#endif /* defined(HAVE_LIBUNWIND) */
131
132	/* Set in leader.  */
133	struct event_handler *event_handler;
134
135	/**
136	 * Process chaining.
137	 **/
138	Process * next;
139
140	/* LEADER points to the leader thread of the POSIX.1 process.
141	   If X->LEADER == X, then X is the leader thread and the
142	   Process structures chained by NEXT represent other threads,
143	   up until, but not including, the next leader thread.
144	   LEADER may be NULL after the leader has already exited.  In
145	   that case this process is waiting to be collected.  */
146	Process * leader;
147
148	struct os_process_data os;
149	struct arch_process_data arch;
150};
151
152/* Initialize a process given a path to binary FILENAME, with a PID,
153 * and add the process to an internal chain of traced processes.  */
154int process_init(struct Process *proc, const char *filename, pid_t pid);
155
156/* PROC underwent an exec.  This is a bit like process_destroy
157 * followed by process_init, except that some state is kept and the
158 * process doesn't lose it's place in the list of processes.  */
159int process_exec(struct Process *proc);
160
161/* Release any memory allocated for PROC (but not PROC itself).  Does
162 * NOT remove PROC from internal chain.
163 *
164 * XXX clearly this init/destroy pair is different than others and
165 * should be fixed.  process_init should presumably be separate from
166 * process_add.  */
167void process_destroy(struct Process *proc);
168
169struct Process *open_program(const char *filename, pid_t pid);
170void open_pid(pid_t pid);
171Process * pid2proc(pid_t pid);
172
173/* Clone the contents of PROC into the memory referenced by RETP.
174 * Returns 0 on success or a negative value on failure.  */
175int process_clone(struct Process *retp, struct Process *proc, pid_t pid);
176
177/* Iterate through the processes that ltrace currently traces.  Tasks
178 * are considered to be processes for the purpose of this iterator.
179 * See callback.h for notes on iteration interfaces.  */
180Process *each_process(Process *start_after,
181		      enum callback_status (*cb)(struct Process *proc,
182						 void *data),
183		      void *data);
184
185/* Iterate through list of tasks of given process PROC.  See
186 * callback.h for notes on iteration interfaces.  */
187Process *each_task(struct Process *proc, struct Process *start_after,
188		   enum callback_status (*cb)(struct Process *proc,
189					      void *data),
190		   void *data);
191
192void change_process_leader(Process *proc, Process *leader);
193
194/* Remove process from the list of traced processes, drop any events
195 * in the event queue, destroy it and free memory.  */
196void remove_process(struct Process *proc);
197
198void install_event_handler(Process *proc, struct event_handler *handler);
199void destroy_event_handler(Process *proc);
200
201/* Add a library LIB to the list of PROC's libraries.  */
202void proc_add_library(struct Process *proc, struct library *lib);
203
204/* Remove LIB from list of PROC's libraries.  Returns 0 if the library
205 * was found and unlinked, otherwise returns a negative value.  */
206int proc_remove_library(struct Process *proc, struct library *lib);
207
208/* Clear a delayed flag.  If a symbol is neither latent, nor delayed,
209 * a breakpoint is inserted for it.  Returns 0 if the activation was
210 * successful or a negative value if it failed.  Note that if a symbol
211 * is both latent and delayed, this will not enable the corresponding
212 * breakpoint.  */
213int proc_activate_delayed_symbol(struct Process *proc,
214				 struct library_symbol *libsym);
215
216/* Iterate through the libraries of PROC.  See callback.h for notes on
217 * iteration interfaces.  */
218struct library *proc_each_library(struct Process *proc, struct library *start,
219				  enum callback_status (*cb)(struct Process *p,
220							     struct library *l,
221							     void *data),
222				  void *data);
223
224/* Insert BP into PROC.  */
225int proc_add_breakpoint(struct Process *proc, struct breakpoint *bp);
226
227/* Remove BP from PROC.  This has no reason to fail in runtime.  If it
228 * does not find BP in PROC, it's hard error guarded by assertion.  */
229void proc_remove_breakpoint(struct Process *proc, struct breakpoint *bp);
230
231/* Iterate through the breakpoints of PROC.  See callback.h for notes
232 * on iteration interfaces.  */
233void *proc_each_breakpoint(struct Process *proc, void *start,
234			   enum callback_status (*cb)(struct Process *proc,
235						      struct breakpoint *bp,
236						      void *data),
237			   void *data);
238
239/* Iterate through the dynamic section at src_addr looking for D_TAG.
240 * If tag is found, fill it's value in RET and return 0.
241 * If tag is not found, return a negative value.  */
242int proc_find_dynamic_entry_addr(struct Process *proc, arch_addr_t src_addr,
243				 int d_tag, arch_addr_t *ret);
244
245/* Finds a symbol corresponding to LIBSYM in a process PROC.  Returns
246 * 0 and sets *RETLIB and *RETSYM if the corresponding pointer is
247 * non-NULL.  Returns a negative value when the symbols couldn't be
248 * found.  */
249int proc_find_symbol(struct Process *proc, struct library_symbol *sym,
250		     struct library **retlib, struct library_symbol **retsym);
251
252#endif /* _PROC_H_ */
253