proc.h revision 7ac04edc87e07fc68f94274ba3ff0fb2a0a98958
1/*
2 * This file is part of ltrace.
3 * Copyright (C) 2010,2011,2012,2013 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#include <stdint.h>
30
31#if defined(HAVE_LIBUNWIND)
32# include <libunwind.h>
33#endif /* defined(HAVE_LIBUNWIND) */
34
35#include "ltrace.h"
36#include "dict.h"
37#include "sysdep.h"
38#include "callback.h"
39#include "forward.h"
40
41struct event_handler {
42	/* Event handler that overrides the default one.  Should
43	 * return NULL if the event was handled, otherwise the
44	 * returned event is passed to the default handler.  */
45	Event *(*on_event)(struct event_handler *self, Event *event);
46
47	/* Called when the event handler removal is requested.  */
48	void (*destroy)(struct event_handler *self);
49};
50
51enum process_state {
52	STATE_ATTACHED = 0,
53	STATE_BEING_CREATED,
54	STATE_IGNORED  /* ignore this process (it's a fork and no -f was used) */
55};
56
57struct output_state {
58	size_t params_left;
59	int need_delim;
60};
61
62struct callstack_element {
63	union {
64		int syscall;
65		struct library_symbol * libfunc;
66	} c_un;
67	int is_syscall;
68	void * return_addr;
69	struct timeval time_spent;
70	struct fetch_context *fetch_context;
71	struct value_dict *arguments;
72	struct output_state out;
73};
74
75/* XXX We should get rid of this.  */
76#define MAX_CALLDEPTH 64
77
78/* XXX We would rather have this all organized a little differently,
79 * have struct process for the whole group and struct task (or struct
80 * lwp, struct thread) for what's there for per-thread stuff.  But for
81 * now this is the less invasive way of structuring it.  */
82struct process {
83	enum process_state state;
84	struct process *parent;         /* needed by STATE_BEING_CREATED */
85	char * filename;
86	pid_t pid;
87
88	/* Dictionary of breakpoints (which is a mapping
89	 * address->breakpoint).  This is NULL for non-leader
90	 * processes.  */
91	struct dict *breakpoints;
92
93	int mask_32bit;           /* 1 if 64-bit ltrace is tracing 32-bit process */
94	unsigned int personality;
95	int tracesysgood;         /* signal indicating a PTRACE_SYSCALL trap */
96
97	size_t callstack_depth;
98	struct callstack_element callstack[MAX_CALLDEPTH];
99
100	/* Linked list of libraries in backwards order of mapping.
101	 * The last element is the executed binary itself.  */
102	struct library *libraries;
103
104	/* Arch-dependent: */
105	void * instruction_pointer;
106	void * stack_pointer;      /* To get return addr, args... */
107	void * return_addr;
108	void * arch_ptr;
109
110	/* XXX We would like to replace this with a pointer to ABI
111	 * object that would provide the relevant services, instead of
112	 * checking the necessary flags in the back end ad
113	 * nauseam.  */
114	short e_machine;
115	char e_class;
116
117	/* XXX this shoudl go to ARM's arch_process_data.  */
118#ifdef __arm__
119	int thumb_mode;           /* ARM execution mode: 0: ARM, 1: Thumb */
120#endif
121
122#if defined(HAVE_LIBUNWIND)
123	/* libunwind address space */
124	unw_addr_space_t unwind_as;
125	void *unwind_priv;
126#endif /* defined(HAVE_LIBUNWIND) */
127
128	/* Set in leader.  */
129	struct event_handler *event_handler;
130
131	/**
132	 * Process chaining.
133	 **/
134	struct process *next;
135
136	/* LEADER points to the leader thread of the POSIX.1 process.
137	   If X->LEADER == X, then X is the leader thread and the
138	   process structures chained by NEXT represent other threads,
139	   up until, but not including, the next leader thread.
140	   LEADER may be NULL after the leader has already exited.  In
141	   that case this process is waiting to be collected.  */
142	struct process *leader;
143
144	struct os_process_data os;
145	struct arch_process_data arch;
146};
147
148/* Initialize a process given a path to binary FILENAME, with a PID,
149 * and add the process to an internal chain of traced processes.  */
150int process_init(struct process *proc, const char *filename, pid_t pid);
151
152/* PROC underwent an exec.  This is a bit like process_destroy
153 * followed by process_init, except that some state is kept and the
154 * process doesn't lose it's place in the list of processes.  */
155int process_exec(struct process *proc);
156
157/* Release any memory allocated for PROC (but not PROC itself).  Does
158 * NOT remove PROC from internal chain.
159 *
160 * XXX clearly this init/destroy pair is different than others and
161 * should be fixed.  process_init should presumably be separate from
162 * process_add.  */
163void process_destroy(struct process *proc);
164
165struct process *open_program(const char *filename, pid_t pid);
166void open_pid(pid_t pid);
167struct process *pid2proc(pid_t pid);
168
169/* Clone the contents of PROC into the memory referenced by RETP.
170 * Returns 0 on success or a negative value on failure.  */
171int process_clone(struct process *retp, struct process *proc, pid_t pid);
172
173/* Iterate through the processes that ltrace currently traces.  Tasks
174 * are considered to be processes for the purpose of this iterator.
175 * See callback.h for notes on iteration interfaces.  */
176struct process *each_process(struct process *start_after,
177			     enum callback_status (*cb)(struct process *proc,
178							void *data),
179			     void *data);
180
181/* Iterate through list of tasks of given process PROC.  See
182 * callback.h for notes on iteration interfaces.  */
183struct process *each_task(struct process *proc, struct process *start_after,
184			  enum callback_status (*cb)(struct process *proc,
185						     void *data),
186			  void *data);
187
188void change_process_leader(struct process *proc, struct process *leader);
189
190/* Remove process from the list of traced processes, drop any events
191 * in the event queue, destroy it and free memory.  */
192void remove_process(struct process *proc);
193
194void install_event_handler(struct process *proc, struct event_handler *handler);
195void destroy_event_handler(struct process *proc);
196
197/* Add a library LIB to the list of PROC's libraries.  */
198void proc_add_library(struct process *proc, struct library *lib);
199
200/* Remove LIB from list of PROC's libraries.  Returns 0 if the library
201 * was found and unlinked, otherwise returns a negative value.  */
202int proc_remove_library(struct process *proc, struct library *lib);
203
204/* Clear a delayed flag.  If a symbol is neither latent, nor delayed,
205 * a breakpoint is inserted for it.  Returns 0 if the activation was
206 * successful or a negative value if it failed.  Note that if a symbol
207 * is both latent and delayed, this will not enable the corresponding
208 * breakpoint.  */
209int proc_activate_delayed_symbol(struct process *proc,
210				 struct library_symbol *libsym);
211
212/* Iterate through the libraries of PROC.  See callback.h for notes on
213 * iteration interfaces.  */
214struct library *proc_each_library(struct process *proc,
215				  struct library *start_after,
216				  enum callback_status (*cb)(struct process *p,
217							     struct library *l,
218							     void *data),
219				  void *data);
220
221/* Insert BP into PROC.  */
222int proc_add_breakpoint(struct process *proc, struct breakpoint *bp);
223
224/* Remove BP from PROC.  This has no reason to fail in runtime.  If it
225 * does not find BP in PROC, it's hard error guarded by assertion.  */
226void proc_remove_breakpoint(struct process *proc, struct breakpoint *bp);
227
228/* Iterate through the breakpoints of PROC.  See callback.h for notes
229 * on iteration interfaces.  */
230void *proc_each_breakpoint(struct process *proc, void *start,
231			   enum callback_status (*cb)(struct process *proc,
232						      struct breakpoint *bp,
233						      void *data),
234			   void *data);
235
236/* Iterate through the dynamic section at src_addr looking for D_TAG.
237 * If tag is found, fill it's value in RET and return 0.
238 * If tag is not found, return a negative value.  */
239int proc_find_dynamic_entry_addr(struct process *proc, arch_addr_t src_addr,
240				 int d_tag, arch_addr_t *ret);
241
242/* Finds a symbol corresponding to LIBSYM in a process PROC.  Returns
243 * 0 and sets *RETLIB and *RETSYM if the corresponding pointer is
244 * non-NULL.  Returns a negative value when the symbols couldn't be
245 * found.  */
246int proc_find_symbol(struct process *proc, struct library_symbol *sym,
247		     struct library **retlib, struct library_symbol **retsym);
248
249/* Iterate through all symbols in all libraries of PROC.  See
250 * callback.h for notes on this interface.  */
251struct library_symbol *proc_each_symbol
252	(struct process *proc, struct library_symbol *start_after,
253	 enum callback_status (*cb)(struct library_symbol *, void *),
254	 void *data);
255
256/* Read 16, 32 or 64-bit quantity located at ADDR in PROC.  The
257 * resulting value is stored in *LP.  0 is returned on success or a
258 * negative value on failure.  This uses umovebytes under the hood
259 * (see backend.h).  */
260int proc_read_16(struct process *proc, arch_addr_t addr, uint16_t *lp);
261int proc_read_32(struct process *proc, arch_addr_t addr, uint32_t *lp);
262int proc_read_64(struct process *proc, arch_addr_t addr, uint64_t *lp);
263
264#endif /* _PROC_H_ */
265