breakpoints.c revision f728123bd75a65a6a1536e198c3c30719e494e71 
1#if HAVE_CONFIG_H
2#include "config.h"
3#endif
4
5#include <stdlib.h>
6#include <string.h>
7#include <assert.h>
8
9#ifdef __powerpc__
10#include <sys/ptrace.h>
11#endif
12
13#include "common.h"
14#include "options.h"
15#include "debug.h"
16#include "dict.h"
17#include "elf.h"
18
19/*****************************************************************************/
20
21Breakpoint *
22address2bpstruct(Process *proc, void *addr) {
23	debug(DEBUG_FUNCTION, "address2bpstruct(pid=%d, addr=%p)", proc->pid, addr);
24	return dict_find_entry(proc->breakpoints, addr);
25}
26
27void
28insert_breakpoint(Process *proc, void *addr,
29		  struct library_symbol *libsym) {
30	Breakpoint *sbp;
31
32	debug(DEBUG_FUNCTION, "insert_breakpoint(pid=%d, addr=%p, symbol=%s)", proc->pid, addr, libsym ? libsym->name : "NULL");
33	debug(1, "symbol=%s, addr=%p", libsym?libsym->name:"(nil)", addr);
34
35	if (!addr)
36		return;
37
38	if (libsym)
39		libsym->needs_init = 0;
40
41	sbp = dict_find_entry(proc->breakpoints, addr);
42	if (!sbp) {
43		sbp = calloc(1, sizeof(Breakpoint));
44		if (!sbp) {
45			return;	/* TODO FIXME XXX: error_mem */
46		}
47		dict_enter(proc->breakpoints, addr, sbp);
48		sbp->addr = addr;
49		sbp->libsym = libsym;
50	}
51#ifdef __arm__
52	sbp->thumb_mode = proc->thumb_mode;
53	proc->thumb_mode = 0;
54#endif
55	sbp->enabled++;
56	if (sbp->enabled == 1 && proc->pid)
57		enable_breakpoint(proc->pid, sbp);
58}
59
60void
61delete_breakpoint(Process *proc, void *addr) {
62	Breakpoint *sbp;
63
64	debug(DEBUG_FUNCTION, "delete_breakpoint(pid=%d, addr=%p)", proc->pid, addr);
65
66	sbp = dict_find_entry(proc->breakpoints, addr);
67	assert(sbp);		/* FIXME: remove after debugging has been done. */
68	/* This should only happen on out-of-memory conditions. */
69	if (sbp == NULL)
70		return;
71
72	sbp->enabled--;
73	if (sbp->enabled == 0)
74		disable_breakpoint(proc->pid, sbp);
75	assert(sbp->enabled >= 0);
76}
77
78static void
79enable_bp_cb(void *addr, void *sbp, void *proc) {
80	debug(DEBUG_FUNCTION, "enable_bp_cb(pid=%d)", ((Process *)proc)->pid);
81	if (((Breakpoint *)sbp)->enabled) {
82		enable_breakpoint(((Process *)proc)->pid, sbp);
83	}
84}
85
86void
87enable_all_breakpoints(Process *proc) {
88	debug(DEBUG_FUNCTION, "enable_all_breakpoints(pid=%d)", proc->pid);
89	if (proc->breakpoints_enabled <= 0) {
90#ifdef __powerpc__
91		unsigned long a;
92
93		/*
94		 * PPC HACK! (XXX FIXME TODO)
95		 * If the dynamic linker hasn't populated the PLT then
96		 * dont enable the breakpoints
97		 */
98		if (options.libcalls) {
99			a = ptrace(PTRACE_PEEKTEXT, proc->pid,
100				   sym2addr(proc, proc->list_of_symbols),
101				   0);
102			if (a == 0x0)
103				return;
104		}
105#endif
106
107		debug(1, "Enabling breakpoints for pid %u...", proc->pid);
108		if (proc->breakpoints) {
109			dict_apply_to_all(proc->breakpoints, enable_bp_cb,
110					  proc);
111		}
112#ifdef __mips__
113		{
114			/*
115			 * I'm sure there is a nicer way to do this. We need to
116			 * insert breakpoints _after_ the child has been started.
117			 */
118			struct library_symbol *sym;
119			struct library_symbol *new_sym;
120			sym=proc->list_of_symbols;
121			while(sym){
122				void *addr= sym2addr(proc,sym);
123				if(!addr){
124					sym=sym->next;
125					continue;
126				}
127				if(dict_find_entry(proc->breakpoints,addr)){
128					sym=sym->next;
129					continue;
130				}
131				debug(2,"inserting bp %p %s",addr,sym->name);
132				new_sym=malloc(sizeof(*new_sym));
133				memcpy(new_sym,sym,sizeof(*new_sym));
134				new_sym->next=proc->list_of_symbols;
135				proc->list_of_symbols=new_sym;
136				insert_breakpoint(proc, addr, new_sym);
137				sym=sym->next;
138			}
139		}
140#endif
141	}
142	proc->breakpoints_enabled = 1;
143}
144
145static void
146disable_bp_cb(void *addr, void *sbp, void *proc) {
147	debug(DEBUG_FUNCTION, "disable_bp_cb(pid=%d)", ((Process *)proc)->pid);
148	if (((Breakpoint *)sbp)->enabled) {
149		disable_breakpoint(((Process *)proc)->pid, sbp);
150	}
151}
152
153void
154disable_all_breakpoints(Process *proc) {
155	debug(DEBUG_FUNCTION, "disable_all_breakpoints(pid=%d)", proc->pid);
156	if (proc->breakpoints_enabled) {
157		debug(1, "Disabling breakpoints for pid %u...", proc->pid);
158		dict_apply_to_all(proc->breakpoints, disable_bp_cb, proc);
159	}
160	proc->breakpoints_enabled = 0;
161}
162
163static void
164free_bp_cb(void *addr, void *sbp, void *data) {
165	debug(DEBUG_FUNCTION, "free_bp_cb(sbp=%p)", sbp);
166	assert(sbp);
167	free(sbp);
168}
169
170void
171breakpoints_init(Process *proc) {
172	struct library_symbol *sym;
173
174	debug(DEBUG_FUNCTION, "breakpoints_init(pid=%d)", proc->pid);
175	if (proc->breakpoints) {	/* let's remove that struct */
176		dict_apply_to_all(proc->breakpoints, free_bp_cb, NULL);
177		dict_clear(proc->breakpoints);
178		proc->breakpoints = NULL;
179	}
180	proc->breakpoints = dict_init(dict_key2hash_int, dict_key_cmp_int);
181
182	if (options.libcalls && proc->filename) {
183		/* FIXME: memory leak when called by exec(): */
184		proc->list_of_symbols = read_elf(proc);
185		if (opt_e) {
186			struct library_symbol **tmp1 = &(proc->list_of_symbols);
187			while (*tmp1) {
188				struct opt_e_t *tmp2 = opt_e;
189				int keep = !opt_e_enable;
190
191				while (tmp2) {
192					if (!strcmp((*tmp1)->name, tmp2->name)) {
193						keep = opt_e_enable;
194					}
195					tmp2 = tmp2->next;
196				}
197				if (!keep) {
198					*tmp1 = (*tmp1)->next;
199				} else {
200					tmp1 = &((*tmp1)->next);
201				}
202			}
203		}
204	} else {
205		proc->list_of_symbols = NULL;
206	}
207	for (sym = proc->list_of_symbols; sym; sym = sym->next) {
208		/* proc->pid==0 delays enabling. */
209		insert_breakpoint(proc, sym2addr(proc, sym), sym);
210	}
211	proc->callstack_depth = 0;
212	proc->breakpoints_enabled = -1;
213}
214
215void
216reinitialize_breakpoints(Process *proc) {
217	struct library_symbol *sym;
218
219	debug(DEBUG_FUNCTION, "reinitialize_breakpoints(pid=%d)", proc->pid);
220
221	sym = proc->list_of_symbols;
222
223	while (sym) {
224		if (sym->needs_init) {
225			insert_breakpoint(proc, sym2addr(proc, sym),
226					  sym);
227			if (sym->needs_init && !sym->is_weak) {
228				fprintf(stderr,
229					"could not re-initialize breakpoint for \"%s\" in file \"%s\"\n",
230					sym->name, proc->filename);
231				exit(1);
232			}
233		}
234		sym = sym->next;
235	}
236}
237