1 /*
2 * Copyright 2006 The Android Open Source Project
3 */
4
5 #include <dirent.h>
6 #include <sys/ptrace.h>
7 #include <stdint.h>
8 #include <thread_db.h>
9 #include <stdlib.h>
10 #include <stdio.h>
11
12 extern int ps_pglobal_lookup (void *, const char *obj, const char *name, void **sym_addr);
13 extern pid_t ps_getpid(struct ps_prochandle *ph);
14
15 /*
16 * This is the list of "special" symbols we care about whose addresses are
17 * cached by gdbserver from the host at init time.
18 */
19 enum {
20 SYM_TD_CREATE,
21 SYM_THREAD_LIST,
22 NUM_SYMS
23 };
24
25 static char const * gSymbols[] = {
26 [SYM_TD_CREATE] = "_thread_created_hook",
27 NULL
28 };
29
30
31 char const **
td_symbol_list(void)32 td_symbol_list(void)
33 {
34 return gSymbols;
35 }
36
37
38 td_err_e
td_ta_new(struct ps_prochandle * proc_handle,td_thragent_t ** agent_out)39 td_ta_new(struct ps_prochandle * proc_handle, td_thragent_t ** agent_out)
40 {
41 td_thragent_t * agent;
42
43 agent = (td_thragent_t *)malloc(sizeof(td_thragent_t));
44 if (!agent) {
45 return TD_MALLOC;
46 }
47
48 agent->pid = ps_getpid(proc_handle);
49 agent->ph = proc_handle;
50 *agent_out = agent;
51
52 return TD_OK;
53 }
54
55
56 td_err_e
td_ta_delete(td_thragent_t * ta)57 td_ta_delete(td_thragent_t * ta)
58 {
59 free(ta);
60 // FIXME: anything else to do?
61 return TD_OK;
62 }
63
64
65 /* NOTE: not used by gdb 7.0 */
66
67 td_err_e
td_ta_set_event(td_thragent_t const * agent,td_thr_events_t * events)68 td_ta_set_event(td_thragent_t const * agent, td_thr_events_t * events)
69 {
70 return TD_OK;
71 }
72
73
74 /* NOTE: not used by gdb 7.0 */
75 static td_thrhandle_t gEventMsgHandle;
76
77 /* NOTE: not used by gdb 7.0 */
78
79 static int
_event_getmsg_helper(td_thrhandle_t const * handle,void * bkpt_addr)80 _event_getmsg_helper(td_thrhandle_t const * handle, void * bkpt_addr)
81 {
82 void * pc;
83
84 #ifdef __i386__
85 /* Get the eip from offset 12*4 = 48 as defined in the struct
86 * user_regs_struct in user_32.h
87 */
88 pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)48 /* eip */, NULL);
89 /* FIXME - pc is a non-decremented breakpoint address, hence the
90 * addition of 1 on test. This seems to work for the thread hook
91 * function in libc.so but should be properly fixed.
92 */
93 if (pc == ((int)bkpt_addr + 1)) {
94 /* The hook function takes the id of the new thread as it's first
95 * param, so grab it from ecx at offset 4 in struct user_regs_struct
96 * (using fastcall convention for x86)
97 */
98 gEventMsgHandle.pid = ptrace(PTRACE_PEEKUSR, handle->tid, (void *)4 /* ecx */, NULL);
99 gEventMsgHandle.tid = gEventMsgHandle.pid;
100 return 0x42;
101 }
102 #elif defined(__arm__)
103 pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)60 /* r15/pc */, NULL);
104
105 if (pc == bkpt_addr) {
106 // The hook function takes the id of the new thread as it's first param,
107 // so grab it from r0.
108 gEventMsgHandle.pid = ptrace(PTRACE_PEEKUSR, handle->tid, (void *)0 /* r0 */, NULL);
109 gEventMsgHandle.tid = gEventMsgHandle.pid;
110 return 0x42;
111 }
112 #elif defined(__mips__)
113 pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)(64*4) /* pc */, NULL);
114 if (pc == bkpt_addr) {
115 // The hook function takes the id of the new thread as it's first param,
116 // so grab it from a0
117 gEventMsgHandle.pid = ptrace(PTRACE_PEEKUSR, handle->tid, (void *)(4*4) /* a0 */, NULL);
118 gEventMsgHandle.tid = gEventMsgHandle.pid;
119 return 0x42;
120 }
121 #endif
122 return 0;
123 }
124
125 /* NOTE: not used by gdb 7.0 */
126
127 td_err_e
td_ta_event_getmsg(td_thragent_t const * agent,td_event_msg_t * event)128 td_ta_event_getmsg(td_thragent_t const * agent, td_event_msg_t * event)
129 {
130 td_err_e err;
131 void * bkpt_addr;
132
133 err = ps_pglobal_lookup(NULL, NULL, gSymbols[SYM_TD_CREATE], &bkpt_addr);
134 if (err) {
135 return err;
136 }
137
138 err = td_ta_thr_iter(agent, _event_getmsg_helper, bkpt_addr, 0, 0, NULL, 0);
139 if (err != 0x42) {
140 return TD_NOMSG;
141 }
142
143 event->event = TD_CREATE;
144 event->th_p = &gEventMsgHandle; // Nasty hack, but it's the only way!
145
146 return TD_OK;
147 }
148
149
150 td_err_e
td_ta_map_lwp2thr(td_thragent_t const * agent,lwpid_t lwpid,td_thrhandle_t * th)151 td_ta_map_lwp2thr(td_thragent_t const * agent, lwpid_t lwpid,
152 td_thrhandle_t *th)
153 {
154 th->pid = ps_getpid(agent->ph);
155 th->tid = lwpid;
156 return TD_OK;
157 }
158
159
160 td_err_e
td_thr_get_info(td_thrhandle_t const * handle,td_thrinfo_t * info)161 td_thr_get_info(td_thrhandle_t const * handle, td_thrinfo_t * info)
162 {
163 info->ti_tid = handle->tid;
164 info->ti_lid = handle->tid; // Our pthreads uses kernel ids for tids
165 info->ti_state = TD_THR_SLEEP; /* XXX this needs to be read from /proc/<pid>/task/<tid>.
166 This is only used to see if the thread is a zombie or not */
167 return TD_OK;
168 }
169
170
171 /* NOTE: not used by gdb 7.0 */
172
173 td_err_e
td_thr_event_enable(td_thrhandle_t const * handle,td_event_e event)174 td_thr_event_enable(td_thrhandle_t const * handle, td_event_e event)
175 {
176 // I don't think we need to do anything here...
177 return TD_OK;
178 }
179
180
181 /* NOTE: not used by gdb 7.0 */
182
183 td_err_e
td_ta_event_addr(td_thragent_t const * agent,td_event_e event,td_notify_t * notify_out)184 td_ta_event_addr(td_thragent_t const * agent, td_event_e event, td_notify_t * notify_out)
185 {
186 int32_t err;
187
188 /*
189 * This is nasty, ps_pglobal_lookup is implemented in gdbserver and looks up
190 * the symbol from it's cache, which is populated at start time with the
191 * symbols returned from td_symbol_list via calls back to the host.
192 */
193
194 switch (event) {
195 case TD_CREATE:
196 err = ps_pglobal_lookup(NULL, NULL, gSymbols[SYM_TD_CREATE], ¬ify_out->u.bptaddr);
197 if (err) {
198 return TD_NOEVENT;
199 }
200 return TD_OK;
201 }
202 return TD_NOEVENT;
203 }
204
205
206 td_err_e
td_ta_clear_event(const td_thragent_t * ta_arg,td_thr_events_t * event)207 td_ta_clear_event(const td_thragent_t * ta_arg, td_thr_events_t * event)
208 {
209 /* Given that gdb 7.0 doesn't use thread events,
210 there's nothing we need to do here. */
211 return TD_OK;
212 }
213
214
215 td_err_e
td_ta_thr_iter(td_thragent_t const * agent,td_thr_iter_f * func,void * cookie,td_thr_state_e state,int32_t prio,sigset_t * sigmask,uint32_t user_flags)216 td_ta_thr_iter(td_thragent_t const * agent, td_thr_iter_f * func, void * cookie,
217 td_thr_state_e state, int32_t prio, sigset_t * sigmask, uint32_t user_flags)
218 {
219 td_err_e err = TD_OK;
220 char path[32];
221 DIR * dir;
222 struct dirent * entry;
223 td_thrhandle_t handle;
224
225 snprintf(path, sizeof(path), "/proc/%d/task/", agent->pid);
226 dir = opendir(path);
227 if (!dir) {
228 return TD_NOEVENT;
229 }
230
231 handle.pid = agent->pid;
232 while ((entry = readdir(dir)) != NULL) {
233 if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
234 continue;
235 }
236 handle.tid = atoi(entry->d_name);
237 if (func(&handle, cookie) != 0) {
238 err = TD_DBERR;
239 break;
240 }
241 }
242
243 closedir(dir);
244
245 return err;
246 }
247
248 td_err_e
td_thr_tls_get_addr(const td_thrhandle_t * th,psaddr_t map_address,size_t offset,psaddr_t * address)249 td_thr_tls_get_addr(const td_thrhandle_t * th,
250 psaddr_t map_address, size_t offset, psaddr_t * address)
251 {
252 return TD_NOAPLIC; // FIXME: TODO
253 }
254