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
14 struct ps_prochandle
15 {
16 pid_t pid;
17 };
18
19
20 /*
21 * This is the list of "special" symbols we care about whose addresses are
22 * cached by gdbserver from the host at init time.
23 */
24 enum {
25 SYM_TD_CREATE,
26 SYM_THREAD_LIST,
27 NUM_SYMS
28 };
29
30 static char const * gSymbols[] = {
31 [SYM_TD_CREATE] = "_thread_created_hook",
32 NULL
33 };
34
35
36 char const **
td_symbol_list(void)37 td_symbol_list(void)
38 {
39 return gSymbols;
40 }
41
42
43 td_err_e
td_ta_new(struct ps_prochandle const * proc_handle,td_thragent_t ** agent_out)44 td_ta_new(struct ps_prochandle const * proc_handle, td_thragent_t ** agent_out)
45 {
46 td_thragent_t * agent;
47
48 agent = (td_thragent_t *)malloc(sizeof(td_thragent_t));
49 if (!agent) {
50 return TD_MALLOC;
51 }
52
53 agent->pid = proc_handle->pid;
54 *agent_out = agent;
55
56 return TD_OK;
57 }
58
59
60 td_err_e
td_ta_set_event(td_thragent_t const * agent,td_thr_events_t * events)61 td_ta_set_event(td_thragent_t const * agent, td_thr_events_t * events)
62 {
63 return TD_OK;
64 }
65
66
67 static td_thrhandle_t gEventMsgHandle;
68
69 static int
_event_getmsg_helper(td_thrhandle_t const * handle,void * bkpt_addr)70 _event_getmsg_helper(td_thrhandle_t const * handle, void * bkpt_addr)
71 {
72 void * pc;
73
74 pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)60 /* r15/pc */, NULL);
75
76 if (pc == bkpt_addr) {
77 // The hook function takes the id of the new thread as it's first param,
78 // so grab it from r0.
79 gEventMsgHandle.pid = ptrace(PTRACE_PEEKUSR, handle->tid, (void *)0 /* r0 */, NULL);
80 gEventMsgHandle.tid = gEventMsgHandle.pid;
81 return 0x42;
82 }
83 return 0;
84 }
85
86 td_err_e
td_ta_event_getmsg(td_thragent_t const * agent,td_event_msg_t * event)87 td_ta_event_getmsg(td_thragent_t const * agent, td_event_msg_t * event)
88 {
89 td_err_e err;
90 void * bkpt_addr;
91
92 err = ps_pglobal_lookup(NULL, NULL, gSymbols[SYM_TD_CREATE], &bkpt_addr);
93 if (err) {
94 return err;
95 }
96
97 err = td_ta_thr_iter(agent, _event_getmsg_helper, bkpt_addr, 0, 0, NULL, 0);
98 if (err != 0x42) {
99 return TD_NOMSG;
100 }
101
102 event->event = TD_CREATE;
103 event->th_p = &gEventMsgHandle; // Nasty hack, but it's the only way!
104
105 return TD_OK;
106 }
107
108
109 td_err_e
td_thr_get_info(td_thrhandle_t const * handle,td_thrinfo_t * info)110 td_thr_get_info(td_thrhandle_t const * handle, td_thrinfo_t * info)
111 {
112 info->ti_tid = handle->tid;
113 info->ti_lid = handle->tid; // Our pthreads uses kernel ids for tids
114 info->ti_state = TD_THR_SLEEP; /* XXX this needs to be read from /proc/<pid>/task/<tid>.
115 This is only used to see if the thread is a zombie or not */
116 return TD_OK;
117 }
118
119
120 td_err_e
td_thr_event_enable(td_thrhandle_t const * handle,td_event_e event)121 td_thr_event_enable(td_thrhandle_t const * handle, td_event_e event)
122 {
123 // I don't think we need to do anything here...
124 return TD_OK;
125 }
126
127
128 td_err_e
td_ta_event_addr(td_thragent_t const * agent,td_event_e event,td_notify_t * notify_out)129 td_ta_event_addr(td_thragent_t const * agent, td_event_e event, td_notify_t * notify_out)
130 {
131 int32_t err;
132
133 /*
134 * This is nasty, ps_pglobal_lookup is implemented in gdbserver and looks up
135 * the symbol from it's cache, which is populated at start time with the
136 * symbols returned from td_symbol_list via calls back to the host.
137 */
138
139 switch (event) {
140 case TD_CREATE:
141 err = ps_pglobal_lookup(NULL, NULL, gSymbols[SYM_TD_CREATE], ¬ify_out->u.bptaddr);
142 if (err) {
143 return TD_NOEVENT;
144 }
145 return TD_OK;
146 }
147 return TD_NOEVENT;
148 }
149
150
151 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)152 td_ta_thr_iter(td_thragent_t const * agent, td_thr_iter_f * func, void * cookie,
153 td_thr_state_e state, int32_t prio, sigset_t * sigmask, uint32_t user_flags)
154 {
155 td_err_e err = TD_OK;
156 char path[32];
157 DIR * dir;
158 struct dirent * entry;
159 td_thrhandle_t handle;
160
161 snprintf(path, sizeof(path), "/proc/%d/task/", agent->pid);
162 dir = opendir(path);
163 if (!dir) {
164 return TD_NOEVENT;
165 }
166
167 handle.pid = agent->pid;
168 while ((entry = readdir(dir)) != NULL) {
169 if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
170 continue;
171 }
172 handle.tid = atoi(entry->d_name);
173 err = func(&handle, cookie);
174 if (err) {
175 break;
176 }
177 }
178
179 closedir(dir);
180
181 return err;
182 }
183
184