1 files changed, 183 insertions, 0 deletions
diff --git a/libthread_db/libthread_db.c b/libthread_db/libthread_db.c
new file mode 100644
index 0000000..f1a78ac
--- /dev/null
+++ b/libthread_db/libthread_db.c
@@ -0,0 +1,183 @@
+/*
+ * Copyright 2006 The Android Open Source Project
+ */
+
+#include <dirent.h>
+#include <sys/ptrace.h>
+#include <stdint.h>
+#include <thread_db.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+extern int ps_pglobal_lookup (void *, const char *obj, const char *name, void **sym_addr);
+
+struct ps_prochandle
+{
+    pid_t pid;
+};
+
+
+/*
+ * This is the list of "special" symbols we care about whose addresses are
+ * cached by gdbserver from the host at init time.
+ */
+enum {
+    SYM_TD_CREATE,
+    SYM_THREAD_LIST,
+    NUM_SYMS
+};
+
+static char const * gSymbols[] = {
+    [SYM_TD_CREATE] = "_thread_created_hook",
+    NULL
+};
+
+
+char const **
+td_symbol_list(void)
+{
+    return gSymbols;
+}
+
+
+td_err_e
+td_ta_new(struct ps_prochandle const * proc_handle, td_thragent_t ** agent_out)
+{
+    td_thragent_t * agent;
+
+    agent = (td_thragent_t *)malloc(sizeof(td_thragent_t));
+    if (!agent) {
+        return TD_MALLOC;
+    }
+
+    agent->pid = proc_handle->pid;
+    *agent_out = agent;
+
+    return TD_OK;
+}
+
+
+td_err_e
+td_ta_set_event(td_thragent_t const * agent, td_thr_events_t * events)
+{
+    return TD_OK;
+}
+
+
+static td_thrhandle_t gEventMsgHandle;
+
+static int
+_event_getmsg_helper(td_thrhandle_t const * handle, void * bkpt_addr)
+{
+    void * pc;
+
+    pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)60 /* r15/pc */, NULL);
+
+    if (pc == bkpt_addr) {
+        // The hook function takes the id of the new thread as it's first param,
+        // so grab it from r0.
+        gEventMsgHandle.pid = ptrace(PTRACE_PEEKUSR, handle->tid, (void *)0 /* r0 */, NULL);
+        gEventMsgHandle.tid = gEventMsgHandle.pid;
+        return 0x42;
+    }
+    return 0;
+}
+
+td_err_e
+td_ta_event_getmsg(td_thragent_t const * agent, td_event_msg_t * event)
+{
+    td_err_e err;
+    void * bkpt_addr;
+
+    err = ps_pglobal_lookup(NULL, NULL, gSymbols[SYM_TD_CREATE], &bkpt_addr);
+    if (err) {
+        return err;
+    }
+
+    err = td_ta_thr_iter(agent, _event_getmsg_helper, bkpt_addr, 0, 0, NULL, 0);
+    if (err != 0x42) {
+        return TD_NOMSG;
+    }
+
+    event->event = TD_CREATE;
+    event->th_p = &gEventMsgHandle; // Nasty hack, but it's the only way!
+
+    return TD_OK;
+}
+
+
+td_err_e
+td_thr_get_info(td_thrhandle_t const * handle, td_thrinfo_t * info)
+{
+    info->ti_tid = handle->tid;
+    info->ti_lid = handle->tid; // Our pthreads uses kernel ids for tids
+    info->ti_state = TD_THR_SLEEP; /* XXX this needs to be read from /proc/<pid>/task/<tid>.
+                                      This is only used to see if the thread is a zombie or not */
+    return TD_OK;
+}
+
+
+td_err_e
+td_thr_event_enable(td_thrhandle_t const * handle, td_event_e event)
+{
+    // I don't think we need to do anything here...
+    return TD_OK;
+}
+
+
+td_err_e
+td_ta_event_addr(td_thragent_t const * agent, td_event_e event, td_notify_t * notify_out)
+{
+    int32_t err;
+
+    /* 
+     * This is nasty, ps_pglobal_lookup is implemented in gdbserver and looks up
+     * the symbol from it's cache, which is populated at start time with the
+     * symbols returned from td_symbol_list via calls back to the host.
+     */
+
+    switch (event) {
+        case TD_CREATE:
+            err = ps_pglobal_lookup(NULL, NULL, gSymbols[SYM_TD_CREATE], &notify_out->u.bptaddr);
+            if (err) {
+                return TD_NOEVENT;
+            }
+            return TD_OK;
+    }
+    return TD_NOEVENT;
+}
+
+
+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)
+{
+    td_err_e err = TD_OK;
+    char path[32];
+    DIR * dir;
+    struct dirent * entry;
+    td_thrhandle_t handle;
+
+    snprintf(path, sizeof(path), "/proc/%d/task/", agent->pid);
+    dir = opendir(path);
+    if (!dir) {
+        return TD_NOEVENT;
+    }
+
+    handle.pid = agent->pid;
+    while ((entry = readdir(dir)) != NULL) {
+        if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
+            continue;
+        }
+        handle.tid = atoi(entry->d_name);
+        err = func(&handle, cookie);
+        if (err) {
+            break;
+        }
+    }
+
+    closedir(dir);
+
+    return err;
+}
+