Fix two issues related to thread private data in asr.

- setting up asr in single thread mode and then starting threads using asr
  would lead to multiple threads sharing the same resolver.
- destruction of a thread that has been using asr would leak data.
Problem originally reported by Alexey Sokolov and Uli Schlachter.
ok kettenis@

1 files changed, 10 insertions, 3 deletions

diff --git a/src/lib/libc/include/thread_private.h b/src/lib/libc/include/thread_private.h
index 98dfaa6322..237c3fbd03 100644
--- a/src/lib/libc/include/thread_private.h
+++ b/src/lib/libc/include/thread_private.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: thread_private.h,v 1.35 2019/02/13 13:22:14 mpi Exp $ */
+/* $OpenBSD: thread_private.h,v 1.36 2021/01/06 19:54:17 otto Exp $ */
 
 /* PUBLIC DOMAIN: No Rights Reserved. Marco S Hyman <marc@snafu.org> */
 
@@ -98,7 +98,8 @@ struct thread_callbacks {
         void    (*tc_mutex_destroy)(void **);
         void    (*tc_tag_lock)(void **);
         void    (*tc_tag_unlock)(void **);
-        void    *(*tc_tag_storage)(void **, void *, size_t, void *);
+        void    *(*tc_tag_storage)(void **, void *, size_t, void (*)(void *),
+           void *);
         __pid_t (*tc_fork)(void);
         __pid_t (*tc_vfork)(void);
         void    (*tc_thread_release)(struct pthread *);
@@ -142,6 +143,7 @@ __END_HIDDEN_DECLS
 #define _THREAD_PRIVATE_MUTEX_LOCK(name)                do {} while (0)
 #define _THREAD_PRIVATE_MUTEX_UNLOCK(name)              do {} while (0)
 #define _THREAD_PRIVATE(keyname, storage, error)        &(storage)
+#define _THREAD_PRIVATE_DT(keyname, storage, dt, error) &(storage)
 #define _MUTEX_LOCK(mutex)                              do {} while (0)
 #define _MUTEX_UNLOCK(mutex)                            do {} while (0)
 #define _MUTEX_DESTROY(mutex)                           do {} while (0)
@@ -168,7 +170,12 @@ __END_HIDDEN_DECLS
 #define _THREAD_PRIVATE(keyname, storage, error)                        \
         (_thread_cb.tc_tag_storage == NULL ? &(storage) :               \
             _thread_cb.tc_tag_storage(&(__THREAD_NAME(keyname)),        \
-                &(storage), sizeof(storage), error))
+                &(storage), sizeof(storage), NULL, (error)))
+
+#define _THREAD_PRIVATE_DT(keyname, storage, dt, error)                 \
+        (_thread_cb.tc_tag_storage == NULL ? &(storage) :               \
+            _thread_cb.tc_tag_storage(&(__THREAD_NAME(keyname)),        \
+                &(storage), sizeof(storage), (dt), (error)))
 
 /*
  * Macros used in libc to access mutexes.