Make name resolution thread-safe

* pthread/pt-alloc.c (initialize_pthread): Reset resolver state.
* pthread/pt-create.c: Include <resolv.h>.
(entry_point): Update the __resp TLS variable to point to the resolver
state of the current thread.
* pthread/pt-internal.h: Define __need_res_state and include <resolv.h>.
(struct __pthread): New `res_state' member.

3 files changed, 9 insertions, 0 deletions

diff --git a/pthread/pt-alloc.c b/pthread/pt-alloc.c
index af544c5..4860f48 100644
--- a/pthread/pt-alloc.c
+++ b/pthread/pt-alloc.c
@@ -68,6 +68,8 @@ initialize_pthread (struct __pthread *new)
 
   new->cancelation_handlers = 0;
 
+  memset (&new->res_state, '\0', sizeof (new->res_state));
+
 #ifdef ENABLE_TLS
   new->tcb = NULL;
 #endif
diff --git a/pthread/pt-create.c b/pthread/pt-create.c
index 5358b08..c2c84b1 100644
--- a/pthread/pt-create.c
+++ b/pthread/pt-create.c
@@ -21,6 +21,7 @@
 #include <errno.h>
 #include <pthread.h>
 #include <signal.h>
+#include <resolv.h>
 
 #include <bits/pt-atomic.h>
 
@@ -45,6 +46,7 @@ entry_point (struct __pthread *self, void *(*start_routine)(void *), void *arg)
 {
 #ifdef ENABLE_TLS
   ___pthread_self = self;
+  __resp = &self->res_state;
 #endif
 
 #ifdef IS_IN_libpthread
diff --git a/pthread/pt-internal.h b/pthread/pt-internal.h
index 7465761..eca63a1 100644
--- a/pthread/pt-internal.h
+++ b/pthread/pt-internal.h
@@ -25,6 +25,8 @@
 #include <sched.h>
 #include <signal.h>
 #include <assert.h>
+#define __need_res_state
+#include <resolv.h>
 
 #include <bits/pt-atomic.h>
 
@@ -107,6 +109,9 @@ struct __pthread
   pthread_mutex_t state_lock;	/* Locks the state.  */
   pthread_cond_t state_cond;	/* Signalled when the state changes.  */
 
+  /* Resolver state.  */
+  struct __res_state res_state;
+
   /* Thread context.  */
   struct pthread_mcontext mcontext;