[glibc] sem_close: Use __twalk_r

[Florian Weimer <fw at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=4aee85f96b881c1cb80a1fff752b8e2130a9a4d9

commit 4aee85f96b881c1cb80a1fff752b8e2130a9a4d9
Author: Florian Weimer <fweimer@redhat.com>
Date:   Fri May 10 14:17:26 2019 +0200

    sem_close: Use __twalk_r

Diff:
---
 ChangeLog        |  6 ++++++
 nptl/sem_close.c | 28 +++++++++++++++-------------
 2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 8f6b8c8..1857303 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2019-05-10  Florian Weimer  <fweimer@redhat.com>
+
+	* nptl/sem_close.c (struct walk_closure): Define.
+	(walker): Adjust for __twalk_r.
+	(sem_close): Call __twalk_r.
+
 2019-05-09  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
 	* support/timespec.c (test_timespec_before_impl,
diff --git a/nptl/sem_close.c b/nptl/sem_close.c
index b8828cb..8941f11 100644
--- a/nptl/sem_close.c
+++ b/nptl/sem_close.c
@@ -21,21 +21,20 @@
 #include <sys/mman.h>
 #include "semaphoreP.h"
 
-
-/* Global variables to parametrize the walk function.  This works
-   since we always have to use locks.  And we have to use the twalk
-   function since the entries are not sorted wrt the mapping
-   address.  */
-static sem_t *the_sem;
-static struct inuse_sem *rec;
+struct walk_closure
+{
+  sem_t *the_sem;
+  struct inuse_sem *rec;
+};
 
 static void
-walker (const void *inodep, const VISIT which, const int depth)
+walker (const void *inodep, VISIT which, void *closure0)
 {
+  struct walk_closure *closure = closure0;
   struct inuse_sem *nodep = *(struct inuse_sem **) inodep;
 
-  if (nodep->sem == the_sem)
-    rec = nodep;
+  if (nodep->sem == closure->the_sem)
+    closure->rec = nodep;
 }
 
 
@@ -48,9 +47,12 @@ sem_close (sem_t *sem)
   lll_lock (__sem_mappings_lock, LLL_PRIVATE);
 
   /* Locate the entry for the mapping the caller provided.  */
-  rec = NULL;
-  the_sem = sem;
-  __twalk (__sem_mappings, walker);
+  struct inuse_sem *rec;
+  {
+    struct walk_closure closure = { .the_sem = sem, .rec = NULL };
+    __twalk_r (__sem_mappings, walker, &closure);
+    rec = closure.rec;
+  }
   if  (rec != NULL)
     {
       /* Check the reference counter.  If it is going to be zero, free