Re: Possible fix for bug #13165

[Adhemerval Zanella <azanella at linux dot vnet dot ibm dot com>]

On 18-08-2014 16:53, Rich Felker wrote:
> A couple days ago I posted ideas for a fix for this issue on the bug
> tracker:
>
> https://sourceware.org/bugzilla/show_bug.cgi?id=13165#c38
>
> Anybody who does glibc development/builds/testing up for trying my
> idea and seeing if it works?
>
> Rich
>
If I understood correctly, you are proposing something like:

diff --git a/nptl/pthread_cond_wait.c b/nptl/pthread_cond_wait.c
index fc5eac4..a16c5d5 100644
--- a/nptl/pthread_cond_wait.c
+++ b/nptl/pthread_cond_wait.c
@@ -118,14 +118,6 @@ __pthread_cond_wait (cond, mutex)
   /* Make sure we are alone.  */
   lll_lock (cond->__data.__lock, pshared);
 
-  /* Now we can release the mutex.  */
-  err = __pthread_mutex_unlock_usercnt (mutex, 0);
-  if (__glibc_unlikely (err))
-    {
-      lll_unlock (cond->__data.__lock, pshared);
-      return err;
-    }
-
   /* We have one new user of the condvar.  */
   ++cond->__data.__total_seq;
   ++cond->__data.__futex;
@@ -153,6 +145,14 @@ __pthread_cond_wait (cond, mutex)
   /* Remember the broadcast counter.  */
   cbuffer.bc_seq = cond->__data.__broadcast_seq;
 
+  /* Now we can release the mutex.  */
+  err = __pthread_mutex_unlock_usercnt (mutex, 0);
+  if (__glibc_unlikely (err))
+    {
+      lll_unlock (cond->__data.__lock, pshared);
+      return err;
+    }
+
   do
     {
       unsigned int futex_val = cond->__data.__futex;

correct? I saw not NPTL issues in nether powerpc64 or x86_64.