[Bug nptl/14232] New: tst-cancel7 and tst-cancelx7 race condition

[Bug nptl/14232] New: tst-cancel7 and tst-cancelx7 race condition

[jsm28 at gcc dot gnu.org]

http://sourceware.org/bugzilla/show_bug.cgi?id=14232

             Bug #: 14232
           Summary: tst-cancel7 and tst-cancelx7 race condition
           Product: glibc
           Version: 2.15
            Status: NEW
          Severity: normal
          Priority: P2
         Component: nptl
        AssignedTo: unassigned@sourceware.org
        ReportedBy: jsm28@gcc.gnu.org
                CC: drepper.fsp@gmail.com
    Classification: Unclassified


The test nptl/tst-cancel7 (and so tst-cancelx7) has a race condition that can
cause failures with "could not read pid" in tst-cancel7.out.

Suppose the function sl waits a while between opening the output file and
writing to it.  Then cancellation of that thread takes effect without the
output having been written and flushed.  This can be reproduced reliably on
x86_64 by inserting a delay loop, e.g.:

diff --git a/nptl/tst-cancel7.c b/nptl/tst-cancel7.c
index 0a972e6..efe46ef 100644
--- a/nptl/tst-cancel7.c
+++ b/nptl/tst-cancel7.c
@@ -42,6 +42,7 @@ tf (void *arg)
   return NULL;
 }

+volatile unsigned long long ll = 0;

 static void
 sl (void)
@@ -50,6 +51,9 @@ sl (void)
   if (f == NULL)
     exit (1);

+  for (ll = 0; ll < (1ULL << 34); ll++)
+    ;
+
   fprintf (f, "%lld\n", (long long) getpid ());
   fflush (f);

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[Bug nptl/14232] tst-cancel7 and tst-cancelx7 race condition

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=14232

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
              Flags|                            |security-

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[Bug nptl/14232] tst-cancel7 and tst-cancelx7 race condition

[adhemerval.zanella at linaro dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=14232

Adhemerval Zanella <adhemerval.zanella at linaro dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |adhemerval.zanella at linaro dot o
                   |                            |rg
           Assignee|unassigned at sourceware dot org   |adhemerval.zanella at linaro dot o
                   |                            |rg
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |2.35

--- Comment #1 from Adhemerval Zanella <adhemerval.zanella at linaro dot org> ---
Fixed on 2.35.

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