svn commit: r318715 - head/lib/libc/sys

[Ngie Cooper]

Author: ngie
Date: Tue May 23 07:26:45 2017
New Revision: 318715
URL: https://svnweb.freebsd.org/changeset/base/318715

Log:
  _umtx_op(2): fix minor manlint issues
  
  - Sort .Xr entries in SEE ALSO section.
  - Sort SEE ALSO and STANDARDS sections properly, in terms of the
    entire document.
  
  Reported by:	make manlint
  MFC after:	2 weeks
  Sponsored by:	Dell EMC Isilon

Modified:
  head/lib/libc/sys/_umtx_op.2

Modified: head/lib/libc/sys/_umtx_op.2
==============================================================================
--- head/lib/libc/sys/_umtx_op.2	Tue May 23 07:21:26 2017	(r318714)
+++ head/lib/libc/sys/_umtx_op.2	Tue May 23 07:26:45 2017	(r318715)
@@ -28,7 +28,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 29, 2016
+.Dd May 23, 2017
 .Dt _UMTX_OP 2
 .Os
 .Sh NAME
@@ -1382,32 +1382,11 @@ Mutex lock requests without timeout spec
 The error is not returned to userspace code since restart
 is handled by usual adjustment of the instruction counter.
 .El
-.Sh BUGS
-A window between a unlocking robust mutex and resetting the pointer in the
-.Dv robust_inact_offset
-member of the registered
-.Vt struct umtx_robust_lists_params
-allows another thread to destroy the mutex, thus making the kernel inspect
-freed or reused memory.
-The
-.Li libthr
-implementation is only vulnerable to this race when operating on
-a shared mutex.
-A possible fix for the current implementation is to strengthen the checks
-for shared mutexes before terminating them, in particular, verifying
-that the mutex memory is mapped from a shared memory object allocated
-by the
-.Dv UMTX_OP_SHM
-request.
-This is not done because it is believed that the race is adequately
-covered by other consistency checks, while adding the check would
-prevent alternative implementations of
-.Li libpthread .
 .Sh SEE ALSO
 .Xr clock_gettime 2 ,
 .Xr mmap 2 ,
-.Xr shm_open 2 ,
 .Xr setrlimit 2 ,
+.Xr shm_open 2 ,
 .Xr sigaction 2 ,
 .Xr thr_exit 2 ,
 .Xr thr_kill 2 ,
@@ -1425,3 +1404,24 @@ to implement
 .St -p1003.1-2001
 .Xr pthread 3
 functionality.
+.Sh BUGS
+A window between a unlocking robust mutex and resetting the pointer in the
+.Dv robust_inact_offset
+member of the registered
+.Vt struct umtx_robust_lists_params
+allows another thread to destroy the mutex, thus making the kernel inspect
+freed or reused memory.
+The
+.Li libthr
+implementation is only vulnerable to this race when operating on
+a shared mutex.
+A possible fix for the current implementation is to strengthen the checks
+for shared mutexes before terminating them, in particular, verifying
+that the mutex memory is mapped from a shared memory object allocated
+by the
+.Dv UMTX_OP_SHM
+request.
+This is not done because it is believed that the race is adequately
+covered by other consistency checks, while adding the check would
+prevent alternative implementations of
+.Li libpthread .