Merge branch 'for-linville' of git://github.com/kvalo/ath6kl

[karo-tx-linux.git] / Documentation / sparse.txt

diff --git a/Documentation/sparse.txt b/Documentation/sparse.txt
index 9b659c79a54704149dae0bbd149b74a4f524a16c..eceab1308a8c2fbde6722232db18bbb57a6e7f2e 100644 (file)
--- a/Documentation/sparse.txt
+++ b/Documentation/sparse.txt
@@ -1,5 +1,5 @@
 Copyright 2004 Linus Torvalds
-Copyright 2004 Pavel Machek <pavel@suse.cz>
+Copyright 2004 Pavel Machek <pavel@ucw.cz>
 Copyright 2006 Bob Copeland <me@bobcopeland.com>
 
 Using sparse for typechecking
@@ -49,6 +49,24 @@ be generated without __CHECK_ENDIAN__.
 __bitwise - noisy stuff; in particular, __le*/__be* are that.  We really
 don't want to drown in noise unless we'd explicitly asked for it.
 
+Using sparse for lock checking
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The following macros are undefined for gcc and defined during a sparse
+run to use the "context" tracking feature of sparse, applied to
+locking.  These annotations tell sparse when a lock is held, with
+regard to the annotated function's entry and exit.
+
+__must_hold - The specified lock is held on function entry and exit.
+
+__acquires - The specified lock is held on function exit, but not entry.
+
+__releases - The specified lock is held on function entry, but not exit.
+
+If the function enters and exits without the lock held, acquiring and
+releasing the lock inside the function in a balanced way, no
+annotation is needed.  The tree annotations above are for cases where
+sparse would otherwise report a context imbalance.
 
 Getting sparse
 ~~~~~~~~~~~~~~