On Thu, Oct 18, 2012 at 07:27:26AM -0700, Ed Cashin wrote: > The context feature of sparse is used with the Linux kernel > sources to check for imbalanced uses of locks. Document the > annotations defined in include/linux/compiler.h that tell sparse > what to expect when a lock is held on function entry, exit, or > both. > > Signed-off-by: Ed Cashin <ecashin@xxxxxxxxxx> Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx> > Documentation/sparse.txt | 18 ++++++++++++++++++ > 1 files changed, 18 insertions(+), 0 deletions(-) > > diff --git a/Documentation/sparse.txt b/Documentation/sparse.txt > index 4909d41..eceab13 100644 > --- a/Documentation/sparse.txt > +++ b/Documentation/sparse.txt > @@ -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 > ~~~~~~~~~~~~~~ > -- > 1.7.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
