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> --- 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
