lkml.org 
[lkml]   [2012]   [Oct]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Documentation/sparse.txt: document context annotations for lock checking
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@coraid.com>

Reviewed-by: Josh Triplett <josh@joshtriplett.org>

> 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
>


\
 
 \ /
  Last update: 2012-10-19 02:01    [W:0.044 / U:0.428 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site