Re: [PATCH] Fix size argument to memset call in nfsacl_encode

From: Jesper Juhl
Date: Thu Feb 03 2011 - 14:42:09 EST


On Thu, 3 Feb 2011, Trond Myklebust wrote:

> On Thu, 2011-02-03 at 20:15 +0100, Jesper Juhl wrote:
> > We want to give memset() the sizeof(struct posix_acl), not
> > sizeof(struct posix_acl *).
> >
> > Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
> > ---
> > nfsacl.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/fs/nfs_common/nfsacl.c b/fs/nfs_common/nfsacl.c
> > index 84c27d6..bc6d81b 100644
> > --- a/fs/nfs_common/nfsacl.c
> > +++ b/fs/nfs_common/nfsacl.c
> > @@ -117,7 +117,7 @@ int nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode,
> > * invoked in contexts where a memory allocation failure is
> > * fatal. Fortunately this fake ACL is small enough to
> > * construct on the stack. */
> > - memset(acl2, 0, sizeof(acl2));
> > + memset(acl2, 0, sizeof(*acl2));
> > posix_acl_init(acl2, 4);
> >
> > /* Insert entries in canonical order: other orders seem
>
> Ccing Milton Miller who also sent in the same patch.
>
> Neither patch is correct afaics. posix_acl_init() will clobber the above
> memset, and so the correct fix is just to get rid of it...
>

posix_acl_init() sets a_refcount and a_count, but what about a_entries ...
no problem, nfsacl_encode() itself takes care of that post the
posix_acl_init() call.. it's all good.

So ...


Remove pointless memset() in nfsacl_encode().

Thanks to Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> for pointing out
that it is not needed since posix_acl_init() will set everything
regardless..

Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
---
nfsacl.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/fs/nfs_common/nfsacl.c b/fs/nfs_common/nfsacl.c
index 84c27d6..ec0f277 100644
--- a/fs/nfs_common/nfsacl.c
+++ b/fs/nfs_common/nfsacl.c
@@ -117,7 +117,6 @@ int nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode,
* invoked in contexts where a memory allocation failure is
* fatal. Fortunately this fake ACL is small enough to
* construct on the stack. */
- memset(acl2, 0, sizeof(acl2));
posix_acl_init(acl2, 4);

/* Insert entries in canonical order: other orders seem


--
Jesper Juhl <jj@xxxxxxxxxxxxx> http://www.chaosbits.net/
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