sparse says:
fs/nfsd/auth.c:31:38: warning: incorrect type in argument 1 (different address spaces)
fs/nfsd/auth.c:31:38: expected struct cred const *cred
fs/nfsd/auth.c:31:38: got struct cred const [noderef] <asn:4>*real_cred
Add a new accessor for the ->real_cred and use that to fetch the
pointer. Accessing current->real_cred directly is actually quite safe
since we know that they can't go away so this is mostly a cosmetic fixup
to silence sparse.
Signed-off-by: Jeff Layton <[email protected]>
---
fs/nfsd/auth.c | 2 +-
include/linux/cred.h | 9 +++++++++
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c
index 72f44823adbb..9d46a0bdd9f9 100644
--- a/fs/nfsd/auth.c
+++ b/fs/nfsd/auth.c
@@ -28,7 +28,7 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
validate_process_creds();
/* discard any old override before preparing the new set */
- revert_creds(get_cred(current->real_cred));
+ revert_creds(get_cred(current_real_cred()));
new = prepare_creds();
if (!new)
return -ENOMEM;
diff --git a/include/linux/cred.h b/include/linux/cred.h
index f61d6c8f5ef3..b2d0820837c4 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -259,6 +259,15 @@ static inline void put_cred(const struct cred *_cred)
rcu_dereference_protected(current->cred, 1)
/**
+ * current_real_cred - Access the current task's objective credentials
+ *
+ * Access the objective credentials of the current task. RCU-safe,
+ * since nobody else can modify it.
+ */
+#define current_real_cred() \
+ rcu_dereference_protected(current->real_cred, 1)
+
+/**
* __task_cred - Access a task's objective credentials
* @task: The task to query
*
--
1.9.3
On Tue, Jul 15, 2014 at 06:28:54AM -0400, Jeff Layton wrote:
> sparse says:
>
> fs/nfsd/auth.c:31:38: warning: incorrect type in argument 1 (different address spaces)
> fs/nfsd/auth.c:31:38: expected struct cred const *cred
> fs/nfsd/auth.c:31:38: got struct cred const [noderef] <asn:4>*real_cred
>
> Add a new accessor for the ->real_cred and use that to fetch the
> pointer. Accessing current->real_cred directly is actually quite safe
> since we know that they can't go away so this is mostly a cosmetic fixup
> to silence sparse.
This looks reasonable, but I'd suggest Ccing linux-kernel for changes to
global headers.
Reviewed-by: Christoph Hellwig <[email protected]>
On Tue, Jul 15, 2014 at 12:59:36PM -0400, Jeff Layton wrote:
> sparse says:
>
> fs/nfsd/auth.c:31:38: warning: incorrect type in argument 1 (different address spaces)
> fs/nfsd/auth.c:31:38: expected struct cred const *cred
> fs/nfsd/auth.c:31:38: got struct cred const [noderef] <asn:4>*real_cred
>
> Add a new accessor for the ->real_cred and use that to fetch the
> pointer. Accessing current->real_cred directly is actually quite safe
> since we know that they can't go away so this is mostly a cosmetic fixup
> to silence sparse.
Thanks, applying, absent any objections.
--b.
>
> Signed-off-by: Jeff Layton <[email protected]>
> ---
> fs/nfsd/auth.c | 2 +-
> include/linux/cred.h | 9 +++++++++
> 2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c
> index 72f44823adbb..9d46a0bdd9f9 100644
> --- a/fs/nfsd/auth.c
> +++ b/fs/nfsd/auth.c
> @@ -28,7 +28,7 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
> validate_process_creds();
>
> /* discard any old override before preparing the new set */
> - revert_creds(get_cred(current->real_cred));
> + revert_creds(get_cred(current_real_cred()));
> new = prepare_creds();
> if (!new)
> return -ENOMEM;
> diff --git a/include/linux/cred.h b/include/linux/cred.h
> index f61d6c8f5ef3..b2d0820837c4 100644
> --- a/include/linux/cred.h
> +++ b/include/linux/cred.h
> @@ -259,6 +259,15 @@ static inline void put_cred(const struct cred *_cred)
> rcu_dereference_protected(current->cred, 1)
>
> /**
> + * current_real_cred - Access the current task's objective credentials
> + *
> + * Access the objective credentials of the current task. RCU-safe,
> + * since nobody else can modify it.
> + */
> +#define current_real_cred() \
> + rcu_dereference_protected(current->real_cred, 1)
> +
> +/**
> * __task_cred - Access a task's objective credentials
> * @task: The task to query
> *
> --
> 1.9.3
>
On Tue, 15 Jul 2014 09:45:27 -0700
Christoph Hellwig <[email protected]> wrote:
> On Tue, Jul 15, 2014 at 06:28:54AM -0400, Jeff Layton wrote:
> > sparse says:
> >
> > fs/nfsd/auth.c:31:38: warning: incorrect type in argument 1 (different address spaces)
> > fs/nfsd/auth.c:31:38: expected struct cred const *cred
> > fs/nfsd/auth.c:31:38: got struct cred const [noderef] <asn:4>*real_cred
> >
> > Add a new accessor for the ->real_cred and use that to fetch the
> > pointer. Accessing current->real_cred directly is actually quite safe
> > since we know that they can't go away so this is mostly a cosmetic fixup
> > to silence sparse.
>
> This looks reasonable, but I'd suggest Ccing linux-kernel for changes to
> global headers.
>
> Reviewed-by: Christoph Hellwig <[email protected]>
Ok, good point. I'll resend and cc there.
FWIW, I also sent a patch to linux-sparse today which will silence the
last sparse warning when building nfsd.ko.
Thanks,
--
Jeff Layton <[email protected]>