Re: [PATCH] ipc: change kern_ipc_perm.deleted type to bool

From: Rafael Aquini
Date: Thu Dec 19 2013 - 12:29:04 EST


On Thu, Dec 19, 2013 at 03:23:02PM -0200, Rafael Aquini wrote:
> struct kern_ipc_perm.deleted is meant to be used as a boolean toogle, and
> the changes introduced by this patch are just to make the case explicit.
>
> Signed-off-by: Rafael Aquini <aquini@xxxxxxxxxx>

s/toogle/toggle

my bad, sorry. shall I resend, or it can be fixed before merging?

Thanks,
-- Rafael

> ---
> * a quick sidenote: this patch goes on top of the recently posted
> [PATCH v3] ipc: introduce ipc_valid_object() helper to sort out IPC_RMID races
>
> include/linux/ipc.h | 2 +-
> ipc/sem.c | 2 +-
> ipc/util.c | 6 +++---
> ipc/util.h | 2 +-
> 4 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/ipc.h b/include/linux/ipc.h
> index 8d861b2..9d84942 100644
> --- a/include/linux/ipc.h
> +++ b/include/linux/ipc.h
> @@ -11,7 +11,7 @@
> struct kern_ipc_perm
> {
> spinlock_t lock;
> - int deleted;
> + bool deleted;
> int id;
> key_t key;
> kuid_t uid;
> diff --git a/ipc/sem.c b/ipc/sem.c
> index 5972e60..1659cd9 100644
> --- a/ipc/sem.c
> +++ b/ipc/sem.c
> @@ -394,7 +394,7 @@ static inline struct sem_array *sem_obtain_lock(struct ipc_namespace *ns,
> /* ipc_rmid() may have already freed the ID while sem_lock
> * was spinning: verify that the structure is still valid
> */
> - if (!ipcp->deleted)
> + if (ipc_valid_object(ipcp))
> return container_of(ipcp, struct sem_array, sem_perm);
>
> sem_unlock(sma, *locknum);
> diff --git a/ipc/util.c b/ipc/util.c
> index 3ae17a4..9dc67fa 100644
> --- a/ipc/util.c
> +++ b/ipc/util.c
> @@ -286,7 +286,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
> idr_preload(GFP_KERNEL);
>
> spin_lock_init(&new->lock);
> - new->deleted = 0;
> + new->deleted = false;
> rcu_read_lock();
> spin_lock(&new->lock);
>
> @@ -447,7 +447,7 @@ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
>
> ids->in_use--;
>
> - ipcp->deleted = 1;
> + ipcp->deleted = true;
>
> return;
> }
> @@ -657,7 +657,7 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
> /* ipc_rmid() may have already freed the ID while ipc_lock
> * was spinning: here verify that the structure is still valid
> */
> - if (!out->deleted)
> + if (ipc_valid_object(out))
> return out;
>
> spin_unlock(&out->lock);
> diff --git a/ipc/util.h b/ipc/util.h
> index d05b708..a1cbc3a 100644
> --- a/ipc/util.h
> +++ b/ipc/util.h
> @@ -195,7 +195,7 @@ static inline void ipc_unlock(struct kern_ipc_perm *perm)
> */
> static inline bool ipc_valid_object(struct kern_ipc_perm *perm)
> {
> - return perm->deleted == 0;
> + return !perm->deleted;
> }
>
> struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
> --
> 1.8.3.1
>
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