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

From: Rafael Aquini
Date: Thu Dec 19 2013 - 12:23:34 EST


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>
---
* 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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