[PATCH 2.6.24-rc8-mm1 06/15] IPC: get rid of the use *_setbuf structure.

From: pierre . peiffer
Date: Tue Jan 29 2008 - 11:19:03 EST


From: Pierre Peiffer <pierre.peiffer@xxxxxxxx>

All IPCs make use of an intermetiate *_setbuf structure to handle the
IPC_SET command. This is not really needed and, moreover, it complicate
a little bit the code.

This patch get rid of the use of it and uses directly the semid64_ds/
msgid64_ds/shmid64_ds structure.

In addition of removing one struture declaration, it also simplifies
and improves a little bit the common 64-bits path.
Moreover, this will simplify the code for handling the IPC_SETALL
command provided in the next patch.

Signed-off-by: Pierre Peiffer <pierre.peiffer@xxxxxxxx>
Acked-by: Serge Hallyn <serue@xxxxxxxxxx>
---

ipc/msg.c | 51 ++++++++++++++++++---------------------------------
ipc/sem.c | 40 ++++++++++++++--------------------------
ipc/shm.c | 41 ++++++++++++++---------------------------
3 files changed, 46 insertions(+), 86 deletions(-)

Index: b/ipc/msg.c
===================================================================
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -351,31 +351,14 @@ copy_msqid_to_user(void __user *buf, str
}
}

-struct msq_setbuf {
- unsigned long qbytes;
- uid_t uid;
- gid_t gid;
- mode_t mode;
-};
-
static inline unsigned long
-copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version)
+copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
{
switch(version) {
case IPC_64:
- {
- struct msqid64_ds tbuf;
-
- if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
+ if (copy_from_user(out, buf, sizeof(*out)))
return -EFAULT;
-
- out->qbytes = tbuf.msg_qbytes;
- out->uid = tbuf.msg_perm.uid;
- out->gid = tbuf.msg_perm.gid;
- out->mode = tbuf.msg_perm.mode;
-
return 0;
- }
case IPC_OLD:
{
struct msqid_ds tbuf_old;
@@ -383,14 +366,14 @@ copy_msqid_from_user(struct msq_setbuf *
if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
return -EFAULT;

- out->uid = tbuf_old.msg_perm.uid;
- out->gid = tbuf_old.msg_perm.gid;
- out->mode = tbuf_old.msg_perm.mode;
+ out->msg_perm.uid = tbuf_old.msg_perm.uid;
+ out->msg_perm.gid = tbuf_old.msg_perm.gid;
+ out->msg_perm.mode = tbuf_old.msg_perm.mode;

if (tbuf_old.msg_qbytes == 0)
- out->qbytes = tbuf_old.msg_lqbytes;
+ out->msg_qbytes = tbuf_old.msg_lqbytes;
else
- out->qbytes = tbuf_old.msg_qbytes;
+ out->msg_qbytes = tbuf_old.msg_qbytes;

return 0;
}
@@ -408,12 +391,12 @@ static int msgctl_down(struct ipc_namesp
struct msqid_ds __user *buf, int version)
{
struct kern_ipc_perm *ipcp;
- struct msq_setbuf setbuf;
+ struct msqid64_ds msqid64;
struct msg_queue *msq;
int err;

if (cmd == IPC_SET) {
- if (copy_msqid_from_user(&setbuf, buf, version))
+ if (copy_msqid_from_user(&msqid64, buf, version))
return -EFAULT;
}

@@ -431,8 +414,10 @@ static int msgctl_down(struct ipc_namesp
goto out_unlock;

if (cmd == IPC_SET) {
- err = audit_ipc_set_perm(setbuf.qbytes, setbuf.uid, setbuf.gid,
- setbuf.mode);
+ err = audit_ipc_set_perm(msqid64.msg_qbytes,
+ msqid64.msg_perm.uid,
+ msqid64.msg_perm.gid,
+ msqid64.msg_perm.mode);
if (err)
goto out_unlock;
}
@@ -454,18 +439,18 @@ static int msgctl_down(struct ipc_namesp
freeque(ns, ipcp);
goto out_up;
case IPC_SET:
- if (setbuf.qbytes > ns->msg_ctlmnb &&
+ if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
!capable(CAP_SYS_RESOURCE)) {
err = -EPERM;
goto out_unlock;
}

- msq->q_qbytes = setbuf.qbytes;
+ msq->q_qbytes = msqid64.msg_qbytes;

- ipcp->uid = setbuf.uid;
- ipcp->gid = setbuf.gid;
+ ipcp->uid = msqid64.msg_perm.uid;
+ ipcp->gid = msqid64.msg_perm.gid;
ipcp->mode = (ipcp->mode & ~S_IRWXUGO) |
- (S_IRWXUGO & setbuf.mode);
+ (S_IRWXUGO & msqid64.msg_perm.mode);
msq->q_ctime = get_seconds();
/* sleeping receivers might be excluded by
* stricter permissions.
Index: b/ipc/sem.c
===================================================================
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -837,28 +837,14 @@ out_free:
return err;
}

-struct sem_setbuf {
- uid_t uid;
- gid_t gid;
- mode_t mode;
-};
-
-static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __user *buf, int version)
+static inline unsigned long
+copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
{
switch(version) {
case IPC_64:
- {
- struct semid64_ds tbuf;
-
- if(copy_from_user(&tbuf, buf, sizeof(tbuf)))
+ if (copy_from_user(out, buf, sizeof(*out)))
return -EFAULT;
-
- out->uid = tbuf.sem_perm.uid;
- out->gid = tbuf.sem_perm.gid;
- out->mode = tbuf.sem_perm.mode;
-
return 0;
- }
case IPC_OLD:
{
struct semid_ds tbuf_old;
@@ -866,9 +852,9 @@ static inline unsigned long copy_semid_f
if(copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
return -EFAULT;

- out->uid = tbuf_old.sem_perm.uid;
- out->gid = tbuf_old.sem_perm.gid;
- out->mode = tbuf_old.sem_perm.mode;
+ out->sem_perm.uid = tbuf_old.sem_perm.uid;
+ out->sem_perm.gid = tbuf_old.sem_perm.gid;
+ out->sem_perm.mode = tbuf_old.sem_perm.mode;

return 0;
}
@@ -887,11 +873,11 @@ static int semctl_down(struct ipc_namesp
{
struct sem_array *sma;
int err;
- struct sem_setbuf uninitialized_var(setbuf);
+ struct semid64_ds semid64;
struct kern_ipc_perm *ipcp;

if(cmd == IPC_SET) {
- if(copy_semid_from_user (&setbuf, arg.buf, version))
+ if (copy_semid_from_user(&semid64, arg.buf, version))
return -EFAULT;
}
down_write(&sem_ids(ns).rw_mutex);
@@ -908,7 +894,9 @@ static int semctl_down(struct ipc_namesp
goto out_unlock;

if (cmd == IPC_SET) {
- err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
+ err = audit_ipc_set_perm(0, semid64.sem_perm.uid,
+ semid64.sem_perm.gid,
+ semid64.sem_perm.mode);
if (err)
goto out_unlock;
}
@@ -927,10 +915,10 @@ static int semctl_down(struct ipc_namesp
freeary(ns, ipcp);
goto out_up;
case IPC_SET:
- ipcp->uid = setbuf.uid;
- ipcp->gid = setbuf.gid;
+ ipcp->uid = semid64.sem_perm.uid;
+ ipcp->gid = semid64.sem_perm.gid;
ipcp->mode = (ipcp->mode & ~S_IRWXUGO)
- | (setbuf.mode & S_IRWXUGO);
+ | (semid64.sem_perm.mode & S_IRWXUGO);
sma->sem_ctime = get_seconds();
break;
default:
Index: b/ipc/shm.c
===================================================================
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -520,28 +520,14 @@ static inline unsigned long copy_shmid_t
}
}

-struct shm_setbuf {
- uid_t uid;
- gid_t gid;
- mode_t mode;
-};
-
-static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version)
+static inline unsigned long
+copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
{
switch(version) {
case IPC_64:
- {
- struct shmid64_ds tbuf;
-
- if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
+ if (copy_from_user(out, buf, sizeof(*out)))
return -EFAULT;
-
- out->uid = tbuf.shm_perm.uid;
- out->gid = tbuf.shm_perm.gid;
- out->mode = tbuf.shm_perm.mode;
-
return 0;
- }
case IPC_OLD:
{
struct shmid_ds tbuf_old;
@@ -549,9 +535,9 @@ static inline unsigned long copy_shmid_f
if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
return -EFAULT;

- out->uid = tbuf_old.shm_perm.uid;
- out->gid = tbuf_old.shm_perm.gid;
- out->mode = tbuf_old.shm_perm.mode;
+ out->shm_perm.uid = tbuf_old.shm_perm.uid;
+ out->shm_perm.gid = tbuf_old.shm_perm.gid;
+ out->shm_perm.mode = tbuf_old.shm_perm.mode;

return 0;
}
@@ -634,12 +620,12 @@ static int shmctl_down(struct ipc_namesp
struct shmid_ds __user *buf, int version)
{
struct kern_ipc_perm *ipcp;
- struct shm_setbuf setbuf;
+ struct shmid64_ds shmid64;
struct shmid_kernel *shp;
int err;

if (cmd == IPC_SET) {
- if (copy_shmid_from_user(&setbuf, buf, version))
+ if (copy_shmid_from_user(&shmid64, buf, version))
return -EFAULT;
}

@@ -657,8 +643,9 @@ static int shmctl_down(struct ipc_namesp
goto out_unlock;

if (cmd == IPC_SET) {
- err = audit_ipc_set_perm(0, setbuf.uid,
- setbuf.gid, setbuf.mode);
+ err = audit_ipc_set_perm(0, shmid64.shm_perm.uid,
+ shmid64.shm_perm.gid,
+ shmid64.shm_perm.mode);
if (err)
goto out_unlock;
}
@@ -678,10 +665,10 @@ static int shmctl_down(struct ipc_namesp
do_shm_rmid(ns, ipcp);
goto out_up;
case IPC_SET:
- ipcp->uid = setbuf.uid;
- ipcp->gid = setbuf.gid;
+ ipcp->uid = shmid64.shm_perm.uid;
+ ipcp->gid = shmid64.shm_perm.gid;
ipcp->mode = (ipcp->mode & ~S_IRWXUGO)
- | (setbuf.mode & S_IRWXUGO);
+ | (shmid64.shm_perm.mode & S_IRWXUGO);
shp->shm_ctim = get_seconds();
break;
default:

--
Pierre Peiffer
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