IPCCTL_PRE_DOWN_NOLO(9) Kernel IPC facilities IPCCTL_PRE_DOWN_NOLO(9)NAME
ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd
SYNOPSIS
struct kern_ipc_perm * ipcctl_pre_down_nolock(struct ipc_namespace * ns, struct ipc_ids * ids, int id, int cmd, struct ipc64_perm * perm,
int extra_perm);
ARGUMENTS
ns
the ipc namespace
ids
the table of ids where to look for the ipc
id
the id of the ipc to retrieve
cmd
the cmd to check
perm
the permission to set
extra_perm
one extra permission parameter used by msq
DESCRIPTION
This function does some common audit and permissions check for some IPC_XXX cmd and is called from semctl_down, shmctl_down and
msgctl_down. It must be called without any lock held and - retrieves the ipc with the given id in the given table. - performs some audit
and permission check, depending on the given cmd - returns a pointer to the ipc object or otherwise, the corresponding error.
Call holding the both the rwsem and the rcu read lock.
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 IPCCTL_PRE_DOWN_NOLO(9)
Check Out this Related Man Page
ipc.h(3HEAD) Headers ipc.h(3HEAD)NAME
ipc.h, ipc - XSI interprocess communication access structure
SYNOPSIS
#include <sys/ipc.h>
DESCRIPTION
The <sys/ipc.h> header is used by three mechanisms for interprocess communication (IPC): messages, semaphores, and shared memory. All use a
common structure type, ipc_perm, to pass information used in determining permission to perform an IPC operation.
The ipc_perm structure contains the following members:
uid_t uid /* owner's user ID */
gid_t gid /* owner's group ID */
uid_t cuid /* creator's user ID */
gid_t cgid /* creator's group ID */
mode_t mode /* read/write permission
The uid_t, gid_t, mode_t, and key_t types are defined as described in <sys/types.h>. See types.h(3HEAD).
Definitions are provided for the constants listed below.
Mode bits:
IPC_CREAT Create entry if key does not exist.
IPC_EXCL Fail if key exists.
IPC_NOWAIT Error if request must wait.
Keys:
IPC_PRIVATE Private key.
Control commands:
IPC_RMID Remove identifier.
IPC_SET Set options.
IPC_STAT Get options.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
SEE ALSO ftok(3C), types.h(3HEAD), attributes(5), standards(5)SunOS 5.10 10 Sep 2004 ipc.h(3HEAD)
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