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
           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 4.8.                 January 2017                   IPCCTL_PRE_DOWN_NOLO(9)