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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

struct ipc_namespace * ns

ipc namespace

struct ipc_ids * ids

the table of ids where to look for the ipc

int id

the id of the ipc to retrieve

int cmd

the cmd to check

struct ipc64_perm * perm

the permission to set

int 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

July 2017 Kernel Hackers Manual 4.11