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| author |   Aleksa Sarai <cyphar@cyphar.com> | 2015-06-09 21:32:09 +1000 |
|---|---|---|
| committer |   Tejun Heo <tj@kernel.org> | 2015-07-14 17:29:23 -0400 |
| commit | 7e47682ea555e7c1edef1d8fd96e2aa4c12abe59 (patch) | |
| tree | 6012cbc180ae7d633be4ed2ff1f1f6f7f188c1a0 /include/linux/cgroup.h | |
| parent | Linux 4.2-rc1 (diff) | |
| download | linux-dev-7e47682ea555e7c1edef1d8fd96e2aa4c12abe59.tar.xz linux-dev-7e47682ea555e7c1edef1d8fd96e2aa4c12abe59.zip | |
cgroup: allow a cgroup subsystem to reject a fork
Add a new cgroup subsystem callback can_fork that conditionally
states whether or not the fork is accepted or rejected by a cgroup
policy. In addition, add a cancel_fork callback so that if an error
occurs later in the forking process, any state modified by can_fork can
be reverted.
Allow for a private opaque pointer to be passed from cgroup_can_fork to
cgroup_post_fork, allowing for the fork state to be stored by each
subsystem separately.
Also add a tagging system for cgroup_subsys.h to allow for CGROUP_<TAG>
enumerations to be be defined and used. In addition, explicitly add a
CGROUP_CANFORK_COUNT macro to make arrays easier to define.
This is in preparation for implementing the pids cgroup subsystem.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index a593e299162e..a71fe2a3984e 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -62,7 +62,12 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *tsk); void cgroup_fork(struct task_struct *p); -void cgroup_post_fork(struct task_struct *p); +extern int cgroup_can_fork(struct task_struct *p, + void *ss_priv[CGROUP_CANFORK_COUNT]); +extern void cgroup_cancel_fork(struct task_struct *p, + void *ss_priv[CGROUP_CANFORK_COUNT]); +extern void cgroup_post_fork(struct task_struct *p, + void *old_ss_priv[CGROUP_CANFORK_COUNT]); void cgroup_exit(struct task_struct *p); int cgroup_init_early(void); @@ -524,7 +529,13 @@ static inline int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry) { return -EINVAL; } static inline void cgroup_fork(struct task_struct *p) {} -static inline void cgroup_post_fork(struct task_struct *p) {} +static inline int cgroup_can_fork(struct task_struct *p, + void *ss_priv[CGROUP_CANFORK_COUNT]) +{ return 0; } +static inline void cgroup_cancel_fork(struct task_struct *p, + void *ss_priv[CGROUP_CANFORK_COUNT]) {} +static inline void cgroup_post_fork(struct task_struct *p, + void *ss_priv[CGROUP_CANFORK_COUNT]) {} static inline void cgroup_exit(struct task_struct *p) {} static inline int cgroup_init_early(void) { return 0; } |