diff options
| author | Rom Lemarchand <romlem@android.com> | 2014-11-07 12:48:17 -0800 |
|---|---|---|
| committer | Michael Bestas <mkbestas@lineageos.org> | 2022-04-19 00:51:42 +0300 |
| commit | 55ab7be4f79903e7448d03ffbd2b6d59daad2ca1 (patch) | |
| tree | c8ef357bc2a4a8242181951fcb3304826fad2cb6 | |
| parent | a2b6897af5af0c731fe0d4cd3dfb0c4342804b59 (diff) | |
cgroup: refactor allow_attach function into common code
move cpu_cgroup_allow_attach to a common subsys_cgroup_allow_attach.
This allows any process with CAP_SYS_NICE to move tasks across cgroups if
they use this function as their allow_attach handler.
Bug: 18260435
Change-Id: I6bb4933d07e889d0dc39e33b4e71320c34a2c90f
Signed-off-by: Rom Lemarchand <romlem@android.com>
Signed-off-by: Chatur27 <jasonbright2709@gmail.com>
| -rw-r--r-- | include/linux/cgroup.h | 16 | ||||
| -rw-r--r-- | kernel/cgroup.c | 19 |
2 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 55d3ff0c5c03..e6ab2f1e6f8b 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -623,6 +623,17 @@ static inline void cgroup_kthread_ready(void) current->no_cgroup_migration = 0; } +/* + * Default Android check for whether the current process is allowed to move a + * task across cgroups, either because CAP_SYS_NICE is set or because the uid + * of the calling process is the same as the moved task or because we are + * running as root. + * Returns 0 if this is allowed, or -EACCES otherwise. + */ +int subsys_cgroup_allow_attach(struct cgroup_subsys_state *css, + struct cgroup_taskset *tset); + + #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state; @@ -645,6 +656,11 @@ static inline int cgroup_init(void) { return 0; } static inline void cgroup_init_kthreadd(void) {} static inline void cgroup_kthread_ready(void) {} +static inline int subsys_cgroup_allow_attach(struct cgroup_subsys_state *css, + struct cgroup_taskset *tset) +{ + return 0; +} #endif /* !CONFIG_CGROUPS */ /* diff --git a/kernel/cgroup.c b/kernel/cgroup.c index b3ad18420b42..59324034aefb 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2825,6 +2825,25 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp, return ret; } +int subsys_cgroup_allow_attach(struct cgroup_subsys_state *css, struct cgroup_taskset *tset) +{ + const struct cred *cred = current_cred(), *tcred; + struct task_struct *task; + + if (capable(CAP_SYS_NICE)) + return 0; + + cgroup_taskset_for_each(task, css, tset) { + tcred = __task_cred(task); + + if (current != task && !uid_eq(cred->euid, tcred->uid) && + !uid_eq(cred->euid, tcred->suid)) + return -EACCES; + } + + return 0; +} + static int cgroup_procs_write_permission(struct task_struct *task, struct cgroup *dst_cgrp, struct kernfs_open_file *of) |