diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 10648e300c930ecb06c58371a6c3822a1192d229..4e8c215e185c1dffe6b59541b32848e18f864937 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -343,16 +343,7 @@ static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd)
*/
static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen)
{
- char *p;
-
- p = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
- if (!p) {
- strncpy(buf, "<unavailable>", buflen);
- return -ENAMETOOLONG;
- }
-
- memmove(buf, p, buf + buflen - p);
- return 0;
+ return cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
}
/**
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 5a9abdee43fe839ff6acd2a50504bcc34696eaa2..6df36361a492405644c9a4c61ba01d14ceeb9d29 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -97,7 +97,7 @@ int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
int cgroup_rm_cftypes(struct cftype *cfts);
void cgroup_file_notify(struct cgroup_file *cfile);
-char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen);
+int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen);
int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry);
int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *tsk);
@@ -538,15 +538,9 @@ static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)
return kernfs_name(cgrp->kn, buf, buflen);
}
-static inline char * __must_check cgroup_path(struct cgroup *cgrp, char *buf,
- size_t buflen)
+static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen)
{
- int ret;
-
- ret = kernfs_path(cgrp->kn, buf, buflen);
- if (ret < 0 || ret >= buflen)
- return NULL;
- return buf;
+ return kernfs_path(cgrp->kn, buf, buflen);
}
static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
@@ -639,8 +633,8 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
struct user_namespace *user_ns,
struct cgroup_namespace *old_ns);
-char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
- struct cgroup_namespace *ns);
+int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
+ struct cgroup_namespace *ns);
#else /* !CONFIG_CGROUPS */
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index d1c51b7f5221fbfbb85ed3d12e4918a970713829..3861161e460f961f0659911a890220c8d9778f8d 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2315,22 +2315,18 @@ static struct file_system_type cgroup2_fs_type = {
.fs_flags = FS_USERNS_MOUNT,
};
-static char *cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen,
- struct cgroup_namespace *ns)
+static int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen,
+ struct cgroup_namespace *ns)
{
struct cgroup *root = cset_cgroup_from_root(ns->root_cset, cgrp->root);
- int ret;
- ret = kernfs_path_from_node(cgrp->kn, root->kn, buf, buflen);
- if (ret < 0 || ret >= buflen)
- return NULL;
- return buf;
+ return kernfs_path_from_node(cgrp->kn, root->kn, buf, buflen);
}
-char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
- struct cgroup_namespace *ns)
+int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
+ struct cgroup_namespace *ns)
{
- char *ret;
+ int ret;
mutex_lock(&cgroup_mutex);
spin_lock_irq(&css_set_lock);
@@ -2357,12 +2353,12 @@ EXPORT_SYMBOL_GPL(cgroup_path_ns);
*
* Return value is the same as kernfs_path().
*/
-char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
+int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
{
struct cgroup_root *root;
struct cgroup *cgrp;
int hierarchy_id = 1;
- char *path = NULL;
+ int ret;
mutex_lock(&cgroup_mutex);
spin_lock_irq(&css_set_lock);
@@ -2371,16 +2367,15 @@ char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
if (root) {
cgrp = task_cgroup_from_root(task, root);
- path = cgroup_path_ns_locked(cgrp, buf, buflen, &init_cgroup_ns);
+ ret = cgroup_path_ns_locked(cgrp, buf, buflen, &init_cgroup_ns);
} else {
/* if no hierarchy exists, everyone is in "/" */
- if (strlcpy(buf, "/", buflen) < buflen)
- path = buf;
+ ret = strlcpy(buf, "/", buflen);
}
spin_unlock_irq(&css_set_lock);
mutex_unlock(&cgroup_mutex);
- return path;
+ return ret;
}
EXPORT_SYMBOL_GPL(task_cgroup_path);
@@ -5716,7 +5711,7 @@ core_initcall(cgroup_wq_init);
int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *tsk)
{
- char *buf, *path;
+ char *buf;
int retval;
struct cgroup_root *root;
@@ -5759,18 +5754,18 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
* " (deleted)" is appended to the cgroup path.
*/
if (cgroup_on_dfl(cgrp) || !(tsk->flags & PF_EXITING)) {
- path = cgroup_path_ns_locked(cgrp, buf, PATH_MAX,
+ retval = cgroup_path_ns_locked(cgrp, buf, PATH_MAX,
current->nsproxy->cgroup_ns);
- if (!path) {
+ if (retval >= PATH_MAX) {
retval = -ENAMETOOLONG;
goto out_unlock;
}
+
+ seq_puts(m, buf);
} else {
- path = "/";
+ seq_puts(m, "/");
}
- seq_puts(m, path);
-
if (cgroup_on_dfl(cgrp) && cgroup_is_dead(cgrp))
seq_puts(m, " (deleted)\n");
else
@@ -6035,8 +6030,9 @@ static void cgroup_release_agent(struct work_struct *work)
{
struct cgroup *cgrp =
container_of(work, struct cgroup, release_agent_work);
- char *pathbuf = NULL, *agentbuf = NULL, *path;
+ char *pathbuf = NULL, *agentbuf = NULL;
char *argv[3], *envp[3];
+ int ret;
mutex_lock(&cgroup_mutex);
@@ -6046,13 +6042,13 @@ static void cgroup_release_agent(struct work_struct *work)
goto out;
spin_lock_irq(&css_set_lock);
- path = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
+ ret = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
spin_unlock_irq(&css_set_lock);
- if (!path)
+ if (ret >= PATH_MAX)
goto out;
argv[0] = agentbuf;
- argv[1] = path;
+ argv[1] = pathbuf;
argv[2] = NULL;
/* minimal command environment */
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index c7fd2778ed50edc52b7c0e5f1f651dcb141c9495..793ae6fd96dcd2118f410a4c6813d257b05d84da 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2689,7 +2689,7 @@ void __cpuset_memory_pressure_bump(void)
int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *tsk)
{
- char *buf, *p;
+ char *buf;
struct cgroup_subsys_state *css;
int retval;
@@ -2700,18 +2700,18 @@ int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
retval = -ENAMETOOLONG;
css = task_get_css(tsk, cpuset_cgrp_id);
- p = cgroup_path_ns(css->cgroup, buf, PATH_MAX,
- current->nsproxy->cgroup_ns);
+ retval = cgroup_path_ns(css->cgroup, buf, PATH_MAX,
+ current->nsproxy->cgroup_ns);
css_put(css);
- if (!p)
+ if (retval >= PATH_MAX)
goto out_free;
- seq_puts(m, p);
+ seq_puts(m, buf);
seq_putc(m, '\n');
retval = 0;
out_free:
kfree(buf);
out:
- return retval;
+ return 0;
}
#endif /* CONFIG_PROC_PID_CPUSET */
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 2a0a9995256d9e920d3c94cf944cd6acb61fa627..23cb609ba4ebce1b71d326a1f3aba7f0dd8bfd55 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -410,7 +410,8 @@ static char *task_group_path(struct task_group *tg)
if (autogroup_path(tg, group_path, PATH_MAX))
return group_path;
- return cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
+ cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
+ return group_path;
}
#endif