diff options
| -rw-r--r-- | block/blk-cgroup.c | 4 | ||||
| -rw-r--r-- | fs/kernfs/dir.c | 84 | ||||
| -rw-r--r-- | fs/sysfs/dir.c | 6 | ||||
| -rw-r--r-- | include/linux/blk-cgroup.h | 11 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 9 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 28 | ||||
| -rw-r--r-- | include/trace/events/cgroup.h | 163 | ||||
| -rw-r--r-- | kernel/cgroup.c | 75 | ||||
| -rw-r--r-- | kernel/cpuset.c | 13 | ||||
| -rw-r--r-- | kernel/sched/debug.c | 3 |
10 files changed, 266 insertions, 130 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index dd38e5ced4a3..b08ccbb9393a 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1340,10 +1340,8 @@ int blkcg_policy_register(struct blkcg_policy *pol) struct blkcg_policy_data *cpd; cpd = pol->cpd_alloc_fn(GFP_KERNEL); - if (!cpd) { - mutex_unlock(&blkcg_pol_mutex); + if (!cpd) goto err_free_cpds; - } blkcg->cpd[pol->plid] = cpd; cpd->blkcg = blkcg; diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index dcd96aac02f5..cf4c636ff4da 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -110,8 +110,9 @@ static struct kernfs_node *kernfs_common_ancestor(struct kernfs_node *a, * kn_to: /n1/n2/n3 [depth=3] * result: /../.. * - * return value: length of the string. If greater than buflen, - * then contents of buf are undefined. On error, -1 is returned. + * Returns the length of the full path. If the full length is equal to or + * greater than @buflen, @buf contains the truncated path with the trailing + * '\0'. On error, -errno is returned. */ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, struct kernfs_node *kn_from, @@ -119,9 +120,8 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, { struct kernfs_node *kn, *common; const char parent_str[] = "/.."; - size_t depth_from, depth_to, len = 0, nlen = 0; - char *p; - int i; + size_t depth_from, depth_to, len = 0; + int i, j; if (!kn_from) kn_from = kernfs_root(kn_to)->kn; @@ -131,7 +131,7 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, common = kernfs_common_ancestor(kn_from, kn_to); if (WARN_ON(!common)) - return -1; + return -EINVAL; depth_to = kernfs_depth(common, kn_to); depth_from = kernfs_depth(common, kn_from); @@ -144,22 +144,16 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, len < buflen ? buflen - len : 0); /* Calculate how many bytes we need for the rest */ - for (kn = kn_to; kn != common; kn = kn->parent) - nlen += strlen(kn->name) + 1; - - if (len + nlen >= buflen) - return len + nlen; - - p = buf + len + nlen; - *p = '\0'; - for (kn = kn_to; kn != common; kn = kn->parent) { - size_t tmp = strlen(kn->name); - p -= tmp; - memcpy(p, kn->name, tmp); - *(--p) = '/'; + for (i = depth_to - 1; i >= 0; i--) { + for (kn = kn_to, j = 0; j < i; j++) + kn = kn->parent; + len += strlcpy(buf + len, "/", + len < buflen ? buflen - len : 0); + len += strlcpy(buf + len, kn->name, + len < buflen ? buflen - len : 0); } - return len + nlen; + return len; } /** @@ -186,29 +180,6 @@ int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen) } /** - * kernfs_path_len - determine the length of the full path of a given node - * @kn: kernfs_node of interest - * - * The returned length doesn't include the space for the terminating '\0'. - */ -size_t kernfs_path_len(struct kernfs_node *kn) -{ - size_t len = 0; - unsigned long flags; - - spin_lock_irqsave(&kernfs_rename_lock, flags); - - do { - len += strlen(kn->name) + 1; - kn = kn->parent; - } while (kn && kn->parent); - - spin_unlock_irqrestore(&kernfs_rename_lock, flags); - - return len; -} - -/** * kernfs_path_from_node - build path of node @to relative to @from. * @from: parent kernfs_node relative to which we need to build the path * @to: kernfs_node of interest @@ -220,8 +191,9 @@ size_t kernfs_path_len(struct kernfs_node *kn) * path (which includes '..'s) as needed to reach from @from to @to is * returned. * - * If @buf isn't long enough, the return value will be greater than @buflen - * and @buf contents are undefined. + * Returns the length of the full path. If the full length is equal to or + * greater than @buflen, @buf contains the truncated path with the trailing + * '\0'. On error, -errno is returned. */ int kernfs_path_from_node(struct kernfs_node *to, struct kernfs_node *from, char *buf, size_t buflen) @@ -237,28 +209,6 @@ int kernfs_path_from_node(struct kernfs_node *to, struct kernfs_node *from, EXPORT_SYMBOL_GPL(kernfs_path_from_node); /** - * kernfs_path - build full path of a given node - * @kn: kernfs_node of interest - * @buf: buffer to copy @kn's name into - * @buflen: size of @buf - * - * Builds and returns the full path of @kn in @buf of @buflen bytes. The - * path is built from the end of @buf so the returned pointer usually - * doesn't match @buf. If @buf isn't long enough, @buf is nul terminated - * and %NULL is returned. - */ -char *kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen) -{ - int ret; - - ret = kernfs_path_from_node(kn, NULL, buf, buflen); - if (ret < 0 || ret >= buflen) - return NULL; - return buf; -} -EXPORT_SYMBOL_GPL(kernfs_path); - -/** * pr_cont_kernfs_name - pr_cont name of a kernfs_node * @kn: kernfs_node of interest * diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 94374e435025..2b67bda2021b 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -21,14 +21,14 @@ DEFINE_SPINLOCK(sysfs_symlink_target_lock); void sysfs_warn_dup(struct kernfs_node *parent, const char *name) { - char *buf, *path = NULL; + char *buf; buf = kzalloc(PATH_MAX, GFP_KERNEL); if (buf) - path = kernfs_path(parent, buf, PATH_MAX); + kernfs_path(parent, buf, PATH_MAX); WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s/%s'\n", - path, name); + buf, name); kfree(buf); } diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index cbdbf34de5b6..3bf5d33800ab 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 440a72164a11..c83c23f0577b 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); @@ -555,8 +555,7 @@ 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) { return kernfs_path(cgrp->kn, buf, buflen); } @@ -658,8 +657,8 @@ 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/include/linux/kernfs.h b/include/linux/kernfs.h index 96356ef012de..7056238fd9f5 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -269,10 +269,8 @@ static inline bool kernfs_ns_enabled(struct kernfs_node *kn) } int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen); -size_t kernfs_path_len(struct kernfs_node *kn); int kernfs_path_from_node(struct kernfs_node *root_kn, struct kernfs_node *kn, char *buf, size_t buflen); -char *kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen); void pr_cont_kernfs_name(struct kernfs_node *kn); void pr_cont_kernfs_path(struct kernfs_node *kn); struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn); @@ -341,12 +339,10 @@ static inline bool kernfs_ns_enabled(struct kernfs_node *kn) static inline int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen) { return -ENOSYS; } -static inline size_t kernfs_path_len(struct kernfs_node *kn) -{ return 0; } - -static inline char *kernfs_path(struct kernfs_node *kn, char *buf, - size_t buflen) -{ return NULL; } +static inline int kernfs_path_from_node(struct kernfs_node *root_kn, + struct kernfs_node *kn, + char *buf, size_t buflen) +{ return -ENOSYS; } static inline void pr_cont_kernfs_name(struct kernfs_node *kn) { } static inline void pr_cont_kernfs_path(struct kernfs_node *kn) { } @@ -436,6 +432,22 @@ static inline void kernfs_init(void) { } #endif /* CONFIG_KERNFS */ +/** + * kernfs_path - build full path of a given node + * @kn: kernfs_node of interest + * @buf: buffer to copy @kn's name into + * @buflen: size of @buf + * + * Builds and returns the full path of @kn in @buf of @buflen bytes. The + * path is built from the end of @buf so the returned pointer usually + * doesn't match @buf. If @buf isn't long enough, @buf is nul terminated + * and %NULL is returned. + */ +static inline int kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen) +{ + return kernfs_path_from_node(kn, NULL, buf, buflen); +} + static inline struct kernfs_node * kernfs_find_and_get(struct kernfs_node *kn, const char *name) { diff --git a/include/trace/events/cgroup.h b/include/trace/events/cgroup.h new file mode 100644 index 000000000000..ab68640a18d0 --- /dev/null +++ b/include/trace/events/cgroup.h @@ -0,0 +1,163 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM cgroup + +#if !defined(_TRACE_CGROUP_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_CGROUP_H + +#include <linux/cgroup.h> +#include <linux/tracepoint.h> + +DECLARE_EVENT_CLASS(cgroup_root, + + TP_PROTO(struct cgroup_root *root), + + TP_ARGS(root), + + TP_STRUCT__entry( + __field( int, root ) + __field( u16, ss_mask ) + __string( name, root->name ) + ), + + TP_fast_assign( + __entry->root = root->hierarchy_id; + __entry->ss_mask = root->subsys_mask; + __assign_str(name, root->name); + ), + + TP_printk("root=%d ss_mask=%#x name=%s", + __entry->root, __entry->ss_mask, __get_str(name)) +); + +DEFINE_EVENT(cgroup_root, cgroup_setup_root, + + TP_PROTO(struct cgroup_root *root), + + TP_ARGS(root) +); + +DEFINE_EVENT(cgroup_root, cgroup_destroy_root, + + TP_PROTO(struct cgroup_root *root), + + TP_ARGS(root) +); + +DEFINE_EVENT(cgroup_root, cgroup_remount, + + TP_PROTO(struct cgroup_root *root), + + TP_ARGS(root) +); + +DECLARE_EVENT_CLASS(cgroup, + + TP_PROTO(struct cgroup *cgrp), + + TP_ARGS(cgrp), + + TP_STRUCT__entry( + __field( int, root ) + __field( int, id ) + __field( int, level ) + __dynamic_array(char, path, + cgrp->kn ? cgroup_path(cgrp, NULL, 0) + 1 + : strlen("(null)")) + ), + + TP_fast_assign( + __entry->root = cgrp->root->hierarchy_id; + __entry->id = cgrp->id; + __entry->level = cgrp->level; + if (cgrp->kn) + cgroup_path(cgrp, __get_dynamic_array(path), + __get_dynamic_array_len(path)); + else + __assign_str(path, "(null)"); + ), + + TP_printk("root=%d id=%d level=%d path=%s", + __entry->root, __entry->id, __entry->level, __get_str(path)) +); + +DEFINE_EVENT(cgroup, cgroup_mkdir, + + TP_PROTO(struct cgroup *cgroup), + + TP_ARGS(cgroup) +); + +DEFINE_EVENT(cgroup, cgroup_rmdir, + + TP_PROTO(struct cgroup *cgroup), + + TP_ARGS(cgroup) +); + +DEFINE_EVENT(cgroup, cgroup_release, + + TP_PROTO(struct cgroup *cgroup), + + TP_ARGS(cgroup) +); + +DEFINE_EVENT(cgroup, cgroup_rename, + + TP_PROTO(struct cgroup *cgroup), + + TP_ARGS(cgroup) +); + +DECLARE_EVENT_CLASS(cgroup_migrate, + + TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup), + + TP_ARGS(dst_cgrp, task, threadgroup), + + TP_STRUCT__entry( + __field( int, dst_root ) + __field( int, dst_id ) + __field( int, dst_level ) + __dynamic_array(char, dst_path, + dst_cgrp->kn ? cgroup_path(dst_cgrp, NULL, 0) + 1 + : strlen("(null)")) + __field( int, pid ) + __string( comm, task->comm ) + ), + + TP_fast_assign( + __entry->dst_root = dst_cgrp->root->hierarchy_id; + __entry->dst_id = dst_cgrp->id; + __entry->dst_level = dst_cgrp->level; + if (dst_cgrp->kn) + cgroup_path(dst_cgrp, __get_dynamic_array(dst_path), + __get_dynamic_array_len(dst_path)); + else + __assign_str(dst_path, "(null)"); + __entry->pid = task->pid; + __assign_str(comm, task->comm); + ), + + TP_printk("dst_root=%d dst_id=%d dst_level=%d dst_path=%s pid=%d comm=%s", + __entry->dst_root, __entry->dst_id, __entry->dst_level, + __get_str(dst_path), __entry->pid, __get_str(comm)) +); + +DEFINE_EVENT(cgroup_migrate, cgroup_attach_task, + + TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup), + + TP_ARGS(dst_cgrp, task, threadgroup) +); + +DEFINE_EVENT(cgroup_migrate, cgroup_transfer_tasks, + + TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup), + + TP_ARGS(dst_cgrp, task, threadgroup) +); + +#endif /* _TRACE_CGROUP_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 44066158f0d1..85bc9beb046d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -64,6 +64,9 @@ #include <linux/file.h> #include <net/sock.h> +#define CREATE_TRACE_POINTS +#include <trace/events/cgroup.h> + /* * pidlists linger the following amount before being destroyed. The goal * is avoiding frequent destruction in the middle of consecutive read calls @@ -1176,6 +1179,8 @@ static void cgroup_destroy_root(struct cgroup_root *root) struct cgroup *cgrp = &root->cgrp; struct cgrp_cset_link *link, *tmp_link; + trace_cgroup_destroy_root(root); + cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp); BUG_ON(atomic_read(&root->nr_cgrps)); @@ -1874,6 +1879,9 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data) strcpy(root->release_agent_path, opts.release_agent); spin_unlock(&release_agent_path_lock); } + + trace_cgroup_remount(root); + out_unlock: kfree(opts.release_agent); kfree(opts.name); @@ -2031,6 +2039,8 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) if (ret) goto destroy_root; + trace_cgroup_setup_root(root); + /* * There must be no failure case after here, since rebinding takes * care of subsystems' refcounts, which are explicitly dropped in @@ -2315,22 +2325,18 @@ 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 +2363,12 @@ 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 +2377,15 @@ 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); @@ -2830,6 +2835,10 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp, ret = cgroup_migrate(leader, threadgroup, dst_cgrp->root); cgroup_migrate_finish(&preloaded_csets); + + if (!ret) + trace_cgroup_attach_task(dst_cgrp, leader, threadgroup); + return ret; } @@ -3611,6 +3620,8 @@ static int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent, mutex_lock(&cgroup_mutex); ret = kernfs_rename(kn, new_parent, new_name_str); + if (!ret) + trace_cgroup_rename(cgrp); mutex_unlock(&cgroup_mutex); @@ -4381,6 +4392,8 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) if (task) { ret = cgroup_migrate(task, false, to->root); + if (!ret) + trace_cgroup_transfer_tasks(to, task, false); put_task_struct(task); } } while (task && !ret); @@ -5046,6 +5059,8 @@ static void css_release_work_fn(struct work_struct *work) ss->css_released(css); } else { /* cgroup release path */ + trace_cgroup_release(cgrp); + cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id); cgrp->id = -1; @@ -5332,6 +5347,8 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, if (ret) goto out_destroy; + trace_cgroup_mkdir(cgrp); + /* let's create and online css's */ kernfs_activate(kn); @@ -5507,6 +5524,9 @@ static int cgroup_rmdir(struct kernfs_node *kn) ret = cgroup_destroy_locked(cgrp); + if (!ret) + trace_cgroup_rmdir(cgrp); + cgroup_kn_unlock(kn); return ret; } @@ -5743,7 +5763,7 @@ 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; @@ -5786,18 +5806,18 @@ 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; + if (retval < 0) 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 @@ -6062,8 +6082,9 @@ 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); @@ -6073,13 +6094,13 @@ 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 < 0 || 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 2b4c20ab5bbe..29f815d2ef7e 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2715,7 +2715,7 @@ 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; @@ -2724,14 +2724,15 @@ int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns, if (!buf) goto out; - 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) + retval = -ENAMETOOLONG; + if (retval < 0) goto out_free; - seq_puts(m, p); + seq_puts(m, buf); seq_putc(m, '\n'); retval = 0; out_free: diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 13935886a471..fa178b62ea79 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -415,7 +415,8 @@ 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 |