History

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: create rcu_my_thread_group_empty() wrapper memcg: css_id() must be called under rcu_read_lock() cgroup: Check task_lock in task_subsys_state() sched: Fix an RCU warning in print_task() cgroup: Fix an RCU warning in alloc_css_id() cgroup: Fix an RCU warning in cgroup_path() KEYS: Fix an RCU warning in the reading of user keys KEYS: Fix an RCU warning

Linus Torvalds committed 16 years ago

Commit 91bc4822 parents e8e8fad ee84b826 files · +43 −10Browse files

Unified · Split

6 files
  1. include/linux/cgroup.h +1 −0
  2. include/linux/rcupdate.h +2 −0
  3. kernel/cgroup.c +11 −5
  4. kernel/rcupdate.c +11 −0
  5. kernel/sched_debug.c +2 −0
  6. mm/memcontrol.c +16 −5
include/linux/cgroup.h+1−0
@@ -530,6 +530,7 @@ static inline struct cgroup_subsys_state *task_subsys_state( · 529 unmodified lines
530530 {
531531 return rcu_dereference_check(task->cgroups->subsys[subsys_id],
532532 rcu_read_lock_held() ||
533+ lockdep_is_held(&task->alloc_lock) ||
533534 cgroup_lock_is_held());
534535 }
535536
include/linux/rcupdate.h+2−0
@@ -190,6 +190,8 @@ static inline int rcu_read_lock_sched_held(void) · 189 unmodified lines
190190
191191 #ifdef CONFIG_PROVE_RCU
192192
193+extern int rcu_my_thread_group_empty(void);
194+
193195 /**
194196 * rcu_dereference_check - rcu_dereference with debug checking
195197 * @p: The pointer to read, prior to dereferencing
kernel/cgroup.c+11−5
@@ -1646,7 +1646,9 @@ static inline struct cftype *__d_cft(struct dentry *dentry) · 1645 unmodified lines
16461646 int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
16471647 {
16481648 char *start;
1649− struct dentry *dentry = rcu_dereference(cgrp->dentry);
1649+ struct dentry *dentry = rcu_dereference_check(cgrp->dentry,
1650+ rcu_read_lock_held() ||
1651+ cgroup_lock_is_held());
16501652
16511653 if (!dentry || cgrp == dummytop) {
16521654 /*
@@ -1662,13 +1664,17 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen) · 9 unmodified lines
16621664 *--start = '\0';
16631665 for (;;) {
16641666 int len = dentry->d_name.len;
1667+
16651668 if ((start -= len) < buf)
16661669 return -ENAMETOOLONG;
1667− memcpy(start, cgrp->dentry->d_name.name, len);
1670+ memcpy(start, dentry->d_name.name, len);
16681671 cgrp = cgrp->parent;
16691672 if (!cgrp)
16701673 break;
1671− dentry = rcu_dereference(cgrp->dentry);
1674+
1675+ dentry = rcu_dereference_check(cgrp->dentry,
1676+ rcu_read_lock_held() ||
1677+ cgroup_lock_is_held());
16721678 if (!cgrp->parent)
16731679 continue;
16741680 if (--start < buf)
@@ -4555,13 +4561,13 @@ static int alloc_css_id(struct cgroup_subsys *ss, struct cgroup *parent, · 2880 unmodified lines
45554561 {
45564562 int subsys_id, i, depth = 0;
45574563 struct cgroup_subsys_state *parent_css, *child_css;
4558− struct css_id *child_id, *parent_id = NULL;
4564+ struct css_id *child_id, *parent_id;
45594565
45604566 subsys_id = ss->subsys_id;
45614567 parent_css = parent->subsys[subsys_id];
45624568 child_css = child->subsys[subsys_id];
4563− depth = css_depth(parent_css) + 1;
45644569 parent_id = parent_css->id;
4570+ depth = parent_id->depth;
45654571
45664572 child_id = get_new_cssid(ss, depth);
45674573 if (IS_ERR(child_id))
kernel/rcupdate.c+11−0
@@ -122,3 +122,14 @@ void wakeme_after_rcu(struct rcu_head *head) · 121 unmodified lines
122122 rcu = container_of(head, struct rcu_synchronize, head);
123123 complete(&rcu->completion);
124124 }
125+
126+#ifdef CONFIG_PROVE_RCU
127+/*
128+ * wrapper function to avoid #include problems.
129+ */
130+int rcu_my_thread_group_empty(void)
131+{
132+ return thread_group_empty(current);
133+}
134+EXPORT_SYMBOL_GPL(rcu_my_thread_group_empty);
135+#endif /* #ifdef CONFIG_PROVE_RCU */
kernel/sched_debug.c+2−0
@@ -114,7 +114,9 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p) · 113 unmodified lines
114114 {
115115 char path[64];
116116
117+ rcu_read_lock();
117118 cgroup_path(task_group(p)->css.cgroup, path, sizeof(path));
119+ rcu_read_unlock();
118120 SEQ_printf(m, " %s", path);
119121 }
120122 #endif
mm/memcontrol.c+16−5
@@ -811,10 +811,12 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) · 810 unmodified lines
811811 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
812812 * hierarchy(even if use_hierarchy is disabled in "mem").
813813 */
814+ rcu_read_lock();
814815 if (mem->use_hierarchy)
815816 ret = css_is_ancestor(&curr->css, &mem->css);
816817 else
817818 ret = (curr == mem);
819+ rcu_read_unlock();
818820 css_put(&curr->css);
819821 return ret;
820822 }
@@ -2312,7 +2314,9 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) · 1491 unmodified lines
23122314
23132315 /* record memcg information */
23142316 if (do_swap_account && swapout && memcg) {
2317+ rcu_read_lock();
23152318 swap_cgroup_record(ent, css_id(&memcg->css));
2319+ rcu_read_unlock();
23162320 mem_cgroup_get(memcg);
23172321 }
23182322 if (swapout && memcg)
@@ -2369,8 +2373,10 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry, · 50 unmodified lines
23692373 {
23702374 unsigned short old_id, new_id;
23712375
2376+ rcu_read_lock();
23722377 old_id = css_id(&from->css);
23732378 new_id = css_id(&to->css);
2379+ rcu_read_unlock();
23742380
23752381 if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
23762382 mem_cgroup_swap_statistics(from, false);
@@ -4038,11 +4044,16 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma, · 1661 unmodified lines
40384044 put_page(page);
40394045 }
40404046 /* throught */
4041− if (ent.val && do_swap_account && !ret &&
4042− css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
4043− ret = MC_TARGET_SWAP;
4044− if (target)
4045− target->ent = ent;
4047+ if (ent.val && do_swap_account && !ret) {
4048+ unsigned short id;
4049+ rcu_read_lock();
4050+ id = css_id(&mc.from->css);
4051+ rcu_read_unlock();
4052+ if (id == lookup_swap_cgroup(ent)) {
4053+ ret = MC_TARGET_SWAP;
4054+ if (target)
4055+ target->ent = ent;
4056+ }
40464057 }
40474058 return ret;
40484059 }