The patch titled cgroups: fix cgroup_iter_next() bug has been removed from the -mm tree. Its filename was cgroups-fix-cgroup_iter_next-bug.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: cgroups: fix cgroup_iter_next() bug From: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> Ee access res->cgroups without the task_lock(), so res->cgroups may be changed. it's unreliable, and "if (l == &res->cgroups->tasks)" may be false forever. We don't need add any lock for fixing this bug. we just access to struct css_set by struct cg_cgroup_link, not by struct task_struct. Since we hold css_set_lock, struct cg_cgroup_link is reliable. Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> Reviewed-by: Paul Menage <menage@xxxxxxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxx> Cc: Balbir Singh <balbir@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/cgroup.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff -puN kernel/cgroup.c~cgroups-fix-cgroup_iter_next-bug kernel/cgroup.c --- a/kernel/cgroup.c~cgroups-fix-cgroup_iter_next-bug +++ a/kernel/cgroup.c @@ -1808,6 +1808,7 @@ struct task_struct *cgroup_iter_next(str { struct task_struct *res; struct list_head *l = it->task; + struct cg_cgroup_link *link; /* If the iterator cg is NULL, we have no tasks */ if (!it->cg_link) @@ -1815,7 +1816,8 @@ struct task_struct *cgroup_iter_next(str res = list_entry(l, struct task_struct, cg_list); /* Advance iterator to find next entry */ l = l->next; - if (l == &res->cgroups->tasks) { + link = list_entry(it->cg_link, struct cg_cgroup_link, cgrp_link_list); + if (l == &link->cg->tasks) { /* We reached the end of this task list - move on to * the next cg_cgroup_link */ cgroup_advance_iter(cgrp, it); _ Patches currently in -mm which might be from laijs@xxxxxxxxxxxxxx are origin.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html