The commit is pushed to "branch-rh7-3.10.0-327.18.2.vz7.14.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git after rh7-3.10.0-327.18.2.vz7.14.18 ------> commit 6a887128c0ff214571da1451d7336e3c9bb8d86a Author: Andrey Ryabinin <aryabi...@virtuozzo.com> Date: Wed Jun 22 17:19:39 2016 +0400
ve/cpustat: don't try to update vcpustats for root_task_group root_task_group doesn't have vcpu stats. Attempt to update them leads to NULL-ptr deref: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff810b440c>] cpu_cgroup_update_vcpustat+0x13c/0x620 ... Call Trace: [<ffffffff810bee3b>] cpu_cgroup_get_stat+0x7b/0x180 [<ffffffff810f1ef7>] ve_get_cpu_stat+0x27/0x70 [<ffffffffa01836a1>] fill_cpu_stat+0x91/0x1e0 [vzmon] [<ffffffffa0183c6b>] vzcalls_ioctl+0x2bb/0x430 [vzmon] [<ffffffffa018d0d5>] vzctl_ioctl+0x45/0x60 [vzdev] [<ffffffff8120cfb5>] do_vfs_ioctl+0x255/0x4f0 [<ffffffff8120d2a4>] SyS_ioctl+0x54/0xa0 [<ffffffff81642ac9>] system_call_fastpath+0x16/0x1b So, return -ENOENT if we asked for vcpu stats of root_task_group. https://jira.sw.ru/browse/PSBM-48721 Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> Reviewed-by: Vladimir Davydov <vdavy...@virtuozzo.com> --- kernel/sched/core.c | 10 ++++++++-- kernel/ve/ve.c | 7 ++++--- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e885549..94deef4 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -9120,20 +9120,26 @@ int cpu_cgroup_proc_loadavg(struct cgroup *cgrp, struct cftype *cft, return 0; } -void cpu_cgroup_get_stat(struct cgroup *cgrp, struct kernel_cpustat *kstat) +int cpu_cgroup_get_stat(struct cgroup *cgrp, struct kernel_cpustat *kstat) { struct task_group *tg = cgroup_tg(cgrp); int nr_vcpus = tg->nr_cpus ?: num_online_cpus(); int i; + kernel_cpustat_zero(kstat); + + if (tg == &root_task_group) + return -ENOENT; + for_each_possible_cpu(i) cpu_cgroup_update_stat(cgrp, i); cpu_cgroup_update_vcpustat(cgrp); - kernel_cpustat_zero(kstat); for (i = 0; i < nr_vcpus; i++) kernel_cpustat_add(tg->vcpustat + i, kstat, kstat); + + return 0; } int cpu_cgroup_get_avenrun(struct cgroup *cgrp, unsigned long *avenrun) diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c index 2459cb5..d196e3e 100644 --- a/kernel/ve/ve.c +++ b/kernel/ve/ve.c @@ -1448,16 +1448,17 @@ int ve_get_cpu_avenrun(struct ve_struct *ve, unsigned long *avenrun) } EXPORT_SYMBOL(ve_get_cpu_avenrun); -void cpu_cgroup_get_stat(struct cgroup *cgrp, struct kernel_cpustat *kstat); +int cpu_cgroup_get_stat(struct cgroup *cgrp, struct kernel_cpustat *kstat); int ve_get_cpu_stat(struct ve_struct *ve, struct kernel_cpustat *kstat) { struct cgroup_subsys_state *css; + int err; css = ve_get_init_css(ve, cpu_cgroup_subsys_id); - cpu_cgroup_get_stat(css->cgroup, kstat); + err = cpu_cgroup_get_stat(css->cgroup, kstat); css_put(css); - return 0; + return err; } EXPORT_SYMBOL(ve_get_cpu_stat); #endif /* CONFIG_CGROUP_SCHED */ _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel