mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-21 18:17:12 +07:00
0b8d616fb5
When assiging and testing taskstats in taskstats_exit() there's a race
when setting up and reading sig->stats when a thread-group with more
than one thread exits:
write to 0xffff8881157bbe10 of 8 bytes by task 7951 on cpu 0:
taskstats_tgid_alloc kernel/taskstats.c:567 [inline]
taskstats_exit+0x6b7/0x717 kernel/taskstats.c:596
do_exit+0x2c2/0x18e0 kernel/exit.c:864
do_group_exit+0xb4/0x1c0 kernel/exit.c:983
get_signal+0x2a2/0x1320 kernel/signal.c:2734
do_signal+0x3b/0xc00 arch/x86/kernel/signal.c:815
exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:159
prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
do_syscall_64+0x2d7/0x2f0 arch/x86/entry/common.c:299
entry_SYSCALL_64_after_hwframe+0x44/0xa9
read to 0xffff8881157bbe10 of 8 bytes by task 7949 on cpu 1:
taskstats_tgid_alloc kernel/taskstats.c:559 [inline]
taskstats_exit+0xb2/0x717 kernel/taskstats.c:596
do_exit+0x2c2/0x18e0 kernel/exit.c:864
do_group_exit+0xb4/0x1c0 kernel/exit.c:983
__do_sys_exit_group kernel/exit.c:994 [inline]
__se_sys_exit_group kernel/exit.c:992 [inline]
__x64_sys_exit_group+0x2e/0x30 kernel/exit.c:992
do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this by using smp_load_acquire() and smp_store_release().
Reported-by: syzbot+c5d03165a1bd1dead0c1@syzkaller.appspotmail.com
Fixes: 34ec12349c
("taskstats: cleanup ->signal->stats allocation")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Will Deacon <will@kernel.org>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://lore.kernel.org/r/20191009114809.8643-1-christian.brauner@ubuntu.com
725 lines
16 KiB
C
725 lines
16 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* taskstats.c - Export per-task statistics to userland
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*
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* Copyright (C) Shailabh Nagar, IBM Corp. 2006
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* (C) Balbir Singh, IBM Corp. 2006
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*/
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#include <linux/kernel.h>
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#include <linux/taskstats_kern.h>
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#include <linux/tsacct_kern.h>
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#include <linux/delayacct.h>
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#include <linux/cpumask.h>
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#include <linux/percpu.h>
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#include <linux/slab.h>
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#include <linux/cgroupstats.h>
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#include <linux/cgroup.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/pid_namespace.h>
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#include <net/genetlink.h>
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#include <linux/atomic.h>
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#include <linux/sched/cputime.h>
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/*
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* Maximum length of a cpumask that can be specified in
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* the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute
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*/
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#define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS)
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static DEFINE_PER_CPU(__u32, taskstats_seqnum);
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static int family_registered;
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struct kmem_cache *taskstats_cache;
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static struct genl_family family;
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static const struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = {
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[TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 },
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[TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 },
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[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING },
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[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },};
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/*
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* We have to use TASKSTATS_CMD_ATTR_MAX here, it is the maxattr in the family.
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* Make sure they are always aligned.
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*/
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static const struct nla_policy cgroupstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = {
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[CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 },
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};
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struct listener {
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struct list_head list;
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pid_t pid;
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char valid;
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};
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struct listener_list {
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struct rw_semaphore sem;
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struct list_head list;
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};
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static DEFINE_PER_CPU(struct listener_list, listener_array);
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enum actions {
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REGISTER,
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DEREGISTER,
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CPU_DONT_CARE
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};
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static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
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size_t size)
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{
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struct sk_buff *skb;
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void *reply;
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/*
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* If new attributes are added, please revisit this allocation
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*/
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skb = genlmsg_new(size, GFP_KERNEL);
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if (!skb)
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return -ENOMEM;
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if (!info) {
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int seq = this_cpu_inc_return(taskstats_seqnum) - 1;
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reply = genlmsg_put(skb, 0, seq, &family, 0, cmd);
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} else
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reply = genlmsg_put_reply(skb, info, &family, 0, cmd);
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if (reply == NULL) {
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nlmsg_free(skb);
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return -EINVAL;
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}
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*skbp = skb;
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return 0;
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}
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/*
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* Send taskstats data in @skb to listener with nl_pid @pid
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*/
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static int send_reply(struct sk_buff *skb, struct genl_info *info)
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{
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struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
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void *reply = genlmsg_data(genlhdr);
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genlmsg_end(skb, reply);
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return genlmsg_reply(skb, info);
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}
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/*
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* Send taskstats data in @skb to listeners registered for @cpu's exit data
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*/
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static void send_cpu_listeners(struct sk_buff *skb,
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struct listener_list *listeners)
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{
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struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
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struct listener *s, *tmp;
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struct sk_buff *skb_next, *skb_cur = skb;
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void *reply = genlmsg_data(genlhdr);
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int rc, delcount = 0;
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genlmsg_end(skb, reply);
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rc = 0;
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down_read(&listeners->sem);
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list_for_each_entry(s, &listeners->list, list) {
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skb_next = NULL;
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if (!list_is_last(&s->list, &listeners->list)) {
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skb_next = skb_clone(skb_cur, GFP_KERNEL);
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if (!skb_next)
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break;
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}
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rc = genlmsg_unicast(&init_net, skb_cur, s->pid);
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if (rc == -ECONNREFUSED) {
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s->valid = 0;
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delcount++;
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}
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skb_cur = skb_next;
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}
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up_read(&listeners->sem);
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if (skb_cur)
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nlmsg_free(skb_cur);
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if (!delcount)
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return;
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/* Delete invalidated entries */
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down_write(&listeners->sem);
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list_for_each_entry_safe(s, tmp, &listeners->list, list) {
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if (!s->valid) {
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list_del(&s->list);
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kfree(s);
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}
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}
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up_write(&listeners->sem);
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}
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static void fill_stats(struct user_namespace *user_ns,
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struct pid_namespace *pid_ns,
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struct task_struct *tsk, struct taskstats *stats)
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{
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memset(stats, 0, sizeof(*stats));
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/*
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* Each accounting subsystem adds calls to its functions to
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* fill in relevant parts of struct taskstsats as follows
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*
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* per-task-foo(stats, tsk);
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*/
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delayacct_add_tsk(stats, tsk);
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/* fill in basic acct fields */
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stats->version = TASKSTATS_VERSION;
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stats->nvcsw = tsk->nvcsw;
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stats->nivcsw = tsk->nivcsw;
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bacct_add_tsk(user_ns, pid_ns, stats, tsk);
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/* fill in extended acct fields */
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xacct_add_tsk(stats, tsk);
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}
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static int fill_stats_for_pid(pid_t pid, struct taskstats *stats)
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{
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struct task_struct *tsk;
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tsk = find_get_task_by_vpid(pid);
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if (!tsk)
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return -ESRCH;
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fill_stats(current_user_ns(), task_active_pid_ns(current), tsk, stats);
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put_task_struct(tsk);
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return 0;
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}
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static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats)
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{
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struct task_struct *tsk, *first;
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unsigned long flags;
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int rc = -ESRCH;
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u64 delta, utime, stime;
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u64 start_time;
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/*
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* Add additional stats from live tasks except zombie thread group
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* leaders who are already counted with the dead tasks
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*/
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rcu_read_lock();
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first = find_task_by_vpid(tgid);
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if (!first || !lock_task_sighand(first, &flags))
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goto out;
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if (first->signal->stats)
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memcpy(stats, first->signal->stats, sizeof(*stats));
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else
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memset(stats, 0, sizeof(*stats));
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tsk = first;
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start_time = ktime_get_ns();
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do {
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if (tsk->exit_state)
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continue;
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/*
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* Accounting subsystem can call its functions here to
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* fill in relevant parts of struct taskstsats as follows
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*
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* per-task-foo(stats, tsk);
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*/
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delayacct_add_tsk(stats, tsk);
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/* calculate task elapsed time in nsec */
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delta = start_time - tsk->start_time;
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/* Convert to micro seconds */
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do_div(delta, NSEC_PER_USEC);
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stats->ac_etime += delta;
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task_cputime(tsk, &utime, &stime);
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stats->ac_utime += div_u64(utime, NSEC_PER_USEC);
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stats->ac_stime += div_u64(stime, NSEC_PER_USEC);
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stats->nvcsw += tsk->nvcsw;
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stats->nivcsw += tsk->nivcsw;
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} while_each_thread(first, tsk);
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unlock_task_sighand(first, &flags);
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rc = 0;
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out:
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rcu_read_unlock();
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stats->version = TASKSTATS_VERSION;
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/*
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* Accounting subsystems can also add calls here to modify
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* fields of taskstats.
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*/
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return rc;
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}
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static void fill_tgid_exit(struct task_struct *tsk)
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{
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unsigned long flags;
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spin_lock_irqsave(&tsk->sighand->siglock, flags);
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if (!tsk->signal->stats)
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goto ret;
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/*
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* Each accounting subsystem calls its functions here to
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* accumalate its per-task stats for tsk, into the per-tgid structure
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*
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* per-task-foo(tsk->signal->stats, tsk);
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*/
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delayacct_add_tsk(tsk->signal->stats, tsk);
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ret:
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spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
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return;
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}
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static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd)
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{
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struct listener_list *listeners;
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struct listener *s, *tmp, *s2;
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unsigned int cpu;
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int ret = 0;
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if (!cpumask_subset(mask, cpu_possible_mask))
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return -EINVAL;
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if (current_user_ns() != &init_user_ns)
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return -EINVAL;
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if (task_active_pid_ns(current) != &init_pid_ns)
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return -EINVAL;
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if (isadd == REGISTER) {
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for_each_cpu(cpu, mask) {
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s = kmalloc_node(sizeof(struct listener),
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GFP_KERNEL, cpu_to_node(cpu));
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if (!s) {
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ret = -ENOMEM;
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goto cleanup;
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}
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s->pid = pid;
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s->valid = 1;
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listeners = &per_cpu(listener_array, cpu);
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down_write(&listeners->sem);
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list_for_each_entry(s2, &listeners->list, list) {
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if (s2->pid == pid && s2->valid)
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goto exists;
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}
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list_add(&s->list, &listeners->list);
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s = NULL;
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exists:
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up_write(&listeners->sem);
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kfree(s); /* nop if NULL */
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}
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return 0;
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}
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/* Deregister or cleanup */
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cleanup:
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for_each_cpu(cpu, mask) {
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listeners = &per_cpu(listener_array, cpu);
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down_write(&listeners->sem);
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list_for_each_entry_safe(s, tmp, &listeners->list, list) {
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if (s->pid == pid) {
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list_del(&s->list);
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kfree(s);
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break;
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}
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}
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up_write(&listeners->sem);
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}
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return ret;
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}
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static int parse(struct nlattr *na, struct cpumask *mask)
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{
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char *data;
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int len;
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int ret;
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if (na == NULL)
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return 1;
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len = nla_len(na);
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if (len > TASKSTATS_CPUMASK_MAXLEN)
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return -E2BIG;
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if (len < 1)
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return -EINVAL;
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data = kmalloc(len, GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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nla_strlcpy(data, na, len);
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ret = cpulist_parse(data, mask);
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kfree(data);
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return ret;
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}
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static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid)
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{
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struct nlattr *na, *ret;
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int aggr;
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aggr = (type == TASKSTATS_TYPE_PID)
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? TASKSTATS_TYPE_AGGR_PID
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: TASKSTATS_TYPE_AGGR_TGID;
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na = nla_nest_start_noflag(skb, aggr);
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if (!na)
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goto err;
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if (nla_put(skb, type, sizeof(pid), &pid) < 0) {
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nla_nest_cancel(skb, na);
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goto err;
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}
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ret = nla_reserve_64bit(skb, TASKSTATS_TYPE_STATS,
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sizeof(struct taskstats), TASKSTATS_TYPE_NULL);
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if (!ret) {
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nla_nest_cancel(skb, na);
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goto err;
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}
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nla_nest_end(skb, na);
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return nla_data(ret);
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err:
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return NULL;
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}
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static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
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{
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int rc = 0;
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struct sk_buff *rep_skb;
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struct cgroupstats *stats;
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struct nlattr *na;
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size_t size;
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u32 fd;
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struct fd f;
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na = info->attrs[CGROUPSTATS_CMD_ATTR_FD];
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if (!na)
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return -EINVAL;
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fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]);
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f = fdget(fd);
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if (!f.file)
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return 0;
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size = nla_total_size(sizeof(struct cgroupstats));
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rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb,
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size);
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if (rc < 0)
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goto err;
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na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS,
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sizeof(struct cgroupstats));
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if (na == NULL) {
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nlmsg_free(rep_skb);
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rc = -EMSGSIZE;
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goto err;
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}
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stats = nla_data(na);
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memset(stats, 0, sizeof(*stats));
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rc = cgroupstats_build(stats, f.file->f_path.dentry);
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if (rc < 0) {
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nlmsg_free(rep_skb);
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goto err;
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}
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rc = send_reply(rep_skb, info);
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err:
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fdput(f);
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return rc;
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}
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static int cmd_attr_register_cpumask(struct genl_info *info)
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{
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cpumask_var_t mask;
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int rc;
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if (!alloc_cpumask_var(&mask, GFP_KERNEL))
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return -ENOMEM;
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rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask);
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if (rc < 0)
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goto out;
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rc = add_del_listener(info->snd_portid, mask, REGISTER);
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out:
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free_cpumask_var(mask);
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return rc;
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}
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static int cmd_attr_deregister_cpumask(struct genl_info *info)
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{
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cpumask_var_t mask;
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int rc;
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if (!alloc_cpumask_var(&mask, GFP_KERNEL))
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return -ENOMEM;
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rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], mask);
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if (rc < 0)
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goto out;
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rc = add_del_listener(info->snd_portid, mask, DEREGISTER);
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out:
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free_cpumask_var(mask);
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return rc;
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}
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static size_t taskstats_packet_size(void)
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{
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size_t size;
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size = nla_total_size(sizeof(u32)) +
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nla_total_size_64bit(sizeof(struct taskstats)) +
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nla_total_size(0);
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return size;
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}
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static int cmd_attr_pid(struct genl_info *info)
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{
|
|
struct taskstats *stats;
|
|
struct sk_buff *rep_skb;
|
|
size_t size;
|
|
u32 pid;
|
|
int rc;
|
|
|
|
size = taskstats_packet_size();
|
|
|
|
rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
rc = -EINVAL;
|
|
pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]);
|
|
stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid);
|
|
if (!stats)
|
|
goto err;
|
|
|
|
rc = fill_stats_for_pid(pid, stats);
|
|
if (rc < 0)
|
|
goto err;
|
|
return send_reply(rep_skb, info);
|
|
err:
|
|
nlmsg_free(rep_skb);
|
|
return rc;
|
|
}
|
|
|
|
static int cmd_attr_tgid(struct genl_info *info)
|
|
{
|
|
struct taskstats *stats;
|
|
struct sk_buff *rep_skb;
|
|
size_t size;
|
|
u32 tgid;
|
|
int rc;
|
|
|
|
size = taskstats_packet_size();
|
|
|
|
rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
rc = -EINVAL;
|
|
tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
|
|
stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid);
|
|
if (!stats)
|
|
goto err;
|
|
|
|
rc = fill_stats_for_tgid(tgid, stats);
|
|
if (rc < 0)
|
|
goto err;
|
|
return send_reply(rep_skb, info);
|
|
err:
|
|
nlmsg_free(rep_skb);
|
|
return rc;
|
|
}
|
|
|
|
static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
|
|
{
|
|
if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK])
|
|
return cmd_attr_register_cpumask(info);
|
|
else if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK])
|
|
return cmd_attr_deregister_cpumask(info);
|
|
else if (info->attrs[TASKSTATS_CMD_ATTR_PID])
|
|
return cmd_attr_pid(info);
|
|
else if (info->attrs[TASKSTATS_CMD_ATTR_TGID])
|
|
return cmd_attr_tgid(info);
|
|
else
|
|
return -EINVAL;
|
|
}
|
|
|
|
static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk)
|
|
{
|
|
struct signal_struct *sig = tsk->signal;
|
|
struct taskstats *stats_new, *stats;
|
|
|
|
/* Pairs with smp_store_release() below. */
|
|
stats = smp_load_acquire(&sig->stats);
|
|
if (stats || thread_group_empty(tsk))
|
|
return stats;
|
|
|
|
/* No problem if kmem_cache_zalloc() fails */
|
|
stats_new = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
|
|
|
|
spin_lock_irq(&tsk->sighand->siglock);
|
|
stats = sig->stats;
|
|
if (!stats) {
|
|
/*
|
|
* Pairs with smp_store_release() above and order the
|
|
* kmem_cache_zalloc().
|
|
*/
|
|
smp_store_release(&sig->stats, stats_new);
|
|
stats = stats_new;
|
|
stats_new = NULL;
|
|
}
|
|
spin_unlock_irq(&tsk->sighand->siglock);
|
|
|
|
if (stats_new)
|
|
kmem_cache_free(taskstats_cache, stats_new);
|
|
|
|
return stats;
|
|
}
|
|
|
|
/* Send pid data out on exit */
|
|
void taskstats_exit(struct task_struct *tsk, int group_dead)
|
|
{
|
|
int rc;
|
|
struct listener_list *listeners;
|
|
struct taskstats *stats;
|
|
struct sk_buff *rep_skb;
|
|
size_t size;
|
|
int is_thread_group;
|
|
|
|
if (!family_registered)
|
|
return;
|
|
|
|
/*
|
|
* Size includes space for nested attributes
|
|
*/
|
|
size = taskstats_packet_size();
|
|
|
|
is_thread_group = !!taskstats_tgid_alloc(tsk);
|
|
if (is_thread_group) {
|
|
/* PID + STATS + TGID + STATS */
|
|
size = 2 * size;
|
|
/* fill the tsk->signal->stats structure */
|
|
fill_tgid_exit(tsk);
|
|
}
|
|
|
|
listeners = raw_cpu_ptr(&listener_array);
|
|
if (list_empty(&listeners->list))
|
|
return;
|
|
|
|
rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size);
|
|
if (rc < 0)
|
|
return;
|
|
|
|
stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID,
|
|
task_pid_nr_ns(tsk, &init_pid_ns));
|
|
if (!stats)
|
|
goto err;
|
|
|
|
fill_stats(&init_user_ns, &init_pid_ns, tsk, stats);
|
|
|
|
/*
|
|
* Doesn't matter if tsk is the leader or the last group member leaving
|
|
*/
|
|
if (!is_thread_group || !group_dead)
|
|
goto send;
|
|
|
|
stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID,
|
|
task_tgid_nr_ns(tsk, &init_pid_ns));
|
|
if (!stats)
|
|
goto err;
|
|
|
|
memcpy(stats, tsk->signal->stats, sizeof(*stats));
|
|
|
|
send:
|
|
send_cpu_listeners(rep_skb, listeners);
|
|
return;
|
|
err:
|
|
nlmsg_free(rep_skb);
|
|
}
|
|
|
|
static const struct genl_ops taskstats_ops[] = {
|
|
{
|
|
.cmd = TASKSTATS_CMD_GET,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.doit = taskstats_user_cmd,
|
|
/* policy enforced later */
|
|
.flags = GENL_ADMIN_PERM | GENL_CMD_CAP_HASPOL,
|
|
},
|
|
{
|
|
.cmd = CGROUPSTATS_CMD_GET,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.doit = cgroupstats_user_cmd,
|
|
/* policy enforced later */
|
|
.flags = GENL_CMD_CAP_HASPOL,
|
|
},
|
|
};
|
|
|
|
static int taskstats_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
|
|
struct genl_info *info)
|
|
{
|
|
const struct nla_policy *policy = NULL;
|
|
|
|
switch (ops->cmd) {
|
|
case TASKSTATS_CMD_GET:
|
|
policy = taskstats_cmd_get_policy;
|
|
break;
|
|
case CGROUPSTATS_CMD_GET:
|
|
policy = cgroupstats_cmd_get_policy;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return nlmsg_validate_deprecated(info->nlhdr, GENL_HDRLEN,
|
|
TASKSTATS_CMD_ATTR_MAX, policy,
|
|
info->extack);
|
|
}
|
|
|
|
static struct genl_family family __ro_after_init = {
|
|
.name = TASKSTATS_GENL_NAME,
|
|
.version = TASKSTATS_GENL_VERSION,
|
|
.maxattr = TASKSTATS_CMD_ATTR_MAX,
|
|
.module = THIS_MODULE,
|
|
.ops = taskstats_ops,
|
|
.n_ops = ARRAY_SIZE(taskstats_ops),
|
|
.pre_doit = taskstats_pre_doit,
|
|
};
|
|
|
|
/* Needed early in initialization */
|
|
void __init taskstats_init_early(void)
|
|
{
|
|
unsigned int i;
|
|
|
|
taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC);
|
|
for_each_possible_cpu(i) {
|
|
INIT_LIST_HEAD(&(per_cpu(listener_array, i).list));
|
|
init_rwsem(&(per_cpu(listener_array, i).sem));
|
|
}
|
|
}
|
|
|
|
static int __init taskstats_init(void)
|
|
{
|
|
int rc;
|
|
|
|
rc = genl_register_family(&family);
|
|
if (rc)
|
|
return rc;
|
|
|
|
family_registered = 1;
|
|
pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* late initcall ensures initialization of statistics collection
|
|
* mechanisms precedes initialization of the taskstats interface
|
|
*/
|
|
late_initcall(taskstats_init);
|