]> git.proxmox.com Git - mirror_ubuntu-kernels.git/blobdiff - kernel/fork.c
Fix tsk->exit_state usage
[mirror_ubuntu-kernels.git] / kernel / fork.c
index 2ce28f165e31a1e671e014b10a852e53cd1c535b..240aa6601f5b51579d0b3d5e727ea47b6839c660 100644 (file)
@@ -29,7 +29,7 @@
 #include <linux/nsproxy.h>
 #include <linux/capability.h>
 #include <linux/cpu.h>
-#include <linux/cpuset.h>
+#include <linux/cgroup.h>
 #include <linux/security.h>
 #include <linux/swap.h>
 #include <linux/syscalls.h>
@@ -50,6 +50,7 @@
 #include <linux/taskstats_kern.h>
 #include <linux/random.h>
 #include <linux/tty.h>
+#include <linux/proc_fs.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -116,7 +117,7 @@ EXPORT_SYMBOL(free_task);
 
 void __put_task_struct(struct task_struct *tsk)
 {
-       WARN_ON(!(tsk->exit_state & (EXIT_DEAD | EXIT_ZOMBIE)));
+       WARN_ON(!tsk->exit_state);
        WARN_ON(atomic_read(&tsk->usage));
        WARN_ON(tsk == current);
 
@@ -949,7 +950,7 @@ asmlinkage long sys_set_tid_address(int __user *tidptr)
 {
        current->clear_child_tid = tidptr;
 
-       return current->pid;
+       return task_pid_vnr(current);
 }
 
 static inline void rt_mutex_init_task(struct task_struct *p)
@@ -973,12 +974,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                                        unsigned long stack_start,
                                        struct pt_regs *regs,
                                        unsigned long stack_size,
-                                       int __user *parent_tidptr,
                                        int __user *child_tidptr,
                                        struct pid *pid)
 {
        int retval;
        struct task_struct *p = NULL;
+       int cgroup_callbacks_done = 0;
 
        if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
                return ERR_PTR(-EINVAL);
@@ -1042,12 +1043,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        p->did_exec = 0;
        delayacct_tsk_init(p);  /* Must remain after dup_task_struct() */
        copy_flags(clone_flags, p);
-       p->pid = pid_nr(pid);
-       retval = -EFAULT;
-       if (clone_flags & CLONE_PARENT_SETTID)
-               if (put_user(p->pid, parent_tidptr))
-                       goto bad_fork_cleanup_delays_binfmt;
-
        INIT_LIST_HEAD(&p->children);
        INIT_LIST_HEAD(&p->sibling);
        p->vfork_done = NULL;
@@ -1087,13 +1082,13 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #endif
        p->io_context = NULL;
        p->audit_context = NULL;
-       cpuset_fork(p);
+       cgroup_fork(p);
 #ifdef CONFIG_NUMA
        p->mempolicy = mpol_copy(p->mempolicy);
        if (IS_ERR(p->mempolicy)) {
                retval = PTR_ERR(p->mempolicy);
                p->mempolicy = NULL;
-               goto bad_fork_cleanup_cpuset;
+               goto bad_fork_cleanup_cgroup;
        }
        mpol_fix_fork_child_flag(p);
 #endif
@@ -1126,10 +1121,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        p->blocked_on = NULL; /* not blocked yet */
 #endif
 
-       p->tgid = p->pid;
-       if (clone_flags & CLONE_THREAD)
-               p->tgid = current->tgid;
-
        if ((retval = security_task_alloc(p)))
                goto bad_fork_cleanup_policy;
        if ((retval = audit_alloc(p)))
@@ -1155,6 +1146,24 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        if (retval)
                goto bad_fork_cleanup_namespaces;
 
+       if (pid != &init_struct_pid) {
+               retval = -ENOMEM;
+               pid = alloc_pid(task_active_pid_ns(p));
+               if (!pid)
+                       goto bad_fork_cleanup_namespaces;
+
+               if (clone_flags & CLONE_NEWPID) {
+                       retval = pid_ns_prepare_proc(task_active_pid_ns(p));
+                       if (retval < 0)
+                               goto bad_fork_free_pid;
+               }
+       }
+
+       p->pid = pid_nr(pid);
+       p->tgid = p->pid;
+       if (clone_flags & CLONE_THREAD)
+               p->tgid = current->tgid;
+
        p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
        /*
         * Clear TID on mm_release()?
@@ -1204,6 +1213,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        /* Perform scheduler related setup. Assign this task to a CPU. */
        sched_fork(p, clone_flags);
 
+       /* Now that the task is set up, run cgroup callbacks if
+        * necessary. We need to run them before the task is visible
+        * on the tasklist. */
+       cgroup_fork_callbacks(p);
+       cgroup_callbacks_done = 1;
+
        /* Need tasklist lock for parent etc handling! */
        write_lock_irq(&tasklist_lock);
 
@@ -1246,7 +1261,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                spin_unlock(&current->sighand->siglock);
                write_unlock_irq(&tasklist_lock);
                retval = -ERESTARTNOINTR;
-               goto bad_fork_cleanup_namespaces;
+               goto bad_fork_free_pid;
        }
 
        if (clone_flags & CLONE_THREAD) {
@@ -1275,11 +1290,22 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                        __ptrace_link(p, current->parent);
 
                if (thread_group_leader(p)) {
-                       p->signal->tty = current->signal->tty;
-                       p->signal->pgrp = process_group(current);
-                       set_signal_session(p->signal, process_session(current));
-                       attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
-                       attach_pid(p, PIDTYPE_SID, task_session(current));
+                       if (clone_flags & CLONE_NEWPID) {
+                               p->nsproxy->pid_ns->child_reaper = p;
+                               p->signal->tty = NULL;
+                               p->signal->pgrp = p->pid;
+                               set_task_session(p, p->pid);
+                               attach_pid(p, PIDTYPE_PGID, pid);
+                               attach_pid(p, PIDTYPE_SID, pid);
+                       } else {
+                               p->signal->tty = current->signal->tty;
+                               p->signal->pgrp = task_pgrp_nr(current);
+                               set_task_session(p, task_session_nr(current));
+                               attach_pid(p, PIDTYPE_PGID,
+                                               task_pgrp(current));
+                               attach_pid(p, PIDTYPE_SID,
+                                               task_session(current));
+                       }
 
                        list_add_tail_rcu(&p->tasks, &init_task.tasks);
                        __get_cpu_var(process_counts)++;
@@ -1292,8 +1318,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        spin_unlock(&current->sighand->siglock);
        write_unlock_irq(&tasklist_lock);
        proc_fork_connector(p);
+       cgroup_post_fork(p);
        return p;
 
+bad_fork_free_pid:
+       if (pid != &init_struct_pid)
+               free_pid(pid);
 bad_fork_cleanup_namespaces:
        exit_task_namespaces(p);
 bad_fork_cleanup_keys:
@@ -1318,10 +1348,9 @@ bad_fork_cleanup_security:
 bad_fork_cleanup_policy:
 #ifdef CONFIG_NUMA
        mpol_free(p->mempolicy);
-bad_fork_cleanup_cpuset:
+bad_fork_cleanup_cgroup:
 #endif
-       cpuset_exit(p);
-bad_fork_cleanup_delays_binfmt:
+       cgroup_exit(p, cgroup_callbacks_done);
        delayacct_tsk_free(p);
        if (p->binfmt)
                module_put(p->binfmt->module);
@@ -1348,7 +1377,7 @@ struct task_struct * __cpuinit fork_idle(int cpu)
        struct task_struct *task;
        struct pt_regs regs;
 
-       task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL, NULL,
+       task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL,
                                &init_struct_pid);
        if (!IS_ERR(task))
                init_idle(task, cpu);
@@ -1387,19 +1416,16 @@ long do_fork(unsigned long clone_flags,
 {
        struct task_struct *p;
        int trace = 0;
-       struct pid *pid = alloc_pid();
        long nr;
 
-       if (!pid)
-               return -EAGAIN;
-       nr = pid->nr;
        if (unlikely(current->ptrace)) {
                trace = fork_traceflag (clone_flags);
                if (trace)
                        clone_flags |= CLONE_PTRACE;
        }
 
-       p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr, pid);
+       p = copy_process(clone_flags, stack_start, regs, stack_size,
+                       child_tidptr, NULL);
        /*
         * Do this prior waking up the new thread - the thread pointer
         * might get invalid after that point, if the thread exits quickly.
@@ -1407,6 +1433,17 @@ long do_fork(unsigned long clone_flags,
        if (!IS_ERR(p)) {
                struct completion vfork;
 
+               /*
+                * this is enough to call pid_nr_ns here, but this if
+                * improves optimisation of regular fork()
+                */
+               nr = (clone_flags & CLONE_NEWPID) ?
+                       task_pid_nr_ns(p, current->nsproxy->pid_ns) :
+                               task_pid_vnr(p);
+
+               if (clone_flags & CLONE_PARENT_SETTID)
+                       put_user(nr, parent_tidptr);
+
                if (clone_flags & CLONE_VFORK) {
                        p->vfork_done = &vfork;
                        init_completion(&vfork);
@@ -1440,7 +1477,6 @@ long do_fork(unsigned long clone_flags,
                        }
                }
        } else {
-               free_pid(pid);
                nr = PTR_ERR(p);
        }
        return nr;
@@ -1617,7 +1653,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
        struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
        struct files_struct *fd, *new_fd = NULL;
        struct sem_undo_list *new_ulist = NULL;
-       struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL;
+       struct nsproxy *new_nsproxy = NULL;
 
        check_unshare_flags(&unshare_flags);
 
@@ -1647,14 +1683,13 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
 
        if (new_fs ||  new_mm || new_fd || new_ulist || new_nsproxy) {
 
-               task_lock(current);
-
                if (new_nsproxy) {
-                       old_nsproxy = current->nsproxy;
-                       current->nsproxy = new_nsproxy;
-                       new_nsproxy = old_nsproxy;
+                       switch_task_namespaces(current, new_nsproxy);
+                       new_nsproxy = NULL;
                }
 
+               task_lock(current);
+
                if (new_fs) {
                        fs = current->fs;
                        current->fs = new_fs;