#include <linux/swap.h>
#include <linux/syscalls.h>
#include <linux/jiffies.h>
-#include <linux/tracehook.h>
#include <linux/futex.h>
#include <linux/compat.h>
+#include <linux/kthread.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/rcupdate.h>
#include <linux/ptrace.h>
#include <linux/taskstats_kern.h>
#include <linux/random.h>
#include <linux/tty.h>
-#include <linux/proc_fs.h>
#include <linux/blkdev.h>
#include <linux/fs_struct.h>
#include <linux/magic.h>
#include <linux/perf_event.h>
#include <linux/posix-timers.h>
#include <linux/user-return-notifier.h>
+#include <linux/oom.h>
+#include <linux/khugepaged.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
* Protected counters by write_lock_irq(&tasklist_lock)
*/
unsigned long total_forks; /* Handle normal Linux uptimes. */
-int nr_threads; /* The idle threads do not count.. */
+int nr_threads; /* The idle threads do not count.. */
int max_threads; /* tunable limit on nr_threads */
}
#ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
-# define alloc_task_struct() kmem_cache_alloc(task_struct_cachep, GFP_KERNEL)
-# define free_task_struct(tsk) kmem_cache_free(task_struct_cachep, (tsk))
+# define alloc_task_struct_node(node) \
+ kmem_cache_alloc_node(task_struct_cachep, GFP_KERNEL, node)
+# define free_task_struct(tsk) \
+ kmem_cache_free(task_struct_cachep, (tsk))
static struct kmem_cache *task_struct_cachep;
#endif
#ifndef __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-static inline struct thread_info *alloc_thread_info(struct task_struct *tsk)
+static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
+ int node)
{
#ifdef CONFIG_DEBUG_STACK_USAGE
gfp_t mask = GFP_KERNEL | __GFP_ZERO;
#else
gfp_t mask = GFP_KERNEL;
#endif
- return (struct thread_info *)__get_free_pages(mask, THREAD_SIZE_ORDER);
+ struct page *page = alloc_pages_node(node, mask, THREAD_SIZE_ORDER);
+
+ return page ? page_address(page) : NULL;
}
static inline void free_thread_info(struct thread_info *ti)
/* SLAB cache for mm_struct structures (tsk->mm) */
static struct kmem_cache *mm_cachep;
+/* Notifier list called when a task struct is freed */
+static ATOMIC_NOTIFIER_HEAD(task_free_notifier);
+
static void account_kernel_stack(struct thread_info *ti, int account)
{
struct zone *zone = page_zone(virt_to_page(ti));
static inline void free_signal_struct(struct signal_struct *sig)
{
taskstats_tgid_free(sig);
+ sched_autogroup_exit(sig);
kmem_cache_free(signal_cachep, sig);
}
free_signal_struct(sig);
}
+int task_free_register(struct notifier_block *n)
+{
+ return atomic_notifier_chain_register(&task_free_notifier, n);
+}
+EXPORT_SYMBOL(task_free_register);
+
+int task_free_unregister(struct notifier_block *n)
+{
+ return atomic_notifier_chain_unregister(&task_free_notifier, n);
+}
+EXPORT_SYMBOL(task_free_unregister);
+
void __put_task_struct(struct task_struct *tsk)
{
WARN_ON(!tsk->exit_state);
delayacct_tsk_free(tsk);
put_signal_struct(tsk->signal);
+ atomic_notifier_call_chain(&task_free_notifier, 0, tsk);
if (!profile_handoff_task(tsk))
free_task(tsk);
}
+EXPORT_SYMBOL_GPL(__put_task_struct);
/*
* macro override instead of weak attribute alias, to workaround
/*
* we need to allow at least 20 threads to boot a system
*/
- if(max_threads < 20)
+ if (max_threads < 20)
max_threads = 20;
init_task.signal->rlim[RLIMIT_NPROC].rlim_cur = max_threads/2;
struct task_struct *tsk;
struct thread_info *ti;
unsigned long *stackend;
-
+ int node = tsk_fork_get_node(orig);
int err;
prepare_to_copy(orig);
- tsk = alloc_task_struct();
+ tsk = alloc_task_struct_node(node);
if (!tsk)
return NULL;
- ti = alloc_thread_info(tsk);
+ ti = alloc_thread_info_node(tsk, node);
if (!ti) {
free_task_struct(tsk);
return NULL;
}
- err = arch_dup_task_struct(tsk, orig);
+ err = arch_dup_task_struct(tsk, orig);
if (err)
goto out;
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
+ clear_tsk_need_resched(tsk);
stackend = end_of_stack(tsk);
*stackend = STACK_END_MAGIC; /* for overflow detection */
tsk->stack_canary = get_random_int();
#endif
- /* One for us, one for whoever does the "release_task()" (usually parent) */
- atomic_set(&tsk->usage,2);
- atomic_set(&tsk->fs_excl, 0);
+ /*
+ * One for us, one for whoever does the "release_task()" (usually
+ * parent)
+ */
+ atomic_set(&tsk->usage, 2);
#ifdef CONFIG_BLK_DEV_IO_TRACE
tsk->btrace_seq = 0;
#endif
#ifdef CONFIG_MMU
static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
{
- struct vm_area_struct *mpnt, *tmp, **pprev;
+ struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
struct rb_node **rb_link, *rb_parent;
int retval;
unsigned long charge;
rb_parent = NULL;
pprev = &mm->mmap;
retval = ksm_fork(mm, oldmm);
+ if (retval)
+ goto out;
+ retval = khugepaged_fork(mm, oldmm);
if (retval)
goto out;
+ prev = NULL;
for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
struct file *file;
if (IS_ERR(pol))
goto fail_nomem_policy;
vma_set_policy(tmp, pol);
+ tmp->vm_mm = mm;
if (anon_vma_fork(tmp, mpnt))
goto fail_nomem_anon_vma_fork;
tmp->vm_flags &= ~VM_LOCKED;
- tmp->vm_mm = mm;
- tmp->vm_next = NULL;
+ tmp->vm_next = tmp->vm_prev = NULL;
file = tmp->vm_file;
if (file) {
struct inode *inode = file->f_path.dentry->d_inode;
get_file(file);
if (tmp->vm_flags & VM_DENYWRITE)
atomic_dec(&inode->i_writecount);
- spin_lock(&mapping->i_mmap_lock);
+ mutex_lock(&mapping->i_mmap_mutex);
if (tmp->vm_flags & VM_SHARED)
mapping->i_mmap_writable++;
- tmp->vm_truncate_count = mpnt->vm_truncate_count;
flush_dcache_mmap_lock(mapping);
/* insert tmp into the share list, just after mpnt */
vma_prio_tree_add(tmp, mpnt);
flush_dcache_mmap_unlock(mapping);
- spin_unlock(&mapping->i_mmap_lock);
+ mutex_unlock(&mapping->i_mmap_mutex);
}
/*
*/
*pprev = tmp;
pprev = &tmp->vm_next;
+ tmp->vm_prev = prev;
+ prev = tmp;
__vma_link_rb(mm, tmp, rb_link, rb_parent);
rb_link = &tmp->vm_rb.rb_right;
goto out;
}
-static inline int mm_alloc_pgd(struct mm_struct * mm)
+static inline int mm_alloc_pgd(struct mm_struct *mm)
{
mm->pgd = pgd_alloc(mm);
if (unlikely(!mm->pgd))
return 0;
}
-static inline void mm_free_pgd(struct mm_struct * mm)
+static inline void mm_free_pgd(struct mm_struct *mm)
{
pgd_free(mm, mm->pgd);
}
#endif
}
-static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
+static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
{
atomic_set(&mm->mm_users, 1);
atomic_set(&mm->mm_count, 1);
mm->cached_hole_size = ~0UL;
mm_init_aio(mm);
mm_init_owner(mm, p);
+ atomic_set(&mm->oom_disable_count, 0);
if (likely(!mm_alloc_pgd(mm))) {
mm->def_flags = 0;
/*
* Allocate and initialize an mm_struct.
*/
-struct mm_struct * mm_alloc(void)
+struct mm_struct *mm_alloc(void)
{
- struct mm_struct * mm;
+ struct mm_struct *mm;
mm = allocate_mm();
- if (mm) {
- memset(mm, 0, sizeof(*mm));
- mm = mm_init(mm, current);
- }
- return mm;
+ if (!mm)
+ return NULL;
+
+ memset(mm, 0, sizeof(*mm));
+ mm_init_cpumask(mm);
+ return mm_init(mm, current);
}
/*
mm_free_pgd(mm);
destroy_context(mm);
mmu_notifier_mm_destroy(mm);
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ VM_BUG_ON(mm->pmd_huge_pte);
+#endif
free_mm(mm);
}
EXPORT_SYMBOL_GPL(__mmdrop);
if (atomic_dec_and_test(&mm->mm_users)) {
exit_aio(mm);
ksm_exit(mm);
+ khugepaged_exit(mm); /* must run before exit_mmap */
exit_mmap(mm);
set_mm_exe_file(mm, NULL);
if (!list_empty(&mm->mmlist)) {
}
EXPORT_SYMBOL_GPL(mmput);
+/*
+ * We added or removed a vma mapping the executable. The vmas are only mapped
+ * during exec and are not mapped with the mmap system call.
+ * Callers must hold down_write() on the mm's mmap_sem for these
+ */
+void added_exe_file_vma(struct mm_struct *mm)
+{
+ mm->num_exe_file_vmas++;
+}
+
+void removed_exe_file_vma(struct mm_struct *mm)
+{
+ mm->num_exe_file_vmas--;
+ if ((mm->num_exe_file_vmas == 0) && mm->exe_file) {
+ fput(mm->exe_file);
+ mm->exe_file = NULL;
+ }
+
+}
+
+void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
+{
+ if (new_exe_file)
+ get_file(new_exe_file);
+ if (mm->exe_file)
+ fput(mm->exe_file);
+ mm->exe_file = new_exe_file;
+ mm->num_exe_file_vmas = 0;
+}
+
+struct file *get_mm_exe_file(struct mm_struct *mm)
+{
+ struct file *exe_file;
+
+ /* We need mmap_sem to protect against races with removal of
+ * VM_EXECUTABLE vmas */
+ down_read(&mm->mmap_sem);
+ exe_file = mm->exe_file;
+ if (exe_file)
+ get_file(exe_file);
+ up_read(&mm->mmap_sem);
+ return exe_file;
+}
+
+static void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
+{
+ /* It's safe to write the exe_file pointer without exe_file_lock because
+ * this is called during fork when the task is not yet in /proc */
+ newmm->exe_file = get_mm_exe_file(oldmm);
+}
+
/**
* get_task_mm - acquire a reference to the task's mm
*
goto fail_nomem;
memcpy(mm, oldmm, sizeof(*mm));
+ mm_init_cpumask(mm);
/* Initializing for Swap token stuff */
mm->token_priority = 0;
mm->last_interval = 0;
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ mm->pmd_huge_pte = NULL;
+#endif
+
if (!mm_init(mm, tsk))
goto fail_nomem;
return NULL;
}
-static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
+static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
{
- struct mm_struct * mm, *oldmm;
+ struct mm_struct *mm, *oldmm;
int retval;
tsk->min_flt = tsk->maj_flt = 0;
/* Initializing for Swap token stuff */
mm->token_priority = 0;
mm->last_interval = 0;
+ if (tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
+ atomic_inc(&mm->oom_disable_count);
tsk->mm = mm;
tsk->active_mm = mm;
struct fs_struct *fs = current->fs;
if (clone_flags & CLONE_FS) {
/* tsk->fs is already what we want */
- write_lock(&fs->lock);
+ spin_lock(&fs->lock);
if (fs->in_exec) {
- write_unlock(&fs->lock);
+ spin_unlock(&fs->lock);
return -EAGAIN;
}
fs->users++;
- write_unlock(&fs->lock);
+ spin_unlock(&fs->lock);
return 0;
}
tsk->fs = copy_fs_struct(fs);
return 0;
}
-static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
+static int copy_files(unsigned long clone_flags, struct task_struct *tsk)
{
struct files_struct *oldf, *newf;
int error = 0;
posix_cpu_timers_init_group(sig);
tty_audit_fork(sig);
+ sched_autogroup_fork(sig);
+
+#ifdef CONFIG_CGROUPS
+ init_rwsem(&sig->threadgroup_fork_lock);
+#endif
sig->oom_adj = current->signal->oom_adj;
+ sig->oom_score_adj = current->signal->oom_score_adj;
+ sig->oom_score_adj_min = current->signal->oom_score_adj_min;
+
+ mutex_init(&sig->cred_guard_mutex);
return 0;
}
{
raw_spin_lock_init(&p->pi_lock);
#ifdef CONFIG_RT_MUTEXES
- plist_head_init_raw(&p->pi_waiters, &p->pi_lock);
+ plist_head_init(&p->pi_waiters);
p->pi_blocked_on = NULL;
#endif
}
p->real_cred->user != INIT_USER)
goto bad_fork_free;
}
+ current->flags &= ~PF_NPROC_EXCEEDED;
retval = copy_creds(p, clone_flags);
if (retval < 0)
posix_cpu_timers_init(p);
- p->lock_depth = -1; /* -1 = no lock */
do_posix_clock_monotonic_gettime(&p->start_time);
p->real_start_time = p->start_time;
monotonic_to_bootbased(&p->real_start_time);
p->io_context = NULL;
p->audit_context = NULL;
+ if (clone_flags & CLONE_THREAD)
+ threadgroup_fork_read_lock(current);
cgroup_fork(p);
#ifdef CONFIG_NUMA
p->mempolicy = mpol_dup(p->mempolicy);
- if (IS_ERR(p->mempolicy)) {
- retval = PTR_ERR(p->mempolicy);
- p->mempolicy = NULL;
- goto bad_fork_cleanup_cgroup;
- }
+ if (IS_ERR(p->mempolicy)) {
+ retval = PTR_ERR(p->mempolicy);
+ p->mempolicy = NULL;
+ goto bad_fork_cleanup_cgroup;
+ }
mpol_fix_fork_child_flag(p);
#endif
+#ifdef CONFIG_CPUSETS
+ p->cpuset_mem_spread_rotor = NUMA_NO_NODE;
+ p->cpuset_slab_spread_rotor = NUMA_NO_NODE;
+#endif
#ifdef CONFIG_TRACE_IRQFLAGS
p->irq_events = 0;
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
#endif
/* Perform scheduler related setup. Assign this task to a CPU. */
- sched_fork(p, clone_flags);
+ sched_fork(p);
retval = perf_event_init_task(p);
if (retval)
goto bad_fork_cleanup_policy;
-
- if ((retval = audit_alloc(p)))
+ retval = audit_alloc(p);
+ if (retval)
goto bad_fork_cleanup_policy;
/* copy all the process information */
- if ((retval = copy_semundo(clone_flags, p)))
+ retval = copy_semundo(clone_flags, p);
+ if (retval)
goto bad_fork_cleanup_audit;
- if ((retval = copy_files(clone_flags, p)))
+ retval = copy_files(clone_flags, p);
+ if (retval)
goto bad_fork_cleanup_semundo;
- if ((retval = copy_fs(clone_flags, p)))
+ retval = copy_fs(clone_flags, p);
+ if (retval)
goto bad_fork_cleanup_files;
- if ((retval = copy_sighand(clone_flags, p)))
+ retval = copy_sighand(clone_flags, p);
+ if (retval)
goto bad_fork_cleanup_fs;
- if ((retval = copy_signal(clone_flags, p)))
+ retval = copy_signal(clone_flags, p);
+ if (retval)
goto bad_fork_cleanup_sighand;
- if ((retval = copy_mm(clone_flags, p)))
+ retval = copy_mm(clone_flags, p);
+ if (retval)
goto bad_fork_cleanup_signal;
- if ((retval = copy_namespaces(clone_flags, p)))
+ retval = copy_namespaces(clone_flags, p);
+ if (retval)
goto bad_fork_cleanup_mm;
- if ((retval = copy_io(clone_flags, p)))
+ retval = copy_io(clone_flags, p);
+ if (retval)
goto bad_fork_cleanup_namespaces;
retval = copy_thread(clone_flags, stack_start, stack_size, p, regs);
if (retval)
pid = alloc_pid(p->nsproxy->pid_ns);
if (!pid)
goto bad_fork_cleanup_io;
-
- if (clone_flags & CLONE_NEWPID) {
- retval = pid_ns_prepare_proc(p->nsproxy->pid_ns);
- if (retval < 0)
- goto bad_fork_free_pid;
- }
}
p->pid = pid_nr(pid);
if (clone_flags & CLONE_THREAD)
p->tgid = current->tgid;
- if (current->nsproxy != p->nsproxy) {
- retval = ns_cgroup_clone(p, pid);
- if (retval)
- goto bad_fork_free_pid;
- }
-
p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
/*
* Clear TID on mm_release()?
*/
- p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
+ p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr : NULL;
+#ifdef CONFIG_BLOCK
+ p->plug = NULL;
+#endif
#ifdef CONFIG_FUTEX
p->robust_list = NULL;
#ifdef CONFIG_COMPAT
* it's process group.
* A fatal signal pending means that current will exit, so the new
* thread can't slip out of an OOM kill (or normal SIGKILL).
- */
+ */
recalc_sigpending();
if (signal_pending(current)) {
spin_unlock(¤t->sighand->siglock);
}
if (likely(p->pid)) {
- tracehook_finish_clone(p, clone_flags, trace);
+ ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
if (thread_group_leader(p)) {
- if (clone_flags & CLONE_NEWPID)
+ if (is_child_reaper(pid))
p->nsproxy->pid_ns->child_reaper = p;
p->signal->leader_pid = pid;
attach_pid(p, PIDTYPE_SID, task_session(current));
list_add_tail(&p->sibling, &p->real_parent->children);
list_add_tail_rcu(&p->tasks, &init_task.tasks);
- __get_cpu_var(process_counts)++;
+ __this_cpu_inc(process_counts);
}
attach_pid(p, PIDTYPE_PID, pid);
nr_threads++;
write_unlock_irq(&tasklist_lock);
proc_fork_connector(p);
cgroup_post_fork(p);
+ if (clone_flags & CLONE_THREAD)
+ threadgroup_fork_read_unlock(current);
perf_event_fork(p);
return p;
bad_fork_cleanup_namespaces:
exit_task_namespaces(p);
bad_fork_cleanup_mm:
- if (p->mm)
+ if (p->mm) {
+ task_lock(p);
+ if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
+ atomic_dec(&p->mm->oom_disable_count);
+ task_unlock(p);
mmput(p->mm);
+ }
bad_fork_cleanup_signal:
if (!(clone_flags & CLONE_THREAD))
free_signal_struct(p->signal);
mpol_put(p->mempolicy);
bad_fork_cleanup_cgroup:
#endif
+ if (clone_flags & CLONE_THREAD)
+ threadgroup_fork_read_unlock(current);
cgroup_exit(p, cgroup_callbacks_done);
delayacct_tsk_free(p);
module_put(task_thread_info(p)->exec_domain->module);
}
/*
- * We hope to recycle these flags after 2.6.26
+ * Determine whether and which event to report to ptracer. When
+ * called from kernel_thread or CLONE_UNTRACED is explicitly
+ * requested, no event is reported; otherwise, report if the event
+ * for the type of forking is enabled.
*/
- if (unlikely(clone_flags & CLONE_STOPPED)) {
- static int __read_mostly count = 100;
-
- if (count > 0 && printk_ratelimit()) {
- char comm[TASK_COMM_LEN];
+ if (likely(user_mode(regs)) && !(clone_flags & CLONE_UNTRACED)) {
+ if (clone_flags & CLONE_VFORK)
+ trace = PTRACE_EVENT_VFORK;
+ else if ((clone_flags & CSIGNAL) != SIGCHLD)
+ trace = PTRACE_EVENT_CLONE;
+ else
+ trace = PTRACE_EVENT_FORK;
- count--;
- printk(KERN_INFO "fork(): process `%s' used deprecated "
- "clone flags 0x%lx\n",
- get_task_comm(comm, current),
- clone_flags & CLONE_STOPPED);
- }
+ if (likely(!ptrace_event_enabled(current, trace)))
+ trace = 0;
}
- /*
- * When called from kernel_thread, don't do user tracing stuff.
- */
- if (likely(user_mode(regs)))
- trace = tracehook_prepare_clone(clone_flags);
-
p = copy_process(clone_flags, stack_start, regs, stack_size,
child_tidptr, NULL, trace);
/*
}
audit_finish_fork(p);
- tracehook_report_clone(regs, clone_flags, nr, p);
/*
* We set PF_STARTING at creation in case tracing wants to
* use this to distinguish a fully live task from one that
- * hasn't gotten to tracehook_report_clone() yet. Now we
- * clear it and set the child going.
+ * hasn't finished SIGSTOP raising yet. Now we clear it
+ * and set the child going.
*/
p->flags &= ~PF_STARTING;
- if (unlikely(clone_flags & CLONE_STOPPED)) {
- /*
- * We'll start up with an immediate SIGSTOP.
- */
- sigaddset(&p->pending.signal, SIGSTOP);
- set_tsk_thread_flag(p, TIF_SIGPENDING);
- __set_task_state(p, TASK_STOPPED);
- } else {
- wake_up_new_task(p, clone_flags);
- }
+ wake_up_new_task(p);
- tracehook_report_clone_complete(trace, regs,
- clone_flags, nr, p);
+ /* forking complete and child started to run, tell ptracer */
+ if (unlikely(trace))
+ ptrace_event(trace, nr);
if (clone_flags & CLONE_VFORK) {
freezer_do_not_count();
wait_for_completion(&vfork);
freezer_count();
- tracehook_report_vfork_done(p, nr);
+ ptrace_event(PTRACE_EVENT_VFORK_DONE, nr);
}
} else {
nr = PTR_ERR(p);
fs_cachep = kmem_cache_create("fs_cache",
sizeof(struct fs_struct), 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
+ /*
+ * FIXME! The "sizeof(struct mm_struct)" currently includes the
+ * whole struct cpumask for the OFFSTACK case. We could change
+ * this to *only* allocate as much of it as required by the
+ * maximum number of CPU's we can ever have. The cpumask_allocation
+ * is at the end of the structure, exactly for that reason.
+ */
mm_cachep = kmem_cache_create("mm_struct",
sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC);
mmap_init();
+ nsproxy_cache_init();
}
/*
- * Check constraints on flags passed to the unshare system call and
- * force unsharing of additional process context as appropriate.
+ * Check constraints on flags passed to the unshare system call.
*/
-static void check_unshare_flags(unsigned long *flags_ptr)
+static int check_unshare_flags(unsigned long unshare_flags)
{
+ if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
+ CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
+ CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET))
+ return -EINVAL;
/*
- * If unsharing a thread from a thread group, must also
- * unshare vm.
- */
- if (*flags_ptr & CLONE_THREAD)
- *flags_ptr |= CLONE_VM;
-
- /*
- * If unsharing vm, must also unshare signal handlers.
- */
- if (*flags_ptr & CLONE_VM)
- *flags_ptr |= CLONE_SIGHAND;
-
- /*
- * If unsharing namespace, must also unshare filesystem information.
+ * Not implemented, but pretend it works if there is nothing to
+ * unshare. Note that unsharing CLONE_THREAD or CLONE_SIGHAND
+ * needs to unshare vm.
*/
- if (*flags_ptr & CLONE_NEWNS)
- *flags_ptr |= CLONE_FS;
-}
-
-/*
- * Unsharing of tasks created with CLONE_THREAD is not supported yet
- */
-static int unshare_thread(unsigned long unshare_flags)
-{
- if (unshare_flags & CLONE_THREAD)
- return -EINVAL;
+ if (unshare_flags & (CLONE_THREAD | CLONE_SIGHAND | CLONE_VM)) {
+ /* FIXME: get_task_mm() increments ->mm_users */
+ if (atomic_read(¤t->mm->mm_users) > 1)
+ return -EINVAL;
+ }
return 0;
}
return 0;
}
-/*
- * Unsharing of sighand is not supported yet
- */
-static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp)
-{
- struct sighand_struct *sigh = current->sighand;
-
- if ((unshare_flags & CLONE_SIGHAND) && atomic_read(&sigh->count) > 1)
- return -EINVAL;
- else
- return 0;
-}
-
-/*
- * Unshare vm if it is being shared
- */
-static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp)
-{
- struct mm_struct *mm = current->mm;
-
- if ((unshare_flags & CLONE_VM) &&
- (mm && atomic_read(&mm->mm_users) > 1)) {
- return -EINVAL;
- }
-
- return 0;
-}
-
/*
* Unshare file descriptor table if it is being shared
*/
*/
SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
{
- int err = 0;
struct fs_struct *fs, *new_fs = NULL;
- struct sighand_struct *new_sigh = NULL;
- struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
struct files_struct *fd, *new_fd = NULL;
struct nsproxy *new_nsproxy = NULL;
int do_sysvsem = 0;
+ int err;
- check_unshare_flags(&unshare_flags);
-
- /* Return -EINVAL for all unsupported flags */
- err = -EINVAL;
- if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
- CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
- CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET))
+ err = check_unshare_flags(unshare_flags);
+ if (err)
goto bad_unshare_out;
+ /*
+ * If unsharing namespace, must also unshare filesystem information.
+ */
+ if (unshare_flags & CLONE_NEWNS)
+ unshare_flags |= CLONE_FS;
/*
* CLONE_NEWIPC must also detach from the undolist: after switching
* to a new ipc namespace, the semaphore arrays from the old
*/
if (unshare_flags & (CLONE_NEWIPC|CLONE_SYSVSEM))
do_sysvsem = 1;
- if ((err = unshare_thread(unshare_flags)))
+ err = unshare_fs(unshare_flags, &new_fs);
+ if (err)
goto bad_unshare_out;
- if ((err = unshare_fs(unshare_flags, &new_fs)))
- goto bad_unshare_cleanup_thread;
- if ((err = unshare_sighand(unshare_flags, &new_sigh)))
+ err = unshare_fd(unshare_flags, &new_fd);
+ if (err)
goto bad_unshare_cleanup_fs;
- if ((err = unshare_vm(unshare_flags, &new_mm)))
- goto bad_unshare_cleanup_sigh;
- if ((err = unshare_fd(unshare_flags, &new_fd)))
- goto bad_unshare_cleanup_vm;
- if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy,
- new_fs)))
+ err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy, new_fs);
+ if (err)
goto bad_unshare_cleanup_fd;
- if (new_fs || new_mm || new_fd || do_sysvsem || new_nsproxy) {
+ if (new_fs || new_fd || do_sysvsem || new_nsproxy) {
if (do_sysvsem) {
/*
* CLONE_SYSVSEM is equivalent to sys_exit().
if (new_fs) {
fs = current->fs;
- write_lock(&fs->lock);
+ spin_lock(&fs->lock);
current->fs = new_fs;
if (--fs->users)
new_fs = NULL;
else
new_fs = fs;
- write_unlock(&fs->lock);
- }
-
- if (new_mm) {
- mm = current->mm;
- active_mm = current->active_mm;
- current->mm = new_mm;
- current->active_mm = new_mm;
- activate_mm(active_mm, new_mm);
- new_mm = mm;
+ spin_unlock(&fs->lock);
}
if (new_fd) {
if (new_fd)
put_files_struct(new_fd);
-bad_unshare_cleanup_vm:
- if (new_mm)
- mmput(new_mm);
-
-bad_unshare_cleanup_sigh:
- if (new_sigh)
- if (atomic_dec_and_test(&new_sigh->count))
- kmem_cache_free(sighand_cachep, new_sigh);
-
bad_unshare_cleanup_fs:
if (new_fs)
free_fs_struct(new_fs);
-bad_unshare_cleanup_thread:
bad_unshare_out:
return err;
}