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-rw-r--r--kernel/fork.c1980
1 files changed, 1301 insertions, 679 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 2a587b3224e..6a13c46cd87 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -11,37 +11,69 @@
* management can be a bitch. See 'mm/memory.c': 'copy_page_range()'
*/
-#include <linux/config.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/unistd.h>
-#include <linux/smp_lock.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/completion.h>
-#include <linux/namespace.h>
#include <linux/personality.h>
#include <linux/mempolicy.h>
#include <linux/sem.h>
#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/iocontext.h>
#include <linux/key.h>
#include <linux/binfmts.h>
#include <linux/mman.h>
+#include <linux/mmu_notifier.h>
#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/vmacache.h>
+#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/hugetlb.h>
+#include <linux/seccomp.h>
#include <linux/swap.h>
#include <linux/syscalls.h>
#include <linux/jiffies.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/mount.h>
#include <linux/audit.h>
+#include <linux/memcontrol.h>
+#include <linux/ftrace.h>
+#include <linux/proc_fs.h>
#include <linux/profile.h>
#include <linux/rmap.h>
+#include <linux/ksm.h>
#include <linux/acct.h>
+#include <linux/tsacct_kern.h>
+#include <linux/cn_proc.h>
+#include <linux/freezer.h>
+#include <linux/delayacct.h>
+#include <linux/taskstats_kern.h>
+#include <linux/random.h>
+#include <linux/tty.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 <linux/signalfd.h>
+#include <linux/uprobes.h>
+#include <linux/aio.h>
+#include <linux/compiler.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -50,90 +82,192 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
+#include <trace/events/sched.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/task.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 */
DEFINE_PER_CPU(unsigned long, process_counts) = 0;
- __cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
+__cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
-EXPORT_SYMBOL(tasklist_lock);
+#ifdef CONFIG_PROVE_RCU
+int lockdep_tasklist_lock_is_held(void)
+{
+ return lockdep_is_held(&tasklist_lock);
+}
+EXPORT_SYMBOL_GPL(lockdep_tasklist_lock_is_held);
+#endif /* #ifdef CONFIG_PROVE_RCU */
int nr_processes(void)
{
int cpu;
int total = 0;
- for_each_online_cpu(cpu)
+ for_each_possible_cpu(cpu)
total += per_cpu(process_counts, cpu);
return total;
}
-#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))
-static kmem_cache_t *task_struct_cachep;
+void __weak arch_release_task_struct(struct task_struct *tsk)
+{
+}
+
+#ifndef CONFIG_ARCH_TASK_STRUCT_ALLOCATOR
+static struct kmem_cache *task_struct_cachep;
+
+static inline struct task_struct *alloc_task_struct_node(int node)
+{
+ return kmem_cache_alloc_node(task_struct_cachep, GFP_KERNEL, node);
+}
+
+static inline void free_task_struct(struct task_struct *tsk)
+{
+ kmem_cache_free(task_struct_cachep, tsk);
+}
+#endif
+
+void __weak arch_release_thread_info(struct thread_info *ti)
+{
+}
+
+#ifndef CONFIG_ARCH_THREAD_INFO_ALLOCATOR
+
+/*
+ * Allocate pages if THREAD_SIZE is >= PAGE_SIZE, otherwise use a
+ * kmemcache based allocator.
+ */
+# if THREAD_SIZE >= PAGE_SIZE
+static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
+ int node)
+{
+ struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP,
+ THREAD_SIZE_ORDER);
+
+ return page ? page_address(page) : NULL;
+}
+
+static inline void free_thread_info(struct thread_info *ti)
+{
+ free_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER);
+}
+# else
+static struct kmem_cache *thread_info_cache;
+
+static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
+ int node)
+{
+ return kmem_cache_alloc_node(thread_info_cache, THREADINFO_GFP, node);
+}
+
+static void free_thread_info(struct thread_info *ti)
+{
+ kmem_cache_free(thread_info_cache, ti);
+}
+
+void thread_info_cache_init(void)
+{
+ thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
+ THREAD_SIZE, 0, NULL);
+ BUG_ON(thread_info_cache == NULL);
+}
+# endif
#endif
/* SLAB cache for signal_struct structures (tsk->signal) */
-kmem_cache_t *signal_cachep;
+static struct kmem_cache *signal_cachep;
/* SLAB cache for sighand_struct structures (tsk->sighand) */
-kmem_cache_t *sighand_cachep;
+struct kmem_cache *sighand_cachep;
/* SLAB cache for files_struct structures (tsk->files) */
-kmem_cache_t *files_cachep;
+struct kmem_cache *files_cachep;
/* SLAB cache for fs_struct structures (tsk->fs) */
-kmem_cache_t *fs_cachep;
+struct kmem_cache *fs_cachep;
/* SLAB cache for vm_area_struct structures */
-kmem_cache_t *vm_area_cachep;
+struct kmem_cache *vm_area_cachep;
/* SLAB cache for mm_struct structures (tsk->mm) */
-static kmem_cache_t *mm_cachep;
+static struct kmem_cache *mm_cachep;
+
+static void account_kernel_stack(struct thread_info *ti, int account)
+{
+ struct zone *zone = page_zone(virt_to_page(ti));
+
+ mod_zone_page_state(zone, NR_KERNEL_STACK, account);
+}
void free_task(struct task_struct *tsk)
{
- free_thread_info(tsk->thread_info);
+ account_kernel_stack(tsk->stack, -1);
+ arch_release_thread_info(tsk->stack);
+ free_thread_info(tsk->stack);
+ rt_mutex_debug_task_free(tsk);
+ ftrace_graph_exit_task(tsk);
+ put_seccomp_filter(tsk);
+ arch_release_task_struct(tsk);
free_task_struct(tsk);
}
EXPORT_SYMBOL(free_task);
+static inline void free_signal_struct(struct signal_struct *sig)
+{
+ taskstats_tgid_free(sig);
+ sched_autogroup_exit(sig);
+ kmem_cache_free(signal_cachep, sig);
+}
+
+static inline void put_signal_struct(struct signal_struct *sig)
+{
+ if (atomic_dec_and_test(&sig->sigcnt))
+ free_signal_struct(sig);
+}
+
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);
- if (unlikely(tsk->audit_context))
- audit_free(tsk);
+ task_numa_free(tsk);
security_task_free(tsk);
- free_uid(tsk->user);
- put_group_info(tsk->group_info);
+ exit_creds(tsk);
+ delayacct_tsk_free(tsk);
+ put_signal_struct(tsk->signal);
if (!profile_handoff_task(tsk))
free_task(tsk);
}
+EXPORT_SYMBOL_GPL(__put_task_struct);
+
+void __init __weak arch_task_cache_init(void) { }
void __init fork_init(unsigned long mempages)
{
-#ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
+#ifndef CONFIG_ARCH_TASK_STRUCT_ALLOCATOR
#ifndef ARCH_MIN_TASKALIGN
#define ARCH_MIN_TASKALIGN L1_CACHE_BYTES
#endif
/* create a slab on which task_structs can be allocated */
task_struct_cachep =
kmem_cache_create("task_struct", sizeof(struct task_struct),
- ARCH_MIN_TASKALIGN, SLAB_PANIC, NULL, NULL);
+ ARCH_MIN_TASKALIGN, SLAB_PANIC | SLAB_NOTRACK, NULL);
#endif
+ /* do the arch specific task caches init */
+ arch_task_cache_init();
+
/*
* The default maximum number of threads is set to a safe
* value: the thread structures can take up at most half
@@ -144,7 +278,7 @@ void __init fork_init(unsigned long mempages)
/*
* 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;
@@ -153,119 +287,175 @@ void __init fork_init(unsigned long mempages)
init_task.signal->rlim[RLIMIT_NPROC];
}
+int __weak arch_dup_task_struct(struct task_struct *dst,
+ struct task_struct *src)
+{
+ *dst = *src;
+ return 0;
+}
+
static struct task_struct *dup_task_struct(struct task_struct *orig)
{
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);
- if (!ti) {
- free_task_struct(tsk);
- return NULL;
- }
+ ti = alloc_thread_info_node(tsk, node);
+ if (!ti)
+ goto free_tsk;
+
+ err = arch_dup_task_struct(tsk, orig);
+ if (err)
+ goto free_ti;
- *ti = *orig->thread_info;
- *tsk = *orig;
- tsk->thread_info = ti;
- ti->task = tsk;
+ tsk->stack = ti;
+
+ 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 */
+
+#ifdef CONFIG_CC_STACKPROTECTOR
+ tsk->stack_canary = get_random_int();
+#endif
+
+ /*
+ * 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
+ tsk->splice_pipe = NULL;
+ tsk->task_frag.page = NULL;
+
+ account_kernel_stack(ti, 1);
- /* One for us, one for whoever does the "release_task()" (usually parent) */
- atomic_set(&tsk->usage,2);
- atomic_set(&tsk->fs_excl, 0);
return tsk;
+
+free_ti:
+ free_thread_info(ti);
+free_tsk:
+ free_task_struct(tsk);
+ return NULL;
}
#ifdef CONFIG_MMU
-static inline int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
+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;
- struct mempolicy *pol;
+ uprobe_start_dup_mmap();
down_write(&oldmm->mmap_sem);
- flush_cache_mm(oldmm);
- down_write(&mm->mmap_sem);
+ flush_cache_dup_mm(oldmm);
+ uprobe_dup_mmap(oldmm, mm);
+ /*
+ * Not linked in yet - no deadlock potential:
+ */
+ down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
mm->locked_vm = 0;
mm->mmap = NULL;
- mm->mmap_cache = NULL;
- mm->free_area_cache = oldmm->mmap_base;
- mm->cached_hole_size = ~0UL;
+ mm->vmacache_seqnum = 0;
mm->map_count = 0;
- cpus_clear(mm->cpu_vm_mask);
+ cpumask_clear(mm_cpumask(mm));
mm->mm_rb = RB_ROOT;
rb_link = &mm->mm_rb.rb_node;
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 (mpnt->vm_flags & VM_DONTCOPY) {
- long pages = vma_pages(mpnt);
- mm->total_vm -= pages;
vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file,
- -pages);
+ -vma_pages(mpnt));
continue;
}
charge = 0;
if (mpnt->vm_flags & VM_ACCOUNT) {
- unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
- if (security_vm_enough_memory(len))
+ unsigned long len = vma_pages(mpnt);
+
+ if (security_vm_enough_memory_mm(oldmm, len)) /* sic */
goto fail_nomem;
charge = len;
}
- tmp = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+ tmp = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
if (!tmp)
goto fail_nomem;
*tmp = *mpnt;
- pol = mpol_copy(vma_policy(mpnt));
- retval = PTR_ERR(pol);
- if (IS_ERR(pol))
+ INIT_LIST_HEAD(&tmp->anon_vma_chain);
+ retval = vma_dup_policy(mpnt, tmp);
+ if (retval)
goto fail_nomem_policy;
- vma_set_policy(tmp, pol);
- tmp->vm_flags &= ~VM_LOCKED;
tmp->vm_mm = mm;
- tmp->vm_next = NULL;
- anon_vma_link(tmp);
+ if (anon_vma_fork(tmp, mpnt))
+ goto fail_nomem_anon_vma_fork;
+ tmp->vm_flags &= ~VM_LOCKED;
+ tmp->vm_next = tmp->vm_prev = NULL;
file = tmp->vm_file;
if (file) {
- struct inode *inode = file->f_dentry->d_inode;
+ struct inode *inode = file_inode(file);
+ struct address_space *mapping = file->f_mapping;
+
get_file(file);
if (tmp->vm_flags & VM_DENYWRITE)
atomic_dec(&inode->i_writecount);
-
+ mutex_lock(&mapping->i_mmap_mutex);
+ if (tmp->vm_flags & VM_SHARED)
+ mapping->i_mmap_writable++;
+ flush_dcache_mmap_lock(mapping);
/* insert tmp into the share list, just after mpnt */
- spin_lock(&file->f_mapping->i_mmap_lock);
- tmp->vm_truncate_count = mpnt->vm_truncate_count;
- flush_dcache_mmap_lock(file->f_mapping);
- vma_prio_tree_add(tmp, mpnt);
- flush_dcache_mmap_unlock(file->f_mapping);
- spin_unlock(&file->f_mapping->i_mmap_lock);
+ if (unlikely(tmp->vm_flags & VM_NONLINEAR))
+ vma_nonlinear_insert(tmp,
+ &mapping->i_mmap_nonlinear);
+ else
+ vma_interval_tree_insert_after(tmp, mpnt,
+ &mapping->i_mmap);
+ flush_dcache_mmap_unlock(mapping);
+ mutex_unlock(&mapping->i_mmap_mutex);
}
/*
+ * Clear hugetlb-related page reserves for children. This only
+ * affects MAP_PRIVATE mappings. Faults generated by the child
+ * are not guaranteed to succeed, even if read-only
+ */
+ if (is_vm_hugetlb_page(tmp))
+ reset_vma_resv_huge_pages(tmp);
+
+ /*
* Link in the new vma and copy the page table entries.
*/
- spin_lock(&mm->page_table_lock);
*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;
rb_parent = &tmp->vm_rb;
mm->map_count++;
- retval = copy_page_range(mm, oldmm, tmp);
- spin_unlock(&mm->page_table_lock);
+ retval = copy_page_range(mm, oldmm, mpnt);
if (tmp->vm_ops && tmp->vm_ops->open)
tmp->vm_ops->open(tmp);
@@ -273,12 +463,17 @@ static inline int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
if (retval)
goto out;
}
+ /* a new mm has just been created */
+ arch_dup_mmap(oldmm, mm);
retval = 0;
out:
up_write(&mm->mmap_sem);
flush_tlb_mm(oldmm);
up_write(&oldmm->mmap_sem);
+ uprobe_end_dup_mmap();
return retval;
+fail_nomem_anon_vma_fork:
+ mpol_put(vma_policy(tmp));
fail_nomem_policy:
kmem_cache_free(vm_area_cachep, tmp);
fail_nomem:
@@ -287,7 +482,7 @@ fail_nomem:
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))
@@ -295,9 +490,9 @@ static inline int mm_alloc_pgd(struct mm_struct * mm)
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->pgd);
+ pgd_free(mm, mm->pgd);
}
#else
#define dup_mmap(mm, oldmm) (0)
@@ -305,51 +500,95 @@ static inline void mm_free_pgd(struct mm_struct * mm)
#define mm_free_pgd(mm)
#endif /* CONFIG_MMU */
- __cacheline_aligned_in_smp DEFINE_SPINLOCK(mmlist_lock);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(mmlist_lock);
-#define allocate_mm() (kmem_cache_alloc(mm_cachep, SLAB_KERNEL))
+#define allocate_mm() (kmem_cache_alloc(mm_cachep, GFP_KERNEL))
#define free_mm(mm) (kmem_cache_free(mm_cachep, (mm)))
+static unsigned long default_dump_filter = MMF_DUMP_FILTER_DEFAULT;
+
+static int __init coredump_filter_setup(char *s)
+{
+ default_dump_filter =
+ (simple_strtoul(s, NULL, 0) << MMF_DUMP_FILTER_SHIFT) &
+ MMF_DUMP_FILTER_MASK;
+ return 1;
+}
+
+__setup("coredump_filter=", coredump_filter_setup);
+
#include <linux/init_task.h>
-static struct mm_struct * mm_init(struct mm_struct * mm)
+static void mm_init_aio(struct mm_struct *mm)
+{
+#ifdef CONFIG_AIO
+ spin_lock_init(&mm->ioctx_lock);
+ mm->ioctx_table = NULL;
+#endif
+}
+
+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);
init_rwsem(&mm->mmap_sem);
INIT_LIST_HEAD(&mm->mmlist);
- mm->core_waiters = 0;
- mm->nr_ptes = 0;
- set_mm_counter(mm, file_rss, 0);
- set_mm_counter(mm, anon_rss, 0);
+ mm->core_state = NULL;
+ atomic_long_set(&mm->nr_ptes, 0);
+ memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
spin_lock_init(&mm->page_table_lock);
- rwlock_init(&mm->ioctx_list_lock);
- mm->ioctx_list = NULL;
- mm->default_kioctx = (struct kioctx)INIT_KIOCTX(mm->default_kioctx, *mm);
- mm->free_area_cache = TASK_UNMAPPED_BASE;
- mm->cached_hole_size = ~0UL;
+ mm_init_aio(mm);
+ mm_init_owner(mm, p);
+ clear_tlb_flush_pending(mm);
- if (likely(!mm_alloc_pgd(mm))) {
+ if (current->mm) {
+ mm->flags = current->mm->flags & MMF_INIT_MASK;
+ mm->def_flags = current->mm->def_flags & VM_INIT_DEF_MASK;
+ } else {
+ mm->flags = default_dump_filter;
mm->def_flags = 0;
+ }
+
+ if (likely(!mm_alloc_pgd(mm))) {
+ mmu_notifier_mm_init(mm);
return mm;
}
+
free_mm(mm);
return NULL;
}
+static void check_mm(struct mm_struct *mm)
+{
+ int i;
+
+ for (i = 0; i < NR_MM_COUNTERS; i++) {
+ long x = atomic_long_read(&mm->rss_stat.count[i]);
+
+ if (unlikely(x))
+ printk(KERN_ALERT "BUG: Bad rss-counter state "
+ "mm:%p idx:%d val:%ld\n", mm, i, x);
+ }
+
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
+ VM_BUG_ON(mm->pmd_huge_pte);
+#endif
+}
+
/*
* 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);
- }
- return mm;
+ if (!mm)
+ return NULL;
+
+ memset(mm, 0, sizeof(*mm));
+ mm_init_cpumask(mm);
+ return mm_init(mm, current);
}
/*
@@ -357,37 +596,76 @@ struct mm_struct * mm_alloc(void)
* is dropped: either by a lazy thread or by
* mmput. Free the page directory and the mm.
*/
-void fastcall __mmdrop(struct mm_struct *mm)
+void __mmdrop(struct mm_struct *mm)
{
BUG_ON(mm == &init_mm);
mm_free_pgd(mm);
destroy_context(mm);
+ mmu_notifier_mm_destroy(mm);
+ check_mm(mm);
free_mm(mm);
}
+EXPORT_SYMBOL_GPL(__mmdrop);
/*
* Decrement the use count and release all resources for an mm.
*/
void mmput(struct mm_struct *mm)
{
+ might_sleep();
+
if (atomic_dec_and_test(&mm->mm_users)) {
+ uprobe_clear_state(mm);
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)) {
spin_lock(&mmlist_lock);
list_del(&mm->mmlist);
spin_unlock(&mmlist_lock);
}
- put_swap_token(mm);
+ if (mm->binfmt)
+ module_put(mm->binfmt->module);
mmdrop(mm);
}
}
EXPORT_SYMBOL_GPL(mmput);
+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;
+}
+
+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 exe_file */
+ 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
*
- * Returns %NULL if the task has no mm. Checks PF_BORROWED_MM (meaning
+ * Returns %NULL if the task has no mm. Checks PF_KTHREAD (meaning
* this kernel workthread has transiently adopted a user mm with use_mm,
* to do its AIO) is not set and if so returns a reference to it, after
* bumping up the use count. User must release the mm via mmput()
@@ -400,7 +678,7 @@ struct mm_struct *get_task_mm(struct task_struct *task)
task_lock(task);
mm = task->mm;
if (mm) {
- if (task->flags & PF_BORROWED_MM)
+ if (task->flags & PF_KTHREAD)
mm = NULL;
else
atomic_inc(&mm->mm_users);
@@ -410,6 +688,58 @@ struct mm_struct *get_task_mm(struct task_struct *task)
}
EXPORT_SYMBOL_GPL(get_task_mm);
+struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
+{
+ struct mm_struct *mm;
+ int err;
+
+ err = mutex_lock_killable(&task->signal->cred_guard_mutex);
+ if (err)
+ return ERR_PTR(err);
+
+ mm = get_task_mm(task);
+ if (mm && mm != current->mm &&
+ !ptrace_may_access(task, mode)) {
+ mmput(mm);
+ mm = ERR_PTR(-EACCES);
+ }
+ mutex_unlock(&task->signal->cred_guard_mutex);
+
+ return mm;
+}
+
+static void complete_vfork_done(struct task_struct *tsk)
+{
+ struct completion *vfork;
+
+ task_lock(tsk);
+ vfork = tsk->vfork_done;
+ if (likely(vfork)) {
+ tsk->vfork_done = NULL;
+ complete(vfork);
+ }
+ task_unlock(tsk);
+}
+
+static int wait_for_vfork_done(struct task_struct *child,
+ struct completion *vfork)
+{
+ int killed;
+
+ freezer_do_not_count();
+ killed = wait_for_completion_killable(vfork);
+ freezer_count();
+
+ if (killed) {
+ task_lock(child);
+ child->vfork_done = NULL;
+ task_unlock(child);
+ }
+
+ put_task_struct(child);
+ return killed;
+}
+
/* Please note the differences between mmput and mm_release.
* mmput is called whenever we stop holding onto a mm_struct,
* error success whatever.
@@ -425,36 +755,123 @@ EXPORT_SYMBOL_GPL(get_task_mm);
*/
void mm_release(struct task_struct *tsk, struct mm_struct *mm)
{
- struct completion *vfork_done = tsk->vfork_done;
+ /* Get rid of any futexes when releasing the mm */
+#ifdef CONFIG_FUTEX
+ if (unlikely(tsk->robust_list)) {
+ exit_robust_list(tsk);
+ tsk->robust_list = NULL;
+ }
+#ifdef CONFIG_COMPAT
+ if (unlikely(tsk->compat_robust_list)) {
+ compat_exit_robust_list(tsk);
+ tsk->compat_robust_list = NULL;
+ }
+#endif
+ if (unlikely(!list_empty(&tsk->pi_state_list)))
+ exit_pi_state_list(tsk);
+#endif
+
+ uprobe_free_utask(tsk);
/* Get rid of any cached register state */
deactivate_mm(tsk, mm);
- /* notify parent sleeping on vfork() */
- if (vfork_done) {
- tsk->vfork_done = NULL;
- complete(vfork_done);
- }
- if (tsk->clear_child_tid && atomic_read(&mm->mm_users) > 1) {
- u32 __user * tidptr = tsk->clear_child_tid;
+ /*
+ * If we're exiting normally, clear a user-space tid field if
+ * requested. We leave this alone when dying by signal, to leave
+ * the value intact in a core dump, and to save the unnecessary
+ * trouble, say, a killed vfork parent shouldn't touch this mm.
+ * Userland only wants this done for a sys_exit.
+ */
+ if (tsk->clear_child_tid) {
+ if (!(tsk->flags & PF_SIGNALED) &&
+ atomic_read(&mm->mm_users) > 1) {
+ /*
+ * We don't check the error code - if userspace has
+ * not set up a proper pointer then tough luck.
+ */
+ put_user(0, tsk->clear_child_tid);
+ sys_futex(tsk->clear_child_tid, FUTEX_WAKE,
+ 1, NULL, NULL, 0);
+ }
tsk->clear_child_tid = NULL;
-
- /*
- * We don't check the error code - if userspace has
- * not set up a proper pointer then tough luck.
- */
- put_user(0, tidptr);
- sys_futex(tidptr, FUTEX_WAKE, 1, NULL, NULL, 0);
}
+
+ /*
+ * All done, finally we can wake up parent and return this mm to him.
+ * Also kthread_stop() uses this completion for synchronization.
+ */
+ if (tsk->vfork_done)
+ complete_vfork_done(tsk);
}
-static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
+/*
+ * Allocate a new mm structure and copy contents from the
+ * mm structure of the passed in task structure.
+ */
+static struct mm_struct *dup_mm(struct task_struct *tsk)
{
- struct mm_struct * mm, *oldmm;
+ struct mm_struct *mm, *oldmm = current->mm;
+ int err;
+
+ mm = allocate_mm();
+ if (!mm)
+ goto fail_nomem;
+
+ memcpy(mm, oldmm, sizeof(*mm));
+ mm_init_cpumask(mm);
+
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
+ mm->pmd_huge_pte = NULL;
+#endif
+ if (!mm_init(mm, tsk))
+ goto fail_nomem;
+
+ if (init_new_context(tsk, mm))
+ goto fail_nocontext;
+
+ dup_mm_exe_file(oldmm, mm);
+
+ err = dup_mmap(mm, oldmm);
+ if (err)
+ goto free_pt;
+
+ mm->hiwater_rss = get_mm_rss(mm);
+ mm->hiwater_vm = mm->total_vm;
+
+ if (mm->binfmt && !try_module_get(mm->binfmt->module))
+ goto free_pt;
+
+ return mm;
+
+free_pt:
+ /* don't put binfmt in mmput, we haven't got module yet */
+ mm->binfmt = NULL;
+ mmput(mm);
+
+fail_nomem:
+ return NULL;
+
+fail_nocontext:
+ /*
+ * If init_new_context() failed, we cannot use mmput() to free the mm
+ * because it calls destroy_context()
+ */
+ mm_free_pgd(mm);
+ free_mm(mm);
+ return NULL;
+}
+
+static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
+{
+ struct mm_struct *mm, *oldmm;
int retval;
tsk->min_flt = tsk->maj_flt = 0;
tsk->nvcsw = tsk->nivcsw = 0;
+#ifdef CONFIG_DETECT_HUNG_TASK
+ tsk->last_switch_count = tsk->nvcsw + tsk->nivcsw;
+#endif
tsk->mm = NULL;
tsk->active_mm = NULL;
@@ -468,150 +885,53 @@ static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
if (!oldmm)
return 0;
+ /* initialize the new vmacache entries */
+ vmacache_flush(tsk);
+
if (clone_flags & CLONE_VM) {
atomic_inc(&oldmm->mm_users);
mm = oldmm;
- /*
- * There are cases where the PTL is held to ensure no
- * new threads start up in user mode using an mm, which
- * allows optimizing out ipis; the tlb_gather_mmu code
- * is an example.
- */
- spin_unlock_wait(&oldmm->page_table_lock);
goto good_mm;
}
retval = -ENOMEM;
- mm = allocate_mm();
+ mm = dup_mm(tsk);
if (!mm)
goto fail_nomem;
- /* Copy the current MM stuff.. */
- memcpy(mm, oldmm, sizeof(*mm));
- if (!mm_init(mm))
- goto fail_nomem;
-
- if (init_new_context(tsk,mm))
- goto fail_nocontext;
-
- retval = dup_mmap(mm, oldmm);
- if (retval)
- goto free_pt;
-
- mm->hiwater_rss = get_mm_rss(mm);
- mm->hiwater_vm = mm->total_vm;
-
good_mm:
tsk->mm = mm;
tsk->active_mm = mm;
return 0;
-free_pt:
- mmput(mm);
fail_nomem:
return retval;
-
-fail_nocontext:
- /*
- * If init_new_context() failed, we cannot use mmput() to free the mm
- * because it calls destroy_context()
- */
- mm_free_pgd(mm);
- free_mm(mm);
- return retval;
}
-static inline struct fs_struct *__copy_fs_struct(struct fs_struct *old)
-{
- struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL);
- /* We don't need to lock fs - think why ;-) */
- if (fs) {
- atomic_set(&fs->count, 1);
- rwlock_init(&fs->lock);
- fs->umask = old->umask;
- read_lock(&old->lock);
- fs->rootmnt = mntget(old->rootmnt);
- fs->root = dget(old->root);
- fs->pwdmnt = mntget(old->pwdmnt);
- fs->pwd = dget(old->pwd);
- if (old->altroot) {
- fs->altrootmnt = mntget(old->altrootmnt);
- fs->altroot = dget(old->altroot);
- } else {
- fs->altrootmnt = NULL;
- fs->altroot = NULL;
- }
- read_unlock(&old->lock);
- }
- return fs;
-}
-
-struct fs_struct *copy_fs_struct(struct fs_struct *old)
-{
- return __copy_fs_struct(old);
-}
-
-EXPORT_SYMBOL_GPL(copy_fs_struct);
-
-static inline int copy_fs(unsigned long clone_flags, struct task_struct * tsk)
+static int copy_fs(unsigned long clone_flags, struct task_struct *tsk)
{
+ struct fs_struct *fs = current->fs;
if (clone_flags & CLONE_FS) {
- atomic_inc(&current->fs->count);
+ /* tsk->fs is already what we want */
+ spin_lock(&fs->lock);
+ if (fs->in_exec) {
+ spin_unlock(&fs->lock);
+ return -EAGAIN;
+ }
+ fs->users++;
+ spin_unlock(&fs->lock);
return 0;
}
- tsk->fs = __copy_fs_struct(current->fs);
+ tsk->fs = copy_fs_struct(fs);
if (!tsk->fs)
return -ENOMEM;
return 0;
}
-static int count_open_files(struct fdtable *fdt)
-{
- int size = fdt->max_fdset;
- int i;
-
- /* Find the last open fd */
- for (i = size/(8*sizeof(long)); i > 0; ) {
- if (fdt->open_fds->fds_bits[--i])
- break;
- }
- i = (i+1) * 8 * sizeof(long);
- return i;
-}
-
-static struct files_struct *alloc_files(void)
-{
- struct files_struct *newf;
- struct fdtable *fdt;
-
- newf = kmem_cache_alloc(files_cachep, SLAB_KERNEL);
- if (!newf)
- goto out;
-
- atomic_set(&newf->count, 1);
-
- spin_lock_init(&newf->file_lock);
- fdt = &newf->fdtab;
- fdt->next_fd = 0;
- fdt->max_fds = NR_OPEN_DEFAULT;
- fdt->max_fdset = __FD_SETSIZE;
- fdt->close_on_exec = &newf->close_on_exec_init;
- fdt->open_fds = &newf->open_fds_init;
- fdt->fd = &newf->fd_array[0];
- INIT_RCU_HEAD(&fdt->rcu);
- fdt->free_files = NULL;
- fdt->next = NULL;
- rcu_assign_pointer(newf->fdt, fdt);
-out:
- return newf;
-}
-
-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;
- struct file **old_fds, **new_fds;
- int open_files, size, i, error = 0, expand;
- struct fdtable *old_fdt, *new_fdt;
+ int error = 0;
/*
* A background process may not have any files ...
@@ -625,240 +945,184 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
goto out;
}
- /*
- * Note: we may be using current for both targets (See exec.c)
- * This works because we cache current->files (old) as oldf. Don't
- * break this.
- */
- tsk->files = NULL;
- error = -ENOMEM;
- newf = alloc_files();
+ newf = dup_fd(oldf, &error);
if (!newf)
goto out;
- spin_lock(&oldf->file_lock);
- old_fdt = files_fdtable(oldf);
- new_fdt = files_fdtable(newf);
- size = old_fdt->max_fdset;
- open_files = count_open_files(old_fdt);
- expand = 0;
-
- /*
- * Check whether we need to allocate a larger fd array or fd set.
- * Note: we're not a clone task, so the open count won't change.
- */
- if (open_files > new_fdt->max_fdset) {
- new_fdt->max_fdset = 0;
- expand = 1;
- }
- if (open_files > new_fdt->max_fds) {
- new_fdt->max_fds = 0;
- expand = 1;
- }
-
- /* if the old fdset gets grown now, we'll only copy up to "size" fds */
- if (expand) {
- spin_unlock(&oldf->file_lock);
- spin_lock(&newf->file_lock);
- error = expand_files(newf, open_files-1);
- spin_unlock(&newf->file_lock);
- if (error < 0)
- goto out_release;
- new_fdt = files_fdtable(newf);
- /*
- * Reacquire the oldf lock and a pointer to its fd table
- * who knows it may have a new bigger fd table. We need
- * the latest pointer.
- */
- spin_lock(&oldf->file_lock);
- old_fdt = files_fdtable(oldf);
- }
-
- old_fds = old_fdt->fd;
- new_fds = new_fdt->fd;
-
- memcpy(new_fdt->open_fds->fds_bits, old_fdt->open_fds->fds_bits, open_files/8);
- memcpy(new_fdt->close_on_exec->fds_bits, old_fdt->close_on_exec->fds_bits, open_files/8);
-
- for (i = open_files; i != 0; i--) {
- struct file *f = *old_fds++;
- if (f) {
- get_file(f);
- } else {
- /*
- * The fd may be claimed in the fd bitmap but not yet
- * instantiated in the files array if a sibling thread
- * is partway through open(). So make sure that this
- * fd is available to the new process.
- */
- FD_CLR(open_files - i, new_fdt->open_fds);
- }
- rcu_assign_pointer(*new_fds++, f);
- }
- spin_unlock(&oldf->file_lock);
-
- /* compute the remainder to be cleared */
- size = (new_fdt->max_fds - open_files) * sizeof(struct file *);
-
- /* This is long word aligned thus could use a optimized version */
- memset(new_fds, 0, size);
-
- if (new_fdt->max_fdset > open_files) {
- int left = (new_fdt->max_fdset-open_files)/8;
- int start = open_files / (8 * sizeof(unsigned long));
-
- memset(&new_fdt->open_fds->fds_bits[start], 0, left);
- memset(&new_fdt->close_on_exec->fds_bits[start], 0, left);
- }
-
tsk->files = newf;
error = 0;
out:
return error;
-
-out_release:
- free_fdset (new_fdt->close_on_exec, new_fdt->max_fdset);
- free_fdset (new_fdt->open_fds, new_fdt->max_fdset);
- free_fd_array(new_fdt->fd, new_fdt->max_fds);
- kmem_cache_free(files_cachep, newf);
- goto out;
}
-/*
- * Helper to unshare the files of the current task.
- * We don't want to expose copy_files internals to
- * the exec layer of the kernel.
- */
-
-int unshare_files(void)
+static int copy_io(unsigned long clone_flags, struct task_struct *tsk)
{
- struct files_struct *files = current->files;
- int rc;
+#ifdef CONFIG_BLOCK
+ struct io_context *ioc = current->io_context;
+ struct io_context *new_ioc;
- if(!files)
- BUG();
-
- /* This can race but the race causes us to copy when we don't
- need to and drop the copy */
- if(atomic_read(&files->count) == 1)
- {
- atomic_inc(&files->count);
+ if (!ioc)
return 0;
+ /*
+ * Share io context with parent, if CLONE_IO is set
+ */
+ if (clone_flags & CLONE_IO) {
+ ioc_task_link(ioc);
+ tsk->io_context = ioc;
+ } else if (ioprio_valid(ioc->ioprio)) {
+ new_ioc = get_task_io_context(tsk, GFP_KERNEL, NUMA_NO_NODE);
+ if (unlikely(!new_ioc))
+ return -ENOMEM;
+
+ new_ioc->ioprio = ioc->ioprio;
+ put_io_context(new_ioc);
}
- rc = copy_files(0, current);
- if(rc)
- current->files = files;
- return rc;
+#endif
+ return 0;
}
-EXPORT_SYMBOL(unshare_files);
-
-static inline int copy_sighand(unsigned long clone_flags, struct task_struct * tsk)
+static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)
{
struct sighand_struct *sig;
- if (clone_flags & (CLONE_SIGHAND | CLONE_THREAD)) {
+ if (clone_flags & CLONE_SIGHAND) {
atomic_inc(&current->sighand->count);
return 0;
}
sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
- tsk->sighand = sig;
+ rcu_assign_pointer(tsk->sighand, sig);
if (!sig)
return -ENOMEM;
- spin_lock_init(&sig->siglock);
atomic_set(&sig->count, 1);
memcpy(sig->action, current->sighand->action, sizeof(sig->action));
return 0;
}
-static inline int copy_signal(unsigned long clone_flags, struct task_struct * tsk)
+void __cleanup_sighand(struct sighand_struct *sighand)
+{
+ if (atomic_dec_and_test(&sighand->count)) {
+ signalfd_cleanup(sighand);
+ kmem_cache_free(sighand_cachep, sighand);
+ }
+}
+
+
+/*
+ * Initialize POSIX timer handling for a thread group.
+ */
+static void posix_cpu_timers_init_group(struct signal_struct *sig)
+{
+ unsigned long cpu_limit;
+
+ /* Thread group counters. */
+ thread_group_cputime_init(sig);
+
+ cpu_limit = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
+ if (cpu_limit != RLIM_INFINITY) {
+ sig->cputime_expires.prof_exp = secs_to_cputime(cpu_limit);
+ sig->cputimer.running = 1;
+ }
+
+ /* The timer lists. */
+ INIT_LIST_HEAD(&sig->cpu_timers[0]);
+ INIT_LIST_HEAD(&sig->cpu_timers[1]);
+ INIT_LIST_HEAD(&sig->cpu_timers[2]);
+}
+
+static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
{
struct signal_struct *sig;
- int ret;
- if (clone_flags & CLONE_THREAD) {
- atomic_inc(&current->signal->count);
- atomic_inc(&current->signal->live);
+ if (clone_flags & CLONE_THREAD)
return 0;
- }
- sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
+
+ sig = kmem_cache_zalloc(signal_cachep, GFP_KERNEL);
tsk->signal = sig;
if (!sig)
return -ENOMEM;
- ret = copy_thread_group_keys(tsk);
- if (ret < 0) {
- kmem_cache_free(signal_cachep, sig);
- return ret;
- }
-
- atomic_set(&sig->count, 1);
+ sig->nr_threads = 1;
atomic_set(&sig->live, 1);
+ atomic_set(&sig->sigcnt, 1);
+
+ /* list_add(thread_node, thread_head) without INIT_LIST_HEAD() */
+ sig->thread_head = (struct list_head)LIST_HEAD_INIT(tsk->thread_node);
+ tsk->thread_node = (struct list_head)LIST_HEAD_INIT(sig->thread_head);
+
init_waitqueue_head(&sig->wait_chldexit);
- sig->flags = 0;
- sig->group_exit_code = 0;
- sig->group_exit_task = NULL;
- sig->group_stop_count = 0;
- sig->curr_target = NULL;
+ sig->curr_target = tsk;
init_sigpending(&sig->shared_pending);
INIT_LIST_HEAD(&sig->posix_timers);
- sig->it_real_value = sig->it_real_incr = 0;
+ hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
sig->real_timer.function = it_real_fn;
- sig->real_timer.data = (unsigned long) tsk;
- init_timer(&sig->real_timer);
-
- sig->it_virt_expires = cputime_zero;
- sig->it_virt_incr = cputime_zero;
- sig->it_prof_expires = cputime_zero;
- sig->it_prof_incr = cputime_zero;
-
- sig->tty = current->signal->tty;
- sig->pgrp = process_group(current);
- sig->session = current->signal->session;
- sig->leader = 0; /* session leadership doesn't inherit */
- sig->tty_old_pgrp = 0;
-
- sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
- sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
- sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
- sig->sched_time = 0;
- INIT_LIST_HEAD(&sig->cpu_timers[0]);
- INIT_LIST_HEAD(&sig->cpu_timers[1]);
- INIT_LIST_HEAD(&sig->cpu_timers[2]);
task_lock(current->group_leader);
memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
task_unlock(current->group_leader);
- if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
- /*
- * New sole thread in the process gets an expiry time
- * of the whole CPU time limit.
- */
- tsk->it_prof_expires =
- secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
- }
+ posix_cpu_timers_init_group(sig);
+
+ tty_audit_fork(sig);
+ sched_autogroup_fork(sig);
+
+#ifdef CONFIG_CGROUPS
+ init_rwsem(&sig->group_rwsem);
+#endif
+
+ sig->oom_score_adj = current->signal->oom_score_adj;
+ sig->oom_score_adj_min = current->signal->oom_score_adj_min;
+
+ sig->has_child_subreaper = current->signal->has_child_subreaper ||
+ current->signal->is_child_subreaper;
+
+ mutex_init(&sig->cred_guard_mutex);
return 0;
}
-static inline void copy_flags(unsigned long clone_flags, struct task_struct *p)
+SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
{
- unsigned long new_flags = p->flags;
+ current->clear_child_tid = tidptr;
- new_flags &= ~(PF_SUPERPRIV | PF_NOFREEZE);
- new_flags |= PF_FORKNOEXEC;
- if (!(clone_flags & CLONE_PTRACE))
- p->ptrace = 0;
- p->flags = new_flags;
+ return task_pid_vnr(current);
}
-asmlinkage long sys_set_tid_address(int __user *tidptr)
+static void rt_mutex_init_task(struct task_struct *p)
{
- current->clear_child_tid = tidptr;
+ raw_spin_lock_init(&p->pi_lock);
+#ifdef CONFIG_RT_MUTEXES
+ p->pi_waiters = RB_ROOT;
+ p->pi_waiters_leftmost = NULL;
+ p->pi_blocked_on = NULL;
+ p->pi_top_task = NULL;
+#endif
+}
+
+#ifdef CONFIG_MEMCG
+void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
+{
+ mm->owner = p;
+}
+#endif /* CONFIG_MEMCG */
+
+/*
+ * Initialize POSIX timer handling for a single task.
+ */
+static void posix_cpu_timers_init(struct task_struct *tsk)
+{
+ tsk->cputime_expires.prof_exp = 0;
+ tsk->cputime_expires.virt_exp = 0;
+ tsk->cputime_expires.sched_exp = 0;
+ INIT_LIST_HEAD(&tsk->cpu_timers[0]);
+ INIT_LIST_HEAD(&tsk->cpu_timers[1]);
+ INIT_LIST_HEAD(&tsk->cpu_timers[2]);
+}
- return current->pid;
+static inline void
+init_task_pid(struct task_struct *task, enum pid_type type, struct pid *pid)
+{
+ task->pids[type].pid = pid;
}
/*
@@ -869,20 +1133,22 @@ asmlinkage long sys_set_tid_address(int __user *tidptr)
* parts of the process environment (as per the clone
* flags). The actual kick-off is left to the caller.
*/
-static task_t *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,
- int pid)
+static struct task_struct *copy_process(unsigned long clone_flags,
+ unsigned long stack_start,
+ unsigned long stack_size,
+ int __user *child_tidptr,
+ struct pid *pid,
+ int trace)
{
int retval;
- struct task_struct *p = NULL;
+ struct task_struct *p;
if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
return ERR_PTR(-EINVAL);
+ if ((clone_flags & (CLONE_NEWUSER|CLONE_FS)) == (CLONE_NEWUSER|CLONE_FS))
+ return ERR_PTR(-EINVAL);
+
/*
* Thread groups must share signals as well, and detached threads
* can only be started up within the thread group.
@@ -898,6 +1164,28 @@ static task_t *copy_process(unsigned long clone_flags,
if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
return ERR_PTR(-EINVAL);
+ /*
+ * Siblings of global init remain as zombies on exit since they are
+ * not reaped by their parent (swapper). To solve this and to avoid
+ * multi-rooted process trees, prevent global and container-inits
+ * from creating siblings.
+ */
+ if ((clone_flags & CLONE_PARENT) &&
+ current->signal->flags & SIGNAL_UNKILLABLE)
+ return ERR_PTR(-EINVAL);
+
+ /*
+ * If the new process will be in a different pid or user namespace
+ * do not allow it to share a thread group or signal handlers or
+ * parent with the forking task.
+ */
+ if (clone_flags & CLONE_SIGHAND) {
+ if ((clone_flags & (CLONE_NEWUSER | CLONE_NEWPID)) ||
+ (task_active_pid_ns(current) !=
+ current->nsproxy->pid_ns_for_children))
+ return ERR_PTR(-EINVAL);
+ }
+
retval = security_task_create(clone_flags);
if (retval)
goto fork_out;
@@ -907,268 +1195,328 @@ static task_t *copy_process(unsigned long clone_flags,
if (!p)
goto fork_out;
+ ftrace_graph_init_task(p);
+ get_seccomp_filter(p);
+
+ rt_mutex_init_task(p);
+
+#ifdef CONFIG_PROVE_LOCKING
+ DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
+ DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
+#endif
retval = -EAGAIN;
- if (atomic_read(&p->user->processes) >=
- p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
- if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
- p->user != &root_user)
+ if (atomic_read(&p->real_cred->user->processes) >=
+ task_rlimit(p, RLIMIT_NPROC)) {
+ if (p->real_cred->user != INIT_USER &&
+ !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN))
goto bad_fork_free;
}
+ current->flags &= ~PF_NPROC_EXCEEDED;
- atomic_inc(&p->user->__count);
- atomic_inc(&p->user->processes);
- get_group_info(p->group_info);
+ retval = copy_creds(p, clone_flags);
+ if (retval < 0)
+ goto bad_fork_free;
/*
* If multiple threads are within copy_process(), then this check
* triggers too late. This doesn't hurt, the check is only there
* to stop root fork bombs.
*/
+ retval = -EAGAIN;
if (nr_threads >= max_threads)
goto bad_fork_cleanup_count;
- if (!try_module_get(p->thread_info->exec_domain->module))
+ if (!try_module_get(task_thread_info(p)->exec_domain->module))
goto bad_fork_cleanup_count;
- if (p->binfmt && !try_module_get(p->binfmt->module))
- goto bad_fork_cleanup_put_domain;
-
- p->did_exec = 0;
- copy_flags(clone_flags, p);
- p->pid = pid;
- retval = -EFAULT;
- if (clone_flags & CLONE_PARENT_SETTID)
- if (put_user(p->pid, parent_tidptr))
- goto bad_fork_cleanup;
-
- p->proc_dentry = NULL;
-
+ delayacct_tsk_init(p); /* Must remain after dup_task_struct() */
+ p->flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER);
+ p->flags |= PF_FORKNOEXEC;
INIT_LIST_HEAD(&p->children);
INIT_LIST_HEAD(&p->sibling);
+ rcu_copy_process(p);
p->vfork_done = NULL;
spin_lock_init(&p->alloc_lock);
- spin_lock_init(&p->proc_lock);
- clear_tsk_thread_flag(p, TIF_SIGPENDING);
init_sigpending(&p->pending);
- p->utime = cputime_zero;
- p->stime = cputime_zero;
- p->sched_time = 0;
- p->rchar = 0; /* I/O counter: bytes read */
- p->wchar = 0; /* I/O counter: bytes written */
- p->syscr = 0; /* I/O counter: read syscalls */
- p->syscw = 0; /* I/O counter: write syscalls */
+ p->utime = p->stime = p->gtime = 0;
+ p->utimescaled = p->stimescaled = 0;
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ p->prev_cputime.utime = p->prev_cputime.stime = 0;
+#endif
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+ seqlock_init(&p->vtime_seqlock);
+ p->vtime_snap = 0;
+ p->vtime_snap_whence = VTIME_SLEEPING;
+#endif
+
+#if defined(SPLIT_RSS_COUNTING)
+ memset(&p->rss_stat, 0, sizeof(p->rss_stat));
+#endif
+
+ p->default_timer_slack_ns = current->timer_slack_ns;
+
+ task_io_accounting_init(&p->ioac);
acct_clear_integrals(p);
- p->it_virt_expires = cputime_zero;
- p->it_prof_expires = cputime_zero;
- p->it_sched_expires = 0;
- INIT_LIST_HEAD(&p->cpu_timers[0]);
- INIT_LIST_HEAD(&p->cpu_timers[1]);
- INIT_LIST_HEAD(&p->cpu_timers[2]);
+ posix_cpu_timers_init(p);
- p->lock_depth = -1; /* -1 = no lock */
do_posix_clock_monotonic_gettime(&p->start_time);
- p->security = NULL;
+ p->real_start_time = p->start_time;
+ monotonic_to_bootbased(&p->real_start_time);
p->io_context = NULL;
- p->io_wait = NULL;
p->audit_context = NULL;
+ if (clone_flags & CLONE_THREAD)
+ threadgroup_change_begin(current);
+ 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;
- }
+ p->mempolicy = mpol_dup(p->mempolicy);
+ if (IS_ERR(p->mempolicy)) {
+ retval = PTR_ERR(p->mempolicy);
+ p->mempolicy = NULL;
+ goto bad_fork_cleanup_threadgroup_lock;
+ }
+#endif
+#ifdef CONFIG_CPUSETS
+ p->cpuset_mem_spread_rotor = NUMA_NO_NODE;
+ p->cpuset_slab_spread_rotor = NUMA_NO_NODE;
+ seqcount_init(&p->mems_allowed_seq);
+#endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+ p->irq_events = 0;
+ p->hardirqs_enabled = 0;
+ p->hardirq_enable_ip = 0;
+ p->hardirq_enable_event = 0;
+ p->hardirq_disable_ip = _THIS_IP_;
+ p->hardirq_disable_event = 0;
+ p->softirqs_enabled = 1;
+ p->softirq_enable_ip = _THIS_IP_;
+ p->softirq_enable_event = 0;
+ p->softirq_disable_ip = 0;
+ p->softirq_disable_event = 0;
+ p->hardirq_context = 0;
+ p->softirq_context = 0;
+#endif
+#ifdef CONFIG_LOCKDEP
+ p->lockdep_depth = 0; /* no locks held yet */
+ p->curr_chain_key = 0;
+ p->lockdep_recursion = 0;
#endif
- p->tgid = p->pid;
- if (clone_flags & CLONE_THREAD)
- p->tgid = current->tgid;
+#ifdef CONFIG_DEBUG_MUTEXES
+ p->blocked_on = NULL; /* not blocked yet */
+#endif
+#ifdef CONFIG_MEMCG
+ p->memcg_batch.do_batch = 0;
+ p->memcg_batch.memcg = NULL;
+#endif
+#ifdef CONFIG_BCACHE
+ p->sequential_io = 0;
+ p->sequential_io_avg = 0;
+#endif
- if ((retval = security_task_alloc(p)))
+ /* Perform scheduler related setup. Assign this task to a CPU. */
+ retval = sched_fork(clone_flags, p);
+ if (retval)
+ goto bad_fork_cleanup_policy;
+
+ retval = perf_event_init_task(p);
+ if (retval)
+ goto bad_fork_cleanup_policy;
+ retval = audit_alloc(p);
+ if (retval)
goto bad_fork_cleanup_policy;
- if ((retval = audit_alloc(p)))
- goto bad_fork_cleanup_security;
/* 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_keys(clone_flags, p)))
+ retval = copy_namespaces(clone_flags, p);
+ if (retval)
goto bad_fork_cleanup_mm;
- if ((retval = copy_namespace(clone_flags, p)))
- goto bad_fork_cleanup_keys;
- retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
+ retval = copy_io(clone_flags, p);
if (retval)
- goto bad_fork_cleanup_namespace;
+ goto bad_fork_cleanup_namespaces;
+ retval = copy_thread(clone_flags, stack_start, stack_size, p);
+ if (retval)
+ goto bad_fork_cleanup_io;
+
+ if (pid != &init_struct_pid) {
+ retval = -ENOMEM;
+ pid = alloc_pid(p->nsproxy->pid_ns_for_children);
+ if (!pid)
+ goto bad_fork_cleanup_io;
+ }
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
+ p->compat_robust_list = NULL;
+#endif
+ INIT_LIST_HEAD(&p->pi_state_list);
+ p->pi_state_cache = NULL;
+#endif
+ /*
+ * sigaltstack should be cleared when sharing the same VM
+ */
+ if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM)
+ p->sas_ss_sp = p->sas_ss_size = 0;
/*
- * Syscall tracing should be turned off in the child regardless
- * of CLONE_PTRACE.
+ * Syscall tracing and stepping should be turned off in the
+ * child regardless of CLONE_PTRACE.
*/
+ user_disable_single_step(p);
clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
#ifdef TIF_SYSCALL_EMU
clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
#endif
-
- /* Our parent execution domain becomes current domain
- These must match for thread signalling to apply */
-
- p->parent_exec_id = p->self_exec_id;
+ clear_all_latency_tracing(p);
/* ok, now we should be set up.. */
- p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
- p->pdeath_signal = 0;
- p->exit_state = 0;
-
- /*
- * Ok, make it visible to the rest of the system.
- * We dont wake it up yet.
- */
- p->group_leader = p;
- INIT_LIST_HEAD(&p->ptrace_children);
- INIT_LIST_HEAD(&p->ptrace_list);
-
- /* Perform scheduler related setup. Assign this task to a CPU. */
- sched_fork(p, clone_flags);
+ p->pid = pid_nr(pid);
+ if (clone_flags & CLONE_THREAD) {
+ p->exit_signal = -1;
+ p->group_leader = current->group_leader;
+ p->tgid = current->tgid;
+ } else {
+ if (clone_flags & CLONE_PARENT)
+ p->exit_signal = current->group_leader->exit_signal;
+ else
+ p->exit_signal = (clone_flags & CSIGNAL);
+ p->group_leader = p;
+ p->tgid = p->pid;
+ }
- /* Need tasklist lock for parent etc handling! */
- write_lock_irq(&tasklist_lock);
+ p->nr_dirtied = 0;
+ p->nr_dirtied_pause = 128 >> (PAGE_SHIFT - 10);
+ p->dirty_paused_when = 0;
- /*
- * The task hasn't been attached yet, so its cpus_allowed mask will
- * not be changed, nor will its assigned CPU.
- *
- * The cpus_allowed mask of the parent may have changed after it was
- * copied first time - so re-copy it here, then check the child's CPU
- * to ensure it is on a valid CPU (and if not, just force it back to
- * parent's CPU). This avoids alot of nasty races.
- */
- p->cpus_allowed = current->cpus_allowed;
- if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
- !cpu_online(task_cpu(p))))
- set_task_cpu(p, smp_processor_id());
+ p->pdeath_signal = 0;
+ INIT_LIST_HEAD(&p->thread_group);
+ p->task_works = NULL;
/*
- * Check for pending SIGKILL! The new thread should not be allowed
- * to slip out of an OOM kill. (or normal SIGKILL.)
+ * Make it visible to the rest of the system, but dont wake it up yet.
+ * Need tasklist lock for parent etc handling!
*/
- if (sigismember(&current->pending.signal, SIGKILL)) {
- write_unlock_irq(&tasklist_lock);
- retval = -EINTR;
- goto bad_fork_cleanup_namespace;
- }
+ write_lock_irq(&tasklist_lock);
/* CLONE_PARENT re-uses the old parent */
- if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
+ if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
p->real_parent = current->real_parent;
- else
+ p->parent_exec_id = current->parent_exec_id;
+ } else {
p->real_parent = current;
- p->parent = p->real_parent;
-
- if (clone_flags & CLONE_THREAD) {
- spin_lock(&current->sighand->siglock);
- /*
- * Important: if an exit-all has been started then
- * do not create this new thread - the whole thread
- * group is supposed to exit anyway.
- */
- if (current->signal->flags & SIGNAL_GROUP_EXIT) {
- spin_unlock(&current->sighand->siglock);
- write_unlock_irq(&tasklist_lock);
- retval = -EAGAIN;
- goto bad_fork_cleanup_namespace;
- }
- p->group_leader = current->group_leader;
-
- if (current->signal->group_stop_count > 0) {
- /*
- * There is an all-stop in progress for the group.
- * We ourselves will stop as soon as we check signals.
- * Make the new thread part of that group stop too.
- */
- current->signal->group_stop_count++;
- set_tsk_thread_flag(p, TIF_SIGPENDING);
- }
+ p->parent_exec_id = current->self_exec_id;
+ }
- if (!cputime_eq(current->signal->it_virt_expires,
- cputime_zero) ||
- !cputime_eq(current->signal->it_prof_expires,
- cputime_zero) ||
- current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY ||
- !list_empty(&current->signal->cpu_timers[0]) ||
- !list_empty(&current->signal->cpu_timers[1]) ||
- !list_empty(&current->signal->cpu_timers[2])) {
- /*
- * Have child wake up on its first tick to check
- * for process CPU timers.
- */
- p->it_prof_expires = jiffies_to_cputime(1);
- }
+ spin_lock(&current->sighand->siglock);
+ /*
+ * Process group and session signals need to be delivered to just the
+ * parent before the fork or both the parent and the child after the
+ * fork. Restart if a signal comes in before we add the new process to
+ * 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(&current->sighand->siglock);
+ write_unlock_irq(&tasklist_lock);
+ retval = -ERESTARTNOINTR;
+ goto bad_fork_free_pid;
}
- /*
- * inherit ioprio
- */
- p->ioprio = current->ioprio;
-
- SET_LINKS(p);
- if (unlikely(p->ptrace & PT_PTRACED))
- __ptrace_link(p, current->parent);
-
- cpuset_fork(p);
-
- attach_pid(p, PIDTYPE_PID, p->pid);
- attach_pid(p, PIDTYPE_TGID, p->tgid);
- if (thread_group_leader(p)) {
- attach_pid(p, PIDTYPE_PGID, process_group(p));
- attach_pid(p, PIDTYPE_SID, p->signal->session);
- if (p->pid)
- __get_cpu_var(process_counts)++;
+ if (likely(p->pid)) {
+ ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
+
+ init_task_pid(p, PIDTYPE_PID, pid);
+ if (thread_group_leader(p)) {
+ init_task_pid(p, PIDTYPE_PGID, task_pgrp(current));
+ init_task_pid(p, PIDTYPE_SID, task_session(current));
+
+ if (is_child_reaper(pid)) {
+ ns_of_pid(pid)->child_reaper = p;
+ p->signal->flags |= SIGNAL_UNKILLABLE;
+ }
+
+ p->signal->leader_pid = pid;
+ p->signal->tty = tty_kref_get(current->signal->tty);
+ list_add_tail(&p->sibling, &p->real_parent->children);
+ list_add_tail_rcu(&p->tasks, &init_task.tasks);
+ attach_pid(p, PIDTYPE_PGID);
+ attach_pid(p, PIDTYPE_SID);
+ __this_cpu_inc(process_counts);
+ } else {
+ current->signal->nr_threads++;
+ atomic_inc(&current->signal->live);
+ atomic_inc(&current->signal->sigcnt);
+ list_add_tail_rcu(&p->thread_group,
+ &p->group_leader->thread_group);
+ list_add_tail_rcu(&p->thread_node,
+ &p->signal->thread_head);
+ }
+ attach_pid(p, PIDTYPE_PID);
+ nr_threads++;
}
- if (!current->signal->tty && p->signal->tty)
- p->signal->tty = NULL;
-
- nr_threads++;
total_forks++;
+ spin_unlock(&current->sighand->siglock);
+ syscall_tracepoint_update(p);
write_unlock_irq(&tasklist_lock);
- retval = 0;
-fork_out:
- if (retval)
- return ERR_PTR(retval);
+ proc_fork_connector(p);
+ cgroup_post_fork(p);
+ if (clone_flags & CLONE_THREAD)
+ threadgroup_change_end(current);
+ perf_event_fork(p);
+
+ trace_task_newtask(p, clone_flags);
+ uprobe_copy_process(p, clone_flags);
+
return p;
-bad_fork_cleanup_namespace:
- exit_namespace(p);
-bad_fork_cleanup_keys:
- exit_keys(p);
+bad_fork_free_pid:
+ if (pid != &init_struct_pid)
+ free_pid(pid);
+bad_fork_cleanup_io:
+ if (p->io_context)
+ exit_io_context(p);
+bad_fork_cleanup_namespaces:
+ exit_task_namespaces(p);
bad_fork_cleanup_mm:
if (p->mm)
mmput(p->mm);
bad_fork_cleanup_signal:
- exit_signal(p);
+ if (!(clone_flags & CLONE_THREAD))
+ free_signal_struct(p->signal);
bad_fork_cleanup_sighand:
- exit_sighand(p);
+ __cleanup_sighand(p->sighand);
bad_fork_cleanup_fs:
exit_fs(p); /* blocking */
bad_fork_cleanup_files:
@@ -1177,59 +1525,45 @@ bad_fork_cleanup_semundo:
exit_sem(p);
bad_fork_cleanup_audit:
audit_free(p);
-bad_fork_cleanup_security:
- security_task_free(p);
bad_fork_cleanup_policy:
+ perf_event_free_task(p);
#ifdef CONFIG_NUMA
- mpol_free(p->mempolicy);
+ mpol_put(p->mempolicy);
+bad_fork_cleanup_threadgroup_lock:
#endif
-bad_fork_cleanup:
- if (p->binfmt)
- module_put(p->binfmt->module);
-bad_fork_cleanup_put_domain:
- module_put(p->thread_info->exec_domain->module);
+ if (clone_flags & CLONE_THREAD)
+ threadgroup_change_end(current);
+ delayacct_tsk_free(p);
+ module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
- put_group_info(p->group_info);
- atomic_dec(&p->user->processes);
- free_uid(p->user);
+ atomic_dec(&p->cred->user->processes);
+ exit_creds(p);
bad_fork_free:
free_task(p);
- goto fork_out;
-}
-
-struct pt_regs * __devinit __attribute__((weak)) idle_regs(struct pt_regs *regs)
-{
- memset(regs, 0, sizeof(struct pt_regs));
- return regs;
+fork_out:
+ return ERR_PTR(retval);
}
-task_t * __devinit fork_idle(int cpu)
+static inline void init_idle_pids(struct pid_link *links)
{
- task_t *task;
- struct pt_regs regs;
+ enum pid_type type;
- task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL, NULL, 0);
- if (!task)
- return ERR_PTR(-ENOMEM);
- init_idle(task, cpu);
- unhash_process(task);
- return task;
+ for (type = PIDTYPE_PID; type < PIDTYPE_MAX; ++type) {
+ INIT_HLIST_NODE(&links[type].node); /* not really needed */
+ links[type].pid = &init_struct_pid;
+ }
}
-static inline int fork_traceflag (unsigned clone_flags)
+struct task_struct *fork_idle(int cpu)
{
- if (clone_flags & CLONE_UNTRACED)
- return 0;
- else if (clone_flags & CLONE_VFORK) {
- if (current->ptrace & PT_TRACE_VFORK)
- return PTRACE_EVENT_VFORK;
- } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
- if (current->ptrace & PT_TRACE_CLONE)
- return PTRACE_EVENT_CLONE;
- } else if (current->ptrace & PT_TRACE_FORK)
- return PTRACE_EVENT_FORK;
+ struct task_struct *task;
+ task = copy_process(CLONE_VM, 0, 0, NULL, &init_struct_pid, 0);
+ if (!IS_ERR(task)) {
+ init_idle_pids(task->pids);
+ init_idle(task, cpu);
+ }
- return 0;
+ return task;
}
/*
@@ -1240,84 +1574,372 @@ static inline int fork_traceflag (unsigned clone_flags)
*/
long do_fork(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 task_struct *p;
int trace = 0;
- long pid = alloc_pidmap();
-
- if (pid < 0)
- return -EAGAIN;
- if (unlikely(current->ptrace)) {
- trace = fork_traceflag (clone_flags);
- if (trace)
- clone_flags |= CLONE_PTRACE;
+ long nr;
+
+ /*
+ * 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 (!(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;
+
+ if (likely(!ptrace_event_enabled(current, trace)))
+ trace = 0;
}
- p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr, pid);
+ p = copy_process(clone_flags, stack_start, stack_size,
+ child_tidptr, NULL, trace);
/*
* Do this prior waking up the new thread - the thread pointer
* might get invalid after that point, if the thread exits quickly.
*/
if (!IS_ERR(p)) {
struct completion vfork;
+ struct pid *pid;
+
+ trace_sched_process_fork(current, p);
+
+ pid = get_task_pid(p, PIDTYPE_PID);
+ nr = pid_vnr(pid);
+
+ if (clone_flags & CLONE_PARENT_SETTID)
+ put_user(nr, parent_tidptr);
if (clone_flags & CLONE_VFORK) {
p->vfork_done = &vfork;
init_completion(&vfork);
+ get_task_struct(p);
}
- if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
- /*
- * We'll start up with an immediate SIGSTOP.
- */
- sigaddset(&p->pending.signal, SIGSTOP);
- set_tsk_thread_flag(p, TIF_SIGPENDING);
- }
+ wake_up_new_task(p);
- if (!(clone_flags & CLONE_STOPPED))
- wake_up_new_task(p, clone_flags);
- else
- p->state = TASK_STOPPED;
-
- if (unlikely (trace)) {
- current->ptrace_message = pid;
- ptrace_notify ((trace << 8) | SIGTRAP);
- }
+ /* forking complete and child started to run, tell ptracer */
+ if (unlikely(trace))
+ ptrace_event_pid(trace, pid);
if (clone_flags & CLONE_VFORK) {
- wait_for_completion(&vfork);
- if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE))
- ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
+ if (!wait_for_vfork_done(p, &vfork))
+ ptrace_event_pid(PTRACE_EVENT_VFORK_DONE, pid);
}
+
+ put_pid(pid);
} else {
- free_pidmap(pid);
- pid = PTR_ERR(p);
+ nr = PTR_ERR(p);
}
- return pid;
+ return nr;
+}
+
+/*
+ * Create a kernel thread.
+ */
+pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
+{
+ return do_fork(flags|CLONE_VM|CLONE_UNTRACED, (unsigned long)fn,
+ (unsigned long)arg, NULL, NULL);
+}
+
+#ifdef __ARCH_WANT_SYS_FORK
+SYSCALL_DEFINE0(fork)
+{
+#ifdef CONFIG_MMU
+ return do_fork(SIGCHLD, 0, 0, NULL, NULL);
+#else
+ /* can not support in nommu mode */
+ return -EINVAL;
+#endif
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_VFORK
+SYSCALL_DEFINE0(vfork)
+{
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
+ 0, NULL, NULL);
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_CLONE
+#ifdef CONFIG_CLONE_BACKWARDS
+SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
+ int __user *, parent_tidptr,
+ int, tls_val,
+ int __user *, child_tidptr)
+#elif defined(CONFIG_CLONE_BACKWARDS2)
+SYSCALL_DEFINE5(clone, unsigned long, newsp, unsigned long, clone_flags,
+ int __user *, parent_tidptr,
+ int __user *, child_tidptr,
+ int, tls_val)
+#elif defined(CONFIG_CLONE_BACKWARDS3)
+SYSCALL_DEFINE6(clone, unsigned long, clone_flags, unsigned long, newsp,
+ int, stack_size,
+ int __user *, parent_tidptr,
+ int __user *, child_tidptr,
+ int, tls_val)
+#else
+SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
+ int __user *, parent_tidptr,
+ int __user *, child_tidptr,
+ int, tls_val)
+#endif
+{
+ return do_fork(clone_flags, newsp, 0, parent_tidptr, child_tidptr);
+}
+#endif
+
+#ifndef ARCH_MIN_MMSTRUCT_ALIGN
+#define ARCH_MIN_MMSTRUCT_ALIGN 0
+#endif
+
+static void sighand_ctor(void *data)
+{
+ struct sighand_struct *sighand = data;
+
+ spin_lock_init(&sighand->siglock);
+ init_waitqueue_head(&sighand->signalfd_wqh);
}
void __init proc_caches_init(void)
{
sighand_cachep = kmem_cache_create("sighand_cache",
sizeof(struct sighand_struct), 0,
- SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
+ SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_DESTROY_BY_RCU|
+ SLAB_NOTRACK, sighand_ctor);
signal_cachep = kmem_cache_create("signal_cache",
sizeof(struct signal_struct), 0,
- SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
- files_cachep = kmem_cache_create("files_cache",
+ SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
+ files_cachep = kmem_cache_create("files_cache",
sizeof(struct files_struct), 0,
- SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
- fs_cachep = kmem_cache_create("fs_cache",
+ SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
+ fs_cachep = kmem_cache_create("fs_cache",
sizeof(struct fs_struct), 0,
- SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
- vm_area_cachep = kmem_cache_create("vm_area_struct",
- sizeof(struct vm_area_struct), 0,
- SLAB_PANIC, NULL, NULL);
+ 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), 0,
- SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
+ 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.
+ */
+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|
+ CLONE_NEWUSER|CLONE_NEWPID))
+ return -EINVAL;
+ /*
+ * 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 (unshare_flags & (CLONE_THREAD | CLONE_SIGHAND | CLONE_VM)) {
+ /* FIXME: get_task_mm() increments ->mm_users */
+ if (atomic_read(&current->mm->mm_users) > 1)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/*
+ * Unshare the filesystem structure if it is being shared
+ */
+static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
+{
+ struct fs_struct *fs = current->fs;
+
+ if (!(unshare_flags & CLONE_FS) || !fs)
+ return 0;
+
+ /* don't need lock here; in the worst case we'll do useless copy */
+ if (fs->users == 1)
+ return 0;
+
+ *new_fsp = copy_fs_struct(fs);
+ if (!*new_fsp)
+ return -ENOMEM;
+
+ return 0;
+}
+
+/*
+ * Unshare file descriptor table if it is being shared
+ */
+static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp)
+{
+ struct files_struct *fd = current->files;
+ int error = 0;
+
+ if ((unshare_flags & CLONE_FILES) &&
+ (fd && atomic_read(&fd->count) > 1)) {
+ *new_fdp = dup_fd(fd, &error);
+ if (!*new_fdp)
+ return error;
+ }
+
+ return 0;
+}
+
+/*
+ * unshare allows a process to 'unshare' part of the process
+ * context which was originally shared using clone. copy_*
+ * functions used by do_fork() cannot be used here directly
+ * because they modify an inactive task_struct that is being
+ * constructed. Here we are modifying the current, active,
+ * task_struct.
+ */
+SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
+{
+ struct fs_struct *fs, *new_fs = NULL;
+ struct files_struct *fd, *new_fd = NULL;
+ struct cred *new_cred = NULL;
+ struct nsproxy *new_nsproxy = NULL;
+ int do_sysvsem = 0;
+ int err;
+
+ /*
+ * If unsharing a user namespace must also unshare the thread.
+ */
+ if (unshare_flags & CLONE_NEWUSER)
+ unshare_flags |= CLONE_THREAD | CLONE_FS;
+ /*
+ * If unsharing a thread from a thread group, must also unshare vm.
+ */
+ if (unshare_flags & CLONE_THREAD)
+ unshare_flags |= CLONE_VM;
+ /*
+ * If unsharing vm, must also unshare signal handlers.
+ */
+ if (unshare_flags & CLONE_VM)
+ unshare_flags |= CLONE_SIGHAND;
+ /*
+ * If unsharing namespace, must also unshare filesystem information.
+ */
+ if (unshare_flags & CLONE_NEWNS)
+ unshare_flags |= CLONE_FS;
+
+ err = check_unshare_flags(unshare_flags);
+ if (err)
+ goto bad_unshare_out;
+ /*
+ * CLONE_NEWIPC must also detach from the undolist: after switching
+ * to a new ipc namespace, the semaphore arrays from the old
+ * namespace are unreachable.
+ */
+ if (unshare_flags & (CLONE_NEWIPC|CLONE_SYSVSEM))
+ do_sysvsem = 1;
+ err = unshare_fs(unshare_flags, &new_fs);
+ if (err)
+ goto bad_unshare_out;
+ err = unshare_fd(unshare_flags, &new_fd);
+ if (err)
+ goto bad_unshare_cleanup_fs;
+ err = unshare_userns(unshare_flags, &new_cred);
+ if (err)
+ goto bad_unshare_cleanup_fd;
+ err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy,
+ new_cred, new_fs);
+ if (err)
+ goto bad_unshare_cleanup_cred;
+
+ if (new_fs || new_fd || do_sysvsem || new_cred || new_nsproxy) {
+ if (do_sysvsem) {
+ /*
+ * CLONE_SYSVSEM is equivalent to sys_exit().
+ */
+ exit_sem(current);
+ }
+
+ if (new_nsproxy)
+ switch_task_namespaces(current, new_nsproxy);
+
+ task_lock(current);
+
+ if (new_fs) {
+ fs = current->fs;
+ spin_lock(&fs->lock);
+ current->fs = new_fs;
+ if (--fs->users)
+ new_fs = NULL;
+ else
+ new_fs = fs;
+ spin_unlock(&fs->lock);
+ }
+
+ if (new_fd) {
+ fd = current->files;
+ current->files = new_fd;
+ new_fd = fd;
+ }
+
+ task_unlock(current);
+
+ if (new_cred) {
+ /* Install the new user namespace */
+ commit_creds(new_cred);
+ new_cred = NULL;
+ }
+ }
+
+bad_unshare_cleanup_cred:
+ if (new_cred)
+ put_cred(new_cred);
+bad_unshare_cleanup_fd:
+ if (new_fd)
+ put_files_struct(new_fd);
+
+bad_unshare_cleanup_fs:
+ if (new_fs)
+ free_fs_struct(new_fs);
+
+bad_unshare_out:
+ return err;
+}
+
+/*
+ * Helper to unshare the files of the current task.
+ * We don't want to expose copy_files internals to
+ * the exec layer of the kernel.
+ */
+
+int unshare_files(struct files_struct **displaced)
+{
+ struct task_struct *task = current;
+ struct files_struct *copy = NULL;
+ int error;
+
+ error = unshare_fd(CLONE_FILES, &copy);
+ if (error || !copy) {
+ *displaced = NULL;
+ return error;
+ }
+ *displaced = task->files;
+ task_lock(task);
+ task->files = copy;
+ task_unlock(task);
+ return 0;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-06 10:23:35 +0000