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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c102
1 files changed, 40 insertions, 62 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 166b8c49257c..44b0791b0a2e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -64,6 +64,7 @@
#include <linux/magic.h>
#include <linux/perf_event.h>
#include <linux/posix-timers.h>
+#include <linux/user-return-notifier.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -86,6 +87,14 @@ DEFINE_PER_CPU(unsigned long, process_counts) = 0;
__cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
+#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;
@@ -249,6 +258,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
goto out;
setup_thread_stack(tsk, orig);
+ clear_user_return_notifier(tsk);
stackend = end_of_stack(tsk);
*stackend = STACK_END_MAGIC; /* for overflow detection */
@@ -326,15 +336,17 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
if (!tmp)
goto fail_nomem;
*tmp = *mpnt;
+ INIT_LIST_HEAD(&tmp->anon_vma_chain);
pol = mpol_dup(vma_policy(mpnt));
retval = PTR_ERR(pol);
if (IS_ERR(pol))
goto fail_nomem_policy;
vma_set_policy(tmp, pol);
+ 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;
- anon_vma_link(tmp);
file = tmp->vm_file;
if (file) {
struct inode *inode = file->f_path.dentry->d_inode;
@@ -389,6 +401,8 @@ out:
flush_tlb_mm(oldmm);
up_write(&oldmm->mmap_sem);
return retval;
+fail_nomem_anon_vma_fork:
+ mpol_put(pol);
fail_nomem_policy:
kmem_cache_free(vm_area_cachep, tmp);
fail_nomem:
@@ -452,8 +466,7 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
(current->mm->flags & MMF_INIT_MASK) : default_dump_filter;
mm->core_state = NULL;
mm->nr_ptes = 0;
- set_mm_counter(mm, file_rss, 0);
- set_mm_counter(mm, anon_rss, 0);
+ memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
spin_lock_init(&mm->page_table_lock);
mm->free_area_cache = TASK_UNMAPPED_BASE;
mm->cached_hole_size = ~0UL;
@@ -822,23 +835,14 @@ void __cleanup_sighand(struct sighand_struct *sighand)
*/
static void posix_cpu_timers_init_group(struct signal_struct *sig)
{
+ unsigned long cpu_limit;
+
/* Thread group counters. */
thread_group_cputime_init(sig);
- /* Expiration times and increments. */
- sig->it[CPUCLOCK_PROF].expires = cputime_zero;
- sig->it[CPUCLOCK_PROF].incr = cputime_zero;
- sig->it[CPUCLOCK_VIRT].expires = cputime_zero;
- sig->it[CPUCLOCK_VIRT].incr = cputime_zero;
-
- /* Cached expiration times. */
- sig->cputime_expires.prof_exp = cputime_zero;
- sig->cputime_expires.virt_exp = cputime_zero;
- sig->cputime_expires.sched_exp = 0;
-
- if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
- sig->cputime_expires.prof_exp =
- secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
+ 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;
}
@@ -855,7 +859,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
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;
@@ -863,43 +867,21 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
atomic_set(&sig->count, 1);
atomic_set(&sig->live, 1);
init_waitqueue_head(&sig->wait_chldexit);
- sig->flags = 0;
if (clone_flags & CLONE_NEWPID)
sig->flags |= SIGNAL_UNKILLABLE;
- sig->group_exit_code = 0;
- sig->group_exit_task = NULL;
- sig->group_stop_count = 0;
sig->curr_target = tsk;
init_sigpending(&sig->shared_pending);
INIT_LIST_HEAD(&sig->posix_timers);
hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
- sig->it_real_incr.tv64 = 0;
sig->real_timer.function = it_real_fn;
- sig->leader = 0; /* session leadership doesn't inherit */
- sig->tty_old_pgrp = NULL;
- sig->tty = NULL;
-
- sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
- sig->gtime = cputime_zero;
- sig->cgtime = 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->inblock = sig->oublock = sig->cinblock = sig->coublock = 0;
- sig->maxrss = sig->cmaxrss = 0;
- task_io_accounting_init(&sig->ioac);
- sig->sum_sched_runtime = 0;
- taskstats_tgid_init(sig);
-
task_lock(current->group_leader);
memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
task_unlock(current->group_leader);
posix_cpu_timers_init_group(sig);
- acct_init_pacct(&sig->pacct);
-
tty_audit_fork(sig);
sig->oom_adj = current->signal->oom_adj;
@@ -934,9 +916,9 @@ SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
static void rt_mutex_init_task(struct task_struct *p)
{
- spin_lock_init(&p->pi_lock);
+ raw_spin_lock_init(&p->pi_lock);
#ifdef CONFIG_RT_MUTEXES
- plist_head_init(&p->pi_waiters, &p->pi_lock);
+ plist_head_init_raw(&p->pi_waiters, &p->pi_lock);
p->pi_blocked_on = NULL;
#endif
}
@@ -1028,7 +1010,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
#endif
retval = -EAGAIN;
if (atomic_read(&p->real_cred->user->processes) >=
- p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
+ task_rlimit(p, RLIMIT_NPROC)) {
if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
p->real_cred->user != INIT_USER)
goto bad_fork_free;
@@ -1066,8 +1048,13 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->gtime = cputime_zero;
p->utimescaled = cputime_zero;
p->stimescaled = cputime_zero;
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING
p->prev_utime = cputime_zero;
p->prev_stime = cputime_zero;
+#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;
@@ -1120,6 +1107,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
#ifdef CONFIG_DEBUG_MUTEXES
p->blocked_on = NULL; /* not blocked yet */
#endif
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+ p->memcg_batch.do_batch = 0;
+ p->memcg_batch.memcg = NULL;
+#endif
p->bts = NULL;
@@ -1199,9 +1190,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
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);
@@ -1229,21 +1221,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
/* Need tasklist lock for parent etc handling! */
write_lock_irq(&tasklist_lock);
- /*
- * 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;
- p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed;
- if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
- !cpu_online(task_cpu(p))))
- set_task_cpu(p, smp_processor_id());
-
/* CLONE_PARENT re-uses the old parent */
if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
p->real_parent = current->real_parent;
@@ -1279,7 +1256,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
}
if (likely(p->pid)) {
- list_add_tail(&p->sibling, &p->real_parent->children);
tracehook_finish_clone(p, clone_flags, trace);
if (thread_group_leader(p)) {
@@ -1291,6 +1267,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->signal->tty = tty_kref_get(current->signal->tty);
attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
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)++;
}
@@ -1310,7 +1287,8 @@ bad_fork_free_pid:
if (pid != &init_struct_pid)
free_pid(pid);
bad_fork_cleanup_io:
- put_io_context(p->io_context);
+ if (p->io_context)
+ exit_io_context(p);
bad_fork_cleanup_namespaces:
exit_task_namespaces(p);
bad_fork_cleanup_mm:
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