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-rw-r--r--kernel/fork.c82
1 files changed, 47 insertions, 35 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 6d6ce2c3a364..0a328cf0cb13 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -162,10 +162,6 @@ static inline void free_task_struct(struct task_struct *tsk)
}
#endif
-void __weak arch_release_thread_stack(unsigned long *stack)
-{
-}
-
#ifndef CONFIG_ARCH_THREAD_STACK_ALLOCATOR
/*
@@ -348,7 +344,6 @@ static void release_task_stack(struct task_struct *tsk)
return; /* Better to leak the stack than to free prematurely */
account_kernel_stack(tsk, -1);
- arch_release_thread_stack(tsk->stack);
free_thread_stack(tsk);
tsk->stack = NULL;
#ifdef CONFIG_VMAP_STACK
@@ -415,7 +410,7 @@ void __put_task_struct(struct task_struct *tsk)
WARN_ON(tsk == current);
cgroup_free(tsk);
- task_numa_free(tsk);
+ task_numa_free(tsk, true);
security_task_free(tsk);
exit_creds(tsk);
delayacct_tsk_free(tsk);
@@ -790,6 +785,15 @@ static void mm_init_aio(struct mm_struct *mm)
#endif
}
+static __always_inline void mm_clear_owner(struct mm_struct *mm,
+ struct task_struct *p)
+{
+#ifdef CONFIG_MEMCG
+ if (mm->owner == p)
+ WRITE_ONCE(mm->owner, NULL);
+#endif
+}
+
static void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
{
#ifdef CONFIG_MEMCG
@@ -1128,24 +1132,8 @@ static int wait_for_vfork_done(struct task_struct *child,
* restoring the old one. . .
* Eric Biederman 10 January 1998
*/
-void mm_release(struct task_struct *tsk, struct mm_struct *mm)
+static void mm_release(struct task_struct *tsk, struct mm_struct *mm)
{
- /* 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 */
@@ -1178,6 +1166,18 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
complete_vfork_done(tsk);
}
+void exit_mm_release(struct task_struct *tsk, struct mm_struct *mm)
+{
+ futex_exit_release(tsk);
+ mm_release(tsk, mm);
+}
+
+void exec_mm_release(struct task_struct *tsk, struct mm_struct *mm)
+{
+ futex_exec_release(tsk);
+ mm_release(tsk, mm);
+}
+
/*
* Allocate a new mm structure and copy contents from the
* mm structure of the passed in task structure.
@@ -1211,6 +1211,7 @@ static struct mm_struct *dup_mm(struct task_struct *tsk)
free_pt:
/* don't put binfmt in mmput, we haven't got module yet */
mm->binfmt = NULL;
+ mm_init_owner(mm, NULL);
mmput(mm);
fail_nomem:
@@ -1528,6 +1529,21 @@ static inline void rcu_copy_process(struct task_struct *p)
#endif /* #ifdef CONFIG_TASKS_RCU */
}
+static void __delayed_free_task(struct rcu_head *rhp)
+{
+ struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
+
+ free_task(tsk);
+}
+
+static __always_inline void delayed_free_task(struct task_struct *tsk)
+{
+ if (IS_ENABLED(CONFIG_MEMCG))
+ call_rcu(&tsk->rcu, __delayed_free_task);
+ else
+ free_task(tsk);
+}
+
/*
* This creates a new process as a copy of the old one,
* but does not actually start it yet.
@@ -1776,14 +1792,8 @@ static __latent_entropy struct task_struct *copy_process(
#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
+ futex_init_task(p);
+
/*
* sigaltstack should be cleared when sharing the same VM
*/
@@ -1960,8 +1970,10 @@ bad_fork_cleanup_io:
bad_fork_cleanup_namespaces:
exit_task_namespaces(p);
bad_fork_cleanup_mm:
- if (p->mm)
+ if (p->mm) {
+ mm_clear_owner(p->mm, p);
mmput(p->mm);
+ }
bad_fork_cleanup_signal:
if (!(clone_flags & CLONE_THREAD))
free_signal_struct(p->signal);
@@ -1992,7 +2004,7 @@ bad_fork_cleanup_count:
bad_fork_free:
p->state = TASK_DEAD;
put_task_stack(p);
- free_task(p);
+ delayed_free_task(p);
fork_out:
return ERR_PTR(retval);
}
@@ -2472,7 +2484,7 @@ int sysctl_max_threads(struct ctl_table *table, int write,
struct ctl_table t;
int ret;
int threads = max_threads;
- int min = MIN_THREADS;
+ int min = 1;
int max = MAX_THREADS;
t = *table;
@@ -2484,7 +2496,7 @@ int sysctl_max_threads(struct ctl_table *table, int write,
if (ret || !write)
return ret;
- set_max_threads(threads);
+ max_threads = threads;
return 0;
}