diff options
Diffstat (limited to 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 61 |
1 files changed, 40 insertions, 21 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 4a7ec0c6c88c..beb31725f7e2 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -162,23 +162,15 @@ void __weak arch_release_thread_stack(unsigned long *stack) static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) { - struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP, - THREAD_SIZE_ORDER); - - if (page) - memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK, - 1 << THREAD_SIZE_ORDER); + struct page *page = alloc_pages_node(node, THREADINFO_GFP, + THREAD_SIZE_ORDER); return page ? page_address(page) : NULL; } static inline void free_thread_stack(unsigned long *stack) { - struct page *page = virt_to_page(stack); - - memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK, - -(1 << THREAD_SIZE_ORDER)); - __free_kmem_pages(page, THREAD_SIZE_ORDER); + __free_pages(virt_to_page(stack), THREAD_SIZE_ORDER); } # else static struct kmem_cache *thread_stack_cache; @@ -223,9 +215,15 @@ static struct kmem_cache *mm_cachep; static void account_kernel_stack(unsigned long *stack, int account) { - struct zone *zone = page_zone(virt_to_page(stack)); + /* All stack pages are in the same zone and belong to the same memcg. */ + struct page *first_page = virt_to_page(stack); + + mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB, + THREAD_SIZE / 1024 * account); - mod_zone_page_state(zone, NR_KERNEL_STACK, account); + memcg_kmem_update_page_stat( + first_page, MEMCG_KERNEL_STACK_KB, + account * (THREAD_SIZE / 1024)); } void free_task(struct task_struct *tsk) @@ -801,6 +799,29 @@ struct file *get_mm_exe_file(struct mm_struct *mm) EXPORT_SYMBOL(get_mm_exe_file); /** + * get_task_exe_file - acquire a reference to the task's executable file + * + * Returns %NULL if task's mm (if any) has no associated executable file or + * this is a kernel thread with borrowed mm (see the comment above get_task_mm). + * User must release file via fput(). + */ +struct file *get_task_exe_file(struct task_struct *task) +{ + struct file *exe_file = NULL; + struct mm_struct *mm; + + task_lock(task); + mm = task->mm; + if (mm) { + if (!(task->flags & PF_KTHREAD)) + exe_file = get_mm_exe_file(mm); + } + task_unlock(task); + return exe_file; +} +EXPORT_SYMBOL(get_task_exe_file); + +/** * get_task_mm - acquire a reference to the task's mm * * Returns %NULL if the task has no mm. Checks PF_KTHREAD (meaning @@ -915,14 +936,12 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) deactivate_mm(tsk, mm); /* - * 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. + * Signal userspace if we're not exiting with a core dump + * because we want to leave the value intact for debugging + * purposes. */ if (tsk->clear_child_tid) { - if (!(tsk->flags & PF_SIGNALED) && + if (!(tsk->signal->flags & SIGNAL_GROUP_COREDUMP) && atomic_read(&mm->mm_users) > 1) { /* * We don't check the error code - if userspace has @@ -1406,7 +1425,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->real_start_time = ktime_get_boot_ns(); p->io_context = NULL; p->audit_context = NULL; - threadgroup_change_begin(current); cgroup_fork(p); #ifdef CONFIG_NUMA p->mempolicy = mpol_dup(p->mempolicy); @@ -1558,6 +1576,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, INIT_LIST_HEAD(&p->thread_group); p->task_works = NULL; + threadgroup_change_begin(current); /* * Ensure that the cgroup subsystem policies allow the new process to be * forked. It should be noted the the new process's css_set can be changed @@ -1658,6 +1677,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, bad_fork_cancel_cgroup: cgroup_cancel_fork(p); bad_fork_free_pid: + threadgroup_change_end(current); if (pid != &init_struct_pid) free_pid(pid); bad_fork_cleanup_thread: @@ -1690,7 +1710,6 @@ bad_fork_cleanup_policy: mpol_put(p->mempolicy); bad_fork_cleanup_threadgroup_lock: #endif - threadgroup_change_end(current); delayacct_tsk_free(p); bad_fork_cleanup_count: atomic_dec(&p->cred->user->processes); |