From 5381e169e78405bd54256860f151596f5a887617 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Thu, 9 Oct 2014 15:25:24 -0700 Subject: [PATCH] proc: introduce proc_mem_open() Extract the mm_access() code from __mem_open() into the new helper, proc_mem_open(), the next patch will add another caller. Signed-off-by: Oleg Nesterov Acked-by: Kirill A. Shutemov Acked-by: Cyrill Gorcunov Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/base.c | 36 +++++++++++++++++++++--------------- fs/proc/internal.h | 2 ++ 2 files changed, 23 insertions(+), 15 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index baf852b648ad..4c542b907754 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -632,29 +632,35 @@ static const struct file_operations proc_single_file_operations = { .release = single_release, }; -static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) + +struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) { - struct task_struct *task = get_proc_task(file_inode(file)); - struct mm_struct *mm; + struct task_struct *task = get_proc_task(inode); + struct mm_struct *mm = ERR_PTR(-ESRCH); - if (!task) - return -ESRCH; + if (task) { + mm = mm_access(task, mode); + put_task_struct(task); - mm = mm_access(task, mode); - put_task_struct(task); + if (!IS_ERR_OR_NULL(mm)) { + /* ensure this mm_struct can't be freed */ + atomic_inc(&mm->mm_count); + /* but do not pin its memory */ + mmput(mm); + } + } + + return mm; +} + +static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) +{ + struct mm_struct *mm = proc_mem_open(inode, mode); if (IS_ERR(mm)) return PTR_ERR(mm); - if (mm) { - /* ensure this mm_struct can't be freed */ - atomic_inc(&mm->mm_count); - /* but do not pin its memory */ - mmput(mm); - } - file->private_data = mm; - return 0; } diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 7da13e49128a..3c685563406f 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -278,6 +278,8 @@ struct proc_maps_private { #endif }; +struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode); + extern const struct file_operations proc_pid_maps_operations; extern const struct file_operations proc_tid_maps_operations; extern const struct file_operations proc_pid_numa_maps_operations; -- 2.20.1