diff options
| -rw-r--r-- | fs/proc/base.c | 7 | ||||
| -rw-r--r-- | include/linux/mm.h | 1 | ||||
| -rw-r--r-- | kernel/fork.c | 23 |
3 files changed, 25 insertions, 6 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index e8bbf6cdb437..d2b8c754f627 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1545,18 +1545,13 @@ static const struct file_operations proc_pid_set_comm_operations = { static int proc_exe_link(struct dentry *dentry, struct path *exe_path) { struct task_struct *task; - struct mm_struct *mm; struct file *exe_file; task = get_proc_task(d_inode(dentry)); if (!task) return -ENOENT; - mm = get_task_mm(task); + exe_file = get_task_exe_file(task); put_task_struct(task); - if (!mm) - return -ENOENT; - exe_file = get_mm_exe_file(mm); - mmput(mm); if (exe_file) { *exe_path = exe_file->f_path; path_get(&exe_file->f_path); diff --git a/include/linux/mm.h b/include/linux/mm.h index 8a761248d01e..cfebb742ee18 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1898,6 +1898,7 @@ extern void mm_drop_all_locks(struct mm_struct *mm); extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file); extern struct file *get_mm_exe_file(struct mm_struct *mm); +extern struct file *get_task_exe_file(struct task_struct *task); extern int may_expand_vm(struct mm_struct *mm, unsigned long npages); extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm, diff --git a/kernel/fork.c b/kernel/fork.c index c485cb156772..8860d1f50d24 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -764,6 +764,29 @@ 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 |