diff options
| -rw-r--r-- | fs/proc/base.c | 7 | ||||
| -rw-r--r-- | include/linux/mm.h | 1 | ||||
| -rw-r--r-- | kernel/audit_watch.c | 8 | ||||
| -rw-r--r-- | kernel/fork.c | 23 |
4 files changed, 30 insertions, 9 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 54e270262979..ac0df4dde823 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1556,18 +1556,13 @@ 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 08ed53eeedd5..ef815b9cd426 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2014,6 +2014,7 @@ 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 bool may_expand_vm(struct mm_struct *, vm_flags_t, unsigned long npages); extern void vm_stat_account(struct mm_struct *, vm_flags_t, long npages); diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c index d6709eb70970..0d302a87f21b 100644 --- a/kernel/audit_watch.c +++ b/kernel/audit_watch.c @@ -19,6 +19,7 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include <linux/file.h> #include <linux/kernel.h> #include <linux/audit.h> #include <linux/kthread.h> @@ -544,10 +545,11 @@ int audit_exe_compare(struct task_struct *tsk, struct audit_fsnotify_mark *mark) unsigned long ino; dev_t dev; - rcu_read_lock(); - exe_file = rcu_dereference(tsk->mm->exe_file); + exe_file = get_task_exe_file(tsk); + if (!exe_file) + return 0; ino = exe_file->f_inode->i_ino; dev = exe_file->f_inode->i_sb->s_dev; - rcu_read_unlock(); + fput(exe_file); return audit_mark_compare(mark, ino, dev); } diff --git a/kernel/fork.c b/kernel/fork.c index aaf782327bf3..36c0daa03c60 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -799,6 +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 |