diff options
| -rw-r--r-- | mm/nommu.c | 52 |
1 files changed, 39 insertions, 13 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index cb86e7d5e7f5..c4c542c736a9 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1971,21 +1971,10 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) } EXPORT_SYMBOL(filemap_fault); -/* - * Access another process' address space. - * - source/target buffer must be kernel space - */ -int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) +static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, + unsigned long addr, void *buf, int len, int write) { struct vm_area_struct *vma; - struct mm_struct *mm; - - if (addr + len < addr) - return 0; - - mm = get_task_mm(tsk); - if (!mm) - return 0; down_read(&mm->mmap_sem); @@ -2010,6 +1999,43 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in } up_read(&mm->mmap_sem); + + return len; +} + +/** + * @access_remote_vm - access another process' address space + * @mm: the mm_struct of the target address space + * @addr: start address to access + * @buf: source or destination buffer + * @len: number of bytes to transfer + * @write: whether the access is a write + * + * The caller must hold a reference on @mm. + */ +int access_remote_vm(struct mm_struct *mm, unsigned long addr, + void *buf, int len, int write) +{ + return __access_remote_vm(NULL, mm, addr, buf, len, write); +} + +/* + * Access another process' address space. + * - source/target buffer must be kernel space + */ +int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) +{ + struct mm_struct *mm; + + if (addr + len < addr) + return 0; + + mm = get_task_mm(tsk); + if (!mm) + return 0; + + len = __access_remote_vm(tsk, mm, addr, buf, len, write); + mmput(mm); return len; } |