diff options
| -rw-r--r-- | mm/process_vm_access.c | 59 |
1 files changed, 19 insertions, 40 deletions
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 15e4c2f312e8..d6bd3fdd6925 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -23,20 +23,11 @@ /** * process_vm_rw_pages - read/write pages from task specified - * @task: task to read/write from - * @mm: mm for task - * @process_pages: struct pages area that can store at least - * nr_pages_to_copy struct page pointers - * @pa: address of page in task to start copying from/to + * @pages: array of pointers to pages we want to copy * @start_offset: offset in page to start copying from/to * @len: number of bytes to copy - * @lvec: iovec array specifying where to copy to/from - * @lvec_cnt: number of elements in iovec array - * @lvec_current: index in iovec array we are up to - * @lvec_offset: offset in bytes from current iovec iov_base we are up to + * @iter: where to copy to/from locally * @vm_write: 0 means copy from, 1 means copy to - * @nr_pages_to_copy: number of pages to copy - * @bytes_copied: returns number of bytes successfully copied * Returns 0 on success, error code otherwise */ static int process_vm_rw_pages(struct page **pages, @@ -79,16 +70,12 @@ static int process_vm_rw_pages(struct page **pages, * process_vm_rw_single_vec - read/write pages from task specified * @addr: start memory address of target process * @len: size of area to copy to/from - * @lvec: iovec array specifying where to copy to/from locally - * @lvec_cnt: number of elements in iovec array - * @lvec_current: index in iovec array we are up to - * @lvec_offset: offset in bytes from current iovec iov_base we are up to + * @iter: where to copy to/from locally * @process_pages: struct pages area that can store at least * nr_pages_to_copy struct page pointers * @mm: mm for task * @task: task to read/write from * @vm_write: 0 means copy from, 1 means copy to - * @bytes_copied: returns number of bytes successfully copied * Returns 0 on success or on failure error code */ static int process_vm_rw_single_vec(unsigned long addr, @@ -103,7 +90,6 @@ static int process_vm_rw_single_vec(unsigned long addr, unsigned long start_offset = addr - pa; unsigned long nr_pages; ssize_t rc = 0; - unsigned long nr_pages_copied = 0; unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES / sizeof(struct pages *); @@ -112,38 +98,32 @@ static int process_vm_rw_single_vec(unsigned long addr, return 0; nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; - while ((nr_pages_copied < nr_pages) && iov_iter_count(iter)) { - int nr_pages_to_copy; - int pages_pinned; - size_t n; - nr_pages_to_copy = min(nr_pages - nr_pages_copied, - max_pages_per_loop); + while (!rc && nr_pages && iov_iter_count(iter)) { + int pages = min(nr_pages, max_pages_per_loop); + size_t bytes; /* Get the pages we're interested in */ down_read(&mm->mmap_sem); - pages_pinned = get_user_pages(task, mm, pa, - nr_pages_to_copy, - vm_write, 0, process_pages, NULL); + pages = get_user_pages(task, mm, pa, pages, + vm_write, 0, process_pages, NULL); up_read(&mm->mmap_sem); - if (pages_pinned <= 0) + if (pages <= 0) return -EFAULT; - n = pages_pinned * PAGE_SIZE - start_offset; - if (n > len) - n = len; + bytes = pages * PAGE_SIZE - start_offset; + if (bytes > len) + bytes = len; rc = process_vm_rw_pages(process_pages, - start_offset, n, iter, + start_offset, bytes, iter, vm_write); - len -= n; + len -= bytes; start_offset = 0; - nr_pages_copied += pages_pinned; - pa += pages_pinned * PAGE_SIZE; - while (pages_pinned) - put_page(process_pages[--pages_pinned]); - if (rc < 0) - break; + nr_pages -= pages; + pa += pages * PAGE_SIZE; + while (pages) + put_page(process_pages[--pages]); } return rc; @@ -156,8 +136,7 @@ static int process_vm_rw_single_vec(unsigned long addr, /** * process_vm_rw_core - core of reading/writing pages from task specified * @pid: PID of process to read/write from/to - * @lvec: iovec array specifying where to copy to/from locally - * @liovcnt: size of lvec array + * @iter: where to copy to/from locally * @rvec: iovec array specifying where to copy to/from in the other process * @riovcnt: size of rvec array * @flags: currently unused |