/**
* 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 task_struct *task,
- struct mm_struct *mm,
- struct page **process_pages,
- unsigned long pa,
- unsigned long start_offset,
- unsigned long len,
- const struct iovec *lvec,
- unsigned long lvec_cnt,
- unsigned long *lvec_current,
- size_t *lvec_offset,
- int vm_write,
- unsigned int nr_pages_to_copy,
- ssize_t *bytes_copied)
+static int process_vm_rw_pages(struct page **pages,
+ unsigned offset,
+ size_t len,
+ struct iov_iter *iter,
+ int vm_write)
{
- int pages_pinned;
- void *target_kaddr;
- int pgs_copied = 0;
- int j;
- int ret;
- ssize_t bytes_to_copy;
- ssize_t rc = 0;
-
- *bytes_copied = 0;
-
- /* 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);
- up_read(&mm->mmap_sem);
-
- if (pages_pinned != nr_pages_to_copy) {
- rc = -EFAULT;
- goto end;
- }
-
/* Do the copy for each page */
- for (pgs_copied = 0;
- (pgs_copied < nr_pages_to_copy) && (*lvec_current < lvec_cnt);
- pgs_copied++) {
- /* Make sure we have a non zero length iovec */
- while (*lvec_current < lvec_cnt
- && lvec[*lvec_current].iov_len == 0)
- (*lvec_current)++;
- if (*lvec_current == lvec_cnt)
- break;
-
- /*
- * Will copy smallest of:
- * - bytes remaining in page
- * - bytes remaining in destination iovec
- */
- bytes_to_copy = min_t(ssize_t, PAGE_SIZE - start_offset,
- len - *bytes_copied);
- bytes_to_copy = min_t(ssize_t, bytes_to_copy,
- lvec[*lvec_current].iov_len
- - *lvec_offset);
-
- target_kaddr = kmap(process_pages[pgs_copied]) + start_offset;
-
- if (vm_write)
- ret = copy_from_user(target_kaddr,
- lvec[*lvec_current].iov_base
- + *lvec_offset,
- bytes_to_copy);
- else
- ret = copy_to_user(lvec[*lvec_current].iov_base
- + *lvec_offset,
- target_kaddr, bytes_to_copy);
- kunmap(process_pages[pgs_copied]);
- if (ret) {
- *bytes_copied += bytes_to_copy - ret;
- pgs_copied++;
- rc = -EFAULT;
- goto end;
- }
- *bytes_copied += bytes_to_copy;
- *lvec_offset += bytes_to_copy;
- if (*lvec_offset == lvec[*lvec_current].iov_len) {
- /*
- * Need to copy remaining part of page into the
- * next iovec if there are any bytes left in page
- */
- (*lvec_current)++;
- *lvec_offset = 0;
- start_offset = (start_offset + bytes_to_copy)
- % PAGE_SIZE;
- if (start_offset)
- pgs_copied--;
+ while (len && iov_iter_count(iter)) {
+ struct page *page = *pages++;
+ size_t copy = PAGE_SIZE - offset;
+ size_t copied;
+
+ if (copy > len)
+ copy = len;
+
+ if (vm_write) {
+ if (copy > iov_iter_count(iter))
+ copy = iov_iter_count(iter);
+ copied = iov_iter_copy_from_user(page, iter,
+ offset, copy);
+ iov_iter_advance(iter, copied);
+ set_page_dirty_lock(page);
} else {
- start_offset = 0;
- }
- }
-
-end:
- if (vm_write) {
- for (j = 0; j < pages_pinned; j++) {
- if (j < pgs_copied)
- set_page_dirty_lock(process_pages[j]);
- put_page(process_pages[j]);
+ copied = copy_page_to_iter(page, offset, copy, iter);
}
- } else {
- for (j = 0; j < pages_pinned; j++)
- put_page(process_pages[j]);
+ len -= copied;
+ if (copied < copy && iov_iter_count(iter))
+ return -EFAULT;
+ offset = 0;
}
-
- return rc;
+ return 0;
}
/* Maximum number of pages kmalloc'd to hold struct page's during copy */
* 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,
unsigned long len,
- const struct iovec *lvec,
- unsigned long lvec_cnt,
- unsigned long *lvec_current,
- size_t *lvec_offset,
+ struct iov_iter *iter,
struct page **process_pages,
struct mm_struct *mm,
struct task_struct *task,
- int vm_write,
- ssize_t *bytes_copied)
+ int vm_write)
{
unsigned long pa = addr & PAGE_MASK;
unsigned long start_offset = addr - pa;
unsigned long nr_pages;
- ssize_t bytes_copied_loop;
ssize_t rc = 0;
- unsigned long nr_pages_copied = 0;
- unsigned long nr_pages_to_copy;
unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES
/ sizeof(struct pages *);
- *bytes_copied = 0;
-
/* Work out address and page range required */
if (len == 0)
return 0;
nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1;
- while ((nr_pages_copied < nr_pages) && (*lvec_current < lvec_cnt)) {
- 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;
- rc = process_vm_rw_pages(task, mm, process_pages, pa,
- start_offset, len,
- lvec, lvec_cnt,
- lvec_current, lvec_offset,
- vm_write, nr_pages_to_copy,
- &bytes_copied_loop);
- start_offset = 0;
- *bytes_copied += bytes_copied_loop;
+ /* Get the pages we're interested in */
+ down_read(&mm->mmap_sem);
+ pages = get_user_pages(task, mm, pa, pages,
+ vm_write, 0, process_pages, NULL);
+ up_read(&mm->mmap_sem);
- if (rc < 0) {
- return rc;
- } else {
- len -= bytes_copied_loop;
- nr_pages_copied += nr_pages_to_copy;
- pa += nr_pages_to_copy * PAGE_SIZE;
- }
+ if (pages <= 0)
+ return -EFAULT;
+
+ bytes = pages * PAGE_SIZE - start_offset;
+ if (bytes > len)
+ bytes = len;
+
+ rc = process_vm_rw_pages(process_pages,
+ start_offset, bytes, iter,
+ vm_write);
+ len -= bytes;
+ start_offset = 0;
+ nr_pages -= pages;
+ pa += pages * PAGE_SIZE;
+ while (pages)
+ put_page(process_pages[--pages]);
}
return rc;
/**
* 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
* return less bytes than expected if an error occurs during the copying
* process.
*/
-static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
- unsigned long liovcnt,
+static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter,
const struct iovec *rvec,
unsigned long riovcnt,
unsigned long flags, int vm_write)
struct mm_struct *mm;
unsigned long i;
ssize_t rc = 0;
- ssize_t bytes_copied_loop;
- ssize_t bytes_copied = 0;
unsigned long nr_pages = 0;
unsigned long nr_pages_iov;
- unsigned long iov_l_curr_idx = 0;
- size_t iov_l_curr_offset = 0;
ssize_t iov_len;
+ size_t total_len = iov_iter_count(iter);
/*
* Work out how many pages of struct pages we're going to need
goto put_task_struct;
}
- for (i = 0; i < riovcnt && iov_l_curr_idx < liovcnt; i++) {
+ for (i = 0; i < riovcnt && iov_iter_count(iter) && !rc; i++)
rc = process_vm_rw_single_vec(
(unsigned long)rvec[i].iov_base, rvec[i].iov_len,
- lvec, liovcnt, &iov_l_curr_idx, &iov_l_curr_offset,
- process_pages, mm, task, vm_write, &bytes_copied_loop);
- bytes_copied += bytes_copied_loop;
- if (rc != 0) {
- /* If we have managed to copy any data at all then
- we return the number of bytes copied. Otherwise
- we return the error code */
- if (bytes_copied)
- rc = bytes_copied;
- goto put_mm;
- }
- }
+ iter, process_pages, mm, task, vm_write);
+
+ /* copied = space before - space after */
+ total_len -= iov_iter_count(iter);
+
+ /* If we have managed to copy any data at all then
+ we return the number of bytes copied. Otherwise
+ we return the error code */
+ if (total_len)
+ rc = total_len;
- rc = bytes_copied;
-put_mm:
mmput(mm);
put_task_struct:
struct iovec iovstack_r[UIO_FASTIOV];
struct iovec *iov_l = iovstack_l;
struct iovec *iov_r = iovstack_r;
+ struct iov_iter iter;
ssize_t rc;
if (flags != 0)
if (rc <= 0)
goto free_iovecs;
+ iov_iter_init(&iter, iov_l, liovcnt, rc, 0);
+
rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV,
iovstack_r, &iov_r);
if (rc <= 0)
goto free_iovecs;
- rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
- vm_write);
+ rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
free_iovecs:
if (iov_r != iovstack_r)
struct iovec iovstack_r[UIO_FASTIOV];
struct iovec *iov_l = iovstack_l;
struct iovec *iov_r = iovstack_r;
+ struct iov_iter iter;
ssize_t rc = -EFAULT;
if (flags != 0)
&iov_l);
if (rc <= 0)
goto free_iovecs;
+ iov_iter_init(&iter, iov_l, liovcnt, rc, 0);
rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt,
UIO_FASTIOV, iovstack_r,
&iov_r);
if (rc <= 0)
goto free_iovecs;
- rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
- vm_write);
+ rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
free_iovecs:
if (iov_r != iovstack_r)
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