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authorAl Viro <viro@zeniv.linux.org.uk>2014-02-05 13:15:28 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2014-04-01 23:19:29 -0400
commit9acc1a0f9af244826de0eea2c38b78410eb0df6d (patch)
tree850049bb9d86b0a88b39b92b9641b37ed7a26a3c
parente21345f9c3f8a806604910cae886e471a860ab86 (diff)
process_vm_access: don't bother with returning the amounts of bytes copied
we can calculate that in the caller just fine, TYVM Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--mm/process_vm_access.c47
1 files changed, 16 insertions, 31 deletions
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 83252d783482..15e4c2f312e8 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -43,13 +43,10 @@ static int process_vm_rw_pages(struct page **pages,
unsigned offset,
size_t len,
struct iov_iter *iter,
- int vm_write,
- ssize_t *bytes_copied)
+ int vm_write)
{
- *bytes_copied = 0;
-
/* Do the copy for each page */
- while (iov_iter_count(iter) && len) {
+ while (len && iov_iter_count(iter)) {
struct page *page = *pages++;
size_t copy = PAGE_SIZE - offset;
size_t copied;
@@ -67,7 +64,6 @@ static int process_vm_rw_pages(struct page **pages,
} else {
copied = copy_page_to_iter(page, offset, copy, iter);
}
- *bytes_copied += copied;
len -= copied;
if (copied < copy && iov_iter_count(iter))
return -EFAULT;
@@ -101,20 +97,16 @@ static int process_vm_rw_single_vec(unsigned long addr,
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 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;
@@ -143,11 +135,9 @@ static int process_vm_rw_single_vec(unsigned long addr,
rc = process_vm_rw_pages(process_pages,
start_offset, n, iter,
- vm_write,
- &bytes_copied_loop);
+ vm_write);
len -= n;
start_offset = 0;
- *bytes_copied += bytes_copied_loop;
nr_pages_copied += pages_pinned;
pa += pages_pinned * PAGE_SIZE;
while (pages_pinned)
@@ -187,11 +177,10 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter,
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;
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
@@ -245,24 +234,20 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter,
goto put_task_struct;
}
- for (i = 0; i < riovcnt && iov_iter_count(iter); 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,
- iter, 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: