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authorAl Viro <viro@zeniv.linux.org.uk>2014-02-05 13:25:32 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2014-04-01 23:19:29 -0400
commit4bafbec7bf60ed56ccbb36a96091bdbd162f075d (patch)
tree329693aee7863633fec5a96ea12421d9b284b002 /mm
parent9acc1a0f9af244826de0eea2c38b78410eb0df6d (diff)
process_vm_access: tidy up a bit
saner variable names, update linuxdoc comments, etc. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm')
-rw-r--r--mm/process_vm_access.c59
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