[v3,31/41] mm/process_vm_access.c: convert put_page() to put_user_page*()

Commit Message

[e-mail] Aug. 7, 2019, 1:33 a.m. UTC

From: John Hubbard <[e-mail]>

For pages that were retained via get_user_pages*(), release those pages
via the new put_user_page*() routines, instead of via put_page() or
release_pages().

This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
("mm: introduce put_user_page*(), placeholder versions").

Cc: Al Viro <[e-mail]>
Cc: Andrea Arcangeli <[e-mail]>
Cc: Christopher Yeoh <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: Heiko Carstens <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jann Horn <[e-mail]>
Cc: Lorenzo Stoakes <[e-mail]>
Cc: Mathieu Desnoyers <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: Rashika Kheria <[e-mail]>
Signed-off-by: John Hubbard <[e-mail]>
---
 mm/process_vm_access.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

Patch

diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 357aa7bef6c0..4d29d54ec93f 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -96,7 +96,7 @@  static int process_vm_rw_single_vec(unsigned long addr,
 		flags |= FOLL_WRITE;
 
 	while (!rc && nr_pages && iov_iter_count(iter)) {
-		int pages = min(nr_pages, max_pages_per_loop);
+		int pinned_pages = min(nr_pages, max_pages_per_loop);
 		int locked = 1;
 		size_t bytes;
 
@@ -106,14 +106,15 @@  static int process_vm_rw_single_vec(unsigned long addr,
 		 * current/current->mm
 		 */
 		down_read(&mm->mmap_sem);
-		pages = get_user_pages_remote(task, mm, pa, pages, flags,
-					      process_pages, NULL, &locked);
+		pinned_pages = get_user_pages_remote(task, mm, pa, pinned_pages,
+						     flags, process_pages, NULL,
+						     &locked);
 		if (locked)
 			up_read(&mm->mmap_sem);
-		if (pages <= 0)
+		if (pinned_pages <= 0)
 			return -EFAULT;
 
-		bytes = pages * PAGE_SIZE - start_offset;
+		bytes = pinned_pages * PAGE_SIZE - start_offset;
 		if (bytes > len)
 			bytes = len;
 
@@ -122,10 +123,9 @@  static int process_vm_rw_single_vec(unsigned long addr,
 					 vm_write);
 		len -= bytes;
 		start_offset = 0;
-		nr_pages -= pages;
-		pa += pages * PAGE_SIZE;
-		while (pages)
-			put_page(process_pages[--pages]);
+		nr_pages -= pinned_pages;
+		pa += pinned_pages * PAGE_SIZE;
+		put_user_pages(process_pages, pinned_pages);
 	}
 
 	return rc;