[PATCH v2 29/34] mm/process_vm_access.c: convert put_page() to put_user_page*()

john.hubbard at gmail.com john.hubbard at gmail.com
Sun Aug 4 22:49:10 UTC 2019


From: John Hubbard <jhubbard at nvidia.com>

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 <viro at zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange at redhat.com>
Cc: Christopher Yeoh <cyeoh at au1.ibm.com>
Cc: Dave Hansen <dave.hansen at linux.intel.com>
Cc: Heiko Carstens <heiko.carstens at de.ibm.com>
Cc: Ingo Molnar <mingo at kernel.org>
Cc: Jann Horn <jann at thejh.net>
Cc: Lorenzo Stoakes <lstoakes at gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
Cc: Mike Rapoport <rppt at linux.vnet.ibm.com>
Cc: Rashika Kheria <rashika.kheria at gmail.com>
Signed-off-by: John Hubbard <jhubbard at nvidia.com>
---
 mm/process_vm_access.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

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;
-- 
2.22.0



More information about the devel mailing list