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mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote()

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Convert process_vm_access to use the new pin_user_pages_remote() call,
which sets FOLL_PIN.  Setting FOLL_PIN is now required for code that
requires tracking of pinned pages.

Also, release the pages via put_user_page*().

Also, rename "pages" to "pinned_pages", as this makes for easier reading
of process_vm_rw_single_vec().

Link: http://lkml.kernel.org/r/20200107224558.2362728-15-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
John Hubbard 2020-01-30 22:13:05 -08:00 committed by Linus Torvalds
parent dfa0a4fff1
commit 803e4572d7
1 changed files with 15 additions and 13 deletions
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28
mm/process_vm_access.c
View file

@ -42,12 +42,11 @@ static int process_vm_rw_pages(struct page **pages,
if (copy > len)
copy = len;
if (vm_write) {
if (vm_write)
copied = copy_page_from_iter(page, offset, copy, iter);
set_page_dirty_lock(page);
} else {
else
copied = copy_page_to_iter(page, offset, copy, iter);
}
len -= copied;
if (copied < copy && iov_iter_count(iter))
return -EFAULT;
@ -96,7 +95,7 @@ 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 +105,15 @@ 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 = pin_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 +122,12 @@ 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;
/* If vm_write is set, the pages need to be made dirty: */
put_user_pages_dirty_lock(process_pages, pinned_pages,
vm_write);
}
return rc;