@@ -327,9 +327,8 @@ static int put_pfn(unsigned long pfn, int prot)
{
if (!is_invalid_reserved_pfn(pfn)) {
struct page *page = pfn_to_page(pfn);
- if (prot & IOMMU_WRITE)
- SetPageDirty(page);
- put_page(page);
+
+ put_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE);
return 1;
}
return 0;
@@ -349,11 +348,11 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
down_read(&mm->mmap_sem);
if (mm == current->mm) {
- ret = get_user_pages(vaddr, 1, flags | FOLL_LONGTERM, page,
- vmas);
+ ret = pin_longterm_pages(vaddr, 1, flags, page, vmas);
} else {
- ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags, page,
- vmas, NULL);
+ ret = pin_longterm_pages_remote(NULL, mm, vaddr, 1,
+ flags, page, vmas,
+ NULL);
/*
* The lifetime of a vaddr_get_pfn() page pin is
* userspace-controlled. In the fs-dax case this could
@@ -363,7 +362,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
*/
if (ret > 0 && vma_is_fsdax(vmas[0])) {
ret = -EOPNOTSUPP;
- put_page(page[0]);
+ put_user_page(page[0]);
}
}
up_read(&mm->mmap_sem);
1. Change vfio from get_user_pages(FOLL_LONGTERM), to pin_longterm_pages(), which sets both FOLL_LONGTERM and FOLL_PIN. 2. Because all FOLL_PIN-acquired pages must be released via put_user_page(), also convert the put_page() call over to put_user_pages(). Note that this effectively changes the code's behavior in vfio_iommu_type1.c: put_pfn(): it now ultimately calls set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate. As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1] [1] https://lore.kernel.org/r/20190723153640.GB720@lst.de Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> --- drivers/vfio/vfio_iommu_type1.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)