migrate_vma_setup() checks that a valid vma is passed so that the page tables can be walked to find the pfns associated with a given address range. However in some cases the pfns are already known, such as when migrating device coherent pages during pin_user_pages() meaning a valid vma isn't required.
Signed-off-by: Alistair Popple apopple@nvidia.com --- mm/migrate.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c index d3cc358..31ba8ca 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2581,24 +2581,24 @@ int migrate_vma_setup(struct migrate_vma *args)
args->start &= PAGE_MASK; args->end &= PAGE_MASK; - if (!args->vma || is_vm_hugetlb_page(args->vma) || - (args->vma->vm_flags & VM_SPECIAL) || vma_is_dax(args->vma)) - return -EINVAL; - if (nr_pages <= 0) - return -EINVAL; - if (args->start < args->vma->vm_start || - args->start >= args->vma->vm_end) - return -EINVAL; - if (args->end <= args->vma->vm_start || args->end > args->vma->vm_end) - return -EINVAL; if (!args->src || !args->dst) return -EINVAL; - - memset(args->src, 0, sizeof(*args->src) * nr_pages); - args->cpages = 0; - args->npages = 0; - - migrate_vma_collect(args); + if (args->vma) { + if (is_vm_hugetlb_page(args->vma) || + (args->vma->vm_flags & VM_SPECIAL) || vma_is_dax(args->vma)) + return -EINVAL; + if (args->start < args->vma->vm_start || + args->start >= args->vma->vm_end) + return -EINVAL; + if (args->end <= args->vma->vm_start || args->end > args->vma->vm_end) + return -EINVAL; + + memset(args->src, 0, sizeof(*args->src) * nr_pages); + args->cpages = 0; + args->npages = 0; + + migrate_vma_collect(args); + }
if (args->cpages) migrate_vma_unmap(args); @@ -2783,7 +2783,7 @@ void migrate_vma_pages(struct migrate_vma *migrate) continue; }
- if (!page) { + if (!page && migrate->vma) { if (!(migrate->src[i] & MIGRATE_PFN_MIGRATE)) continue; if (!notified) {