Commit 80dbe1fb authored by Alex Williamson's avatar Alex Williamson

vfio/type1: Prune vfio_pin_page_external()

With vfio_lock_acct() testing the locked memory limit under mmap_sem,
it's redundant to do it here for a single page.  We can also reorder
our tests such that we can avoid testing for reserved pages if we're
not doing accounting and let vfio_lock_acct() test the process
CAP_IPC_LOCK.  Finally, this function oddly returns 1 on success.
Update to return zero on success, -errno on error.  Since the function
only pins a single page, there's no need to return the number of pages
pinned.

N.B. vfio_pin_pages_remote() can pin a large contiguous range of pages
before calling vfio_lock_acct().  If we were to similarly remove the
extra test there, a user could temporarily pin far more pages than
they're allowed.
Suggested-by: default avatarKirti Wankhede <kwankhede@nvidia.com>
Suggested-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarKirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 0cfef2b7
...@@ -482,43 +482,26 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova, ...@@ -482,43 +482,26 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr, static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
unsigned long *pfn_base, bool do_accounting) unsigned long *pfn_base, bool do_accounting)
{ {
unsigned long limit;
bool lock_cap = has_capability(dma->task, CAP_IPC_LOCK);
struct mm_struct *mm; struct mm_struct *mm;
int ret; int ret;
bool rsvd;
mm = get_task_mm(dma->task); mm = get_task_mm(dma->task);
if (!mm) if (!mm)
return -ENODEV; return -ENODEV;
ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base); ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
if (ret) if (!ret && do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
goto pin_page_exit; ret = vfio_lock_acct(dma->task, 1, NULL);
rsvd = is_invalid_reserved_pfn(*pfn_base);
limit = task_rlimit(dma->task, RLIMIT_MEMLOCK) >> PAGE_SHIFT;
if (!rsvd && !lock_cap && mm->locked_vm + 1 > limit) {
put_pfn(*pfn_base, dma->prot);
pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK (%ld) exceeded\n",
__func__, dma->task->comm, task_pid_nr(dma->task),
limit << PAGE_SHIFT);
ret = -ENOMEM;
goto pin_page_exit;
}
if (!rsvd && do_accounting) {
ret = vfio_lock_acct(dma->task, 1, &lock_cap);
if (ret) { if (ret) {
put_pfn(*pfn_base, dma->prot); put_pfn(*pfn_base, dma->prot);
goto pin_page_exit; if (ret == -ENOMEM)
pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK "
"(%ld) exceeded\n", __func__,
dma->task->comm, task_pid_nr(dma->task),
task_rlimit(dma->task, RLIMIT_MEMLOCK));
} }
} }
ret = 1;
pin_page_exit:
mmput(mm); mmput(mm);
return ret; return ret;
} }
...@@ -598,10 +581,8 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, ...@@ -598,10 +581,8 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
remote_vaddr = dma->vaddr + iova - dma->iova; remote_vaddr = dma->vaddr + iova - dma->iova;
ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i], ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i],
do_accounting); do_accounting);
if (ret <= 0) { if (ret)
WARN_ON(!ret);
goto pin_unwind; goto pin_unwind;
}
ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]); ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]);
if (ret) { if (ret) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment