On 23.09.2021 04:56, Julien Grall wrote:
> We could push the patch in the branch we have. However the Linux we use is
> not fairly old (I think I did a push last year) and not even the latest
> stable.
I don't think that's a problem here - this looks to be 5.4.17-ish, which
the patch should be good for (and it does apply cleanly to plain 5.4.0).
Ian, for your setting up of a one-off flight (as just talked about),
you can find the patch at
https://lists.xen.org/archives/html/xen-devel/2021-09/msg01691.html
(and perhaps in your mailbox). In case that's easier I've also attached
it here.
Jan
xen/privcmd: replace kcalloc() by kvcalloc() when allocating empty pages
Osstest has been suffering test failures for a little while from order-4
allocation failures, resulting from alloc_empty_pages() calling
kcalloc(). As there's no need for physically contiguous space here,
switch to kvcalloc().
Signed-off-by: Jan Beulich <jbeul...@suse.com>
Cc: sta...@vger.kernel.org
Reviewed-by: Juergen Gross <jgr...@suse.com>
---
RFC: I cannot really test this, as alloc_empty_pages() only gets used in
the auto-translated case (i.e. on Arm or PVH Dom0, the latter of
which I'm not trusting enough yet to actually start playing with
guests).
There are quite a few more kcalloc() where it's not immediately clear
how large the element counts could possibly grow nor whether it would be
fine to replace them (i.e. physically contiguous space not required).
I wasn't sure whether to Cc stable@ here; the issue certainly has been
present for quite some time. But it didn't look to cause issues until
recently.
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -420,7 +420,7 @@ static int alloc_empty_pages(struct vm_a
int rc;
struct page **pages;
- pages = kcalloc(numpgs, sizeof(pages[0]), GFP_KERNEL);
+ pages = kvcalloc(numpgs, sizeof(pages[0]), GFP_KERNEL);
if (pages == NULL)
return -ENOMEM;
@@ -428,7 +428,7 @@ static int alloc_empty_pages(struct vm_a
if (rc != 0) {
pr_warn("%s Could not alloc %d pfns rc:%d\n", __func__,
numpgs, rc);
- kfree(pages);
+ kvfree(pages);
return -ENOMEM;
}
BUG_ON(vma->vm_private_data != NULL);
@@ -912,7 +912,7 @@ static void privcmd_close(struct vm_area
else
pr_crit("unable to unmap MFN range: leaking %d pages. rc=%d\n",
numpgs, rc);
- kfree(pages);
+ kvfree(pages);
}
static vm_fault_t privcmd_fault(struct vm_fault *vmf)
