On 26.08.20 20:37, Julien Grall wrote:
Hi Simon,
On 25/08/2020 10:31, Simon Leiner wrote:
As virt_to_gfn uses virt_to_phys, it will return invalid addresses when
used with vmalloc'd addresses. This patch introduces a warning, when
virt_to_gfn is used in this way.
Signed-off-by: Simon Leiner <si...@leiner.me>
---
include/xen/arm/page.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/xen/arm/page.h b/include/xen/arm/page.h
index d7f6af50e200..b0d303b633d0 100644
--- a/include/xen/arm/page.h
+++ b/include/xen/arm/page.h
@@ -76,7 +76,11 @@ static inline unsigned long bfn_to_pfn(unsigned
long bfn)
#define bfn_to_local_pfn(bfn) bfn_to_pfn(bfn)
/* VIRT <-> GUEST conversion */
-#define virt_to_gfn(v) (pfn_to_gfn(virt_to_phys(v) >>
XEN_PAGE_SHIFT))
+#define
virt_to_gfn(v) \
+
({ \
+ WARN_ON_ONCE(is_vmalloc_addr(v)); \
virt_to_gfn() will usually be called from generic code. WARN_ON_ONCE()
"Usually" is a bit gross here. The only generic call site I could find
is xenbus_grant_ring(). All other instances (I counted 22) are not
generic at all.
will only catch one instance and it means we would have to fix the first
instance and then re-run to catch the others.
So I think we want to switch to WARN_ON() here.
No, please don't. In case there would be a frequent path the result
would be a basically unusable system due to massive console clobbering.
Juergen
