diff mbox series

[V2,2/2] proc/kcore: Do not try to access unaccepted memory

Message ID 20230911112114.91323-3-adrian.hunter@intel.com
State Accepted
Commit e538a582097878c536c68002c79722e4a037c080
Headers show
Series Do not try to access unaccepted memory | expand

Commit Message

Adrian Hunter Sept. 11, 2023, 11:21 a.m. UTC 
Support for unaccepted memory was added recently, refer commit
dcdfdd40fa82 ("mm: Add support for unaccepted memory"), whereby a virtual
machine may need to accept memory before it can be used.

Do not try to access unaccepted memory because it can cause the guest to
fail.

For /proc/kcore, which is read-only and does not support mmap, this means a
read of unaccepted memory will return zeros.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 fs/proc/kcore.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)


Changes in V2:

          Change patch subject and commit message
          Do not open code pfn_is_unaccepted_memory()
diff mbox series

Patch

diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 23fc24d16b31..6422e569b080 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -546,7 +546,8 @@  static ssize_t read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter)
 			 * and explicitly excluded physical ranges.
 			 */
 			if (!page || PageOffline(page) ||
-			    is_page_hwpoison(page) || !pfn_is_ram(pfn)) {
+			    is_page_hwpoison(page) || !pfn_is_ram(pfn) ||
+			    pfn_is_unaccepted_memory(pfn)) {
 				if (iov_iter_zero(tsz, iter) != tsz) {
 					ret = -EFAULT;
 					goto out;