Messages in this thread Patch in this message | | | From | Adrian Hunter <> | Subject | [PATCH V2 2/2] proc/kcore: Do not try to access unaccepted memory | Date | Mon, 11 Sep 2023 14:21:14 +0300 |
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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 --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; -- 2.34.1
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