[RFCv2 09/13] shmem: Fail shmem_getpage_gfp() on poisoned pages

From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Dave Hansen <dave.hansen@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Sean Christopherson <seanjc@google.com>,
	Jim Mattson <jmattson@google.com>
Cc: David Rientjes <rientjes@google.com>,
	"Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
	"Kleen, Andi" <andi.kleen@intel.com>,
	"Yamahata, Isaku" <isaku.yamahata@intel.com>,
	Erdem Aktas <erdemaktas@google.com>,
	Steve Rutherford <srutherford@google.com>,
	Peter Gonda <pgonda@google.com>,
	David Hildenbrand <david@redhat.com>,
	x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [RFCv2 09/13] shmem: Fail shmem_getpage_gfp() on poisoned pages
Date: Fri, 16 Apr 2021 18:41:02 +0300	[thread overview]
Message-ID: <20210416154106.23721-10-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20210416154106.23721-1-kirill.shutemov@linux.intel.com>

Forbid access to poisoned pages.

TODO: Probably more fine-grained approach is needed. It shuld be a
allowed to fault-in these pages as hwpoison entries.

Not-Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 mm/shmem.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/mm/shmem.c b/mm/shmem.c
index 7c6b6d8f6c39..d29a0c9be19c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1832,6 +1832,13 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
 
 	if (page)
 		hindex = page->index;
+
+	if (page && PageHWPoison(page)) {
+		unlock_page(page);
+		put_page(page);
+		return -EIO;
+	}
+
 	if (page && sgp == SGP_WRITE)
 		mark_page_accessed(page);
 
-- 
2.26.3

