Received-SPF: pass (google.com: domain of linux-kernel+bounces-7835-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Thu, 21 Dec 2023 04:30:59 +0000
From: Matthew Wilcox <willy@infradead.org>
To: "Aithal, Srikanth" <sraithal@amd.com>
Cc: kernel test robot <oliver.sang@intel.com>, oe-lkp@lists.linux.dev,
	lkp@intel.com, Linux Memory Management List <linux-mm@kvack.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	David Hildenbrand <david@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: [linux-next:master] [mm] bbcbf2a3f0: kernel_BUG_at_mm/memory.c
Message-ID: <ZYO/g/Dg0+DN59Gq@casper.infradead.org>
References: <202312192319.fa8f5709-oliver.sang@intel.com>
 <2b7ae17e-0429-47ab-8101-00486ef9841e@amd.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <2b7ae17e-0429-47ab-8101-00486ef9841e@amd.com>

On Thu, Dec 21, 2023 at 08:26:37AM +0530, Aithal, Srikanth wrote:
> Starting from next-20231214 until next-20231220 have noted regression where
> kernel hangs randomly while running virtualization tests [multiple
> start-shutdown and reboot] against AMD sev guest type, with below call
> trace:

This is an entirely different problem, already reported and fix sent
about 24 hours ago.

diff --git a/mm/swap_state.c b/mm/swap_state.c
index 793b5b9e4f96..8a3a8f1ab20a 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -894,6 +894,9 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
 		swap_vma_readahead(entry, gfp_mask, mpol, ilx, vmf) :
 		swap_cluster_readahead(entry, gfp_mask, mpol, ilx);
 	mpol_cond_put(mpol);
+
+	if (!folio)
+		return NULL;
 	return folio_file_page(folio, swp_offset(entry));
 }