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Date:   Sun, 21 May 2023 22:05:15 -0700 (PDT)
From:   Hugh Dickins <hughd@google.com>
To:     Andrew Morton <akpm@linux-foundation.org>
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Subject: [PATCH 13/31] mm/hmm: retry if pte_offset_map() fails
In-Reply-To: <68a97fbe-5c1e-7ac6-72c-7b9c6290b370@google.com>
Message-ID: <2edc4657-b6ff-3d6e-2342-6b60bfccc5b@google.com>
References: <68a97fbe-5c1e-7ac6-72c-7b9c6290b370@google.com>
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Precedence: bulk

hmm_vma_walk_pmd() is called through mm_walk, but already has a goto
again loop of its own, so take part in that if pte_offset_map() fails.

Signed-off-by: Hugh Dickins <hughd@google.com>
---
 mm/hmm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/hmm.c b/mm/hmm.c
index e23043345615..b1a9159d7c92 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -381,6 +381,8 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp,
 	}
 
 	ptep = pte_offset_map(pmdp, addr);
+	if (!ptep)
+		goto again;
 	for (; addr < end; addr += PAGE_SIZE, ptep++, hmm_pfns++) {
 		int r;
 
-- 
2.35.3