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Date:   Tue, 9 May 2023 21:49:22 -0700 (PDT)
From:   Hugh Dickins <hughd@google.com>
To:     Andrew Morton <akpm@linux-foundation.org>
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Subject: [PATCH 06/23] microblaze: allow pte_offset_map() to fail
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Precedence: bulk

In rare transient cases, not yet made possible, pte_offset_map() and
pte_offset_map_lock() may not find a page table: handle appropriately.

Signed-off-by: Hugh Dickins <hughd@google.com>
---
 arch/microblaze/kernel/signal.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c
index c3aebec71c0c..c78a0ff48066 100644
--- a/arch/microblaze/kernel/signal.c
+++ b/arch/microblaze/kernel/signal.c
@@ -194,7 +194,7 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 
 	preempt_disable();
 	ptep = pte_offset_map(pmdp, address);
-	if (pte_present(*ptep)) {
+	if (ptep && pte_present(*ptep)) {
 		address = (unsigned long) page_address(pte_page(*ptep));
 		/* MS: I need add offset in page */
 		address += ((unsigned long)frame->tramp) & ~PAGE_MASK;
@@ -203,7 +203,8 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 		invalidate_icache_range(address, address + 8);
 		flush_dcache_range(address, address + 8);
 	}
-	pte_unmap(ptep);
+	if (ptep)
+		pte_unmap(ptep);
 	preempt_enable();
 	if (err)
 		return -EFAULT;
-- 
2.35.3