From e4eab1ce1f679507c02ea48e6b6edaef33f8fee3 Mon Sep 17 00:00:00 2001
From: Sven Schnelle <svens@stackframe.org>
Date: Wed, 5 Jun 2019 22:32:19 +0200
Subject: parisc: add WARN_ON() to clear_fixmap

Calling clear_fixmap() on an already cleared fixed mapping is
a bad thing to do. Add a WARN_ON() to catch such issues.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
---
 arch/parisc/mm/fixmap.c | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'arch/parisc/mm')

diff --git a/arch/parisc/mm/fixmap.c b/arch/parisc/mm/fixmap.c
index c8d41b54fb19..36321bcd75ba 100644
--- a/arch/parisc/mm/fixmap.c
+++ b/arch/parisc/mm/fixmap.c
@@ -35,6 +35,9 @@ void clear_fixmap(enum fixed_addresses idx)
 	pmd_t *pmd = pmd_offset(pgd, vaddr);
 	pte_t *pte = pte_offset_kernel(pmd, vaddr);
 
+	if (WARN_ON(pte_none(*pte)))
+		return;
+
 	pte_clear(&init_mm, vaddr, pte);
 
 	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
-- 
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