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From: Sven Schnelle <svens@stackframe.org>
To: deller@gmx.de
Cc: linux-parisc@vger.kernel.org, Sven Schnelle <svens@stackframe.org>
Subject: [PATCH 3/6] parisc: add WARN_ON() to clear_fixmap
Date: Mon, 27 May 2019 21:04:47 +0200	[thread overview]
Message-ID: <20190527190450.14988-4-svens@stackframe.org> (raw)
In-Reply-To: <20190527190450.14988-1-svens@stackframe.org>

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>
---
 arch/parisc/mm/fixmap.c | 3 +++
 1 file changed, 3 insertions(+)

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);
-- 
2.20.1


  parent reply	other threads:[~2019-05-27 19:05 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-27 19:04 [PATCH 0/6] Dynamic FTRACE for PA-RISC Sven Schnelle
2019-05-27 19:04 ` [PATCH 1/6] parisc: add support for patching multiple words Sven Schnelle
2019-05-28  8:19   ` Rolf Eike Beer
2019-05-29 17:49     ` Sven Schnelle
2019-05-29 17:58       ` Rolf Eike Beer
2019-05-29 18:18         ` Sven Schnelle
2019-05-27 19:04 ` [PATCH 2/6] parisc: add spinlock to patch function Sven Schnelle
2019-05-27 19:04 ` Sven Schnelle [this message]
2019-05-27 19:04 ` [PATCH 4/6] parisc: use pr_debug() in kernel/module.c Sven Schnelle
2019-05-28  8:24   ` Rolf Eike Beer
2019-05-29 17:54     ` Sven Schnelle
2019-05-27 19:04 ` [PATCH 5/6] compiler.h: add CC_USING_PATCHABLE_FUNCTION_ENTRY Sven Schnelle
2019-05-27 19:04 ` [PATCH 6/6] parisc: add dynamic ftrace Sven Schnelle
2019-05-28  8:26   ` Rolf Eike Beer

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