From: Sven Schnelle <svens@stackframe.org>
To: deller@gmx.de
Cc: linux-parisc@vger.kernel.org, Sven Schnelle <svens@stackframe.org>
Subject: [PATCH v3 3/6] parisc: add WARN_ON() to clear_fixmap
Date: Wed, 5 Jun 2019 22:32:19 +0200 [thread overview]
Message-ID: <20190605203222.6194-4-svens@stackframe.org> (raw)
In-Reply-To: <20190605203222.6194-1-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
next prev parent reply other threads:[~2019-06-05 20:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-05 20:32 [PATCH v3 0/6] Dynamic FTRACE for PA-RISC Sven Schnelle
2019-06-05 20:32 ` [PATCH v3 1/6] parisc: add support for patching multiple words Sven Schnelle
2019-06-05 20:32 ` [PATCH v3 2/6] parisc: add spinlock to patch function Sven Schnelle
2019-06-05 20:32 ` Sven Schnelle [this message]
2019-06-05 20:32 ` [PATCH v3 4/6] parisc: use pr_debug() in kernel/module.c Sven Schnelle
2019-06-05 20:32 ` [PATCH v3 5/6] compiler.h: add CC_USING_PATCHABLE_FUNCTION_ENTRY Sven Schnelle
2019-06-05 20:32 ` [PATCH v3 6/6] parisc: add dynamic ftrace Sven Schnelle
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