From: Miles Chen <miles.chen@mediatek.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
<linux-mediatek@lists.infradead.org>, <wsd_upstream@mediatek.com>,
Miles Chen <miles.chen@mediatek.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>
Subject: [PATCH] arm64: mm: check virtual addr in virt_to_page() if CONFIG_DEBUG_VIRTUAL=y
Date: Tue, 16 Apr 2019 01:36:36 +0800 [thread overview]
Message-ID: <1555349796-9456-1-git-send-email-miles.chen@mediatek.com> (raw)
This change uses the original virt_to_page() (the one with __pa()) to
check the given virtual address if CONFIG_DEBUG_VIRTUAL=y.
Recently, I worked on a bug: a driver passes a symbol address to
dma_map_single() and the virt_to_page() (called by dma_map_single())
does not work for non-linear addresses after commit 9f2875912dac
("arm64: mm: restrict virt_to_page() to the linear mapping").
I tried to trap the bug by enabling CONFIG_DEBUG_VIRTUAL but it
did not work - bacause the commit removes the __pa() from
virt_to_page() but CONFIG_DEBUG_VIRTUAL checks the virtual address
in __pa()/__virt_to_phys().
A simple solution is to use the original virt_to_page()
(the one with__pa()) if CONFIG_DEBUG_VIRTUAL=y.
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
arch/arm64/include/asm/memory.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 290195168bb3..2cb8248fa2c8 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -302,7 +302,7 @@ static inline void *phys_to_virt(phys_addr_t x)
*/
#define ARCH_PFN_OFFSET ((unsigned long)PHYS_PFN_OFFSET)
-#ifndef CONFIG_SPARSEMEM_VMEMMAP
+#if !defined(CONFIG_SPARSEMEM_VMEMMAP) || defined(CONFIG_DEBUG_VIRTUAL)
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define _virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#else
--
2.18.0
next reply other threads:[~2019-04-15 17:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-15 17:36 Miles Chen [this message]
2019-04-16 11:30 ` [PATCH] arm64: mm: check virtual addr in virt_to_page() if CONFIG_DEBUG_VIRTUAL=y Catalin Marinas
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