| Message ID | 1555349796-9456-1-git-send-email-miles.chen@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: mm: check virtual addr in virt_to_page() if CONFIG_DEBUG_VIRTUAL=y | expand |
On Tue, Apr 16, 2019 at 01:36:36AM +0800, Miles Chen wrote: > 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 IIUC, this shouldn't change the behaviour of virt_addr_valid(). The patch looks fine to me. Acked-by: Catalin Marinas <catalin.marinas@arm.com>
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
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(-)