On Fri, 11 Nov 2016, Florian Fainelli wrote:
> When CONFIG_DEBUG_VM is turned on, virt_to_phys() maps to
> debug_virt_to_phys() which helps catch vmalloc space addresses being
> passed. This is helpful in debugging bogus drivers that just assume
> linear mappings all over the place.
>
> For ARM, ARM64, Unicore32 and Microblaze, the architectures define
> __virt_to_phys() as being the functional implementation of the address
> translation, so we special case the debug stub to call into
> __virt_to_phys directly.
>
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
> arch/arm/include/asm/memory.h | 4 ++++
> arch/arm64/include/asm/memory.h | 4 ++++
> include/asm-generic/memory_model.h | 4 ++++
> mm/debug.c | 15 +++++++++++++++
> 4 files changed, 27 insertions(+)
>
> diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
> index 76cbd9c674df..448dec9b8b00 100644
> --- a/arch/arm/include/asm/memory.h
> +++ b/arch/arm/include/asm/memory.h
> @@ -260,11 +260,15 @@ static inline unsigned long __phys_to_virt(phys_addr_t x)
> * translation for translating DMA addresses. Use the driver
> * DMA support - see dma-mapping.h.
> */
> +#ifndef CONFIG_DEBUG_VM
> #define virt_to_phys virt_to_phys
> static inline phys_addr_t virt_to_phys(const volatile void *x)
> {
> return __virt_to_phys((unsigned long)(x));
> }
> +#else
> +#define virt_to_phys debug_virt_to_phys
> +#endif
[...]
Why don't you do something more like:
static inline phys_addr_t virt_to_phys(const volatile void *x)
{
+ debug_virt_to_phys(x);
return __virt_to_phys((unsigned long)(x));
}
[...]
static inline void debug_virt_to_phys(const void *address)
{
#ifdef CONFIG_DEBUG_VM
BUG_ON(is_vmalloc_addr(address));
#endif
}
?
Nicolas
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