Hi Florian
On Thu, Jul 14, 2022 at 03:25:12PM -0700, Florian Fainelli wrote:
> It is permissible for kernel code to call virt_to_phys() against virtual
> addresses that are in KSEG0 or KSEG1 and we need to be dealing with both
> types. Rewrite the test condition to ensure that the kernel virtual
> addresses are above PAGE_OFFSET which they must be, and below KSEG2
> where the non-linear mapping starts.
>
> For EVA, there is not much that we can do given the linear address range
> that is offered, so just return any virtual address as being valid.
>
> Finally, when HIGHMEM is not enabled, all virtual addresses are assumed
> to be valid as well.
>
> Fixes: dfad83cb7193 ("MIPS: Add support for CONFIG_DEBUG_VIRTUAL")
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
No objections now. Thanks.
Reviewed-by: Serge Semin <fancer.lancer@xxxxxxxxx>
-Serge(y)
> ---
> Changes in v2:
>
> - handle lack of HIGHMEM and EVA
>
> arch/mips/mm/physaddr.c | 14 ++++----------
> 1 file changed, 4 insertions(+), 10 deletions(-)
>
> diff --git a/arch/mips/mm/physaddr.c b/arch/mips/mm/physaddr.c
> index a1ced5e44951..f9b8c85e9843 100644
> --- a/arch/mips/mm/physaddr.c
> +++ b/arch/mips/mm/physaddr.c
> @@ -5,6 +5,7 @@
> #include <linux/mmdebug.h>
> #include <linux/mm.h>
>
> +#include <asm/addrspace.h>
> #include <asm/sections.h>
> #include <asm/io.h>
> #include <asm/page.h>
> @@ -12,15 +13,6 @@
>
> static inline bool __debug_virt_addr_valid(unsigned long x)
> {
> - /* high_memory does not get immediately defined, and there
> - * are early callers of __pa() against PAGE_OFFSET
> - */
> - if (!high_memory && x >= PAGE_OFFSET)
> - return true;
> -
> - if (high_memory && x >= PAGE_OFFSET && x < (unsigned long)high_memory)
> - return true;
> -
> /*
> * MAX_DMA_ADDRESS is a virtual address that may not correspond to an
> * actual physical address. Enough code relies on
> @@ -30,7 +22,9 @@ static inline bool __debug_virt_addr_valid(unsigned long x)
> if (x == MAX_DMA_ADDRESS)
> return true;
>
> - return false;
> + return x >= PAGE_OFFSET && (KSEGX(x) < KSEG2 ||
> + IS_ENABLED(CONFIG_EVA) ||
> + !IS_ENABLED(CONFIG_HIGHMEM));
> }
>
> phys_addr_t __virt_to_phys(volatile const void *x)
> --
> 2.25.1
>
