Re: [PATCH] target/arm: Avoid target_ulong for physical address lookups

[Richard Henderson <richard.henderson@linaro.org>]

On 9/23/24 11:22, Ard Biesheuvel wrote:
> From: Ard Biesheuvel<ardb@kernel.org>
> 
> target_ulong is typedef'ed as a 32-bit integer when building the
> qemu-system-arm target, and this is smaller than the size of an
> intermediate physical address when LPAE is being used.
> 
> Given that Linux may place leaf level user page tables in high memory
> when built for LPAE, the kernel will crash with an external abort as
> soon as it enters user space when running with more than ~3 GiB of
> system RAM.
> 
> So replace target_ulong with hwaddr in places where it may carry an
> address value that is not representable in 32 bits.
> 
> Fixes: f3639a64f602ea ("target/arm: Use softmmu tlbs for page table walking")
> Reported-by: Arnd Bergmann<arnd@arndb.de>
> Signed-off-by: Ard Biesheuvel<ardb@kernel.org>
> ---
>   target/arm/internals.h |  4 ++--
>   target/arm/ptw.c       | 16 ++++++++--------
>   2 files changed, 10 insertions(+), 10 deletions(-)

Ouch, my bad.  Thanks for catching.

Nit: The type "vaddr" is probably more descriptive than "hwaddr" as input to 
get_phys_addr.  Both are typedefs of uint64_t, so there's no functional difference between 
them.

Anyway,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~