Re: [Qemu-devel] [PATCH] [PATCH] target/riscv/pmp.c: pmpcfg_csr_read return type demotion

[Peter Maydell]

On 18 October 2018 at 18:37, Philippe Mathieu-Daudé <address@hidden> wrote:
> Hi Lee,
>
> On 18/10/2018 08:44, Dayeol Lee wrote:
>> There is a data type demotion bug in target/riscv/pmp.c
>> When the target_ulong is 8 bytes, pmpcfg_csr_read returns only lower 4
>> bytes.
>> ---
>>  target/riscv/pmp.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
>> index c828950..4b6c20e 100644
>> --- a/target/riscv/pmp.c
>> +++ b/target/riscv/pmp.c
>> @@ -337,7 +337,7 @@ target_ulong pmpcfg_csr_read(CPURISCVState *env, 
>> uint32_t reg_index)
>>
>>      for (i = 0; i < sizeof(target_ulong); i++) {
>>          val = pmp_read_cfg(env, (reg_index * sizeof(target_ulong)) + i);
>> -        cfg_val |= (val << (i * 8));
>> +        cfg_val |= ((target_ulong)val << ((target_ulong)i * 8));
>
> Casting 'val' seems correct, however you don't need to cast the 'i'.

You could just declare 'val' as a target_ulong to start with,
and avoid the need for a cast at all, I think ?

thanks
-- PMM