Re: [PATCH RFC] arm/kvm: report registers we failed to set

[Cornelia Huck <cohuck@redhat.com>]

On Tue, Jul 22 2025, Sebastian Ott <sebott@redhat.com> wrote:

> On Mon, 21 Jul 2025, Cornelia Huck wrote:
>> +/* pretty-print a KVM register */
>> +#define CP_REG_ARM64_SYSREG_OP(_reg, _op)                       \
>> +    ((uint8_t)((_reg & CP_REG_ARM64_SYSREG_ ## _op ## _MASK) >> \
>> +               CP_REG_ARM64_SYSREG_ ## _op ## _SHIFT))
>> +
>> +#define PRI_CP_REG_ARM64_SYSREG(_reg)                    \
>> +    ({                                                   \
>> +        char _out[32];                                   \
>> +        snprintf(_out, sizeof(_out),                     \
>> +                 "op0:%d op1:%d crn:%d crm:%d op2:%d",   \
>> +                 CP_REG_ARM64_SYSREG_OP(_reg, OP0),      \
>> +                 CP_REG_ARM64_SYSREG_OP(_reg, OP1),      \
>> +                 CP_REG_ARM64_SYSREG_OP(_reg, CRN),      \
>> +                 CP_REG_ARM64_SYSREG_OP(_reg, CRM),      \
>> +                 CP_REG_ARM64_SYSREG_OP(_reg, OP2));     \
>> +        _out;                                            \
>> +    })
>
> Gcc correctly complains about a dangling pointer here.

Hum, I maybe should switch to a system with a less ancient
compiler... thanks for testing.