Re: [PATCH v3 4/5] x86: Port the basic alternative mechanism from Linux to Xen

["Jan Beulich" <JBeulich@suse.com>]

>>> On 30.05.14 at 10:56, <feng.wu@intel.com> wrote:
> +#ifdef K8_NOP1
> +static const unsigned char k8nops[] __initconst = {
> +    K8_NOP1,
> +    K8_NOP2,
> +    K8_NOP3,
> +    K8_NOP4,
> +    K8_NOP5,
> +    K8_NOP6,
> +    K8_NOP7,
> +    K8_NOP8
> +};
> +static const unsigned char * const k8_nops[ASM_NOP_MAX+1] __initconst = {
> +    NULL,
> +    k8nops,
> +    k8nops + 1,
> +    k8nops + 1 + 2,
> +    k8nops + 1 + 2 + 3,
> +    k8nops + 1 + 2 + 3 + 4,
> +    k8nops + 1 + 2 + 3 + 4 + 5,
> +    k8nops + 1 + 2 + 3 + 4 + 5 + 6,
> +    k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7
> +};
> +#endif
> +
> +#ifdef P6_NOP1
> +static const unsigned char p6nops[] __initconst = {
> +    P6_NOP1,
> +    P6_NOP2,
> +    P6_NOP3,
> +    P6_NOP4,
> +    P6_NOP5,
> +    P6_NOP6,
> +    P6_NOP7,
> +    P6_NOP8
> +};
> +static const unsigned char * const p6_nops[ASM_NOP_MAX+1] __initconst = {
> +    NULL,
> +    p6nops,
> +    p6nops + 1,
> +    p6nops + 1 + 2,
> +    p6nops + 1 + 2 + 3,
> +    p6nops + 1 + 2 + 3 + 4,
> +    p6nops + 1 + 2 + 3 + 4 + 5,
> +    p6nops + 1 + 2 + 3 + 4 + 5 + 6,
> +    p6nops + 1 + 2 + 3 + 4 + 5 + 6 + 7
> +};
> +#endif

The uses of __initconst together with -fPIC cause build problems on
older gcc. I fixed this up in a temporary way, but put a work item on
my todo list to deal with this properly while at once converting
alternative.o to alternative.init.o (as the file consists of only init
code and data).

Jan