Re: [PATCH v4 06/15] mm/execmem, arch: convert simple overrides of module_alloc to execmem

Peter Zijlstra
2024-04-15T08:03:46Z

On Thu, Apr 11, 2024 at 07:00:42PM +0300, Mike Rapoport wrote:
> +static struct execmem_info execmem_info __ro_after_init = {
> + .ranges = {
> + [EXECMEM_DEFAULT] = {
> + .start = MODULES_VADDR,
> + .end = MODULES_END,
> + .alignment = 1,
> + },
> + },
> +};
> +
> +struct execmem_info __init *execmem_arch_setup(void)
> {
> + execmem_info.ranges[EXECMEM_DEFAULT].pgprot = PAGE_KERNEL;
> +
> + return &execmem_info;
> }

> +static struct execmem_info execmem_info __ro_after_init = {
> + .ranges = {
> + [EXECMEM_DEFAULT] = {
> + .start = MODULES_VADDR,
> + .end = MODULES_END,
> + .pgprot = PAGE_KERNEL_EXEC,
> + .alignment = 1,
> + },
> + },
> +};
> +
> +struct execmem_info __init *execmem_arch_setup(void)
> {
> + return &execmem_info;
> }

> +static struct execmem_info execmem_info __ro_after_init = {
> + .ranges = {
> + [EXECMEM_DEFAULT] = {
> + .pgprot = PAGE_KERNEL_RWX,
> + .alignment = 1,
> + },
> + },
> +};
> +
> +struct execmem_info __init *execmem_arch_setup(void)
> {
> + execmem_info.ranges[EXECMEM_DEFAULT].start = VMALLOC_START;
> + execmem_info.ranges[EXECMEM_DEFAULT].end = VMALLOC_END;
> +
> + return &execmem_info;
> }

> +static struct execmem_info execmem_info __ro_after_init = {
> + .ranges = {
> + [EXECMEM_DEFAULT] = {
> + .pgprot = PAGE_KERNEL,
> + .alignment = 1,
> + },
> + },
> +};
> +
> +struct execmem_info __init *execmem_arch_setup(void)
> {
> + execmem_info.ranges[EXECMEM_DEFAULT].start = MODULES_VADDR;
> + execmem_info.ranges[EXECMEM_DEFAULT].end = MODULES_END;
> +
> + return &execmem_info;
> }

> +static struct execmem_info execmem_info __ro_after_init = {
> + .ranges = {
> + [EXECMEM_DEFAULT] = {
> #ifdef CONFIG_SPARC64
> + .start = MODULES_VADDR,
> + .end = MODULES_END,
> #else
> + .start = VMALLOC_START,
> + .end = VMALLOC_END,
> +#endif
> + .alignment = 1,
> + },
> + },
> +};
> +
> +struct execmem_info __init *execmem_arch_setup(void)
> {
> + execmem_info.ranges[EXECMEM_DEFAULT].pgprot = PAGE_KERNEL;
>
> + return &execmem_info;
> }

I'm amazed by the weird and inconsistent breakup of initializations.

What exactly is wrong with something like:

static struct execmem_info execmem_info __ro_after_init;

struct execmem_info __init *execmem_arch_setup(void)
{
execmem_info = (struct execmem_info){
.ranges = {
[EXECMEM_DEFAULT] = {
.start = MODULES_VADDR,
.end = MODULES_END,
.pgprot = PAGE_KERNEL,
.alignment = 1,
},
},
};
return &execmem_info;
}