Re: [PATCH V5 15/21] riscv: compat: Add hw capability check for elf

Christoph Hellwig
2022-02-02T07:52:08Z

On Tue, Feb 01, 2022 at 11:05:39PM +0800, guoren@kernel.org wrote:
> +bool compat_elf_check_arch(Elf32_Ehdr *hdr)
> +{
> + if (compat_mode_support && (hdr->e_machine == EM_RISCV))
> + return true;
> + else
> + return false;
> +}

This can be simplified to:

return compat_mode_support && hdr->e_machine == EM_RISCV;

I'd also rename compat_mode_support to compat_mode_supported

> +
> +static int compat_mode_detect(void)
> +{
> + unsigned long tmp = csr_read(CSR_STATUS);
> +
> + csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32);
> +
> + if ((csr_read(CSR_STATUS) & SR_UXL) != SR_UXL_32) {
> + pr_info("riscv: 32bit compat mode detect failed\n");
> + compat_mode_support = false;
> + } else {
> + compat_mode_support = true;
> + pr_info("riscv: 32bit compat mode detected\n");
> + }

I don't think we need these printks here.

Also this could be simplified to:

compat_mode_supported = (csr_read(CSR_STATUS) & SR_UXL) == SR_UXL_32;