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

Guo Ren
2022-02-03T02:44:17Z

On Wed, Feb 2, 2022 at 3:52 PM Christoph Hellwig <hch@lst.de> wrote:
>
> 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;
Good point.

>
> I'd also rename compat_mode_support to compat_mode_supported
Okay

>
> > +
> > +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.
Okay

>
> Also this could be simplified to:
>
> compat_mode_supported = (csr_read(CSR_STATUS) & SR_UXL) == SR_UXL_32;
Okay

--
Best Regards
Guo Ren

ML: https://lore.kernel.org/linux-csky/