Re: [PATCH] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel

bhe
2019-03-29T09:17:03Z

On 03/29/19 at 04:29pm, Chao Fan wrote:
> On Fri, Mar 29, 2019 at 07:20:38AM +0000, Junichi Nomura wrote:
> >Commit 3a63f70bf4c3a ("x86/boot: Early parse RSDP and save it in
> >boot_params") broke kexec boot on EFI systems. efi_get_rsdp_addr()
> >in the early parsing code tries to search RSDP from EFI table but
> >that will crash because the table address is virtual when the kernel
> >was booted by kexec.
> [...]
> >- guid = tbl->guid;
> >- table = tbl->table;
> >- }
> >-
> >- if (!(efi_guidcmp(guid, ACPI_TABLE_GUID)))
> >- rsdp_addr = table;
> >- else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID)))
> >- return table;
> >- }
> >+ return __efi_get_rsdp_addr(config_tables, nr_tables, efi_64);
> >+#else
> >+ return 0;
> > #endif
> >- return rsdp_addr;
>
> I remeber the rsdp_addr is defined before #ifdef CONFIG_EFI
> If so, you don't need
> #else
> return 0;

it doesn't change the old logic. Junichi moved rsdp_addr definition inside
the CONFIG_EFI iedeffery block.
>
> BY the way, what's your patch based on? I like add patch on my local
> branch and then review code, but failed.
> I try to use 'patch -p1 <' your patch to the latest tip master branch,
> but failed.
>
> Thanks,
> Chao Fan
>
> > }
> >
> > static u8 compute_checksum(u8 *buffer, u32 length)
> >@@ -221,6 +284,9 @@ acpi_physical_address get_rsdp_addr(void)
> > pa = boot_params->acpi_rsdp_addr;
> >
> > if (!pa)
> >+ pa = kexec_get_rsdp_addr();
> >+
> >+ if (!pa)
> > pa = efi_get_rsdp_addr();
> >
> > if (!pa)
> >
> >
>
>