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

Chao Fan
2019-03-29T08:30:28Z

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;

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)
>
>