lkml.org 
[lkml]   [2019]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [tip:x86/boot] x86/boot: Early parse RSDP and save it in boot_params
On Fri, Feb 08, 2019 at 10:53:22PM +0100, Borislav Petkov wrote:
> On Fri, Feb 08, 2019 at 12:44:51PM -0800, Guenter Roeck wrote:
> > Yes, the kernel boots if I comment out that function and have it return 0.
>
> Thanks, this localizes the issue significantly.

Some observations:

} else {
efi_config_table_32_t *tmp_table;

tmp_table = config_tables;
guid = tmp_table->guid; <--- *
table = tmp_table->table;
}

It blows up at that tmp_table->guid deref above. Singlestepping through
it with gdb shows:

# arch/x86/boot/compressed/acpi.c:114: guid = tmp_table->guid;
movq (%rdi), %rax # MEM[(struct efi_config_table_32_t *)config_tables_37].guid, guid
movq 8(%rdi), %rsi # MEM[(struct efi_config_table_32_t *)config_tables_37].guid, guid
# arch/x86/boot/compressed/acpi.c:115: table = tmp_table->table;
movl 16(%rdi), %r10d # MEM[(struct efi_config_table_32_t *)config_tables_37].table, table
jmp .L30 #

and %rdi has:

rdi 0x630646870

which is an address above 4G but we're using a 32-bit EFI BIOS.

Which begs the question whether EFI system tables can even be mapped at
something above 4G with a 32-bit EFI and whether that could work ok.
Hmm.

Lemme add Ard and mfleming for insight here.

Thx.

--
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

\
 
 \ /
  Last update: 2019-02-11 01:23    [W:0.104 / U:1.676 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site