Messages in this thread | | | Date | Mon, 11 Feb 2019 01:22:20 +0100 | From | Borislav Petkov <> | Subject | Re: [tip:x86/boot] x86/boot: Early parse RSDP and save it in boot_params |
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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.
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