From 4b52016247aeaa55ca3e3bc2e03cd91114c145c2 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 22 Nov 2022 17:10:07 +0100 Subject: x86/boot/compressed, efi: Merge multiple definitions of image_offset into one There is no need for head_32.S and head_64.S both declaring a copy of the global 'image_offset' variable, so drop those and make the extern C declaration the definition. When image_offset is moved to the .c file, it needs to be placed particularly in the .data section because it lands by default in the .bss section which is cleared too late, in .Lrelocated, before the first access to it and thus garbage gets read, leading to SEV guests exploding in early boot. This happens only when the SEV guest kernel is loaded through grub. If supplied with qemu's -kernel command line option, that memory is always cleared upfront by qemu and all is fine there. [ bp: Expand commit message with SEV aspect. ] Signed-off-by: Ard Biesheuvel Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20221122161017.2426828-8-ardb@kernel.org --- drivers/firmware/efi/libstub/x86-stub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index 33a7811e12c6..a0bfd31358ba 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -23,7 +23,7 @@ const efi_system_table_t *efi_system_table; const efi_dxe_services_table_t *efi_dxe_table; -extern u32 image_offset; +u32 image_offset __section(".data"); static efi_loaded_image_t *image = NULL; static efi_status_t -- cgit v1.2.3