The MLE (measured launch environment) header must be locatable by the boot loader and TXT must be setup to do a launch with this header's location. While the offset to the kernel_info structure does not need to be at a fixed offset, the offsets in the header must be relative offsets from the start of the setup kernel. The support in the linker file achieves this. Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxxx> Suggested-by: Ard Biesheuvel <ardb@xxxxxxxxxx> Reviewed-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- arch/x86/boot/compressed/kernel_info.S | 50 +++++++++++++++++++++++--- arch/x86/boot/compressed/vmlinux.lds.S | 7 ++++ 2 files changed, 53 insertions(+), 4 deletions(-) diff --git a/arch/x86/boot/compressed/kernel_info.S b/arch/x86/boot/compressed/kernel_info.S index f818ee8fba38..a0604a0d1756 100644 --- a/arch/x86/boot/compressed/kernel_info.S +++ b/arch/x86/boot/compressed/kernel_info.S @@ -1,12 +1,20 @@ /* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/linkage.h> #include <asm/bootparam.h> - .section ".rodata.kernel_info", "a" +/* + * The kernel_info structure is not placed at a fixed offest in the + * kernel image. So this macro and the support in the linker file + * allow the relative offsets for the MLE header within the kernel + * image to be configured at build time. + */ +#define roffset(X) ((X) - kernel_info) - .global kernel_info + .section ".rodata.kernel_info", "a" -kernel_info: + .balign 16 +SYM_DATA_START(kernel_info) /* Header, Linux top (structure). */ .ascii "LToP" /* Size. */ @@ -17,6 +25,40 @@ kernel_info: /* Maximal allowed type for setup_data and setup_indirect structs. */ .long SETUP_TYPE_MAX + /* Offset to the MLE header structure */ +#if IS_ENABLED(CONFIG_SECURE_LAUNCH) + .long roffset(mle_header_offset) +#else + .long 0 +#endif + kernel_info_var_len_data: /* Empty for time being... */ -kernel_info_end: +SYM_DATA_END_LABEL(kernel_info, SYM_L_LOCAL, kernel_info_end) + +#if IS_ENABLED(CONFIG_SECURE_LAUNCH) + /* + * The MLE Header per the TXT Specification, section 2.1 + * MLE capabilities, see table 4. Capabilities set: + * bit 0: Support for GETSEC[WAKEUP] for RLP wakeup + * bit 1: Support for RLP wakeup using MONITOR address + * bit 2: The ECX register will contain the pointer to the MLE page table + * bit 5: TPM 1.2 family: Details/authorities PCR usage support + * bit 9: Supported format of TPM 2.0 event log - TCG compliant + */ +SYM_DATA_START(mle_header) + .long 0x9082ac5a /* UUID0 */ + .long 0x74a7476f /* UUID1 */ + .long 0xa2555c0f /* UUID2 */ + .long 0x42b651cb /* UUID3 */ + .long 0x00000034 /* MLE header size */ + .long 0x00020002 /* MLE version 2.2 */ + .long roffset(sl_stub_entry_offset) /* Linear entry point of MLE (virt. address) */ + .long 0x00000000 /* First valid page of MLE */ + .long 0x00000000 /* Offset within binary of first byte of MLE */ + .long roffset(_edata_offset) /* Offset within binary of last byte + 1 of MLE */ + .long 0x00000227 /* Bit vector of MLE-supported capabilities */ + .long 0x00000000 /* Starting linear address of command line (unused) */ + .long 0x00000000 /* Ending linear address of command line (unused) */ +SYM_DATA_END(mle_header) +#endif diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index 083ec6d7722a..f82184801462 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -118,3 +118,10 @@ SECTIONS } ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!") } + +#ifdef CONFIG_SECURE_LAUNCH +PROVIDE(kernel_info_offset = ABSOLUTE(kernel_info - startup_32)); +PROVIDE(mle_header_offset = kernel_info_offset + ABSOLUTE(mle_header - startup_32)); +PROVIDE(sl_stub_entry_offset = kernel_info_offset + ABSOLUTE(sl_stub_entry - startup_32)); +PROVIDE(_edata_offset = kernel_info_offset + ABSOLUTE(_edata - startup_32)); +#endif -- 2.39.3
