Commit 7f22ca39 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Borislav Petkov
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x86/boot/compressed: Move efi32_pe_entry() out of head_64.S 



Move the implementation of efi32_pe_entry() into efi-mixed.S, which is a
more suitable location that only gets built if EFI mixed mode is
actually enabled.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221122161017.2426828-7-ardb@kernel.org
parent 73a6dec8

arch/x86/boot/compressed/efi_mixed.S

+82 −0
Original line number Diff line number Diff line
@@ -257,6 +257,88 @@ SYM_FUNC_START(efi32_entry) 
	jmp	startup_32

SYM_FUNC_END(efi32_entry)



#define ST32_boottime		60 // offsetof(efi_system_table_32_t, boottime)

#define BS32_handle_protocol	88 // offsetof(efi_boot_services_32_t, handle_protocol)

#define LI32_image_base		32 // offsetof(efi_loaded_image_32_t, image_base)



/*

 * efi_status_t efi32_pe_entry(efi_handle_t image_handle,

 *			       efi_system_table_32_t *sys_table)

 */

SYM_FUNC_START(efi32_pe_entry)

	pushl	%ebp

	movl	%esp, %ebp

	pushl	%eax				// dummy push to allocate loaded_image



	pushl	%ebx				// save callee-save registers

	pushl	%edi



	call	verify_cpu			// check for long mode support

	testl	%eax, %eax

	movl	$0x80000003, %eax		// EFI_UNSUPPORTED

	jnz	2f



	call	1f

1:	pop	%ebx



	/* Get the loaded image protocol pointer from the image handle */

	leal	-4(%ebp), %eax

	pushl	%eax				// &loaded_image

	leal	(loaded_image_proto - 1b)(%ebx), %eax

	pushl	%eax				// pass the GUID address

	pushl	8(%ebp)				// pass the image handle



	/*

	 * Note the alignment of the stack frame.

	 *   sys_table

	 *   handle             <-- 16-byte aligned on entry by ABI

	 *   return address

	 *   frame pointer

	 *   loaded_image       <-- local variable

	 *   saved %ebx		<-- 16-byte aligned here

	 *   saved %edi

	 *   &loaded_image

	 *   &loaded_image_proto

	 *   handle             <-- 16-byte aligned for call to handle_protocol

	 */



	movl	12(%ebp), %eax			// sys_table

	movl	ST32_boottime(%eax), %eax	// sys_table->boottime

	call	*BS32_handle_protocol(%eax)	// sys_table->boottime->handle_protocol

	addl	$12, %esp			// restore argument space

	testl	%eax, %eax

	jnz	2f



	movl	8(%ebp), %ecx			// image_handle

	movl	12(%ebp), %edx			// sys_table

	movl	-4(%ebp), %esi			// loaded_image

	movl	LI32_image_base(%esi), %esi	// loaded_image->image_base

	leal	(startup_32 - 1b)(%ebx), %ebp	// runtime address of startup_32

	/*

	 * We need to set the image_offset variable here since startup_32() will

	 * use it before we get to the 64-bit efi_pe_entry() in C code.

	 */

	subl	%esi, %ebp			// calculate image_offset

	movl	%ebp, (image_offset - 1b)(%ebx)	// save image_offset

	xorl	%esi, %esi

	jmp	efi32_entry			// pass %ecx, %edx, %esi

						// no other registers remain live



2:	popl	%edi				// restore callee-save registers

	popl	%ebx

	leave

	RET

SYM_FUNC_END(efi32_pe_entry)



	.section ".rodata"

	/* EFI loaded image protocol GUID */

	.balign 4

SYM_DATA_START_LOCAL(loaded_image_proto)

	.long	0x5b1b31a1

	.word	0x9562, 0x11d2

	.byte	0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b

SYM_DATA_END(loaded_image_proto)



	.data

	.balign	8

SYM_DATA_START_LOCAL(efi32_boot_gdt)

arch/x86/boot/compressed/head_64.S

+1 −86
Original line number Diff line number Diff line
@@ -673,6 +673,7 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lno_longmode) 
	jmp     1b

SYM_FUNC_END(.Lno_longmode)



	.globl	verify_cpu

#include "../../kernel/verify_cpu.S"



	.data
@@ -720,92 +721,6 @@ SYM_DATA_END_LABEL(boot32_idt, SYM_L_GLOBAL, boot32_idt_end) 
#ifdef CONFIG_EFI_STUB

SYM_DATA(image_offset, .long 0)

#endif

#ifdef CONFIG_EFI_MIXED

#define ST32_boottime		60 // offsetof(efi_system_table_32_t, boottime)

#define BS32_handle_protocol	88 // offsetof(efi_boot_services_32_t, handle_protocol)

#define LI32_image_base		32 // offsetof(efi_loaded_image_32_t, image_base)



	.text

	.code32

SYM_FUNC_START(efi32_pe_entry)

/*

 * efi_status_t efi32_pe_entry(efi_handle_t image_handle,

 *			       efi_system_table_32_t *sys_table)

 */



	pushl	%ebp

	movl	%esp, %ebp

	pushl	%eax				// dummy push to allocate loaded_image



	pushl	%ebx				// save callee-save registers

	pushl	%edi



	call	verify_cpu			// check for long mode support

	testl	%eax, %eax

	movl	$0x80000003, %eax		// EFI_UNSUPPORTED

	jnz	2f



	call	1f

1:	pop	%ebx



	/* Get the loaded image protocol pointer from the image handle */

	leal	-4(%ebp), %eax

	pushl	%eax				// &loaded_image

	leal	(loaded_image_proto - 1b)(%ebx), %eax

	pushl	%eax				// pass the GUID address

	pushl	8(%ebp)				// pass the image handle



	/*

	 * Note the alignment of the stack frame.

	 *   sys_table

	 *   handle             <-- 16-byte aligned on entry by ABI

	 *   return address

	 *   frame pointer

	 *   loaded_image       <-- local variable

	 *   saved %ebx		<-- 16-byte aligned here

	 *   saved %edi

	 *   &loaded_image

	 *   &loaded_image_proto

	 *   handle             <-- 16-byte aligned for call to handle_protocol

	 */



	movl	12(%ebp), %eax			// sys_table

	movl	ST32_boottime(%eax), %eax	// sys_table->boottime

	call	*BS32_handle_protocol(%eax)	// sys_table->boottime->handle_protocol

	addl	$12, %esp			// restore argument space

	testl	%eax, %eax

	jnz	2f



	movl	8(%ebp), %ecx			// image_handle

	movl	12(%ebp), %edx			// sys_table

	movl	-4(%ebp), %esi			// loaded_image

	movl	LI32_image_base(%esi), %esi	// loaded_image->image_base

	leal	(startup_32 - 1b)(%ebx), %ebp	// runtime address of startup_32

	/*

	 * We need to set the image_offset variable here since startup_32() will

	 * use it before we get to the 64-bit efi_pe_entry() in C code.

	 */

	subl	%esi, %ebp			// calculate image_offset

	movl	%ebp, (image_offset - 1b)(%ebx)	// save image_offset

	xorl	%esi, %esi

	jmp	efi32_entry			// pass %ecx, %edx, %esi

						// no other registers remain live



2:	popl	%edi				// restore callee-save registers

	popl	%ebx

	leave

	RET

SYM_FUNC_END(efi32_pe_entry)



	.section ".rodata"

	/* EFI loaded image protocol GUID */

	.balign 4

SYM_DATA_START_LOCAL(loaded_image_proto)

	.long	0x5b1b31a1

	.word	0x9562, 0x11d2

	.byte	0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b

SYM_DATA_END(loaded_image_proto)

#endif



#ifdef CONFIG_AMD_MEM_ENCRYPT

	__HEAD