Commit 30c9ca16 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Borislav Petkov
Browse files

x86/boot/compressed: Adhere to calling convention in get_sev_encryption_bit() 



Make get_sev_encryption_bit() follow the ordinary i386 calling
convention, and only call it if CONFIG_AMD_MEM_ENCRYPT is actually
enabled. This clarifies the calling code, and makes it more
maintainable.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221122161017.2426828-16-ardb@kernel.org
parent 9d7eaae6

arch/x86/boot/compressed/head_64.S

+3 −2
Original line number Diff line number Diff line
@@ -180,12 +180,13 @@ SYM_FUNC_START(startup_32) 
  */

	/*

	 * If SEV is active then set the encryption mask in the page tables.

	 * This will insure that when the kernel is copied and decompressed

	 * This will ensure that when the kernel is copied and decompressed

	 * it will be done so encrypted.

	 */

	call	get_sev_encryption_bit

	xorl	%edx, %edx

#ifdef	CONFIG_AMD_MEM_ENCRYPT

	call	get_sev_encryption_bit

	xorl	%edx, %edx

	testl	%eax, %eax

	jz	1f

	subl	$32, %eax	/* Encryption bit is always above bit 31 */

arch/x86/boot/compressed/mem_encrypt.S

+0 −10
Original line number Diff line number Diff line
@@ -18,12 +18,7 @@ 
	.text

	.code32

SYM_FUNC_START(get_sev_encryption_bit)

	xor	%eax, %eax



#ifdef CONFIG_AMD_MEM_ENCRYPT

	push	%ebx

	push	%ecx

	push	%edx



	movl	$0x80000000, %eax	/* CPUID to check the highest leaf */

	cpuid
@@ -54,12 +49,7 @@ SYM_FUNC_START(get_sev_encryption_bit) 
	xor	%eax, %eax



.Lsev_exit:

	pop	%edx

	pop	%ecx

	pop	%ebx



#endif	/* CONFIG_AMD_MEM_ENCRYPT */



	RET

SYM_FUNC_END(get_sev_encryption_bit)