Commit ab09b58e authored by Uros Bizjak's avatar Uros Bizjak Committed by Borislav Petkov
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x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%reg 



Use TEST %reg,%reg which sets the zero flag in the same way as CMP
$0,%reg, but the encoding uses one byte less.

Signed-off-by: default avatarUros Bizjak <ubizjak@gmail.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20201029160258.139216-1-ubizjak@gmail.com
parent 61b39ad9

arch/x86/boot/compressed/head_64.S

+4 −4
Original line number Diff line number Diff line
@@ -241,12 +241,12 @@ SYM_FUNC_START(startup_32) 
	leal	rva(startup_64)(%ebp), %eax

#ifdef CONFIG_EFI_MIXED

	movl	rva(efi32_boot_args)(%ebp), %edi

	cmp	$0, %edi

	testl	%edi, %edi

	jz	1f

	leal	rva(efi64_stub_entry)(%ebp), %eax

	movl	rva(efi32_boot_args+4)(%ebp), %esi

	movl	rva(efi32_boot_args+8)(%ebp), %edx	// saved bootparams pointer

	cmpl	$0, %edx

	testl	%edx, %edx

	jnz	1f

	/*

	 * efi_pe_entry uses MS calling convention, which requires 32 bytes of
@@ -592,7 +592,7 @@ SYM_CODE_START(trampoline_32bit_src) 
	movl	%eax, %cr0



	/* Check what paging mode we want to be in after the trampoline */

	cmpl	$0, %edx

	testl	%edx, %edx

	jz	1f



	/* We want 5-level paging: don't touch CR3 if it already points to 5-level page tables */
@@ -622,7 +622,7 @@ SYM_CODE_START(trampoline_32bit_src) 


	/* Enable PAE and LA57 (if required) paging modes */

	movl	$X86_CR4_PAE, %eax

	cmpl	$0, %edx

	testl	%edx, %edx

	jz	1f

	orl	$X86_CR4_LA57, %eax

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