On Thu, Oct 29, 2020 at 03:29:15PM +0100, Uros Bizjak wrote: > Use TEST %reg,%reg which sets the zero flag in the same way > as CMP $0,%reg, but the encoding uses one byte less. > > Cc: Thomas Gleixner <t...@linutronix.de> > Cc: Ingo Molnar <mi...@redhat.com> > Cc: Borislav Petkov <b...@alien8.de> > Cc: "H. Peter Anvin" <h...@zytor.com> > Signed-off-by: Uros Bizjak <ubiz...@gmail.com>
Please use x86/boot/64 or x86/boot/compressed/64 for the commit subject. x86/entry is used for syscall/exception handler entries in the main kernel. > --- > arch/x86/boot/compressed/head_64.S | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/boot/compressed/head_64.S > b/arch/x86/boot/compressed/head_64.S > index 017de6cc87dc..e94874f4bbc1 100644 > --- a/arch/x86/boot/compressed/head_64.S > +++ b/arch/x86/boot/compressed/head_64.S > @@ -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 > 1: > -- > 2.26.2 >
