linux-kernel - [GIT PULL] x86/boot changes for v4.10

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Date:   Mon, 12 Dec 2016 10:31:50 +0100
From:   Ingo Molnar <mingo@...nel.org>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Peter Zijlstra <a.p.zijlstra@...llo.nl>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: [GIT PULL] x86/boot changes for v4.10

Linus,

Please pull the latest x86-boot-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-boot-for-linus

   # HEAD: 6248f4567442081994ad61c63bd9870e147983e0 x86/boot/64: Optimize fixmap page fixup

Misc cleanups/simplifications by Borislav Petkov, Paul Bolle and Wei Yang.

 Thanks,

	Ingo

------------------>
Borislav Petkov (1):
      x86/boot/64: Optimize fixmap page fixup

Paul Bolle (1):
      x86/boot/build: Remove always empty $(USERINCLUDE)

Wei Yang (1):
      x86/boot: Simplify the GDTR calculation assembly code a bit


 arch/x86/boot/Makefile             | 2 +-
 arch/x86/boot/compressed/head_64.S | 3 +--
 arch/x86/kernel/head_64.S          | 8 ++++++--
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index 12ea8f8384f4..0d810fb15eac 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -65,7 +65,7 @@ clean-files += cpustr.h
 
 # ---------------------------------------------------------------------------
 
-KBUILD_CFLAGS	:= $(USERINCLUDE) $(REALMODE_CFLAGS) -D_SETUP
+KBUILD_CFLAGS	:= $(REALMODE_CFLAGS) -D_SETUP
 KBUILD_AFLAGS	:= $(KBUILD_CFLAGS) -D__ASSEMBLY__
 GCOV_PROFILE := n
 UBSAN_SANITIZE := n
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index efdfba21a5b2..4d85e600db78 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -119,8 +119,7 @@ ENTRY(startup_32)
  */
 
 	/* Load new GDT with the 64bit segments using 32bit descriptor */
-	leal	gdt(%ebp), %eax
-	movl	%eax, gdt+2(%ebp)
+	addl	%ebp, gdt+2(%ebp)
 	lgdt	gdt(%ebp)
 
 	/* Enable PAE mode */
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index b4421cc191b0..a4a814ffb8ca 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -147,6 +147,9 @@ L3_START_KERNEL = pud_index(__START_KERNEL_map)
 	decl	%ecx
 	jnz	1b
 
+	test %rbp, %rbp
+	jz .Lskip_fixup
+
 	/*
 	 * Fixup the kernel text+data virtual addresses. Note that
 	 * we might write invalid pmds, when the kernel is relocated
@@ -154,9 +157,9 @@ L3_START_KERNEL = pud_index(__START_KERNEL_map)
 	 * beyond _end.
 	 */
 	leaq	level2_kernel_pgt(%rip), %rdi
-	leaq	4096(%rdi), %r8
+	leaq	PAGE_SIZE(%rdi), %r8
 	/* See if it is a valid page table entry */
-1:	testb	$1, 0(%rdi)
+1:	testb	$_PAGE_PRESENT, 0(%rdi)
 	jz	2f
 	addq	%rbp, 0(%rdi)
 	/* Go to the next page */
@@ -167,6 +170,7 @@ L3_START_KERNEL = pud_index(__START_KERNEL_map)
 	/* Fixup phys_base */
 	addq	%rbp, phys_base(%rip)
 
+.Lskip_fixup:
 	movq	$(early_level4_pgt - __START_KERNEL_map), %rax
 	jmp 1f
 ENTRY(secondary_startup_64)