Merge 4.15-rc6 into char-misc-next

We want the fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6 files changed, 79 insertions, 17 deletions

diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 1e9c322e973a..f25e1530e064 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -80,6 +80,7 @@ vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
 ifdef CONFIG_X86_64
 	vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/pagetable.o
 	vmlinux-objs-y += $(obj)/mem_encrypt.o
+	vmlinux-objs-y += $(obj)/pgtable_64.o
 endif
 
 $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 20919b4f3133..fc313e29fe2c 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -305,10 +305,18 @@ ENTRY(startup_64)
 	leaq	boot_stack_end(%rbx), %rsp
 
 #ifdef CONFIG_X86_5LEVEL
-	/* Check if 5-level paging has already enabled */
-	movq	%cr4, %rax
-	testl	$X86_CR4_LA57, %eax
-	jnz	lvl5
+	/*
+	 * Check if we need to enable 5-level paging.
+	 * RSI holds real mode data and need to be preserved across
+	 * a function call.
+	 */
+	pushq	%rsi
+	call	l5_paging_required
+	popq	%rsi
+
+	/* If l5_paging_required() returned zero, we're done here. */
+	cmpq	$0, %rax
+	je	lvl5
 
 	/*
 	 * At this point we are in long mode with 4-level paging enabled,
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index b50c42455e25..98761a1576ce 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -169,6 +169,16 @@ void __puthex(unsigned long value)
 	}
 }
 
+static bool l5_supported(void)
+{
+	/* Check if leaf 7 is supported. */
+	if (native_cpuid_eax(0) < 7)
+		return 0;
+
+	/* Check if la57 is supported. */
+	return native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31));
+}
+
 #if CONFIG_X86_NEED_RELOCS
 static void handle_relocations(void *output, unsigned long output_len,
 			       unsigned long virt_addr)
@@ -362,6 +372,12 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
 	console_init();
 	debug_putstr("early console in extract_kernel\n");
 
+	if (IS_ENABLED(CONFIG_X86_5LEVEL) && !l5_supported()) {
+		error("This linux kernel as configured requires 5-level paging\n"
+			"This CPU does not support the required 'cr4.la57' feature\n"
+			"Unable to boot - please use a kernel appropriate for your CPU\n");
+	}
+
 	free_mem_ptr     = heap;	/* Heap */
 	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
 
diff --git a/arch/x86/boot/compressed/pagetable.c b/arch/x86/boot/compressed/pagetable.c
index d5364ca2e3f9..b5e5e02f8cde 100644
--- a/arch/x86/boot/compressed/pagetable.c
+++ b/arch/x86/boot/compressed/pagetable.c
@@ -23,6 +23,9 @@
  */
 #undef CONFIG_AMD_MEM_ENCRYPT
 
+/* No PAGE_TABLE_ISOLATION support needed either: */
+#undef CONFIG_PAGE_TABLE_ISOLATION
+
 #include "misc.h"
 
 /* These actually do the work of building the kernel identity maps. */
diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c
new file mode 100644
index 000000000000..b4469a37e9a1
--- /dev/null
+++ b/arch/x86/boot/compressed/pgtable_64.c
@@ -0,0 +1,28 @@
+#include <asm/processor.h>
+
+/*
+ * __force_order is used by special_insns.h asm code to force instruction
+ * serialization.
+ *
+ * It is not referenced from the code, but GCC < 5 with -fPIE would fail
+ * due to an undefined symbol. Define it to make these ancient GCCs work.
+ */
+unsigned long __force_order;
+
+int l5_paging_required(void)
+{
+	/* Check if leaf 7 is supported. */
+
+	if (native_cpuid_eax(0) < 7)
+		return 0;
+
+	/* Check if la57 is supported. */
+	if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))))
+		return 0;
+
+	/* Check if 5-level paging has already been enabled. */
+	if (native_read_cr4() & X86_CR4_LA57)
+		return 0;
+
+	return 1;
+}
diff --git a/arch/x86/boot/genimage.sh b/arch/x86/boot/genimage.sh
index 49f4970f693b..6a10d52a4145 100644
--- a/arch/x86/boot/genimage.sh
+++ b/arch/x86/boot/genimage.sh
@@ -44,9 +44,9 @@ FDINITRD=$6
 
 # Make sure the files actually exist
 verify "$FBZIMAGE"
-verify "$MTOOLSRC"
 
 genbzdisk() {
+	verify "$MTOOLSRC"
 	mformat a:
 	syslinux $FIMAGE
 	echo "$KCMDLINE" | mcopy - a:syslinux.cfg
@@ -57,6 +57,7 @@ genbzdisk() {
 }
 
 genfdimage144() {
+	verify "$MTOOLSRC"
 	dd if=/dev/zero of=$FIMAGE bs=1024 count=1440 2> /dev/null
 	mformat v:
 	syslinux $FIMAGE
@@ -68,6 +69,7 @@ genfdimage144() {
 }
 
 genfdimage288() {
+	verify "$MTOOLSRC"
 	dd if=/dev/zero of=$FIMAGE bs=1024 count=2880 2> /dev/null
 	mformat w:
 	syslinux $FIMAGE
@@ -78,39 +80,43 @@ genfdimage288() {
 	mcopy $FBZIMAGE w:linux
 }
 
-genisoimage() {
+geniso() {
 	tmp_dir=`dirname $FIMAGE`/isoimage
 	rm -rf $tmp_dir
 	mkdir $tmp_dir
-	for i in lib lib64 share end ; do
+	for i in lib lib64 share ; do
 		for j in syslinux ISOLINUX ; do
 			if [ -f /usr/$i/$j/isolinux.bin ] ; then
 				isolinux=/usr/$i/$j/isolinux.bin
-				cp $isolinux $tmp_dir
 			fi
 		done
 		for j in syslinux syslinux/modules/bios ; do
 			if [ -f /usr/$i/$j/ldlinux.c32 ]; then
 				ldlinux=/usr/$i/$j/ldlinux.c32
-				cp $ldlinux $tmp_dir
 			fi
 		done
 		if [ -n "$isolinux" -a -n "$ldlinux" ] ; then
 			break
 		fi
-		if [ $i = end -a -z "$isolinux" ] ; then
-			echo 'Need an isolinux.bin file, please install syslinux/isolinux.'
-			exit 1
-		fi
 	done
+	if [ -z "$isolinux" ] ; then
+		echo 'Need an isolinux.bin file, please install syslinux/isolinux.'
+		exit 1
+	fi
+	if [ -z "$ldlinux" ] ; then
+		echo 'Need an ldlinux.c32 file, please install syslinux/isolinux.'
+		exit 1
+	fi
+	cp $isolinux $tmp_dir
+	cp $ldlinux $tmp_dir
 	cp $FBZIMAGE $tmp_dir/linux
 	echo "$KCMDLINE" > $tmp_dir/isolinux.cfg
 	if [ -f "$FDINITRD" ] ; then
 		cp "$FDINITRD" $tmp_dir/initrd.img
 	fi
-	mkisofs -J -r -input-charset=utf-8 -quiet -o $FIMAGE -b isolinux.bin \
-		-c boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table \
-		$tmp_dir
+	genisoimage -J -r -input-charset=utf-8 -quiet -o $FIMAGE \
+		-b isolinux.bin -c boot.cat -no-emul-boot -boot-load-size 4 \
+		-boot-info-table $tmp_dir
 	isohybrid $FIMAGE 2>/dev/null || true
 	rm -rf $tmp_dir
 }
@@ -119,6 +125,6 @@ case $1 in
 	bzdisk)     genbzdisk;;
 	fdimage144) genfdimage144;;
 	fdimage288) genfdimage288;;
-	isoimage)   genisoimage;;
+	isoimage)   geniso;;
 	*)          echo 'Unknown image format'; exit 1;
 esac