From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 4 Dec 2017 15:07:46 +0100
Subject: x86/entry: Align entry text section to PMD boundary
Git-commit: 2f7412ba9c6af5ab16bdbb4a3fdb1dcd2b4fd3c2
Patch-mainline: v4.15-rc6
References: bsc#1068032 CVE-2017-5754

The (irq)entry text must be visible in the user space page tables. To allow
simple PMD based sharing, make the entry text PMD aligned.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kernel/vmlinux.lds.S |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -60,11 +60,17 @@ jiffies_64 = jiffies;
 		. = ALIGN(HPAGE_SIZE);				\
 		__end_rodata_hpage_align = .;
 
+#define ALIGN_ENTRY_TEXT_BEGIN	. = ALIGN(PMD_SIZE);
+#define ALIGN_ENTRY_TEXT_END	. = ALIGN(PMD_SIZE);
+
 #else
 
 #define X64_ALIGN_RODATA_BEGIN
 #define X64_ALIGN_RODATA_END
 
+#define ALIGN_ENTRY_TEXT_BEGIN
+#define ALIGN_ENTRY_TEXT_END
+
 #endif
 
 PHDRS {
@@ -101,8 +107,10 @@ SECTIONS
 		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
+		ALIGN_ENTRY_TEXT_BEGIN
 		ENTRY_TEXT
 		IRQENTRY_TEXT
+		ALIGN_ENTRY_TEXT_END
 		SOFTIRQENTRY_TEXT
 		*(.fixup)
 		*(.gnu.warning)