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)