x86/entry: Align entry text section to PMD boundary

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 <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Laight <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Eduardo Valentin <[email protected]>
Cc: Greg KH <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: KAGA-KOKO

arch/x86/kernel/vmlinux.lds.S

@@ -61,11 +61,17 @@ 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 {
@@ -102,8 +108,10 @@ SECTIONS
 		CPUIDLE_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT
+		ALIGN_ENTRY_TEXT_BEGIN
 		ENTRY_TEXT
 		IRQENTRY_TEXT
+		ALIGN_ENTRY_TEXT_END
 		SOFTIRQENTRY_TEXT
 		*(.fixup)
 		*(.gnu.warning)