Patch "vmlinux.lds: account for destructor sections" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    vmlinux.lds: account for destructor sections

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     vmlinux.lds-account-for-destructor-sections.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From e41f501d391265ff568f3e49d6128cc30856a36f Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Thu, 14 Jul 2016 12:07:29 -0700
Subject: vmlinux.lds: account for destructor sections

From: Dmitry Vyukov <dvyukov@google.com>

commit e41f501d391265ff568f3e49d6128cc30856a36f upstream.

If CONFIG_KASAN is enabled and gcc is configured with
--disable-initfini-array and/or gold linker is used, gcc emits
.ctors/.dtors and .text.startup/.text.exit sections instead of
.init_array/.fini_array.  .dtors section is not explicitly accounted in
the linker script and messes vvar/percpu layout.

We want:
  ffffffff822bfd80 D _edata
  ffffffff822c0000 D __vvar_beginning_hack
  ffffffff822c0000 A __vvar_page
  ffffffff822c0080 0000000000000098 D vsyscall_gtod_data
  ffffffff822c1000 A __init_begin
  ffffffff822c1000 D init_per_cpu__irq_stack_union
  ffffffff822c1000 A __per_cpu_load
  ffffffff822d3000 D init_per_cpu__gdt_page

We got:
  ffffffff8279a600 D _edata
  ffffffff8279b000 A __vvar_page
  ffffffff8279c000 A __init_begin
  ffffffff8279c000 D init_per_cpu__irq_stack_union
  ffffffff8279c000 A __per_cpu_load
  ffffffff8279e000 D __vvar_beginning_hack
  ffffffff8279e080 0000000000000098 D vsyscall_gtod_data
  ffffffff827ae000 D init_per_cpu__gdt_page

This happens because __vvar_page and .vvar get different addresses in
arch/x86/kernel/vmlinux.lds.S:

	. = ALIGN(PAGE_SIZE);
	__vvar_page = .;

	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
		/* work around gold bug 13023 */
		__vvar_beginning_hack = .;

Discard .dtors/.fini_array/.text.exit, since we don't call dtors.
Merge .text.startup into init text.

Link: http://lkml.kernel.org/r/1467386363-120030-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 include/asm-generic/vmlinux.lds.h |    4 ++++
 1 file changed, 4 insertions(+)

--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -531,15 +531,19 @@
 
 #define INIT_TEXT							\
 	*(.init.text)							\
+	*(.text.startup)						\
 	MEM_DISCARD(init.text)
 
 #define EXIT_DATA							\
 	*(.exit.data)							\
+	*(.fini_array)							\
+	*(.dtors)							\
 	MEM_DISCARD(exit.data)						\
 	MEM_DISCARD(exit.rodata)
 
 #define EXIT_TEXT							\
 	*(.exit.text)							\
+	*(.text.exit)							\
 	MEM_DISCARD(exit.text)
 
 #define EXIT_CALL							\


Patches currently in stable-queue which might be from dvyukov@google.com are

queue-4.4/vmlinux.lds-account-for-destructor-sections.patch