From e41f501d391265ff568f3e49d6128cc30856a36f Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Thu, 14 Jul 2016 12:07:29 -0700 Subject: [PATCH] vmlinux.lds: account for destructor sections 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 Reviewed-by: Andrey Ryabinin Cc: [4.0+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/vmlinux.lds.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 6a67ab94b553..081d0f258d4c 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -542,15 +542,19 @@ #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 \ -- 2.20.1