[PATCH] mm: fix section name for .data..ro_after_init

Kees Cook
2017-03-27T19:22:16Z

A section name for .data..ro_after_init was added by both:

commit d07a980c1b8d ("s390: add proper __ro_after_init support")

and

commit d7c19b066dcf ("mm: kmemleak: scan .data.ro_after_init")

The latter adds incorrect wrapping around the existing s390 section,
and came later. I'd prefer the s390 naming, so this moves the
s390-specific name up to the asm-generic/sections.h and renames the
section as used by kmemleak (and in the future, kernel/extable.c).

Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Eddie Kovsky <ewk@edkovsky.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/s390/include/asm/sections.h | 1 -
arch/s390/kernel/vmlinux.lds.S | 2 --
include/asm-generic/sections.h | 6 +++---
include/asm-generic/vmlinux.lds.h | 4 ++--
mm/kmemleak.c | 2 +-
5 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/arch/s390/include/asm/sections.h b/arch/s390/include/asm/sections.h
index 5ce29fe100ba..fbd9116eb17b 100644
--- a/arch/s390/include/asm/sections.h
+++ b/arch/s390/include/asm/sections.h
@@ -4,6 +4,5 @@
#include <asm-generic/sections.h>

extern char _eshared[], _ehead[];
-extern char __start_ro_after_init[], __end_ro_after_init[];

#endif
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index 5ccf95396251..72307f108c40 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -63,11 +63,9 @@ SECTIONS

. = ALIGN(PAGE_SIZE);
__start_ro_after_init = .;
- __start_data_ro_after_init = .;
.data..ro_after_init : {
*(.data..ro_after_init)
}
- __end_data_ro_after_init = .;
EXCEPTION_TABLE(16)
. = ALIGN(PAGE_SIZE);
__end_ro_after_init = .;
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 4df64a1fc09e..532372c6cf15 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -14,8 +14,8 @@
* [_sdata, _edata]: contains .data.* sections, may also contain .rodata.*
* and/or .init.* sections.
* [__start_rodata, __end_rodata]: contains .rodata.* sections
- * [__start_data_ro_after_init, __end_data_ro_after_init]:
- * contains data.ro_after_init section
+ * [__start_ro_after_init, __end_ro_after_init]:
+ * contains .data..ro_after_init section
* [__init_begin, __init_end]: contains .init.* sections, but .init.text.*
* may be out of this range on some architectures.
* [_sinittext, _einittext]: contains .init.text.* sections
@@ -33,7 +33,7 @@ extern char _data[], _sdata[], _edata[];
extern char __bss_start[], __bss_stop[];
extern char __init_begin[], __init_end[];
extern char _sinittext[], _einittext[];
-extern char __start_data_ro_after_init[], __end_data_ro_after_init[];
+extern char __start_ro_after_init[], __end_ro_after_init[];
extern char _end[];
extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
extern char __kprobes_text_start[], __kprobes_text_end[];
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 0968d13b3885..f9f21e2c59f3 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -260,9 +260,9 @@
*/
#ifndef RO_AFTER_INIT_DATA
#define RO_AFTER_INIT_DATA \
- __start_data_ro_after_init = .; \
+ __start_ro_after_init = .; \
*(.data..ro_after_init) \
- __end_data_ro_after_init = .;
+ __end_ro_after_init = .;
#endif

/*
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 26c874e90b12..20036d4f9f13 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1416,7 +1416,7 @@ static void kmemleak_scan(void)
/* data/bss scanning */
scan_large_block(_sdata, _edata);
scan_large_block(__bss_start, __bss_stop);
- scan_large_block(__start_data_ro_after_init, __end_data_ro_after_init);
+ scan_large_block(__start_ro_after_init, __end_ro_after_init);

#ifdef CONFIG_SMP
/* per-cpu sections scanning */
--
2.7.4

--
Kees Cook
Pixel Security