mm: kmemleak: scan .data.ro_after_init
Limit the number of kmemleak false positives by including
.data.ro_after_init in memory scanning. To achieve this we need to add
symbols for start and end of the section to the linker scripts.
The problem was been uncovered by commit 56989f6d8568 ("genetlink: mark
families as __ro_after_init").
Link: http://lkml.kernel.org/r/1478274173-15218-1-git-send-email-jakub.kicinski@netronome.com
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index 000e6e91..3667d20 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -62,9 +62,11 @@
. = 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 af0254c..4df64a1 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -14,6 +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
* [__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
@@ -31,6 +33,7 @@
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 _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 3074796..31e1d63 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -259,7 +259,10 @@
* own by defining an empty RO_AFTER_INIT_DATA.
*/
#ifndef RO_AFTER_INIT_DATA
-#define RO_AFTER_INIT_DATA *(.data..ro_after_init)
+#define RO_AFTER_INIT_DATA \
+ __start_data_ro_after_init = .; \
+ *(.data..ro_after_init) \
+ __end_data_ro_after_init = .;
#endif
/*
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index e5355a5..d1380ed 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1414,6 +1414,7 @@
/* 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);
#ifdef CONFIG_SMP
/* per-cpu sections scanning */