The patch titled
Subject: kasan: disable memory hotplug
has been added to the -mm tree. Its filename is
kasan-disable-memory-hotplug.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kasan-disable-memory-hotplug.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kasan-disable-memory-hotplug.patch
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------------------------------------------------------
From: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
Subject: kasan: disable memory hotplug
Currently memory hotplug won't work with KASan. As we don't have shadow
for hotplugged memory, kernel will crash on the first access to it. To
make this work we will need to allocate shadow for new memory.
At some future point proper memory hotplug support will be implemented.
Until then, print a warning at startup and disable memory hot-add.
Signed-off-by: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Konstantin Serebryany <kcc@xxxxxxxxxx>
Cc: Dmitry Chernenkov <dmitryc@xxxxxxxxxx>
Cc: Andrey Konovalov <adech.fo@xxxxxxxxx>
Cc: Yuri Gribov <tetra2005@xxxxxxxxx>
Cc: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
Cc: Sasha Levin <sasha.levin@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/kasan.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff -puN mm/kasan/kasan.c~kasan-disable-memory-hotplug mm/kasan/kasan.c
--- a/mm/kasan/kasan.c~kasan-disable-memory-hotplug
+++ a/mm/kasan/kasan.c
@@ -20,6 +20,7 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
+#include <linux/memory.h>
#include <linux/mm.h>
#include <linux/printk.h>
#include <linux/sched.h>
@@ -300,3 +301,23 @@ EXPORT_SYMBOL(__asan_storeN_noabort);
/* to shut up compiler complaints */
void __asan_handle_no_return(void) {}
EXPORT_SYMBOL(__asan_handle_no_return);
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static int kasan_mem_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ return (action == MEM_GOING_ONLINE) ? NOTIFY_BAD : NOTIFY_OK;
+}
+
+static int __init kasan_memhotplug_init(void)
+{
+ pr_err("WARNING: KASan doesn't support memory hot-add\n");
+ pr_err("Memory hot-add will be disabled\n");
+
+ hotplug_memory_notifier(kasan_mem_notifier, 0);
+
+ return 0;
+}
+
+module_init(kasan_memhotplug_init);
+#endif
_
Patches currently in -mm which might be from a.ryabinin@xxxxxxxxxxx are
compiler-introduce-__aliassymbol-shortcut.patch
add-kernel-address-sanitizer-infrastructure.patch
kasan-disable-memory-hotplug.patch
x86_64-add-kasan-support.patch
mm-page_alloc-add-kasan-hooks-on-alloc-and-free-paths.patch
mm-slub-introduce-virt_to_obj-function.patch
mm-slub-share-object_err-function.patch
mm-slub-introduce-metadata_access_enable-metadata_access_disable.patch
mm-slub-add-kernel-address-sanitizer-support-for-slub-allocator.patch
fs-dcache-manually-unpoison-dname-after-allocation-to-shut-up-kasans-reports.patch
kmemleak-disable-kasan-instrumentation-for-kmemleak.patch
lib-add-kasan-test-module.patch
x86_64-kasan-add-interceptors-for-memset-memmove-memcpy-functions.patch
kasan-enable-stack-instrumentation.patch
mm-vmalloc-add-flag-preventing-guard-hole-allocation.patch
mm-vmalloc-pass-additional-vm_flags-to-__vmalloc_node_range.patch
kernel-add-support-for-init_array-constructors.patch
module-fix-types-of-device-tables-aliases.patch
kasan-enable-instrumentation-of-global-variables.patch
hugetlb-sysctl-pass-extra1-=-null-rather-then-extra1-=-zero.patch
mm-hugetlb-fix-type-of-hugetlb_treat_as_movable-variable.patch
proc-pagemap-walk-page-tables-under-pte-lock.patch
linux-next.patch
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