The patch titled
Subject: kmemleak: account for tagged pointers when calculating pointer range
has been added to the -mm tree. Its filename is
kmemleak-account-for-tagged-pointers-when-calculating-pointer-range.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kmemleak-account-for-tagged-pointers-when-calculating-pointer-range.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kmemleak-account-for-tagged-pointers-when-calculating-pointer-range.patch
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kmemleak: account for tagged pointers when calculating pointer range
kmemleak keeps two global variables, min_addr and max_addr, which store
the range of valid (encountered by kmemleak) pointer values, which it
later uses to speed up pointer lookup when scanning blocks.
With tagged pointers this range will get bigger than it needs to be. This
patch makes kmemleak untag pointers before saving them to min_addr and
max_addr and when performing a lookup.
Link: http://lkml.kernel.org/r/df99854703d906040a7a898ac892167e3ffe90d9.1549921721.git.andreyknvl@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgeniy Stepanov <eugenis@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Kostya Serebryany <kcc@xxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Qian Cai <cai@xxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/kmemleak.c~kmemleak-account-for-tagged-pointers-when-calculating-pointer-range
+++ a/mm/kmemleak.c
@@ -574,6 +574,7 @@ static struct kmemleak_object *create_ob
unsigned long flags;
struct kmemleak_object *object, *parent;
struct rb_node **link, *rb_parent;
+ unsigned long untagged_ptr;
object = kmem_cache_alloc(object_cache, gfp_kmemleak_mask(gfp));
if (!object) {
@@ -619,8 +620,9 @@ static struct kmemleak_object *create_ob
write_lock_irqsave(&kmemleak_lock, flags);
- min_addr = min(min_addr, ptr);
- max_addr = max(max_addr, ptr + size);
+ untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr);
+ min_addr = min(min_addr, untagged_ptr);
+ max_addr = max(max_addr, untagged_ptr + size);
link = &object_tree_root.rb_node;
rb_parent = NULL;
while (*link) {
@@ -1333,6 +1335,7 @@ static void scan_block(void *_start, voi
unsigned long *start = PTR_ALIGN(_start, BYTES_PER_POINTER);
unsigned long *end = _end - (BYTES_PER_POINTER - 1);
unsigned long flags;
+ unsigned long untagged_ptr;
read_lock_irqsave(&kmemleak_lock, flags);
for (ptr = start; ptr < end; ptr++) {
@@ -1347,7 +1350,8 @@ static void scan_block(void *_start, voi
pointer = *ptr;
kasan_enable_current();
- if (pointer < min_addr || pointer >= max_addr)
+ untagged_ptr = (unsigned long)kasan_reset_tag((void *)pointer);
+ if (untagged_ptr < min_addr || untagged_ptr >= max_addr)
continue;
/*
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-fix-assigning-tags-twice.patch
kasan-kmemleak-pass-tagged-pointers-to-kmemleak.patch
kmemleak-account-for-tagged-pointers-when-calculating-pointer-range.patch
kasan-slub-move-kasan_poison_slab-hook-before-page_address.patch
kasan-slub-fix-conflicts-with-config_slab_freelist_hardened.patch
