lkml.org 
[lkml]   [2020]   [Nov]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
Subject[PATCH mm v4 15/19] kasan: simplify assign_tag and set_tag calls
From
set_tag() already ignores the tag for the generic mode, so just call it
as is. Add a check for the generic mode to assign_tag(), and simplify its
call in ____kasan_kmalloc().

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Link: https://linux-review.googlesource.com/id/I18905ca78fb4a3d60e1a34a4ca00247272480438
---
mm/kasan/common.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 1a88e4005181..821678a58ac6 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -234,6 +234,9 @@ void __kasan_poison_object_data(struct kmem_cache *cache, void *object)
static u8 assign_tag(struct kmem_cache *cache, const void *object,
bool init, bool keep_tag)
{
+ if (IS_ENABLED(CONFIG_KASAN_GENERIC))
+ return 0xff;
+
/*
* 1. When an object is kmalloc()'ed, two hooks are called:
* kasan_slab_alloc() and kasan_kmalloc(). We assign the
@@ -276,8 +279,8 @@ void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
__memset(alloc_meta, 0, sizeof(*alloc_meta));
}

- if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS))
- object = set_tag(object, assign_tag(cache, object, true, false));
+ /* Tag is ignored in set_tag() without CONFIG_KASAN_SW/HW_TAGS */
+ object = set_tag(object, assign_tag(cache, object, true, false));

return (void *)object;
}
@@ -364,7 +367,7 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object,
{
unsigned long redzone_start;
unsigned long redzone_end;
- u8 tag = 0xff;
+ u8 tag;

if (gfpflags_allow_blocking(flags))
quarantine_reduce();
@@ -379,9 +382,7 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object,
KASAN_GRANULE_SIZE);
redzone_end = round_up((unsigned long)object + cache->object_size,
KASAN_GRANULE_SIZE);
-
- if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS))
- tag = assign_tag(cache, object, false, keep_tag);
+ tag = assign_tag(cache, object, false, keep_tag);

/* Tag is ignored in set_tag without CONFIG_KASAN_SW/HW_TAGS */
unpoison_range(set_tag(object, tag), size);
--
2.29.2.454.gaff20da3a2-goog
\
 
 \ /
  Last update: 2020-11-23 21:39    [W:0.075 / U:0.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site