The patch titled
Subject: mm, slub: change run-time assertion in kmalloc_index() to compile-time
has been removed from the -mm tree. Its filename was
mm-slub-change-run-time-assertion-in-kmalloc_index-to-compile-time.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
Subject: mm, slub: change run-time assertion in kmalloc_index() to compile-time
Currently when size is not supported by kmalloc_index, compiler will
generate a run-time BUG() while compile-time error is also possible, and
better. So change BUG to BUILD_BUG_ON_MSG to make compile-time check
possible.
Also remove code that allocates more than 32MB because current
implementation supports only up to 32MB.
[42.hyeyoo@xxxxxxxxx: fix support for clang 10]
Link: https://lkml.kernel.org/r/20210518181247.GA10062@hyeyoo
[vbabka@xxxxxxx: fix false-positive assert in kernel/bpf/local_storage.c]
Link: https://lkml.kernel.org/r/bea97388-01df-8eac-091b-a3c89b4a4a09@suse.czLink: https://lkml.kernel.org/r/20210511173448.GA54466@hyeyoo
[elver@xxxxxxxxxx: kfence fix]
Link: https://lkml.kernel.org/r/20210512195227.245000695c9014242e9a00e5@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/slab.h | 17 ++++++++++++++---
mm/kfence/kfence_test.c | 5 +++--
mm/slab_common.c | 7 +++----
3 files changed, 20 insertions(+), 9 deletions(-)
--- a/include/linux/slab.h~mm-slub-change-run-time-assertion-in-kmalloc_index-to-compile-time
+++ a/include/linux/slab.h
@@ -346,8 +346,14 @@ static __always_inline enum kmalloc_cach
* 1 = 65 .. 96 bytes
* 2 = 129 .. 192 bytes
* n = 2^(n-1)+1 .. 2^n
+ *
+ * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized;
+ * typical usage is via kmalloc_index() and therefore evaluated at compile-time.
+ * Callers where !size_is_constant should only be test modules, where runtime
+ * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab().
*/
-static __always_inline unsigned int kmalloc_index(size_t size)
+static __always_inline unsigned int __kmalloc_index(size_t size,
+ bool size_is_constant)
{
if (!size)
return 0;
@@ -382,12 +388,17 @@ static __always_inline unsigned int kmal
if (size <= 8 * 1024 * 1024) return 23;
if (size <= 16 * 1024 * 1024) return 24;
if (size <= 32 * 1024 * 1024) return 25;
- if (size <= 64 * 1024 * 1024) return 26;
- BUG();
+
+ if ((IS_ENABLED(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 110000)
+ && !IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
+ BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
+ else
+ BUG();
/* Will never be reached. Needed because the compiler may complain */
return -1;
}
+#define kmalloc_index(s) __kmalloc_index(s, true)
#endif /* !CONFIG_SLOB */
void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
--- a/mm/kfence/kfence_test.c~mm-slub-change-run-time-assertion-in-kmalloc_index-to-compile-time
+++ a/mm/kfence/kfence_test.c
@@ -197,7 +197,7 @@ static void test_cache_destroy(void)
static inline size_t kmalloc_cache_alignment(size_t size)
{
- return kmalloc_caches[kmalloc_type(GFP_KERNEL)][kmalloc_index(size)]->align;
+ return kmalloc_caches[kmalloc_type(GFP_KERNEL)][__kmalloc_index(size, false)]->align;
}
/* Must always inline to match stack trace against caller. */
@@ -267,7 +267,8 @@ static void *test_alloc(struct kunit *te
if (is_kfence_address(alloc)) {
struct page *page = virt_to_head_page(alloc);
- struct kmem_cache *s = test_cache ?: kmalloc_caches[kmalloc_type(GFP_KERNEL)][kmalloc_index(size)];
+ struct kmem_cache *s = test_cache ?:
+ kmalloc_caches[kmalloc_type(GFP_KERNEL)][__kmalloc_index(size, false)];
/*
* Verify that various helpers return the right values
--- a/mm/slab_common.c~mm-slub-change-run-time-assertion-in-kmalloc_index-to-compile-time
+++ a/mm/slab_common.c
@@ -754,8 +754,8 @@ struct kmem_cache *kmalloc_slab(size_t s
/*
* kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
- * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
- * kmalloc-67108864.
+ * kmalloc_index() supports up to 2^25=32MB, so the final entry of the table is
+ * kmalloc-32M.
*/
const struct kmalloc_info_struct kmalloc_info[] __initconst = {
INIT_KMALLOC_INFO(0, 0),
@@ -783,8 +783,7 @@ const struct kmalloc_info_struct kmalloc
INIT_KMALLOC_INFO(4194304, 4M),
INIT_KMALLOC_INFO(8388608, 8M),
INIT_KMALLOC_INFO(16777216, 16M),
- INIT_KMALLOC_INFO(33554432, 32M),
- INIT_KMALLOC_INFO(67108864, 64M)
+ INIT_KMALLOC_INFO(33554432, 32M)
};
/*
_
Patches currently in -mm which might be from 42.hyeyoo@xxxxxxxxx are
