There are few places that call kmem_cache_debug(s) (which tests if any of debug
flags are enabled for a cache) immediatelly followed by a test for a specific
flag. The compiler can probably eliminate the extra check, but we can make the
code nicer by introducing kmem_cache_debug_flags() that works like
kmem_cache_debug() (including the static key check) but tests for specifig
flag(s). The next patches will add more users.
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
mm/slub.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index 24d3e5f832aa..c8e8b4ae2451 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -122,18 +122,28 @@ DEFINE_STATIC_KEY_FALSE(slub_debug_enabled);
#endif
#endif
-static inline int kmem_cache_debug(struct kmem_cache *s)
+/*
+ * Returns true if any of the specified slub_debug flags is enabled for the
+ * cache. Use only for flags parsed by setup_slub_debug() as it also enables
+ * the static key.
+ */
+static inline int kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
{
#ifdef CONFIG_SLUB_DEBUG
if (static_branch_unlikely(&slub_debug_enabled))
- return s->flags & SLAB_DEBUG_FLAGS;
+ return s->flags & flags;
#endif
return 0;
}
+static inline int kmem_cache_debug(struct kmem_cache *s)
+{
+ return kmem_cache_debug_flags(s, SLAB_DEBUG_FLAGS);
+}
+
void *fixup_red_left(struct kmem_cache *s, void *p)
{
- if (kmem_cache_debug(s) && s->flags & SLAB_RED_ZONE)
+ if (kmem_cache_debug_flags(s, SLAB_RED_ZONE))
p += s->red_left_pad;
return p;
@@ -4076,7 +4086,7 @@ void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
offset = (ptr - page_address(page)) % s->size;
/* Adjust for redzone and reject if within the redzone. */
- if (kmem_cache_debug(s) && s->flags & SLAB_RED_ZONE) {
+ if (kmem_cache_debug_flags(s, SLAB_RED_ZONE)) {
if (offset < s->red_left_pad)
usercopy_abort("SLUB object in left red zone",
s->name, to_user, offset, n);
--
2.26.2
