mm: percpu: add codetag reference into pcpuobj_ext

To store codetag for every per-cpu allocation, a codetag reference is
embedded into pcpuobj_ext when CONFIG_MEM_ALLOC_PROFILING=y.  Hooks to use
the newly introduced codetag are added.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kent Overstreet <[email protected]>
Signed-off-by: Suren Baghdasaryan <[email protected]>
Tested-by: Kees Cook <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Alice Ryhl <[email protected]>
Cc: Andreas Hindborg <[email protected]>
Cc: Benno Lossin <[email protected]>
Cc: "Björn Roy Baron" <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Gary Guo <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Pasha Tatashin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Wedson Almeida Filho <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: Kent Overstreet

mm/percpu-internal.h

@@ -36,9 +36,12 @@ struct pcpuobj_ext {
 #ifdef CONFIG_MEMCG_KMEM
 	struct obj_cgroup	*cgroup;
 #endif
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+	union codetag_ref	tag;
+#endif
 };
 
-#ifdef CONFIG_MEMCG_KMEM
+#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MEM_ALLOC_PROFILING)
 #define NEED_PCPUOBJ_EXT
 #endif
 
@@ -86,7 +89,11 @@ struct pcpu_chunk {
 
 static inline bool need_pcpuobj_ext(void)
 {
-	return !mem_cgroup_kmem_disabled();
+	if (IS_ENABLED(CONFIG_MEM_ALLOC_PROFILING))
+		return true;
+	if (!mem_cgroup_kmem_disabled())
+		return true;
+	return false;
 }
 
 extern spinlock_t pcpu_lock;

mm/percpu.c

@@ -1699,6 +1699,32 @@ static void pcpu_memcg_free_hook(struct pcpu_chunk *chunk, int off, size_t size)
 }
 #endif /* CONFIG_MEMCG_KMEM */
 
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+static void pcpu_alloc_tag_alloc_hook(struct pcpu_chunk *chunk, int off,
+				      size_t size)
+{
+	if (mem_alloc_profiling_enabled() && likely(chunk->obj_exts)) {
+		alloc_tag_add(&chunk->obj_exts[off >> PCPU_MIN_ALLOC_SHIFT].tag,
+			      current->alloc_tag, size);
+	}
+}
+
+static void pcpu_alloc_tag_free_hook(struct pcpu_chunk *chunk, int off, size_t size)
+{
+	if (mem_alloc_profiling_enabled() && likely(chunk->obj_exts))
+		alloc_tag_sub(&chunk->obj_exts[off >> PCPU_MIN_ALLOC_SHIFT].tag, size);
+}
+#else
+static void pcpu_alloc_tag_alloc_hook(struct pcpu_chunk *chunk, int off,
+				      size_t size)
+{
+}
+
+static void pcpu_alloc_tag_free_hook(struct pcpu_chunk *chunk, int off, size_t size)
+{
+}
+#endif
+
 /**
  * pcpu_alloc - the percpu allocator
  * @size: size of area to allocate in bytes