1 files changed, 217 insertions, 0 deletions
diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h
new file mode 100644
index 000000000000..abd24016a900
--- /dev/null
+++ b/include/linux/alloc_tag.h
@@ -0,0 +1,217 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * allocation tagging
+ */
+#ifndef _LINUX_ALLOC_TAG_H
+#define _LINUX_ALLOC_TAG_H
+
+#include <linux/bug.h>
+#include <linux/codetag.h>
+#include <linux/container_of.h>
+#include <linux/preempt.h>
+#include <asm/percpu.h>
+#include <linux/cpumask.h>
+#include <linux/smp.h>
+#include <linux/static_key.h>
+#include <linux/irqflags.h>
+
+struct alloc_tag_counters {
+	u64 bytes;
+	u64 calls;
+};
+
+/*
+ * An instance of this structure is created in a special ELF section at every
+ * allocation callsite. At runtime, the special section is treated as
+ * an array of these. Embedded codetag utilizes codetag framework.
+ */
+struct alloc_tag {
+	struct codetag			ct;
+	struct alloc_tag_counters __percpu	*counters;
+} __aligned(8);
+
+#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
+
+#define CODETAG_EMPTY	((void *)1)
+
+static inline bool is_codetag_empty(union codetag_ref *ref)
+{
+	return ref->ct == CODETAG_EMPTY;
+}
+
+static inline void set_codetag_empty(union codetag_ref *ref)
+{
+	if (ref)
+		ref->ct = CODETAG_EMPTY;
+}
+
+#else /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */
+
+static inline bool is_codetag_empty(union codetag_ref *ref) { return false; }
+static inline void set_codetag_empty(union codetag_ref *ref) {}
+
+#endif /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */
+
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+
+struct codetag_bytes {
+	struct codetag *ct;
+	s64 bytes;
+};
+
+size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep);
+
+static inline struct alloc_tag *ct_to_alloc_tag(struct codetag *ct)
+{
+	return container_of(ct, struct alloc_tag, ct);
+}
+
+#ifdef ARCH_NEEDS_WEAK_PER_CPU
+/*
+ * When percpu variables are required to be defined as weak, static percpu
+ * variables can't be used inside a function (see comments for DECLARE_PER_CPU_SECTION).
+ * Instead we will accound all module allocations to a single counter.
+ */
+DECLARE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag);
+
+#define DEFINE_ALLOC_TAG(_alloc_tag)						\
+	static struct alloc_tag _alloc_tag __used __aligned(8)			\
+	__section("alloc_tags") = {						\
+		.ct = CODE_TAG_INIT,						\
+		.counters = &_shared_alloc_tag };
+
+#else /* ARCH_NEEDS_WEAK_PER_CPU */
+
+#define DEFINE_ALLOC_TAG(_alloc_tag)						\
+	static DEFINE_PER_CPU(struct alloc_tag_counters, _alloc_tag_cntr);	\
+	static struct alloc_tag _alloc_tag __used __aligned(8)			\
+	__section("alloc_tags") = {						\
+		.ct = CODE_TAG_INIT,						\
+		.counters = &_alloc_tag_cntr };
+
+#endif /* ARCH_NEEDS_WEAK_PER_CPU */
+
+DECLARE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
+			mem_alloc_profiling_key);
+
+static inline bool mem_alloc_profiling_enabled(void)
+{
+	return static_branch_maybe(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
+				   &mem_alloc_profiling_key);
+}
+
+static inline struct alloc_tag_counters alloc_tag_read(struct alloc_tag *tag)
+{
+	struct alloc_tag_counters v = { 0, 0 };
+	struct alloc_tag_counters *counter;
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		counter = per_cpu_ptr(tag->counters, cpu);
+		v.bytes += counter->bytes;
+		v.calls += counter->calls;
+	}
+
+	return v;
+}
+
+#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
+static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag)
+{
+	WARN_ONCE(ref && ref->ct,
+		  "alloc_tag was not cleared (got tag for %s:%u)\n",
+		  ref->ct->filename, ref->ct->lineno);
+
+	WARN_ONCE(!tag, "current->alloc_tag not set");
+}
+
+static inline void alloc_tag_sub_check(union codetag_ref *ref)
+{
+	WARN_ONCE(ref && !ref->ct, "alloc_tag was not set\n");
+}
+#else
+static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag) {}
+static inline void alloc_tag_sub_check(union codetag_ref *ref) {}
+#endif
+
+/* Caller should verify both ref and tag to be valid */
+static inline void __alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag)
+{
+	ref->ct = &tag->ct;
+	/*
+	 * We need in increment the call counter every time we have a new
+	 * allocation or when we split a large allocation into smaller ones.
+	 * Each new reference for every sub-allocation needs to increment call
+	 * counter because when we free each part the counter will be decremented.
+	 */
+	this_cpu_inc(tag->counters->calls);
+}
+
+static inline void alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag)
+{
+	alloc_tag_add_check(ref, tag);
+	if (!ref || !tag)
+		return;
+
+	__alloc_tag_ref_set(ref, tag);
+}
+
+static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag, size_t bytes)
+{
+	alloc_tag_add_check(ref, tag);
+	if (!ref || !tag)
+		return;
+
+	__alloc_tag_ref_set(ref, tag);
+	this_cpu_add(tag->counters->bytes, bytes);
+}
+
+static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes)
+{
+	struct alloc_tag *tag;
+
+	alloc_tag_sub_check(ref);
+	if (!ref || !ref->ct)
+		return;
+
+	if (is_codetag_empty(ref)) {
+		ref->ct = NULL;
+		return;
+	}
+
+	tag = ct_to_alloc_tag(ref->ct);
+
+	this_cpu_sub(tag->counters->bytes, bytes);
+	this_cpu_dec(tag->counters->calls);
+
+	ref->ct = NULL;
+}
+
+#define alloc_tag_record(p)	((p) = current->alloc_tag)
+
+#else /* CONFIG_MEM_ALLOC_PROFILING */
+
+#define DEFINE_ALLOC_TAG(_alloc_tag)
+static inline bool mem_alloc_profiling_enabled(void) { return false; }
+static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag,
+				 size_t bytes) {}
+static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes) {}
+#define alloc_tag_record(p)	do {} while (0)
+
+#endif /* CONFIG_MEM_ALLOC_PROFILING */
+
+#define alloc_hooks_tag(_tag, _do_alloc)				\
+({									\
+	struct alloc_tag * __maybe_unused _old = alloc_tag_save(_tag);	\
+	typeof(_do_alloc) _res = _do_alloc;				\
+	alloc_tag_restore(_tag, _old);					\
+	_res;								\
+})
+
+#define alloc_hooks(_do_alloc)						\
+({									\
+	DEFINE_ALLOC_TAG(_alloc_tag);					\
+	alloc_hooks_tag(&_alloc_tag, _do_alloc);			\
+})
+
+#endif /* _LINUX_ALLOC_TAG_H */