fixup! lib: add allocation tagging support for memory allocation profilingcodetags_v1

 - fix the warning on module unload
 - add a show_mem() hook

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

3 files changed, 59 insertions, 6 deletions

diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h
index d7551b0b386c..27badfa7993b 100644
--- a/include/linux/alloc_tag.h
+++ b/include/linux/alloc_tag.h
@@ -24,6 +24,8 @@ struct alloc_tag {
 
 #ifdef CONFIG_MEM_ALLOC_PROFILING
 
+void alloc_tags_show_mem_report(struct seq_buf *s);
+
 static inline struct alloc_tag *ctc_to_alloc_tag(struct codetag_with_ctx *ctc)
 {
 	return container_of(ctc, struct alloc_tag, ctc);
diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index adf8b5da18db..b40684e12416 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -13,6 +13,8 @@
 
 #define STACK_BUF_SIZE 1024
 
+static struct codetag_type *alloc_tag_cttype;
+
 DEFINE_STATIC_KEY_TRUE(mem_alloc_profiling_key);
 
 /*
@@ -133,6 +135,43 @@ static ssize_t allocations_file_read(struct file *file, char __user *ubuf,
 	return err ? : buf.ret;
 }
 
+void alloc_tags_show_mem_report(struct seq_buf *s)
+{
+	struct codetag_iterator iter;
+	struct codetag *ct;
+	struct {
+		struct codetag		*tag;
+		size_t			bytes;
+	} tags[10], n;
+	unsigned i, nr = 0;
+
+	codetag_init_iter(&iter, alloc_tag_cttype);
+
+	codetag_lock_module_list(alloc_tag_cttype, true);
+	while ((ct = codetag_next_ct(&iter))) {
+		n.tag	= ct;
+		n.bytes = lazy_percpu_counter_read(&ct_to_alloc_tag(ct)->bytes_allocated);
+
+		for (i = 0; i < nr; i++)
+			if (n.bytes > tags[i].bytes)
+				break;
+
+		if (i < ARRAY_SIZE(tags)) {
+			nr -= nr == ARRAY_SIZE(tags);
+			memmove(&tags[i + 1],
+				&tags[i],
+				sizeof(tags[0]) * (nr - i));
+			nr++;
+			tags[i] = n;
+		}
+	}
+
+	for (i = 0; i < nr; i++)
+		alloc_tag_to_text(s, tags[i].tag);
+
+	codetag_lock_module_list(alloc_tag_cttype, false);
+}
+
 static const struct file_operations allocations_file_ops = {
 	.owner	= THIS_MODULE,
 	.open	= allocations_file_open,
@@ -376,7 +415,7 @@ static void alloc_tag_module_unload(struct codetag_type *cttype, struct codetag_
 		size_t bytes = lazy_percpu_counter_read(&tag->bytes_allocated);
 
 		if (!WARN(bytes, "%s:%u module %s func:%s has %zu allocated at module unload",
-			  ct->filename, ct->lineno, ct->modname, ct->function))
+			  ct->filename, ct->lineno, ct->modname, ct->function, bytes))
 			lazy_percpu_counter_exit(&tag->bytes_allocated);
 	}
 }
@@ -399,7 +438,6 @@ EXPORT_SYMBOL(page_alloc_tagging_ops);
 
 static int __init alloc_tag_init(void)
 {
-	struct codetag_type *cttype;
 	const struct codetag_type_desc desc = {
 		.section	= "alloc_tags",
 		.tag_size	= sizeof(struct alloc_tag),
@@ -407,10 +445,10 @@ static int __init alloc_tag_init(void)
 		.free_ctx	= alloc_tag_ops_free_ctx,
 	};
 
-	cttype = codetag_register_type(&desc);
-	if (IS_ERR_OR_NULL(cttype))
-		return PTR_ERR(cttype);
+	alloc_tag_cttype = codetag_register_type(&desc);
+	if (IS_ERR_OR_NULL(alloc_tag_cttype))
+		return PTR_ERR(alloc_tag_cttype);
 
-	return dbgfs_init(cttype);
+	return dbgfs_init(alloc_tag_cttype);
 }
 module_init(alloc_tag_init);
diff --git a/lib/show_mem.c b/lib/show_mem.c
index 0d7585cde2a6..382dc57db82a 100644
--- a/lib/show_mem.c
+++ b/lib/show_mem.c
@@ -7,6 +7,7 @@
 
 #include <linux/mm.h>
 #include <linux/cma.h>
+#include <linux/seq_buf.h>
 
 void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx)
 {
@@ -41,4 +42,16 @@ void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx)
 #ifdef CONFIG_MEMORY_FAILURE
 	printk("%lu pages hwpoisoned\n", atomic_long_read(&num_poisoned_pages));
 #endif
+	if (IS_ENABLED(CONFIG_MEM_ALLOC_PROFILING)) {
+		struct seq_buf s;
+		char *buf = kmalloc(4096, GFP_ATOMIC);
+
+		if (buf) {
+			printk("Memory allocations:\n");
+			seq_buf_init(&s, buf, 4096);
+			alloc_tags_show_mem_report(&s);
+			printk("%s", buf);
+			kfree(buf);
+		}
+	}
 }