alloc_tag: handle module codetag load errors as module load failures

Failures inside codetag_load_module() are currently ignored.  As a result
an error there would not cause a module load failure and freeing of the
associated resources.  Correct this behavior by propagating the error code
to the caller and handling possible errors.  With this change, error to
allocate percpu counters, which happens at this stage, will not be ignored
and will cause a module load failure and freeing of resources.  With this
change we also do not need to disable memory allocation profiling when
this error happens, instead we fail to load the module.

Link: https://lkml.kernel.org/r/20250521160602.1940771-1-surenb@google.com
Fixes: 10075262888b ("alloc_tag: allocate percpu counters for module tags dynamically")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: Casey Chen <cachen@purestorage.com>
Closes: https://lore.kernel.org/all/20250520231620.15259-1-cachen@purestorage.com/
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: David Wang <00107082@163.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Luis Chamberalin <mcgrof@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2 files changed, 32 insertions, 14 deletions

diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index 45dae7da70e1..d48b80f3f007 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -607,15 +607,16 @@ out:
 	mas_unlock(&mas);
 }
 
-static void load_module(struct module *mod, struct codetag *start, struct codetag *stop)
+static int load_module(struct module *mod, struct codetag *start, struct codetag *stop)
 {
 	/* Allocate module alloc_tag percpu counters */
 	struct alloc_tag *start_tag;
 	struct alloc_tag *stop_tag;
 	struct alloc_tag *tag;
 
+	/* percpu counters for core allocations are already statically allocated */
 	if (!mod)
-		return;
+		return 0;
 
 	start_tag = ct_to_alloc_tag(start);
 	stop_tag = ct_to_alloc_tag(stop);
@@ -627,12 +628,13 @@ static void load_module(struct module *mod, struct codetag *start, struct codeta
 				free_percpu(tag->counters);
 				tag->counters = NULL;
 			}
-			shutdown_mem_profiling(true);
-			pr_err("Failed to allocate memory for allocation tag percpu counters in the module %s. Memory allocation profiling is disabled!\n",
+			pr_err("Failed to allocate memory for allocation tag percpu counters in the module %s\n",
 			       mod->name);
-			break;
+			return -ENOMEM;
 		}
 	}
+
+	return 0;
 }
 
 static void replace_module(struct module *mod, struct module *new_mod)
diff --git a/lib/codetag.c b/lib/codetag.c
index de332e98d6f5..650d54d7e14d 100644
--- a/lib/codetag.c
+++ b/lib/codetag.c
@@ -167,6 +167,7 @@ static int codetag_module_init(struct codetag_type *cttype, struct module *mod)
 {
 	struct codetag_range range;
 	struct codetag_module *cmod;
+	int mod_id;
 	int err;
 
 	range = get_section_range(mod, cttype->desc.section);
@@ -190,11 +191,20 @@ static int codetag_module_init(struct codetag_type *cttype, struct module *mod)
 	cmod->range = range;
 
 	down_write(&cttype->mod_lock);
-	err = idr_alloc(&cttype->mod_idr, cmod, 0, 0, GFP_KERNEL);
-	if (err >= 0) {
-		cttype->count += range_size(cttype, &range);
-		if (cttype->desc.module_load)
-			cttype->desc.module_load(mod, range.start, range.stop);
+	mod_id = idr_alloc(&cttype->mod_idr, cmod, 0, 0, GFP_KERNEL);
+	if (mod_id >= 0) {
+		if (cttype->desc.module_load) {
+			err = cttype->desc.module_load(mod, range.start, range.stop);
+			if (!err)
+				cttype->count += range_size(cttype, &range);
+			else
+				idr_remove(&cttype->mod_idr, mod_id);
+		} else {
+			cttype->count += range_size(cttype, &range);
+			err = 0;
+		}
+	} else {
+		err = mod_id;
 	}
 	up_write(&cttype->mod_lock);
 
@@ -295,17 +305,23 @@ void codetag_module_replaced(struct module *mod, struct module *new_mod)
 	mutex_unlock(&codetag_lock);
 }
 
-void codetag_load_module(struct module *mod)
+int codetag_load_module(struct module *mod)
 {
 	struct codetag_type *cttype;
+	int ret = 0;
 
 	if (!mod)
-		return;
+		return 0;
 
 	mutex_lock(&codetag_lock);
-	list_for_each_entry(cttype, &codetag_types, link)
-		codetag_module_init(cttype, mod);
+	list_for_each_entry(cttype, &codetag_types, link) {
+		ret = codetag_module_init(cttype, mod);
+		if (ret)
+			break;
+	}
 	mutex_unlock(&codetag_lock);
+
+	return ret;
 }
 
 void codetag_unload_module(struct module *mod)