From 3e09c500bb5b0606282d04438404f67df132835a Mon Sep 17 00:00:00 2001
From: Suren Baghdasaryan <surenb@google.com>
Date: Wed, 23 Oct 2024 10:07:55 -0700
Subject: [PATCH] alloc_tag: introduce shutdown_mem_profiling helper function

Implement a helper function to disable memory allocation profiling and use
it when creation of /proc/allocinfo fails.  Ensure /proc/allocinfo does
not get created when memory allocation profiling is disabled.

Link: https://lkml.kernel.org/r/20241023170759.999909-3-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Huth <thuth@redhat.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xiongwei Song <xiongwei.song@windriver.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 lib/alloc_tag.c | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index 81e5f9a70f22..435aa837e550 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -8,6 +8,14 @@
 #include <linux/seq_buf.h>
 #include <linux/seq_file.h>
 
+#define ALLOCINFO_FILE_NAME		"allocinfo"
+
+#ifdef CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
+static bool mem_profiling_support __meminitdata = true;
+#else
+static bool mem_profiling_support __meminitdata;
+#endif
+
 static struct codetag_type *alloc_tag_cttype;
 
 DEFINE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag);
@@ -144,9 +152,26 @@ size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sl
 	return nr;
 }
 
+static void __init shutdown_mem_profiling(void)
+{
+	if (mem_alloc_profiling_enabled())
+		static_branch_disable(&mem_alloc_profiling_key);
+
+	if (!mem_profiling_support)
+		return;
+
+	mem_profiling_support = false;
+}
+
 static void __init procfs_init(void)
 {
-	proc_create_seq("allocinfo", 0400, NULL, &allocinfo_seq_op);
+	if (!mem_profiling_support)
+		return;
+
+	if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
+		pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
+		shutdown_mem_profiling();
+	}
 }
 
 static bool alloc_tag_module_unload(struct codetag_type *cttype,
@@ -174,12 +199,6 @@ static bool alloc_tag_module_unload(struct codetag_type *cttype,
 	return module_unused;
 }
 
-#ifdef CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
-static bool mem_profiling_support __meminitdata = true;
-#else
-static bool mem_profiling_support __meminitdata;
-#endif
-
 static int __init setup_early_mem_profiling(char *str)
 {
 	bool enable;