ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 261 insertions, 0 deletions

diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
new file mode 100644
index 000000000..36c9c06e9
--- /dev/null
+++ b/fs/gfs2/main.c
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/rcupdate.h>
+#include <linux/rculist_bl.h>
+#include <linux/atomic.h>
+#include <linux/mempool.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "super.h"
+#include "sys.h"
+#include "util.h"
+#include "glock.h"
+#include "quota.h"
+#include "recovery.h"
+#include "dir.h"
+#include "glops.h"
+
+struct workqueue_struct *gfs2_control_wq;
+
+static void gfs2_init_inode_once(void *foo)
+{
+	struct gfs2_inode *ip = foo;
+
+	inode_init_once(&ip->i_inode);
+	atomic_set(&ip->i_sizehint, 0);
+	init_rwsem(&ip->i_rw_mutex);
+	INIT_LIST_HEAD(&ip->i_ordered);
+	ip->i_qadata = NULL;
+	gfs2_holder_mark_uninitialized(&ip->i_rgd_gh);
+	memset(&ip->i_res, 0, sizeof(ip->i_res));
+	RB_CLEAR_NODE(&ip->i_res.rs_node);
+	ip->i_hash_cache = NULL;
+	gfs2_holder_mark_uninitialized(&ip->i_iopen_gh);
+}
+
+static void gfs2_init_glock_once(void *foo)
+{
+	struct gfs2_glock *gl = foo;
+
+	INIT_LIST_HEAD(&gl->gl_holders);
+	INIT_LIST_HEAD(&gl->gl_ail_list);
+	atomic_set(&gl->gl_ail_count, 0);
+	atomic_set(&gl->gl_revokes, 0);
+}
+
+static void gfs2_init_gl_aspace_once(void *foo)
+{
+	struct gfs2_glock_aspace *gla = foo;
+
+	gfs2_init_glock_once(&gla->glock);
+	address_space_init_once(&gla->mapping);
+}
+
+/**
+ * init_gfs2_fs - Register GFS2 as a filesystem
+ *
+ * Returns: 0 on success, error code on failure
+ */
+
+static int __init init_gfs2_fs(void)
+{
+	int error;
+
+	gfs2_str2qstr(&gfs2_qdot, ".");
+	gfs2_str2qstr(&gfs2_qdotdot, "..");
+	gfs2_quota_hash_init();
+
+	error = gfs2_sys_init();
+	if (error)
+		return error;
+
+	error = list_lru_init(&gfs2_qd_lru);
+	if (error)
+		goto fail_lru;
+
+	error = gfs2_glock_init();
+	if (error)
+		goto fail_glock;
+
+	error = -ENOMEM;
+	gfs2_glock_cachep = kmem_cache_create("gfs2_glock",
+					      sizeof(struct gfs2_glock),
+					      0, SLAB_RECLAIM_ACCOUNT,
+					      gfs2_init_glock_once);
+	if (!gfs2_glock_cachep)
+		goto fail_cachep1;
+
+	gfs2_glock_aspace_cachep = kmem_cache_create("gfs2_glock(aspace)",
+					sizeof(struct gfs2_glock_aspace),
+					0, 0, gfs2_init_gl_aspace_once);
+
+	if (!gfs2_glock_aspace_cachep)
+		goto fail_cachep2;
+
+	gfs2_inode_cachep = kmem_cache_create("gfs2_inode",
+					      sizeof(struct gfs2_inode),
+					      0,  SLAB_RECLAIM_ACCOUNT|
+						  SLAB_ACCOUNT,
+					      gfs2_init_inode_once);
+	if (!gfs2_inode_cachep)
+		goto fail_cachep3;
+
+	gfs2_bufdata_cachep = kmem_cache_create("gfs2_bufdata",
+						sizeof(struct gfs2_bufdata),
+					        0, 0, NULL);
+	if (!gfs2_bufdata_cachep)
+		goto fail_cachep4;
+
+	gfs2_rgrpd_cachep = kmem_cache_create("gfs2_rgrpd",
+					      sizeof(struct gfs2_rgrpd),
+					      0, 0, NULL);
+	if (!gfs2_rgrpd_cachep)
+		goto fail_cachep5;
+
+	gfs2_quotad_cachep = kmem_cache_create("gfs2_quotad",
+					       sizeof(struct gfs2_quota_data),
+					       0, SLAB_RECLAIM_ACCOUNT, NULL);
+	if (!gfs2_quotad_cachep)
+		goto fail_cachep6;
+
+	gfs2_qadata_cachep = kmem_cache_create("gfs2_qadata",
+					       sizeof(struct gfs2_qadata),
+					       0, 0, NULL);
+	if (!gfs2_qadata_cachep)
+		goto fail_cachep7;
+
+	gfs2_trans_cachep = kmem_cache_create("gfs2_trans",
+					       sizeof(struct gfs2_trans),
+					       0, 0, NULL);
+	if (!gfs2_trans_cachep)
+		goto fail_cachep8;
+
+	error = gfs2_qd_shrinker_init();
+	if (error)
+		goto fail_shrinker;
+
+	error = -ENOMEM;
+	gfs2_recovery_wq = alloc_workqueue("gfs2_recovery",
+					  WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_PERCPU,
+					  0);
+	if (!gfs2_recovery_wq)
+		goto fail_wq1;
+
+	gfs2_control_wq = alloc_workqueue("gfs2_control",
+					  WQ_UNBOUND | WQ_FREEZABLE, 0);
+	if (!gfs2_control_wq)
+		goto fail_wq2;
+
+	gfs2_freeze_wq = alloc_workqueue("gfs2_freeze", WQ_PERCPU, 0);
+
+	if (!gfs2_freeze_wq)
+		goto fail_wq3;
+
+	gfs2_page_pool = mempool_create_page_pool(64, 0);
+	if (!gfs2_page_pool)
+		goto fail_mempool;
+
+	gfs2_register_debugfs();
+	error = register_filesystem(&gfs2_fs_type);
+	if (error)
+		goto fail_fs1;
+
+	error = register_filesystem(&gfs2meta_fs_type);
+	if (error)
+		goto fail_fs2;
+
+
+	pr_info("GFS2 installed\n");
+
+	return 0;
+
+fail_fs2:
+	unregister_filesystem(&gfs2_fs_type);
+fail_fs1:
+	mempool_destroy(gfs2_page_pool);
+fail_mempool:
+	destroy_workqueue(gfs2_freeze_wq);
+fail_wq3:
+	destroy_workqueue(gfs2_control_wq);
+fail_wq2:
+	destroy_workqueue(gfs2_recovery_wq);
+fail_wq1:
+	gfs2_qd_shrinker_exit();
+fail_shrinker:
+	kmem_cache_destroy(gfs2_trans_cachep);
+fail_cachep8:
+	kmem_cache_destroy(gfs2_qadata_cachep);
+fail_cachep7:
+	kmem_cache_destroy(gfs2_quotad_cachep);
+fail_cachep6:
+	kmem_cache_destroy(gfs2_rgrpd_cachep);
+fail_cachep5:
+	kmem_cache_destroy(gfs2_bufdata_cachep);
+fail_cachep4:
+	kmem_cache_destroy(gfs2_inode_cachep);
+fail_cachep3:
+	kmem_cache_destroy(gfs2_glock_aspace_cachep);
+fail_cachep2:
+	kmem_cache_destroy(gfs2_glock_cachep);
+fail_cachep1:
+	gfs2_glock_exit();
+fail_glock:
+	list_lru_destroy(&gfs2_qd_lru);
+fail_lru:
+	gfs2_sys_uninit();
+	return error;
+}
+
+/**
+ * exit_gfs2_fs - Unregister the file system
+ *
+ */
+
+static void __exit exit_gfs2_fs(void)
+{
+	gfs2_qd_shrinker_exit();
+	gfs2_glock_exit();
+	gfs2_unregister_debugfs();
+	unregister_filesystem(&gfs2_fs_type);
+	unregister_filesystem(&gfs2meta_fs_type);
+	destroy_workqueue(gfs2_recovery_wq);
+	destroy_workqueue(gfs2_control_wq);
+	destroy_workqueue(gfs2_freeze_wq);
+	list_lru_destroy(&gfs2_qd_lru);
+
+	rcu_barrier();
+
+	mempool_destroy(gfs2_page_pool);
+	kmem_cache_destroy(gfs2_trans_cachep);
+	kmem_cache_destroy(gfs2_qadata_cachep);
+	kmem_cache_destroy(gfs2_quotad_cachep);
+	kmem_cache_destroy(gfs2_rgrpd_cachep);
+	kmem_cache_destroy(gfs2_bufdata_cachep);
+	kmem_cache_destroy(gfs2_inode_cachep);
+	kmem_cache_destroy(gfs2_glock_aspace_cachep);
+	kmem_cache_destroy(gfs2_glock_cachep);
+
+	gfs2_sys_uninit();
+}
+
+MODULE_DESCRIPTION("Global File System");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+
+module_init(init_gfs2_fs);
+module_exit(exit_gfs2_fs);
+