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, 262 insertions, 0 deletions

diff --git a/fs/befs/debug.c b/fs/befs/debug.c
new file mode 100644
index 000000000..02fa66fb8
--- /dev/null
+++ b/fs/befs/debug.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/befs/debug.c
+ *
+ * Copyright (C) 2001 Will Dyson (will_dyson at pobox.com)
+ *
+ * With help from the ntfs-tng driver by Anton Altparmakov
+ *
+ * Copyright (C) 1999  Makoto Kato (m_kato@ga2.so-net.ne.jp)
+ *
+ * debug functions
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#ifdef __KERNEL__
+
+#include <linux/stdarg.h>
+#include <linux/string.h>
+#include <linux/spinlock.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+
+#endif				/* __KERNEL__ */
+
+#include "befs.h"
+
+void
+befs_error(const struct super_block *sb, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	pr_err("(%s): %pV\n", sb->s_id, &vaf);
+	va_end(args);
+}
+
+void
+befs_warning(const struct super_block *sb, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	pr_warn("(%s): %pV\n", sb->s_id, &vaf);
+	va_end(args);
+}
+
+void
+befs_debug(const struct super_block *sb, const char *fmt, ...)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	pr_debug("(%s): %pV\n", sb->s_id, &vaf);
+	va_end(args);
+
+#endif				//CONFIG_BEFS_DEBUG
+}
+
+void
+befs_dump_inode(const struct super_block *sb, befs_inode *inode)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	befs_block_run tmp_run;
+
+	befs_debug(sb, "befs_inode information");
+
+	befs_debug(sb, "  magic1 %08x", fs32_to_cpu(sb, inode->magic1));
+
+	tmp_run = fsrun_to_cpu(sb, inode->inode_num);
+	befs_debug(sb, "  inode_num %u, %hu, %hu",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	befs_debug(sb, "  uid %u", fs32_to_cpu(sb, inode->uid));
+	befs_debug(sb, "  gid %u", fs32_to_cpu(sb, inode->gid));
+	befs_debug(sb, "  mode %08x", fs32_to_cpu(sb, inode->mode));
+	befs_debug(sb, "  flags %08x", fs32_to_cpu(sb, inode->flags));
+	befs_debug(sb, "  create_time %llu",
+		   fs64_to_cpu(sb, inode->create_time));
+	befs_debug(sb, "  last_modified_time %llu",
+		   fs64_to_cpu(sb, inode->last_modified_time));
+
+	tmp_run = fsrun_to_cpu(sb, inode->parent);
+	befs_debug(sb, "  parent [%u, %hu, %hu]",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	tmp_run = fsrun_to_cpu(sb, inode->attributes);
+	befs_debug(sb, "  attributes [%u, %hu, %hu]",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	befs_debug(sb, "  type %08x", fs32_to_cpu(sb, inode->type));
+	befs_debug(sb, "  inode_size %u", fs32_to_cpu(sb, inode->inode_size));
+
+	if (S_ISLNK(fs32_to_cpu(sb, inode->mode))) {
+		befs_debug(sb, "  Symbolic link [%s]", inode->data.symlink);
+	} else {
+		int i;
+
+		for (i = 0; i < BEFS_NUM_DIRECT_BLOCKS; i++) {
+			tmp_run =
+			    fsrun_to_cpu(sb, inode->data.datastream.direct[i]);
+			befs_debug(sb, "  direct %d [%u, %hu, %hu]", i,
+				   tmp_run.allocation_group, tmp_run.start,
+				   tmp_run.len);
+		}
+		befs_debug(sb, "  max_direct_range %llu",
+			   fs64_to_cpu(sb,
+				       inode->data.datastream.
+				       max_direct_range));
+
+		tmp_run = fsrun_to_cpu(sb, inode->data.datastream.indirect);
+		befs_debug(sb, "  indirect [%u, %hu, %hu]",
+			   tmp_run.allocation_group,
+			   tmp_run.start, tmp_run.len);
+
+		befs_debug(sb, "  max_indirect_range %llu",
+			   fs64_to_cpu(sb,
+				       inode->data.datastream.
+				       max_indirect_range));
+
+		tmp_run =
+		    fsrun_to_cpu(sb, inode->data.datastream.double_indirect);
+		befs_debug(sb, "  double indirect [%u, %hu, %hu]",
+			   tmp_run.allocation_group, tmp_run.start,
+			   tmp_run.len);
+
+		befs_debug(sb, "  max_double_indirect_range %llu",
+			   fs64_to_cpu(sb,
+				       inode->data.datastream.
+				       max_double_indirect_range));
+
+		befs_debug(sb, "  size %llu",
+			   fs64_to_cpu(sb, inode->data.datastream.size));
+	}
+
+#endif				//CONFIG_BEFS_DEBUG
+}
+
+/*
+ * Display super block structure for debug.
+ */
+
+void
+befs_dump_super_block(const struct super_block *sb, befs_super_block *sup)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	befs_block_run tmp_run;
+
+	befs_debug(sb, "befs_super_block information");
+
+	befs_debug(sb, "  name %s", sup->name);
+	befs_debug(sb, "  magic1 %08x", fs32_to_cpu(sb, sup->magic1));
+	befs_debug(sb, "  fs_byte_order %08x",
+		   fs32_to_cpu(sb, sup->fs_byte_order));
+
+	befs_debug(sb, "  block_size %u", fs32_to_cpu(sb, sup->block_size));
+	befs_debug(sb, "  block_shift %u", fs32_to_cpu(sb, sup->block_shift));
+
+	befs_debug(sb, "  num_blocks %llu", fs64_to_cpu(sb, sup->num_blocks));
+	befs_debug(sb, "  used_blocks %llu", fs64_to_cpu(sb, sup->used_blocks));
+	befs_debug(sb, "  inode_size %u", fs32_to_cpu(sb, sup->inode_size));
+
+	befs_debug(sb, "  magic2 %08x", fs32_to_cpu(sb, sup->magic2));
+	befs_debug(sb, "  blocks_per_ag %u",
+		   fs32_to_cpu(sb, sup->blocks_per_ag));
+	befs_debug(sb, "  ag_shift %u", fs32_to_cpu(sb, sup->ag_shift));
+	befs_debug(sb, "  num_ags %u", fs32_to_cpu(sb, sup->num_ags));
+
+	befs_debug(sb, "  flags %08x", fs32_to_cpu(sb, sup->flags));
+
+	tmp_run = fsrun_to_cpu(sb, sup->log_blocks);
+	befs_debug(sb, "  log_blocks %u, %hu, %hu",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	befs_debug(sb, "  log_start %lld", fs64_to_cpu(sb, sup->log_start));
+	befs_debug(sb, "  log_end %lld", fs64_to_cpu(sb, sup->log_end));
+
+	befs_debug(sb, "  magic3 %08x", fs32_to_cpu(sb, sup->magic3));
+
+	tmp_run = fsrun_to_cpu(sb, sup->root_dir);
+	befs_debug(sb, "  root_dir %u, %hu, %hu",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	tmp_run = fsrun_to_cpu(sb, sup->indices);
+	befs_debug(sb, "  indices %u, %hu, %hu",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+#endif				//CONFIG_BEFS_DEBUG
+}
+
+#if 0
+/* unused */
+void
+befs_dump_small_data(const struct super_block *sb, befs_small_data *sd)
+{
+}
+
+/* unused */
+void
+befs_dump_run(const struct super_block *sb, befs_disk_block_run run)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	befs_block_run n = fsrun_to_cpu(sb, run);
+
+	befs_debug(sb, "[%u, %hu, %hu]", n.allocation_group, n.start, n.len);
+
+#endif				//CONFIG_BEFS_DEBUG
+}
+#endif  /*  0  */
+
+void
+befs_dump_index_entry(const struct super_block *sb,
+		      befs_disk_btree_super *super)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	befs_debug(sb, "Btree super structure");
+	befs_debug(sb, "  magic %08x", fs32_to_cpu(sb, super->magic));
+	befs_debug(sb, "  node_size %u", fs32_to_cpu(sb, super->node_size));
+	befs_debug(sb, "  max_depth %08x", fs32_to_cpu(sb, super->max_depth));
+
+	befs_debug(sb, "  data_type %08x", fs32_to_cpu(sb, super->data_type));
+	befs_debug(sb, "  root_node_pointer %016LX",
+		   fs64_to_cpu(sb, super->root_node_ptr));
+	befs_debug(sb, "  free_node_pointer %016LX",
+		   fs64_to_cpu(sb, super->free_node_ptr));
+	befs_debug(sb, "  maximum size %016LX",
+		   fs64_to_cpu(sb, super->max_size));
+
+#endif				//CONFIG_BEFS_DEBUG
+}
+
+void
+befs_dump_index_node(const struct super_block *sb, befs_btree_nodehead *node)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	befs_debug(sb, "Btree node structure");
+	befs_debug(sb, "  left %016LX", fs64_to_cpu(sb, node->left));
+	befs_debug(sb, "  right %016LX", fs64_to_cpu(sb, node->right));
+	befs_debug(sb, "  overflow %016LX", fs64_to_cpu(sb, node->overflow));
+	befs_debug(sb, "  all_key_count %hu",
+		   fs16_to_cpu(sb, node->all_key_count));
+	befs_debug(sb, "  all_key_length %hu",
+		   fs16_to_cpu(sb, node->all_key_length));
+
+#endif				//CONFIG_BEFS_DEBUG
+}