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, 113 insertions, 0 deletions

diff --git a/fs/udf/ialloc.c b/fs/udf/ialloc.c
new file mode 100644
index 000000000..5f1f969f4
--- /dev/null
+++ b/fs/udf/ialloc.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ialloc.c
+ *
+ * PURPOSE
+ *	Inode allocation handling routines for the OSTA-UDF(tm) filesystem.
+ *
+ * COPYRIGHT
+ *  (C) 1998-2001 Ben Fennema
+ *
+ * HISTORY
+ *
+ *  02/24/99 blf  Created.
+ *
+ */
+
+#include "udfdecl.h"
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "udf_i.h"
+#include "udf_sb.h"
+
+void udf_free_inode(struct inode *inode)
+{
+	udf_free_blocks(inode->i_sb, NULL, &UDF_I(inode)->i_location, 0, 1);
+}
+
+struct inode *udf_new_inode(struct inode *dir, umode_t mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	struct inode *inode;
+	udf_pblk_t block;
+	uint32_t start = UDF_I(dir)->i_location.logicalBlockNum;
+	struct udf_inode_info *iinfo;
+	struct udf_inode_info *dinfo = UDF_I(dir);
+	int err;
+
+	inode = new_inode(sb);
+
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	iinfo = UDF_I(inode);
+	if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_EXTENDED_FE)) {
+		iinfo->i_efe = 1;
+		if (UDF_VERS_USE_EXTENDED_FE > sbi->s_udfrev)
+			sbi->s_udfrev = UDF_VERS_USE_EXTENDED_FE;
+		iinfo->i_data = kzalloc(inode->i_sb->s_blocksize -
+					sizeof(struct extendedFileEntry),
+					GFP_KERNEL);
+	} else {
+		iinfo->i_efe = 0;
+		iinfo->i_data = kzalloc(inode->i_sb->s_blocksize -
+					sizeof(struct fileEntry),
+					GFP_KERNEL);
+	}
+	if (!iinfo->i_data) {
+		make_bad_inode(inode);
+		iput(inode);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	err = -ENOSPC;
+	block = udf_new_block(dir->i_sb, NULL,
+			      dinfo->i_location.partitionReferenceNum,
+			      start, &err);
+	if (err) {
+		make_bad_inode(inode);
+		iput(inode);
+		return ERR_PTR(err);
+	}
+
+	iinfo->i_unique = lvid_get_unique_id(sb);
+	inode->i_generation = iinfo->i_unique;
+
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
+	if (UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET))
+		inode->i_uid = sbi->s_uid;
+	if (UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET))
+		inode->i_gid = sbi->s_gid;
+
+	iinfo->i_location.logicalBlockNum = block;
+	iinfo->i_location.partitionReferenceNum =
+				dinfo->i_location.partitionReferenceNum;
+	inode->i_ino = udf_get_lb_pblock(sb, &iinfo->i_location, 0);
+	inode->i_blocks = 0;
+	iinfo->i_lenEAttr = 0;
+	iinfo->i_lenAlloc = 0;
+	iinfo->i_use = 0;
+	iinfo->i_checkpoint = 1;
+	iinfo->i_extraPerms = FE_PERM_U_CHATTR;
+	udf_update_extra_perms(inode, mode);
+
+	if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_AD_IN_ICB))
+		iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
+	else if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
+		iinfo->i_alloc_type = ICBTAG_FLAG_AD_SHORT;
+	else
+		iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG;
+	simple_inode_init_ts(inode);
+	iinfo->i_crtime = inode_get_mtime(inode);
+	if (unlikely(insert_inode_locked(inode) < 0)) {
+		make_bad_inode(inode);
+		iput(inode);
+		return ERR_PTR(-EIO);
+	}
+	mark_inode_dirty(inode);
+
+	return inode;
+}