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, 162 insertions, 0 deletions

diff --git a/fs/nfsd/attr4.h b/fs/nfsd/attr4.h
new file mode 100644
index 000000000..f0b51f805
--- /dev/null
+++ b/fs/nfsd/attr4.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * NFSv4 file attributes supported by this implementation
+ */
+
+#ifndef _LINUX_NFSD_ATTR4_H
+#define _LINUX_NFSD_ATTR4_H
+
+#include <linux/types.h>
+#include <linux/nfs4.h>
+
+/*
+ * The following attributes are not implemented by NFSD:
+ *    ARCHIVE       (deprecated anyway)
+ *    HIDDEN        (unlikely to be supported any time soon)
+ *    MIMETYPE      (unlikely to be supported any time soon)
+ *    QUOTA_*       (unlikely to be supported any time soon)
+ *    SYSTEM        (unlikely to be supported any time soon)
+ *    TIME_BACKUP   (unlikely to be supported any time soon)
+ */
+#define NFSD4_SUPPORTED_ATTRS_WORD0                                                         \
+(FATTR4_WORD0_SUPPORTED_ATTRS   | FATTR4_WORD0_TYPE         | FATTR4_WORD0_FH_EXPIRE_TYPE   \
+ | FATTR4_WORD0_CHANGE          | FATTR4_WORD0_SIZE         | FATTR4_WORD0_LINK_SUPPORT     \
+ | FATTR4_WORD0_SYMLINK_SUPPORT | FATTR4_WORD0_NAMED_ATTR   | FATTR4_WORD0_FSID             \
+ | FATTR4_WORD0_UNIQUE_HANDLES  | FATTR4_WORD0_LEASE_TIME   | FATTR4_WORD0_RDATTR_ERROR     \
+ | FATTR4_WORD0_ACLSUPPORT      | FATTR4_WORD0_CANSETTIME   | FATTR4_WORD0_CASE_INSENSITIVE \
+ | FATTR4_WORD0_CASE_PRESERVING | FATTR4_WORD0_CHOWN_RESTRICTED                             \
+ | FATTR4_WORD0_FILEHANDLE      | FATTR4_WORD0_FILEID       | FATTR4_WORD0_FILES_AVAIL      \
+ | FATTR4_WORD0_FILES_FREE      | FATTR4_WORD0_FILES_TOTAL  | FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_HOMOGENEOUS      \
+ | FATTR4_WORD0_MAXFILESIZE     | FATTR4_WORD0_MAXLINK      | FATTR4_WORD0_MAXNAME          \
+ | FATTR4_WORD0_MAXREAD         | FATTR4_WORD0_MAXWRITE     | FATTR4_WORD0_ACL)
+
+#define NFSD4_SUPPORTED_ATTRS_WORD1                                                         \
+(FATTR4_WORD1_MODE              | FATTR4_WORD1_NO_TRUNC     | FATTR4_WORD1_NUMLINKS         \
+ | FATTR4_WORD1_OWNER	        | FATTR4_WORD1_OWNER_GROUP  | FATTR4_WORD1_RAWDEV           \
+ | FATTR4_WORD1_SPACE_AVAIL     | FATTR4_WORD1_SPACE_FREE   | FATTR4_WORD1_SPACE_TOTAL      \
+ | FATTR4_WORD1_SPACE_USED      | FATTR4_WORD1_TIME_ACCESS  | FATTR4_WORD1_TIME_ACCESS_SET  \
+ | FATTR4_WORD1_TIME_DELTA      | FATTR4_WORD1_TIME_METADATA   | FATTR4_WORD1_TIME_CREATE      \
+ | FATTR4_WORD1_TIME_MODIFY     | FATTR4_WORD1_TIME_MODIFY_SET | FATTR4_WORD1_MOUNTED_ON_FILEID)
+
+#define NFSD4_SUPPORTED_ATTRS_WORD2 0
+
+/* 4.1 */
+#ifdef CONFIG_NFSD_PNFS
+#define PNFSD_SUPPORTED_ATTRS_WORD1	FATTR4_WORD1_FS_LAYOUT_TYPES
+#define PNFSD_SUPPORTED_ATTRS_WORD2 \
+(FATTR4_WORD2_LAYOUT_BLKSIZE	| FATTR4_WORD2_LAYOUT_TYPES)
+#else
+#define PNFSD_SUPPORTED_ATTRS_WORD1	0
+#define PNFSD_SUPPORTED_ATTRS_WORD2	0
+#endif /* CONFIG_NFSD_PNFS */
+
+#define NFSD4_1_SUPPORTED_ATTRS_WORD0 \
+	NFSD4_SUPPORTED_ATTRS_WORD0
+
+#define NFSD4_1_SUPPORTED_ATTRS_WORD1 \
+	(NFSD4_SUPPORTED_ATTRS_WORD1	| PNFSD_SUPPORTED_ATTRS_WORD1)
+
+#define NFSD4_1_SUPPORTED_ATTRS_WORD2 \
+	(NFSD4_SUPPORTED_ATTRS_WORD2	| PNFSD_SUPPORTED_ATTRS_WORD2 | \
+	 FATTR4_WORD2_SUPPATTR_EXCLCREAT)
+
+/* 4.2 */
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#define NFSD4_2_SECURITY_ATTRS		FATTR4_WORD2_SECURITY_LABEL
+#else
+#define NFSD4_2_SECURITY_ATTRS		0
+#endif
+
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+#define NFSD4_2_POSIX_ACL_ATTRS \
+	(FATTR4_WORD2_ACL_TRUEFORM | \
+	FATTR4_WORD2_ACL_TRUEFORM_SCOPE | \
+	FATTR4_WORD2_POSIX_DEFAULT_ACL | \
+	FATTR4_WORD2_POSIX_ACCESS_ACL)
+#else
+#define NFSD4_2_POSIX_ACL_ATTRS		0
+#endif
+
+#define NFSD4_2_SUPPORTED_ATTRS_WORD2 \
+	(NFSD4_1_SUPPORTED_ATTRS_WORD2 | \
+	FATTR4_WORD2_MODE_UMASK | \
+	FATTR4_WORD2_CLONE_BLKSIZE | \
+	NFSD4_2_SECURITY_ATTRS | \
+	FATTR4_WORD2_XATTR_SUPPORT | \
+	FATTR4_WORD2_TIME_DELEG_ACCESS | \
+	FATTR4_WORD2_TIME_DELEG_MODIFY | \
+	FATTR4_WORD2_OPEN_ARGUMENTS | \
+	NFSD4_2_POSIX_ACL_ATTRS)
+
+/* These will return ERR_INVAL if specified in GETATTR or READDIR. */
+#define NFSD_WRITEONLY_ATTRS_WORD1 \
+	(FATTR4_WORD1_TIME_ACCESS_SET   | FATTR4_WORD1_TIME_MODIFY_SET)
+
+/*
+ * These are the only attrs allowed in CREATE/OPEN/SETATTR. Don't add
+ * a writeable attribute here without also adding code to parse it to
+ * nfsd4_decode_fattr4().
+ */
+#define NFSD_WRITEABLE_ATTRS_WORD0 \
+	(FATTR4_WORD0_SIZE | FATTR4_WORD0_ACL)
+#define NFSD_WRITEABLE_ATTRS_WORD1 \
+	(FATTR4_WORD1_MODE | FATTR4_WORD1_OWNER | FATTR4_WORD1_OWNER_GROUP \
+	| FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_CREATE \
+	| FATTR4_WORD1_TIME_MODIFY_SET)
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#define MAYBE_FATTR4_WORD2_SECURITY_LABEL \
+	FATTR4_WORD2_SECURITY_LABEL
+#else
+#define MAYBE_FATTR4_WORD2_SECURITY_LABEL 0
+#endif
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+#define MAYBE_FATTR4_WORD2_POSIX_ACL_ATTRS \
+	FATTR4_WORD2_POSIX_DEFAULT_ACL | FATTR4_WORD2_POSIX_ACCESS_ACL
+#else
+#define MAYBE_FATTR4_WORD2_POSIX_ACL_ATTRS 0
+#endif
+#define NFSD_WRITEABLE_ATTRS_WORD2 \
+	(FATTR4_WORD2_MODE_UMASK \
+	| MAYBE_FATTR4_WORD2_SECURITY_LABEL \
+	| FATTR4_WORD2_TIME_DELEG_ACCESS \
+	| FATTR4_WORD2_TIME_DELEG_MODIFY \
+	| MAYBE_FATTR4_WORD2_POSIX_ACL_ATTRS \
+	)
+
+#define NFSD_SUPPATTR_EXCLCREAT_WORD0 \
+	NFSD_WRITEABLE_ATTRS_WORD0
+/*
+ * we currently store the exclusive create verifier in the v_{a,m}time
+ * attributes so the client can't set these at create time using EXCLUSIVE4_1
+ */
+#define NFSD_SUPPATTR_EXCLCREAT_WORD1 \
+	(NFSD_WRITEABLE_ATTRS_WORD1 & \
+	 ~(FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_MODIFY_SET))
+/*
+ * The FATTR4_WORD2_TIME_DELEG attributes are not to be allowed for
+ * OPEN(create) with EXCLUSIVE4_1. It doesn't make sense to set a
+ * delegated timestamp on a new file.
+ *
+ * This mask includes NFSv4.2-only attributes (e.g., POSIX ACLs).
+ * Version filtering occurs via nfsd_suppattrs[] before this mask
+ * is applied, so pre-4.2 clients never see unsupported attributes.
+ */
+#define NFSD_SUPPATTR_EXCLCREAT_WORD2 \
+	(NFSD_WRITEABLE_ATTRS_WORD2 & \
+	~(FATTR4_WORD2_TIME_DELEG_ACCESS | FATTR4_WORD2_TIME_DELEG_MODIFY))
+
+extern const u32 nfsd_suppattrs[3][3];
+
+static inline bool bmval_is_subset(const u32 *bm1, const u32 *bm2)
+{
+	return !((bm1[0] & ~bm2[0]) ||
+	         (bm1[1] & ~bm2[1]) ||
+		 (bm1[2] & ~bm2[2]));
+}
+
+static inline bool nfsd_attrs_supported(u32 minorversion, const u32 *bmval)
+{
+	return bmval_is_subset(bmval, nfsd_suppattrs[minorversion]);
+}
+
+#endif /* _LINUX_NFSD_ATTR4_H */