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, 57 insertions, 0 deletions

diff --git a/include/crypto/des.h b/include/crypto/des.h
new file mode 100644
index 000000000..73eec617f
--- /dev/null
+++ b/include/crypto/des.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* 
+ * DES & Triple DES EDE Cipher Algorithms.
+ */
+
+#ifndef __CRYPTO_DES_H
+#define __CRYPTO_DES_H
+
+#include <linux/types.h>
+
+#define DES_KEY_SIZE		8
+#define DES_EXPKEY_WORDS	32
+#define DES_BLOCK_SIZE		8
+
+#define DES3_EDE_KEY_SIZE	(3 * DES_KEY_SIZE)
+#define DES3_EDE_EXPKEY_WORDS	(3 * DES_EXPKEY_WORDS)
+#define DES3_EDE_BLOCK_SIZE	DES_BLOCK_SIZE
+
+struct des_ctx {
+	u32 expkey[DES_EXPKEY_WORDS];
+};
+
+struct des3_ede_ctx {
+	u32 expkey[DES3_EDE_EXPKEY_WORDS];
+};
+
+void des_encrypt(const struct des_ctx *ctx, u8 *dst, const u8 *src);
+void des_decrypt(const struct des_ctx *ctx, u8 *dst, const u8 *src);
+
+void des3_ede_encrypt(const struct des3_ede_ctx *dctx, u8 *dst, const u8 *src);
+void des3_ede_decrypt(const struct des3_ede_ctx *dctx, u8 *dst, const u8 *src);
+
+/**
+ * des_expand_key - Expand a DES input key into a key schedule
+ * @ctx: the key schedule
+ * @key: buffer containing the input key
+ * @keylen: size of the buffer contents
+ *
+ * Returns: 0 on success, -EINVAL if the input key is rejected and -ENOKEY if
+ * the key is accepted but has been found to be weak.
+ */
+int des_expand_key(struct des_ctx *ctx, const u8 *key, unsigned int keylen);
+
+/**
+ * des3_ede_expand_key - Expand a triple DES input key into a key schedule
+ * @ctx: the key schedule
+ * @key: buffer containing the input key
+ * @keylen: size of the buffer contents
+ *
+ * Returns: 0 on success, -EINVAL if the input key is rejected and -ENOKEY if
+ * the key is accepted but has been found to be weak. Note that weak keys will
+ * be rejected (and -EINVAL will be returned) when running in FIPS mode.
+ */
+int des3_ede_expand_key(struct des3_ede_ctx *ctx, const u8 *key,
+			unsigned int keylen);
+
+#endif /* __CRYPTO_DES_H */