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, 243 insertions, 0 deletions

diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h
new file mode 100644
index 000000000..2c7a04465
--- /dev/null
+++ b/block/blk-crypto-internal.h
@@ -0,0 +1,243 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#ifndef __LINUX_BLK_CRYPTO_INTERNAL_H
+#define __LINUX_BLK_CRYPTO_INTERNAL_H
+
+#include <linux/bio.h>
+#include <linux/blk-mq.h>
+
+/* Represents a crypto mode supported by blk-crypto  */
+struct blk_crypto_mode {
+	const char *name; /* name of this mode, shown in sysfs */
+	const char *cipher_str; /* crypto API name (for fallback case) */
+	unsigned int keysize; /* key size in bytes */
+	unsigned int security_strength; /* security strength in bytes */
+	unsigned int ivsize; /* iv size in bytes */
+};
+
+extern const struct blk_crypto_mode blk_crypto_modes[];
+
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+
+int blk_crypto_sysfs_register(struct gendisk *disk);
+
+void blk_crypto_sysfs_unregister(struct gendisk *disk);
+
+void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
+			     unsigned int inc);
+
+bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
+
+bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
+			     struct bio_crypt_ctx *bc2);
+
+static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
+						struct bio *bio)
+{
+	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
+				       bio->bi_crypt_context);
+}
+
+static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
+						 struct bio *bio)
+{
+	return bio_crypt_ctx_mergeable(bio->bi_crypt_context,
+				       bio->bi_iter.bi_size, req->crypt_ctx);
+}
+
+static inline bool bio_crypt_ctx_merge_rq(struct request *req,
+					  struct request *next)
+{
+	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
+				       next->crypt_ctx);
+}
+
+static inline void blk_crypto_rq_set_defaults(struct request *rq)
+{
+	rq->crypt_ctx = NULL;
+	rq->crypt_keyslot = NULL;
+}
+
+static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
+{
+	return rq->crypt_ctx;
+}
+
+static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
+{
+	return rq->crypt_keyslot;
+}
+
+blk_status_t blk_crypto_get_keyslot(struct blk_crypto_profile *profile,
+				    const struct blk_crypto_key *key,
+				    struct blk_crypto_keyslot **slot_ptr);
+
+void blk_crypto_put_keyslot(struct blk_crypto_keyslot *slot);
+
+int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
+			   const struct blk_crypto_key *key);
+
+int blk_crypto_ioctl(struct block_device *bdev, unsigned int cmd,
+		     void __user *argp);
+
+static inline bool blk_crypto_supported(struct bio *bio)
+{
+	return blk_crypto_config_supported_natively(bio->bi_bdev,
+			&bio->bi_crypt_context->bc_key->crypto_cfg);
+}
+
+#else /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+static inline int blk_crypto_sysfs_register(struct gendisk *disk)
+{
+	return 0;
+}
+
+static inline void blk_crypto_sysfs_unregister(struct gendisk *disk)
+{
+}
+
+static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
+					       struct bio *bio)
+{
+	return true;
+}
+
+static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
+						 struct bio *bio)
+{
+	return true;
+}
+
+static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
+						struct bio *bio)
+{
+	return true;
+}
+
+static inline bool bio_crypt_ctx_merge_rq(struct request *req,
+					  struct request *next)
+{
+	return true;
+}
+
+static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
+
+static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
+{
+	return false;
+}
+
+static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
+{
+	return false;
+}
+
+static inline int blk_crypto_ioctl(struct block_device *bdev, unsigned int cmd,
+				   void __user *argp)
+{
+	return -ENOTTY;
+}
+
+static inline bool blk_crypto_supported(struct bio *bio)
+{
+	return false;
+}
+
+#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
+static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes)
+{
+	if (bio_has_crypt_ctx(bio))
+		__bio_crypt_advance(bio, bytes);
+}
+
+void __bio_crypt_free_ctx(struct bio *bio);
+static inline void bio_crypt_free_ctx(struct bio *bio)
+{
+	if (bio_has_crypt_ctx(bio))
+		__bio_crypt_free_ctx(bio);
+}
+
+static inline void bio_crypt_do_front_merge(struct request *rq,
+					    struct bio *bio)
+{
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+	if (bio_has_crypt_ctx(bio))
+		memcpy(rq->crypt_ctx->bc_dun, bio->bi_crypt_context->bc_dun,
+		       sizeof(rq->crypt_ctx->bc_dun));
+#endif
+}
+
+blk_status_t __blk_crypto_rq_get_keyslot(struct request *rq);
+static inline blk_status_t blk_crypto_rq_get_keyslot(struct request *rq)
+{
+	if (blk_crypto_rq_is_encrypted(rq))
+		return __blk_crypto_rq_get_keyslot(rq);
+	return BLK_STS_OK;
+}
+
+void __blk_crypto_rq_put_keyslot(struct request *rq);
+static inline void blk_crypto_rq_put_keyslot(struct request *rq)
+{
+	if (blk_crypto_rq_has_keyslot(rq))
+		__blk_crypto_rq_put_keyslot(rq);
+}
+
+void __blk_crypto_free_request(struct request *rq);
+static inline void blk_crypto_free_request(struct request *rq)
+{
+	if (blk_crypto_rq_is_encrypted(rq))
+		__blk_crypto_free_request(rq);
+}
+
+int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
+			     gfp_t gfp_mask);
+/**
+ * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio
+ *			    is inserted
+ * @rq: The request to prepare
+ * @bio: The first bio being inserted into the request
+ * @gfp_mask: Memory allocation flags
+ *
+ * Return: 0 on success, -ENOMEM if out of memory.  -ENOMEM is only possible if
+ *	   @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM.
+ */
+static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
+					 gfp_t gfp_mask)
+{
+	if (bio_has_crypt_ctx(bio))
+		return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask);
+	return 0;
+}
+
+bool blk_crypto_fallback_bio_prep(struct bio *bio);
+
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
+
+int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
+
+int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
+
+#else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
+
+static inline int
+blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
+{
+	pr_warn_once("crypto API fallback is disabled\n");
+	return -ENOPKG;
+}
+
+static inline int
+blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
+{
+	return 0;
+}
+
+#endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
+
+#endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */