Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 276 insertions, 0 deletions

diff --git a/include/crypto/gf128hash.h b/include/crypto/gf128hash.h
new file mode 100644
index 000000000..41c557d55
--- /dev/null
+++ b/include/crypto/gf128hash.h
@@ -0,0 +1,276 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * GF(2^128) polynomial hashing: GHASH and POLYVAL
+ *
+ * Copyright 2025 Google LLC
+ */
+
+#ifndef _CRYPTO_GF128HASH_H
+#define _CRYPTO_GF128HASH_H
+
+#include <crypto/ghash.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#define POLYVAL_BLOCK_SIZE	16
+#define POLYVAL_DIGEST_SIZE	16
+
+/**
+ * struct polyval_elem - An element of the POLYVAL finite field
+ * @bytes: View of the element as a byte array (unioned with @lo and @hi)
+ * @lo: The low 64 terms of the element's polynomial
+ * @hi: The high 64 terms of the element's polynomial
+ *
+ * This represents an element of the finite field GF(2^128), using the POLYVAL
+ * convention: little-endian byte order and natural bit order.
+ */
+struct polyval_elem {
+	union {
+		u8 bytes[POLYVAL_BLOCK_SIZE];
+		struct {
+			__le64 lo;
+			__le64 hi;
+		};
+	};
+};
+
+/**
+ * struct ghash_key - Prepared key for GHASH
+ *
+ * Use ghash_preparekey() to initialize this.
+ */
+struct ghash_key {
+#if defined(CONFIG_CRYPTO_LIB_GF128HASH_ARCH) && defined(CONFIG_PPC64)
+	/** @htable: GHASH key format used by the POWER8 assembly code */
+	u64 htable[4][2];
+#elif defined(CONFIG_CRYPTO_LIB_GF128HASH_ARCH) && \
+	(defined(CONFIG_RISCV) || defined(CONFIG_S390))
+	/** @h_raw: The hash key H, in GHASH format */
+	u8 h_raw[GHASH_BLOCK_SIZE];
+#endif
+	/** @h: The hash key H, in POLYVAL format */
+	struct polyval_elem h;
+};
+
+/**
+ * struct polyval_key - Prepared key for POLYVAL
+ *
+ * This may contain just the raw key H, or it may contain precomputed key
+ * powers, depending on the platform's POLYVAL implementation.  Use
+ * polyval_preparekey() to initialize this.
+ *
+ * By H^i we mean H^(i-1) * H * x^-128, with base case H^1 = H.  I.e. the
+ * exponentiation repeats the POLYVAL dot operation, with its "extra" x^-128.
+ */
+struct polyval_key {
+#if defined(CONFIG_CRYPTO_LIB_GF128HASH_ARCH) && \
+	(defined(CONFIG_ARM64) || defined(CONFIG_X86))
+	/** @h_powers: Powers of the hash key H^8 through H^1 */
+	struct polyval_elem h_powers[8];
+#else
+	/** @h: The hash key H */
+	struct polyval_elem h;
+#endif
+};
+
+/**
+ * struct ghash_ctx - Context for computing a GHASH value
+ * @key: Pointer to the prepared GHASH key.  The user of the API is
+ *	 responsible for ensuring that the key lives as long as the context.
+ * @acc: The accumulator.  It is stored in POLYVAL format rather than GHASH
+ *	 format, since most implementations want it in POLYVAL format.
+ * @partial: Number of data bytes processed so far modulo GHASH_BLOCK_SIZE
+ */
+struct ghash_ctx {
+	const struct ghash_key *key;
+	struct polyval_elem acc;
+	size_t partial;
+};
+
+/**
+ * struct polyval_ctx - Context for computing a POLYVAL value
+ * @key: Pointer to the prepared POLYVAL key.  The user of the API is
+ *	 responsible for ensuring that the key lives as long as the context.
+ * @acc: The accumulator
+ * @partial: Number of data bytes processed so far modulo POLYVAL_BLOCK_SIZE
+ */
+struct polyval_ctx {
+	const struct polyval_key *key;
+	struct polyval_elem acc;
+	size_t partial;
+};
+
+/**
+ * ghash_preparekey() - Prepare a GHASH key
+ * @key: (output) The key structure to initialize
+ * @raw_key: The raw hash key
+ *
+ * Initialize a GHASH key structure from a raw key.
+ *
+ * Context: Any context.
+ */
+void ghash_preparekey(struct ghash_key *key,
+		      const u8 raw_key[GHASH_BLOCK_SIZE]);
+
+/**
+ * polyval_preparekey() - Prepare a POLYVAL key
+ * @key: (output) The key structure to initialize
+ * @raw_key: The raw hash key
+ *
+ * Initialize a POLYVAL key structure from a raw key.  This may be a simple
+ * copy, or it may involve precomputing powers of the key, depending on the
+ * platform's POLYVAL implementation.
+ *
+ * Context: Any context.
+ */
+void polyval_preparekey(struct polyval_key *key,
+			const u8 raw_key[POLYVAL_BLOCK_SIZE]);
+
+/**
+ * ghash_init() - Initialize a GHASH context for a new message
+ * @ctx: The context to initialize
+ * @key: The key to use.  Note that a pointer to the key is saved in the
+ *	 context, so the key must live at least as long as the context.
+ */
+static inline void ghash_init(struct ghash_ctx *ctx,
+			      const struct ghash_key *key)
+{
+	*ctx = (struct ghash_ctx){ .key = key };
+}
+
+/**
+ * polyval_init() - Initialize a POLYVAL context for a new message
+ * @ctx: The context to initialize
+ * @key: The key to use.  Note that a pointer to the key is saved in the
+ *	 context, so the key must live at least as long as the context.
+ */
+static inline void polyval_init(struct polyval_ctx *ctx,
+				const struct polyval_key *key)
+{
+	*ctx = (struct polyval_ctx){ .key = key };
+}
+
+/**
+ * polyval_import_blkaligned() - Import a POLYVAL accumulator value
+ * @ctx: The context to initialize
+ * @key: The key to import.  Note that a pointer to the key is saved in the
+ *	 context, so the key must live at least as long as the context.
+ * @acc: The accumulator value to import.
+ *
+ * This imports an accumulator that was saved by polyval_export_blkaligned().
+ * The same key must be used.
+ */
+static inline void
+polyval_import_blkaligned(struct polyval_ctx *ctx,
+			  const struct polyval_key *key,
+			  const struct polyval_elem *acc)
+{
+	*ctx = (struct polyval_ctx){ .key = key, .acc = *acc };
+}
+
+/**
+ * polyval_export_blkaligned() - Export a POLYVAL accumulator value
+ * @ctx: The context to export the accumulator value from
+ * @acc: (output) The exported accumulator value
+ *
+ * This exports the accumulator from a POLYVAL context.  The number of data
+ * bytes processed so far must be a multiple of POLYVAL_BLOCK_SIZE.
+ */
+static inline void polyval_export_blkaligned(const struct polyval_ctx *ctx,
+					     struct polyval_elem *acc)
+{
+	*acc = ctx->acc;
+}
+
+/**
+ * ghash_update() - Update a GHASH context with message data
+ * @ctx: The context to update; must have been initialized
+ * @data: The message data
+ * @len: The data length in bytes.  Doesn't need to be block-aligned.
+ *
+ * This can be called any number of times.
+ *
+ * Context: Any context.
+ */
+void ghash_update(struct ghash_ctx *ctx, const u8 *data, size_t len);
+
+/**
+ * polyval_update() - Update a POLYVAL context with message data
+ * @ctx: The context to update; must have been initialized
+ * @data: The message data
+ * @len: The data length in bytes.  Doesn't need to be block-aligned.
+ *
+ * This can be called any number of times.
+ *
+ * Context: Any context.
+ */
+void polyval_update(struct polyval_ctx *ctx, const u8 *data, size_t len);
+
+/**
+ * ghash_final() - Finish computing a GHASH value
+ * @ctx: The context to finalize
+ * @out: The output value
+ *
+ * If the total data length isn't a multiple of GHASH_BLOCK_SIZE, then the
+ * final block is automatically zero-padded.
+ *
+ * After finishing, this zeroizes @ctx.  So the caller does not need to do it.
+ *
+ * Context: Any context.
+ */
+void ghash_final(struct ghash_ctx *ctx, u8 out[GHASH_BLOCK_SIZE]);
+
+/**
+ * polyval_final() - Finish computing a POLYVAL value
+ * @ctx: The context to finalize
+ * @out: The output value
+ *
+ * If the total data length isn't a multiple of POLYVAL_BLOCK_SIZE, then the
+ * final block is automatically zero-padded.
+ *
+ * After finishing, this zeroizes @ctx.  So the caller does not need to do it.
+ *
+ * Context: Any context.
+ */
+void polyval_final(struct polyval_ctx *ctx, u8 out[POLYVAL_BLOCK_SIZE]);
+
+/**
+ * ghash() - Compute a GHASH value
+ * @key: The prepared key
+ * @data: The message data
+ * @len: The data length in bytes.  Doesn't need to be block-aligned.
+ * @out: The output value
+ *
+ * Context: Any context.
+ */
+static inline void ghash(const struct ghash_key *key, const u8 *data,
+			 size_t len, u8 out[GHASH_BLOCK_SIZE])
+{
+	struct ghash_ctx ctx;
+
+	ghash_init(&ctx, key);
+	ghash_update(&ctx, data, len);
+	ghash_final(&ctx, out);
+}
+
+/**
+ * polyval() - Compute a POLYVAL value
+ * @key: The prepared key
+ * @data: The message data
+ * @len: The data length in bytes.  Doesn't need to be block-aligned.
+ * @out: The output value
+ *
+ * Context: Any context.
+ */
+static inline void polyval(const struct polyval_key *key,
+			   const u8 *data, size_t len,
+			   u8 out[POLYVAL_BLOCK_SIZE])
+{
+	struct polyval_ctx ctx;
+
+	polyval_init(&ctx, key);
+	polyval_update(&ctx, data, len);
+	polyval_final(&ctx, out);
+}
+
+#endif /* _CRYPTO_GF128HASH_H */