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, 219 insertions, 0 deletions

diff --git a/include/crypto/rng.h b/include/crypto/rng.h
new file mode 100644
index 000000000..07f494b2c
--- /dev/null
+++ b/include/crypto/rng.h
@@ -0,0 +1,219 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RNG: Random Number Generator  algorithms under the crypto API
+ *
+ * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
+ * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#ifndef _CRYPTO_RNG_H
+#define _CRYPTO_RNG_H
+
+#include <linux/atomic.h>
+#include <linux/container_of.h>
+#include <linux/crypto.h>
+#include <linux/fips.h>
+#include <linux/random.h>
+
+struct crypto_rng;
+
+/**
+ * struct rng_alg - random number generator definition
+ *
+ * @generate:	The function defined by this variable obtains a
+ *		random number. The random number generator transform
+ *		must generate the random number out of the context
+ *		provided with this call, plus any additional data
+ *		if provided to the call.
+ * @seed:	Seed or reseed the random number generator.  With the
+ *		invocation of this function call, the random number
+ *		generator shall become ready for generation.  If the
+ *		random number generator requires a seed for setting
+ *		up a new state, the seed must be provided by the
+ *		consumer while invoking this function. The required
+ *		size of the seed is defined with @seedsize .
+ * @set_ent:	Set entropy that would otherwise be obtained from
+ *		entropy source.  Internal use only.
+ * @seedsize:	The seed size required for a random number generator
+ *		initialization defined with this variable. Some
+ *		random number generators does not require a seed
+ *		as the seeding is implemented internally without
+ *		the need of support by the consumer. In this case,
+ *		the seed size is set to zero.
+ * @base:	Common crypto API algorithm data structure.
+ */
+struct rng_alg {
+	int (*generate)(struct crypto_rng *tfm,
+			const u8 *src, unsigned int slen,
+			u8 *dst, unsigned int dlen);
+	int (*seed)(struct crypto_rng *tfm, const u8 *seed, unsigned int slen);
+	void (*set_ent)(struct crypto_rng *tfm, const u8 *data,
+			unsigned int len);
+
+	unsigned int seedsize;
+
+	struct crypto_alg base;
+};
+
+struct crypto_rng {
+	struct crypto_tfm base;
+};
+
+int __crypto_stdrng_get_bytes(void *buf, unsigned int len);
+
+/**
+ * crypto_stdrng_get_bytes() - get cryptographically secure random bytes
+ * @buf: output buffer holding the random numbers
+ * @len: length of the output buffer
+ *
+ * This function fills the caller-allocated buffer with random numbers using the
+ * normal Linux RNG if fips_enabled=0, or the highest-priority "stdrng"
+ * algorithm in the crypto_rng subsystem if fips_enabled=1.
+ *
+ * Context: May sleep
+ * Return: 0 function was successful; < 0 if an error occurred
+ */
+static inline int crypto_stdrng_get_bytes(void *buf, unsigned int len)
+{
+	might_sleep();
+	if (fips_enabled)
+		return __crypto_stdrng_get_bytes(buf, len);
+	return get_random_bytes_wait(buf, len);
+}
+
+/**
+ * DOC: Random number generator API
+ *
+ * The random number generator API is used with the ciphers of type
+ * CRYPTO_ALG_TYPE_RNG (listed as type "rng" in /proc/crypto)
+ */
+
+/**
+ * crypto_alloc_rng() -- allocate RNG handle
+ * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
+ *	      message digest cipher
+ * @type: specifies the type of the cipher
+ * @mask: specifies the mask for the cipher
+ *
+ * Allocate a cipher handle for a random number generator. The returned struct
+ * crypto_rng is the cipher handle that is required for any subsequent
+ * API invocation for that random number generator.
+ *
+ * For all random number generators, this call creates a new private copy of
+ * the random number generator that does not share a state with other
+ * instances. The only exception is the "krng" random number generator which
+ * is a kernel crypto API use case for the get_random_bytes() function of the
+ * /dev/random driver.
+ *
+ * Return: allocated cipher handle in case of success; IS_ERR() is true in case
+ *	   of an error, PTR_ERR() returns the error code.
+ */
+struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask);
+
+static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm)
+{
+	return &tfm->base;
+}
+
+static inline struct rng_alg *__crypto_rng_alg(struct crypto_alg *alg)
+{
+	return container_of(alg, struct rng_alg, base);
+}
+
+/**
+ * crypto_rng_alg() - obtain 'struct rng_alg' pointer from RNG handle
+ * @tfm: RNG handle
+ *
+ * Return: Pointer to 'struct rng_alg', derived from @tfm RNG handle
+ */
+static inline struct rng_alg *crypto_rng_alg(struct crypto_rng *tfm)
+{
+	return __crypto_rng_alg(crypto_rng_tfm(tfm)->__crt_alg);
+}
+
+/**
+ * crypto_free_rng() - zeroize and free RNG handle
+ * @tfm: cipher handle to be freed
+ *
+ * If @tfm is a NULL or error pointer, this function does nothing.
+ */
+static inline void crypto_free_rng(struct crypto_rng *tfm)
+{
+	crypto_destroy_tfm(tfm, crypto_rng_tfm(tfm));
+}
+
+/**
+ * crypto_rng_generate() - get random number
+ * @tfm: cipher handle
+ * @src: Input buffer holding additional data, may be NULL
+ * @slen: Length of additional data
+ * @dst: output buffer holding the random numbers
+ * @dlen: length of the output buffer
+ *
+ * This function fills the caller-allocated buffer with random
+ * numbers using the random number generator referenced by the
+ * cipher handle.
+ *
+ * Return: 0 function was successful; < 0 if an error occurred
+ */
+static inline int crypto_rng_generate(struct crypto_rng *tfm,
+				      const u8 *src, unsigned int slen,
+				      u8 *dst, unsigned int dlen)
+{
+	return crypto_rng_alg(tfm)->generate(tfm, src, slen, dst, dlen);
+}
+
+/**
+ * crypto_rng_get_bytes() - get random number
+ * @tfm: cipher handle
+ * @rdata: output buffer holding the random numbers
+ * @dlen: length of the output buffer
+ *
+ * This function fills the caller-allocated buffer with random numbers using the
+ * random number generator referenced by the cipher handle.
+ *
+ * Return: 0 function was successful; < 0 if an error occurred
+ */
+static inline int crypto_rng_get_bytes(struct crypto_rng *tfm,
+				       u8 *rdata, unsigned int dlen)
+{
+	return crypto_rng_generate(tfm, NULL, 0, rdata, dlen);
+}
+
+/**
+ * crypto_rng_reset() - re-initialize the RNG
+ * @tfm: cipher handle
+ * @seed: seed input data
+ * @slen: length of the seed input data
+ *
+ * The reset function completely re-initializes the random number generator
+ * referenced by the cipher handle by clearing the current state. The new state
+ * is initialized with the caller provided seed or automatically, depending on
+ * the random number generator type. (The SP800-90A DRBGs perform an automatic
+ * seeding.) The seed is provided as a parameter to this function call. The
+ * provided seed should have the length of the seed size defined for the random
+ * number generator as defined by crypto_rng_seedsize.
+ *
+ * Return: 0 if the setting of the key was successful; < 0 if an error occurred
+ */
+int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed,
+		     unsigned int slen);
+
+/**
+ * crypto_rng_seedsize() - obtain seed size of RNG
+ * @tfm: cipher handle
+ *
+ * The function returns the seed size for the random number generator
+ * referenced by the cipher handle. This value may be zero if the random
+ * number generator does not implement or require a reseeding. For example,
+ * the SP800-90A DRBGs implement an automated reseeding after reaching a
+ * pre-defined threshold.
+ *
+ * Return: seed size for the random number generator
+ */
+static inline int crypto_rng_seedsize(struct crypto_rng *tfm)
+{
+	return crypto_rng_alg(tfm)->seedsize;
+}
+
+#endif