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, 391 insertions, 0 deletions

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
new file mode 100644
index 000000000..075f38a67
--- /dev/null
+++ b/drivers/crypto/atmel-ecc.c
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip / Atmel ECC (I2C) driver.
+ *
+ * Copyright (c) 2017, Microchip Technology Inc.
+ * Author: Tudor Ambarus
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <crypto/internal/kpp.h>
+#include <crypto/ecdh.h>
+#include <crypto/kpp.h>
+#include "atmel-i2c.h"
+
+static struct atmel_ecc_driver_data driver_data;
+
+/**
+ * struct atmel_ecdh_ctx - transformation context
+ * @client: I2C client device
+ * @fallback: ECDH fallback used for caller-provided private keys
+ * @public_key: cached public key for the device-generated private key
+ * @do_fallback: true when ECDH operations should use @fallback
+ *
+ * The caller must not invoke set_secret() while generate_public_key()
+ * or compute_shared_secret() are in flight.
+ */
+struct atmel_ecdh_ctx {
+	struct i2c_client *client;
+	struct crypto_kpp *fallback;
+	const u8 *public_key;
+	bool do_fallback;
+};
+
+static void atmel_ecdh_done(struct atmel_i2c_work_data *work_data, void *areq,
+			    int status)
+{
+	struct kpp_request *req = areq;
+	struct atmel_i2c_cmd *cmd = &work_data->cmd;
+	size_t copied, n_sz;
+
+	if (status)
+		goto free_work_data;
+
+	/* copy only as much as requested, capped at 32 bytes */
+	n_sz = min(ATMEL_ECC_NIST_P256_N_SIZE, req->dst_len);
+
+	/* copy the shared secret */
+	copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst, n_sz),
+				     &cmd->data[RSP_DATA_IDX], n_sz);
+	if (copied != n_sz)
+		status = -EINVAL;
+
+free_work_data:
+	kfree_sensitive(work_data);
+	kpp_request_complete(req, status);
+}
+
+/*
+ * If no private key is provided, generate one in the device and cache
+ * the corresponding public key. The generated private key never leaves
+ * the device.
+ */
+static int atmel_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
+				 unsigned int len)
+{
+	struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
+	struct atmel_i2c_cmd *cmd;
+	void *public_key;
+	struct ecdh params;
+	int ret = -ENOMEM;
+
+	kfree(ctx->public_key);
+	ctx->public_key = NULL;
+	ctx->do_fallback = false;
+
+	if (crypto_ecdh_decode_key(buf, len, &params) < 0) {
+		dev_err(&ctx->client->dev, "crypto_ecdh_decode_key failed\n");
+		return -EINVAL;
+	}
+
+	if (params.key_size) {
+		ret = crypto_kpp_set_secret(ctx->fallback, buf, len);
+		ctx->do_fallback = !ret;
+		return ret;
+	}
+
+	cmd = kmalloc_obj(*cmd);
+	if (!cmd)
+		return -ENOMEM;
+
+	public_key = kmalloc(ATMEL_ECC_PUBKEY_SIZE, GFP_KERNEL);
+	if (!public_key)
+		goto free_cmd;
+
+	atmel_i2c_init_genkey_cmd(cmd, DATA_SLOT_2);
+
+	ret = atmel_i2c_send_receive(ctx->client, cmd);
+	if (ret) {
+		kfree(public_key);
+		goto free_cmd;
+	}
+
+	memcpy(public_key, &cmd->data[RSP_DATA_IDX], ATMEL_ECC_PUBKEY_SIZE);
+	ctx->public_key = public_key;
+
+free_cmd:
+	kfree(cmd);
+	return ret;
+}
+
+static int atmel_ecdh_generate_public_key(struct kpp_request *req)
+{
+	struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
+	struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
+	size_t copied, nbytes;
+
+	if (ctx->do_fallback) {
+		kpp_request_set_tfm(req, ctx->fallback);
+		return crypto_kpp_generate_public_key(req);
+	}
+
+	if (!ctx->public_key)
+		return -EINVAL;
+
+	/* copy only as much as requested, capped at 64 bytes */
+	nbytes = min(ATMEL_ECC_PUBKEY_SIZE, req->dst_len);
+
+	/* public key was saved at private key generation */
+	copied = sg_copy_from_buffer(req->dst,
+				     sg_nents_for_len(req->dst, nbytes),
+				     ctx->public_key, nbytes);
+	if (copied != nbytes)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int atmel_ecdh_compute_shared_secret(struct kpp_request *req)
+{
+	struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
+	struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
+	struct atmel_i2c_work_data *work_data;
+	gfp_t gfp;
+	int ret;
+
+	if (ctx->do_fallback) {
+		kpp_request_set_tfm(req, ctx->fallback);
+		return crypto_kpp_compute_shared_secret(req);
+	}
+
+	if (!ctx->public_key)
+		return -EINVAL;
+
+	/* A P-256 public key must contain two 32-byte coordinates */
+	if (req->src_len != ATMEL_ECC_PUBKEY_SIZE)
+		return -EINVAL;
+
+	gfp = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? GFP_KERNEL :
+							     GFP_ATOMIC;
+
+	work_data = kmalloc_obj(*work_data, gfp);
+	if (!work_data)
+		return -ENOMEM;
+
+	work_data->ctx = ctx;
+	work_data->client = ctx->client;
+
+	ret = atmel_i2c_init_ecdh_cmd(&work_data->cmd, req->src);
+	if (ret)
+		goto free_work_data;
+
+	atmel_i2c_enqueue(work_data, atmel_ecdh_done, req);
+
+	return -EINPROGRESS;
+
+free_work_data:
+	kfree(work_data);
+	return ret;
+}
+
+static struct i2c_client *atmel_ecc_i2c_client_alloc(void)
+{
+	struct atmel_i2c_client_priv *i2c_priv, *min_i2c_priv = NULL;
+	struct i2c_client *client = ERR_PTR(-ENODEV);
+	int min_tfm_cnt = INT_MAX;
+	int tfm_cnt;
+
+	spin_lock(&driver_data.i2c_list_lock);
+
+	if (list_empty(&driver_data.i2c_client_list)) {
+		spin_unlock(&driver_data.i2c_list_lock);
+		return ERR_PTR(-ENODEV);
+	}
+
+	list_for_each_entry(i2c_priv, &driver_data.i2c_client_list,
+			    i2c_client_list_node) {
+		tfm_cnt = atomic_read(&i2c_priv->tfm_count);
+		if (tfm_cnt < min_tfm_cnt) {
+			min_tfm_cnt = tfm_cnt;
+			min_i2c_priv = i2c_priv;
+		}
+		if (!min_tfm_cnt)
+			break;
+	}
+
+	if (min_i2c_priv) {
+		atomic_inc(&min_i2c_priv->tfm_count);
+		client = min_i2c_priv->client;
+	}
+
+	spin_unlock(&driver_data.i2c_list_lock);
+
+	return client;
+}
+
+static void atmel_ecc_i2c_client_free(struct i2c_client *client)
+{
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+
+	atomic_dec(&i2c_priv->tfm_count);
+}
+
+static int atmel_ecdh_init_tfm(struct crypto_kpp *tfm)
+{
+	const char *alg = kpp_alg_name(tfm);
+	struct crypto_kpp *fallback;
+	struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
+
+	ctx->client = atmel_ecc_i2c_client_alloc();
+	if (IS_ERR(ctx->client)) {
+		pr_err("tfm - i2c_client binding failed\n");
+		return PTR_ERR(ctx->client);
+	}
+
+	fallback = crypto_alloc_kpp(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
+	if (IS_ERR(fallback)) {
+		dev_err(&ctx->client->dev, "Failed to allocate transformation for '%s': %ld\n",
+			alg, PTR_ERR(fallback));
+		atmel_ecc_i2c_client_free(ctx->client);
+		return PTR_ERR(fallback);
+	}
+
+	crypto_kpp_set_flags(fallback, crypto_kpp_get_flags(tfm));
+	ctx->fallback = fallback;
+
+	return 0;
+}
+
+static void atmel_ecdh_exit_tfm(struct crypto_kpp *tfm)
+{
+	struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
+
+	kfree(ctx->public_key);
+	crypto_free_kpp(ctx->fallback);
+	atmel_ecc_i2c_client_free(ctx->client);
+}
+
+static unsigned int atmel_ecdh_max_size(struct crypto_kpp *tfm)
+{
+	struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
+
+	return crypto_kpp_maxsize(ctx->fallback);
+}
+
+static struct kpp_alg atmel_ecdh_nist_p256 = {
+	.set_secret = atmel_ecdh_set_secret,
+	.generate_public_key = atmel_ecdh_generate_public_key,
+	.compute_shared_secret = atmel_ecdh_compute_shared_secret,
+	.init = atmel_ecdh_init_tfm,
+	.exit = atmel_ecdh_exit_tfm,
+	.max_size = atmel_ecdh_max_size,
+	.base = {
+		.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
+		.cra_name = "ecdh-nist-p256",
+		.cra_driver_name = "atmel-ecdh",
+		.cra_priority = ATMEL_ECC_PRIORITY,
+		.cra_module = THIS_MODULE,
+		.cra_ctxsize = sizeof(struct atmel_ecdh_ctx),
+	},
+};
+
+static int atmel_ecc_probe(struct i2c_client *client)
+{
+	struct atmel_i2c_client_priv *i2c_priv;
+	int ret;
+
+	ret = atmel_i2c_probe(client);
+	if (ret)
+		return ret;
+
+	i2c_priv = i2c_get_clientdata(client);
+
+	spin_lock(&driver_data.i2c_list_lock);
+	list_add_tail(&i2c_priv->i2c_client_list_node,
+		      &driver_data.i2c_client_list);
+	spin_unlock(&driver_data.i2c_list_lock);
+
+	ret = crypto_register_kpp(&atmel_ecdh_nist_p256);
+	if (ret) {
+		spin_lock(&driver_data.i2c_list_lock);
+		list_del(&i2c_priv->i2c_client_list_node);
+		spin_unlock(&driver_data.i2c_list_lock);
+
+		dev_err(&client->dev, "%s alg registration failed\n",
+			atmel_ecdh_nist_p256.base.cra_driver_name);
+	} else {
+		dev_info(&client->dev, "atmel ecc algorithms registered in /proc/crypto\n");
+	}
+
+	return ret;
+}
+
+static void atmel_ecc_remove(struct i2c_client *client)
+{
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+
+	/* Return EBUSY if i2c client already allocated. */
+	if (atomic_read(&i2c_priv->tfm_count)) {
+		/*
+		 * After we return here, the memory backing the device is freed.
+		 * That happens no matter what the return value of this function
+		 * is because in the Linux device model there is no error
+		 * handling for unbinding a driver.
+		 * If there is still some action pending, it probably involves
+		 * accessing the freed memory.
+		 */
+		dev_emerg(&client->dev, "Device is busy, expect memory corruption.\n");
+		return;
+	}
+
+	crypto_unregister_kpp(&atmel_ecdh_nist_p256);
+
+	spin_lock(&driver_data.i2c_list_lock);
+	list_del(&i2c_priv->i2c_client_list_node);
+	spin_unlock(&driver_data.i2c_list_lock);
+}
+
+static const struct of_device_id atmel_ecc_dt_ids[] = {
+	{ .compatible = "atmel,atecc508a", },
+	{ .compatible = "atmel,atecc608b", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, atmel_ecc_dt_ids);
+
+static const struct i2c_device_id atmel_ecc_id[] = {
+	{ .name = "atecc508a" },
+	{ .name = "atecc608b" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, atmel_ecc_id);
+
+static struct i2c_driver atmel_ecc_driver = {
+	.driver = {
+		.name	= "atmel-ecc",
+		.of_match_table = atmel_ecc_dt_ids,
+	},
+	.probe		= atmel_ecc_probe,
+	.remove		= atmel_ecc_remove,
+	.id_table	= atmel_ecc_id,
+};
+
+static int __init atmel_ecc_init(void)
+{
+	spin_lock_init(&driver_data.i2c_list_lock);
+	INIT_LIST_HEAD(&driver_data.i2c_client_list);
+	return i2c_add_driver(&atmel_ecc_driver);
+}
+
+static void __exit atmel_ecc_exit(void)
+{
+	atmel_i2c_flush_queue();
+	i2c_del_driver(&atmel_ecc_driver);
+}
+
+module_init(atmel_ecc_init);
+module_exit(atmel_ecc_exit);
+
+MODULE_AUTHOR("Tudor Ambarus");
+MODULE_DESCRIPTION("Microchip / Atmel ECC (I2C) driver");
+MODULE_LICENSE("GPL v2");