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, 650 insertions, 0 deletions

diff --git a/drivers/md/dm-ima.c b/drivers/md/dm-ima.c
new file mode 100644
index 000000000..5e7232582
--- /dev/null
+++ b/drivers/md/dm-ima.c
@@ -0,0 +1,650 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Microsoft Corporation
+ *
+ * Author: Tushar Sugandhi <tusharsu@linux.microsoft.com>
+ *
+ * Enables IMA measurements for DM targets
+ */
+
+#include "dm-core.h"
+#include "dm-ima.h"
+
+#include <linux/ima.h>
+#include <linux/sched/mm.h>
+#include <crypto/sha2.h>
+
+#define DM_MSG_PREFIX "ima"
+
+/*
+ * Internal function to prefix separator characters in input buffer with escape
+ * character, so that they don't interfere with the construction of key-value pairs,
+ * and clients can split the key1=val1,key2=val2,key3=val3; pairs properly.
+ */
+static void fix_separator_chars(char *buf)
+{
+	int l = strlen(buf);
+	int i, j, sp = 0;
+
+	for (i = 0; i < l; i++)
+		if (buf[i] == '\\' || buf[i] == ';' || buf[i] == '=' || buf[i] == ',')
+			sp++;
+
+	if (!sp)
+		return;
+
+	buf[l + sp] = '\0';
+	for (i = l-1, j = i+sp; i >= 0; i--) {
+		buf[j--] = buf[i];
+		if (buf[i] == '\\' || buf[i] == ';' || buf[i] == '=' || buf[i] == ',')
+			buf[j--] = '\\';
+	}
+}
+
+static void fix_context_strings(struct dm_ima_context *context)
+{
+	fix_separator_chars(context->dev_name);
+	fix_separator_chars(context->dev_uuid);
+}
+
+/*
+ * Internal function to allocate memory for IMA measurements.
+ */
+static void *dm_ima_alloc(size_t len, bool noio)
+{
+	unsigned int noio_flag;
+	void *ptr;
+
+	if (noio)
+		noio_flag = memalloc_noio_save();
+
+	ptr = kzalloc(len, GFP_KERNEL);
+
+	if (noio)
+		memalloc_noio_restore(noio_flag);
+
+	return ptr;
+}
+
+void dm_ima_init(struct mapped_device *md)
+{
+	md->ima.update_idx = 0;
+	md->ima.measure_idx = 0;
+	init_waitqueue_head(&md->ima.ima_wq);
+	spin_lock_init(&md->ima.ima_lock);
+}
+
+void dm_ima_alloc_context(struct dm_ima_context **context, bool noio)
+{
+	*context = dm_ima_alloc(sizeof(struct dm_ima_context), noio);
+}
+
+void dm_ima_free_context(struct dm_ima_context *context)
+{
+	if (likely(context)) {
+		kfree(context->table.device_metadata);
+		kfree(context->table.hash);
+		kfree(context);
+	}
+}
+
+static void wait_to_measure(struct dm_ima_measurements *ima,
+			    unsigned int update_idx)
+{
+	spin_lock_irq(&ima->ima_lock);
+	wait_event_lock_irq(ima->ima_wq,
+			    ima->measure_idx == update_idx,
+			    ima->ima_lock);
+	spin_unlock_irq(&ima->ima_lock);
+}
+
+static void wake_next_measure(struct dm_ima_measurements *ima)
+{
+	spin_lock_irq(&ima->ima_lock);
+	ima->measure_idx++;
+	spin_unlock_irq(&ima->ima_lock);
+	wake_up_all(&ima->ima_wq);
+}
+
+/*
+ * Helper function for swapping the table, to make sure that the
+ * correct table metadata is saved and restored.
+ */
+void dm_ima_context_table_op(struct mapped_device *md,
+			     struct dm_ima_context *context,
+			     enum dm_ima_table_op op)
+{
+	struct dm_ima_measurements *ima = &md->ima;
+
+	if (unlikely(!context))
+		return;
+
+	wait_to_measure(ima, context->update_idx);
+
+	if (op == DM_IMA_TABLE_SAVE) {
+		context->table = ima->inactive_table;
+		memset(&ima->inactive_table, 0, sizeof(ima->inactive_table));
+	} else {
+		ima->inactive_table = context->table;
+		memset(&context->table, 0, sizeof(context->table));
+	}
+
+	wake_next_measure(ima);
+}
+
+/*
+ * Internal function to copy device data for IMA measurements.
+ */
+static void dm_ima_copy_device_data(struct mapped_device *md, char *device_data,
+				    struct dm_ima_context *context,
+				    unsigned int num_targets)
+{
+	memset(device_data, 0, DM_IMA_DEVICE_BUF_LEN);
+	scnprintf(device_data, DM_IMA_DEVICE_BUF_LEN,
+		  "name=%s,uuid=%s,major=%d,minor=%d,minor_count=%d,num_targets=%u;",
+		  context->dev_name, context->dev_uuid, md->disk->major,
+		  md->disk->first_minor, md->disk->minors, num_targets);
+
+}
+
+/*
+ * Internal wrapper function to call IMA to measure DM data.
+ */
+static void dm_ima_measure_data(const char *event_name, const void *buf, size_t buf_len,
+				bool noio)
+{
+	unsigned int noio_flag;
+
+	if (noio)
+		noio_flag = memalloc_noio_save();
+
+	ima_measure_critical_data(DM_NAME, event_name, buf, buf_len,
+				  false, NULL, 0);
+
+	if (noio)
+		memalloc_noio_restore(noio_flag);
+}
+
+static sector_t dm_ima_capacity(struct mapped_device *md)
+{
+	return (md->ima.active_table.device_metadata) ?
+		md->ima.active_table.capacity : get_capacity(md->disk);
+}
+
+/*
+ * Build up the IMA data for each target, and finally measure.
+ */
+void dm_ima_measure_on_table_load(struct dm_table *table,
+				  struct dm_ima_context *context)
+{
+	size_t device_data_buf_len, target_metadata_buf_len, target_data_buf_len, l = 0;
+	char *target_metadata_buf = NULL, *target_data_buf = NULL, *digest_buf = NULL;
+	char *ima_buf = NULL, *device_data_buf = NULL;
+	status_type_t type = STATUSTYPE_IMA;
+	size_t cur_total_buf_len = 0;
+	unsigned int num_targets, i;
+	struct sha256_ctx hash_ctx;
+	u8 digest[SHA256_DIGEST_SIZE];
+	bool noio = false;
+	char table_load_event_name[] = "dm_table_load";
+
+	if (unlikely(!context))
+		return;
+
+	wait_to_measure(&table->md->ima, context->update_idx);
+
+	ima_buf = dm_ima_alloc(DM_IMA_MEASUREMENT_BUF_LEN, noio);
+	if (!ima_buf)
+		goto error;
+
+	target_metadata_buf = dm_ima_alloc(DM_IMA_TARGET_METADATA_BUF_LEN, noio);
+	if (!target_metadata_buf)
+		goto error;
+
+	target_data_buf = dm_ima_alloc(DM_IMA_TARGET_DATA_BUF_LEN, noio);
+	if (!target_data_buf)
+		goto error;
+
+	num_targets = table->num_targets;
+
+	device_data_buf = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, noio);
+	if (!device_data_buf)
+		goto error;
+
+	fix_context_strings(context);
+	dm_ima_copy_device_data(table->md, device_data_buf, context,
+				num_targets);
+
+	sha256_init(&hash_ctx);
+
+	memcpy(ima_buf + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+	l += strlen(DM_IMA_VERSION_STR);
+
+	device_data_buf_len = strlen(device_data_buf);
+	memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
+	l += device_data_buf_len;
+
+	for (i = 0; i < num_targets; i++) {
+		struct dm_target *ti = dm_table_get_target(table, i);
+
+		/*
+		 * First retrieve the target metadata.
+		 */
+		target_metadata_buf_len =
+			scnprintf(target_metadata_buf,
+				  DM_IMA_TARGET_METADATA_BUF_LEN,
+				  "target_index=%d,target_begin=%llu,target_len=%llu,",
+				  i, ti->begin, ti->len);
+
+		/*
+		 * Then retrieve the actual target data.
+		 */
+		if (ti->type->status)
+			ti->type->status(ti, type, 0, target_data_buf,
+					 DM_IMA_TARGET_DATA_BUF_LEN);
+		else
+			target_data_buf[0] = '\0';
+
+		target_data_buf_len = strlen(target_data_buf);
+
+		/*
+		 * Check if the total data can fit into the IMA buffer.
+		 */
+		cur_total_buf_len = l + target_metadata_buf_len + target_data_buf_len;
+
+		/*
+		 * IMA measurements for DM targets are best-effort.
+		 * If the total data buffered so far, including the current target,
+		 * is too large to fit into DM_IMA_MEASUREMENT_BUF_LEN, measure what
+		 * we have in the current buffer, and continue measuring the remaining
+		 * targets by prefixing the device metadata again.
+		 */
+		if (unlikely(cur_total_buf_len >= DM_IMA_MEASUREMENT_BUF_LEN)) {
+			dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
+			sha256_update(&hash_ctx, (const u8 *)ima_buf, l);
+
+			memset(ima_buf, 0, DM_IMA_MEASUREMENT_BUF_LEN);
+			l = 0;
+
+			/*
+			 * Each new "dm_table_load" entry in IMA log should have device data
+			 * prefix, so that multiple records from the same "dm_table_load" for
+			 * a given device can be linked together.
+			 */
+			memcpy(ima_buf + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+			l += strlen(DM_IMA_VERSION_STR);
+
+			memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
+			l += device_data_buf_len;
+		}
+
+		/*
+		 * Fill-in all the target metadata, so that multiple targets for the same
+		 * device can be linked together.
+		 */
+		memcpy(ima_buf + l, target_metadata_buf, target_metadata_buf_len);
+		l += target_metadata_buf_len;
+
+		memcpy(ima_buf + l, target_data_buf, target_data_buf_len);
+		l += target_data_buf_len;
+	}
+
+	dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
+	sha256_update(&hash_ctx, (const u8 *)ima_buf, l);
+
+	/*
+	 * Finalize the table hash, and store it in table->md->ima.inactive_table.hash,
+	 * so that the table data can be verified against the future device state change
+	 * events, e.g. resume, rename, remove, table-clear etc.
+	 */
+	sha256_final(&hash_ctx, digest);
+
+	digest_buf = kasprintf(GFP_KERNEL, "sha256:%*phN", SHA256_DIGEST_SIZE,
+			       digest);
+	if (!digest_buf)
+		goto error;
+
+	kfree(table->md->ima.inactive_table.hash);
+	table->md->ima.inactive_table.hash = digest_buf;
+	table->md->ima.inactive_table.hash_len = strlen(digest_buf);
+	table->md->ima.inactive_table.num_targets = num_targets;
+	table->md->ima.inactive_table.capacity = dm_table_get_size(table);
+
+
+	kfree(table->md->ima.inactive_table.device_metadata);
+	table->md->ima.inactive_table.device_metadata = device_data_buf;
+	table->md->ima.inactive_table.device_metadata_len = device_data_buf_len;
+
+	goto exit;
+error:
+	kfree(digest_buf);
+	kfree(device_data_buf);
+exit:
+	kfree(ima_buf);
+	kfree(target_metadata_buf);
+	kfree(target_data_buf);
+
+	wake_next_measure(&table->md->ima);
+}
+
+/*
+ * Measure IMA data on device resume.
+ */
+void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap,
+				     struct dm_ima_context *context)
+{
+	char *device_table_data = NULL;
+	char active[] = "active_table_hash=";
+	unsigned int active_len = strlen(active);
+	unsigned int l = 0;
+	bool noio = true;
+	bool nodata = true;
+
+	if (unlikely(!context))
+		return;
+
+	wait_to_measure(&md->ima, context->update_idx);
+
+	if (swap) {
+		kfree(md->ima.active_table.hash);
+		kfree(md->ima.active_table.device_metadata);
+		md->ima.active_table = context->table;
+		memset(&context->table, 0, sizeof(context->table));
+		if (md->ima.active_table.device_metadata) {
+			/*
+			 * A rename could have happened while the swap was
+			 * going on. In that case, the saved table info would
+			 * still have the old name. Update the metadata to be
+			 * sure that it has the current name
+			 */
+			struct dm_ima_device_table_metadata *table = &md->ima.active_table;
+			fix_context_strings(context);
+			dm_ima_copy_device_data(md, table->device_metadata,
+						context, table->num_targets);
+			table->device_metadata_len = strlen(table->device_metadata);
+		}
+	}
+
+	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, noio);
+	if (!device_table_data)
+		goto error;
+
+	memcpy(device_table_data + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+	l += strlen(DM_IMA_VERSION_STR);
+
+	if (md->ima.active_table.device_metadata) {
+		memcpy(device_table_data + l, md->ima.active_table.device_metadata,
+		       md->ima.active_table.device_metadata_len);
+		l += md->ima.active_table.device_metadata_len;
+
+		nodata = false;
+	}
+
+	if (md->ima.active_table.hash) {
+		memcpy(device_table_data + l, active, active_len);
+		l += active_len;
+
+		memcpy(device_table_data + l, md->ima.active_table.hash,
+		       md->ima.active_table.hash_len);
+		l += md->ima.active_table.hash_len;
+
+		memcpy(device_table_data + l, ";", 1);
+		l++;
+
+		nodata = false;
+	}
+
+	if (nodata) {
+		fix_context_strings(context);
+		l = scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
+			      "%sname=%s,uuid=%s;device_resume=no_data;",
+			      DM_IMA_VERSION_STR, context->dev_name,
+			      context->dev_uuid);
+	}
+	l += scnprintf(device_table_data + l, DM_IMA_DEVICE_BUF_LEN - l,
+		       "current_device_capacity=%llu;", dm_ima_capacity(md));
+
+	dm_ima_measure_data("dm_device_resume", device_table_data, l, noio);
+
+error:
+	kfree(device_table_data);
+
+	wake_next_measure(&md->ima);
+}
+
+/*
+ * Measure IMA data on remove.
+ */
+void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all,
+				     struct dm_ima_context *context,
+				     unsigned int idx)
+{
+	char *device_table_data;
+	char active_table_str[] = "active_table_hash=";
+	char inactive_table_str[] = "inactive_table_hash=";
+	char device_active_str[] = "device_active_metadata=";
+	char device_inactive_str[] = "device_inactive_metadata=";
+	unsigned int active_table_len = strlen(active_table_str);
+	unsigned int inactive_table_len = strlen(inactive_table_str);
+	unsigned int device_active_len = strlen(device_active_str);
+	unsigned int device_inactive_len = strlen(device_inactive_str);
+	unsigned int l = 0;
+	bool noio = true;
+	bool nodata = true;
+
+	wait_to_measure(&md->ima, idx);
+
+	if (unlikely(!context))
+		goto exit;
+
+	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN*2, noio);
+	if (!device_table_data)
+		goto exit;
+
+	memcpy(device_table_data + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+	l += strlen(DM_IMA_VERSION_STR);
+
+	if (md->ima.active_table.device_metadata) {
+		memcpy(device_table_data + l, device_active_str, device_active_len);
+		l += device_active_len;
+
+		memcpy(device_table_data + l, md->ima.active_table.device_metadata,
+		       md->ima.active_table.device_metadata_len);
+		l += md->ima.active_table.device_metadata_len;
+
+		nodata = false;
+	}
+
+	if (md->ima.inactive_table.device_metadata) {
+		memcpy(device_table_data + l, device_inactive_str, device_inactive_len);
+		l += device_inactive_len;
+
+		memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
+		       md->ima.inactive_table.device_metadata_len);
+		l += md->ima.inactive_table.device_metadata_len;
+
+		nodata = false;
+	}
+
+	if (md->ima.active_table.hash) {
+		memcpy(device_table_data + l, active_table_str, active_table_len);
+		l += active_table_len;
+
+		memcpy(device_table_data + l, md->ima.active_table.hash,
+			   md->ima.active_table.hash_len);
+		l += md->ima.active_table.hash_len;
+
+		memcpy(device_table_data + l, ",", 1);
+		l++;
+
+		nodata = false;
+	}
+
+	if (md->ima.inactive_table.hash) {
+		memcpy(device_table_data + l, inactive_table_str, inactive_table_len);
+		l += inactive_table_len;
+
+		memcpy(device_table_data + l, md->ima.inactive_table.hash,
+		       md->ima.inactive_table.hash_len);
+		l += md->ima.inactive_table.hash_len;
+
+		memcpy(device_table_data + l, ",", 1);
+		l++;
+
+		nodata = false;
+	}
+	/*
+	 * In case both active and inactive tables, and corresponding
+	 * device metadata is cleared/missing - record the name and uuid
+	 * in IMA measurements.
+	 */
+	if (nodata) {
+		fix_context_strings(context);
+		l = scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
+			      "%sname=%s,uuid=%s;device_remove=no_data;",
+			      DM_IMA_VERSION_STR, context->dev_name,
+			      context->dev_uuid);
+	}
+
+	l += scnprintf(device_table_data + l, (DM_IMA_DEVICE_BUF_LEN * 2) - l,
+		       "remove_all=%c;current_device_capacity=%llu;",
+		       remove_all ? 'y' : 'n', dm_ima_capacity(md));
+
+	dm_ima_measure_data("dm_device_remove", device_table_data, l, noio);
+
+	kfree(device_table_data);
+exit:
+	kfree(md->ima.active_table.device_metadata);
+	kfree(md->ima.inactive_table.device_metadata);
+
+	kfree(md->ima.active_table.hash);
+	kfree(md->ima.inactive_table.hash);
+
+	memset(&md->ima.active_table, 0, sizeof(md->ima.active_table));
+	memset(&md->ima.inactive_table, 0, sizeof(md->ima.inactive_table));
+
+	wake_next_measure(&md->ima);
+}
+
+/*
+ * Measure ima data on table clear.
+ */
+void dm_ima_measure_on_table_clear(struct mapped_device *md,
+				   struct dm_ima_context *context)
+{
+	unsigned int l = 0;
+	char *device_table_data = NULL;
+	char inactive_str[] = "inactive_table_hash=";
+	unsigned int inactive_len = strlen(inactive_str);
+	bool noio = true;
+	bool nodata = true;
+
+	if (unlikely(!context))
+		return;
+
+	wait_to_measure(&md->ima, context->update_idx);
+
+	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, noio);
+	if (!device_table_data)
+		goto error;
+
+	memcpy(device_table_data + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+	l += strlen(DM_IMA_VERSION_STR);
+
+	if (md->ima.inactive_table.device_metadata_len &&
+	    md->ima.inactive_table.hash_len) {
+		memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
+		       md->ima.inactive_table.device_metadata_len);
+		l += md->ima.inactive_table.device_metadata_len;
+
+		memcpy(device_table_data + l, inactive_str, inactive_len);
+		l += inactive_len;
+
+		memcpy(device_table_data + l, md->ima.inactive_table.hash,
+			   md->ima.inactive_table.hash_len);
+
+		l += md->ima.inactive_table.hash_len;
+
+		memcpy(device_table_data + l, ";", 1);
+		l++;
+
+		nodata = false;
+	}
+
+	if (nodata) {
+		fix_context_strings(context);
+		l = scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
+			      "%sname=%s,uuid=%s;table_clear=no_data;",
+			      DM_IMA_VERSION_STR, context->dev_name,
+			      context->dev_uuid);
+	}
+
+	l += scnprintf(device_table_data + l, DM_IMA_DEVICE_BUF_LEN - l,
+		       "current_device_capacity=%llu;", dm_ima_capacity(md));
+
+	dm_ima_measure_data("dm_table_clear", device_table_data, l, noio);
+
+error:
+	kfree(md->ima.inactive_table.hash);
+	kfree(md->ima.inactive_table.device_metadata);
+	memset(&md->ima.inactive_table, 0, sizeof(md->ima.inactive_table));
+
+	kfree(device_table_data);
+
+	wake_next_measure(&md->ima);
+}
+
+/*
+ * Measure IMA data on device rename.
+ */
+void dm_ima_measure_on_device_rename(struct mapped_device *md,
+				     struct dm_ima_context *context)
+{
+	char *old_device_data = NULL;
+	char *combined_device_data = NULL;
+	bool noio = true;
+	int len;
+	struct dm_ima_device_table_metadata *table;
+
+	if (unlikely(!context))
+		return;
+
+	wait_to_measure(&md->ima, context->update_idx);
+
+	fix_context_strings(context);
+
+	combined_device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN * 2, noio);
+	if (!combined_device_data)
+		goto exit;
+
+	if (md->ima.active_table.device_metadata)
+		old_device_data = md->ima.active_table.device_metadata;
+	else if (md->ima.inactive_table.device_metadata)
+		old_device_data = md->ima.inactive_table.device_metadata;
+	else
+		old_device_data = "device_rename=no_data;";
+	len = scnprintf(combined_device_data, DM_IMA_DEVICE_BUF_LEN * 2,
+			"%s%snew_name=%s,new_uuid=%s;current_device_capacity=%llu;",
+			DM_IMA_VERSION_STR, old_device_data, context->dev_name,
+			context->dev_uuid, dm_ima_capacity(md));
+
+	dm_ima_measure_data("dm_device_rename", combined_device_data, len, noio);
+	kfree(combined_device_data);
+
+exit:
+	if (md->ima.active_table.device_metadata) {
+		table = &md->ima.active_table;
+		dm_ima_copy_device_data(md, table->device_metadata, context,
+					table->num_targets);
+		table->device_metadata_len = strlen(table->device_metadata);
+	}
+
+	if (md->ima.inactive_table.device_metadata) {
+		table = &md->ima.inactive_table;
+		dm_ima_copy_device_data(md, table->device_metadata, context,
+					table->num_targets);
+		table->device_metadata_len = strlen(table->device_metadata);
+	}
+
+	wake_next_measure(&md->ima);
+}