Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 874 insertions, 0 deletions

diff --git a/net/ethtool/bitset.c b/net/ethtool/bitset.c
new file mode 100644
index 000000000..a3a2cc648
--- /dev/null
+++ b/net/ethtool/bitset.c
@@ -0,0 +1,874 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/ethtool_netlink.h>
+#include <linux/bitmap.h>
+
+#include "bitset.h"
+#include "netlink.h"
+
+/* Some bitmaps are internally represented as an array of unsigned long, some
+ * as an array of u32 (some even as single u32 for now). To avoid the need of
+ * wrappers on caller side, we provide two set of functions: those with "32"
+ * suffix in their names expect u32 based bitmaps, those without it expect
+ * unsigned long bitmaps.
+ */
+
+static u32 ethnl_lower_bits(unsigned int n)
+{
+	return ~(u32)0 >> (32 - n % 32);
+}
+
+static u32 ethnl_upper_bits(unsigned int n)
+{
+	return ~(u32)0 << (n % 32);
+}
+
+/**
+ * ethnl_bitmap32_clear() - Clear u32 based bitmap
+ * @dst:   bitmap to clear
+ * @start: beginning of the interval
+ * @end:   end of the interval
+ * @mod:   set if bitmap was modified
+ *
+ * Clear @nbits bits of a bitmap with indices @start <= i < @end
+ */
+static void ethnl_bitmap32_clear(u32 *dst, unsigned int start, unsigned int end,
+				 bool *mod)
+{
+	unsigned int start_word = start / 32;
+	unsigned int end_word = end / 32;
+	unsigned int i;
+	u32 mask;
+
+	if (end <= start)
+		return;
+
+	if (start % 32) {
+		mask = ethnl_upper_bits(start);
+		if (end_word == start_word) {
+			mask &= ethnl_lower_bits(end);
+			if (dst[start_word] & mask) {
+				dst[start_word] &= ~mask;
+				*mod = true;
+			}
+			return;
+		}
+		if (dst[start_word] & mask) {
+			dst[start_word] &= ~mask;
+			*mod = true;
+		}
+		start_word++;
+	}
+
+	for (i = start_word; i < end_word; i++) {
+		if (dst[i]) {
+			dst[i] = 0;
+			*mod = true;
+		}
+	}
+	if (end % 32) {
+		mask = ethnl_lower_bits(end);
+		if (dst[end_word] & mask) {
+			dst[end_word] &= ~mask;
+			*mod = true;
+		}
+	}
+}
+
+/**
+ * ethnl_bitmap32_not_zero() - Check if any bit is set in an interval
+ * @map:   bitmap to test
+ * @start: beginning of the interval
+ * @end:   end of the interval
+ *
+ * Return: true if there is non-zero bit with  index @start <= i < @end,
+ *         false if the whole interval is zero
+ */
+static bool ethnl_bitmap32_not_zero(const u32 *map, unsigned int start,
+				    unsigned int end)
+{
+	unsigned int start_word = start / 32;
+	unsigned int end_word = end / 32;
+	u32 mask;
+
+	if (end <= start)
+		return false;
+
+	if (start % 32) {
+		mask = ethnl_upper_bits(start);
+		if (end_word == start_word) {
+			mask &= ethnl_lower_bits(end);
+			return map[start_word] & mask;
+		}
+		if (map[start_word] & mask)
+			return true;
+		start_word++;
+	}
+
+	if (memchr_inv(map + start_word, '\0',
+		       (end_word - start_word) * sizeof(u32)))
+		return true;
+	if (end % 32 == 0)
+		return false;
+	return map[end_word] & ethnl_lower_bits(end);
+}
+
+/**
+ * ethnl_bitmap32_update() - Modify u32 based bitmap according to value/mask
+ *			     pair
+ * @dst:   bitmap to update
+ * @nbits: bit size of the bitmap
+ * @value: values to set
+ * @mask:  mask of bits to set
+ * @mod:   set to true if bitmap is modified, preserve if not
+ *
+ * Set bits in @dst bitmap which are set in @mask to values from @value, leave
+ * the rest untouched. If destination bitmap was modified, set @mod to true,
+ * leave as it is if not.
+ */
+static void ethnl_bitmap32_update(u32 *dst, unsigned int nbits,
+				  const u32 *value, const u32 *mask, bool *mod)
+{
+	while (nbits > 0) {
+		u32 real_mask = mask ? *mask : ~(u32)0;
+		u32 new_value;
+
+		if (nbits < 32)
+			real_mask &= ethnl_lower_bits(nbits);
+		new_value = (*dst & ~real_mask) | (*value & real_mask);
+		if (new_value != *dst) {
+			*dst = new_value;
+			*mod = true;
+		}
+
+		if (nbits <= 32)
+			break;
+		dst++;
+		nbits -= 32;
+		value++;
+		if (mask)
+			mask++;
+	}
+}
+
+static bool ethnl_bitmap32_test_bit(const u32 *map, unsigned int index)
+{
+	return map[index / 32] & (1U << (index % 32));
+}
+
+/**
+ * ethnl_bitset32_size() - Calculate size of bitset nested attribute
+ * @val:     value bitmap (u32 based)
+ * @mask:    mask bitmap (u32 based, optional)
+ * @nbits:   bit length of the bitset
+ * @names:   array of bit names (optional)
+ * @compact: assume compact format for output
+ *
+ * Estimate length of netlink attribute composed by a later call to
+ * ethnl_put_bitset32() call with the same arguments.
+ *
+ * Return: negative error code or attribute length estimate
+ */
+int ethnl_bitset32_size(const u32 *val, const u32 *mask, unsigned int nbits,
+			ethnl_string_array_t names, bool compact)
+{
+	unsigned int len = 0;
+
+	/* list flag */
+	if (!mask)
+		len += nla_total_size(sizeof(u32));
+	/* size */
+	len += nla_total_size(sizeof(u32));
+
+	if (compact) {
+		unsigned int nwords = DIV_ROUND_UP(nbits, 32);
+
+		/* value, mask */
+		len += (mask ? 2 : 1) * nla_total_size(nwords * sizeof(u32));
+	} else {
+		unsigned int bits_len = 0;
+		unsigned int bit_len, i;
+
+		for (i = 0; i < nbits; i++) {
+			const char *name = names ? names[i] : NULL;
+
+			if (!ethnl_bitmap32_test_bit(mask ?: val, i))
+				continue;
+			/* index */
+			bit_len = nla_total_size(sizeof(u32));
+			/* name */
+			if (name)
+				bit_len += ethnl_strz_size(name);
+			/* value */
+			if (mask && ethnl_bitmap32_test_bit(val, i))
+				bit_len += nla_total_size(0);
+
+			/* bit nest */
+			bits_len += nla_total_size(bit_len);
+		}
+		/* bits nest */
+		len += nla_total_size(bits_len);
+	}
+
+	/* outermost nest */
+	return nla_total_size(len);
+}
+
+/**
+ * ethnl_put_bitset32() - Put a bitset nest into a message
+ * @skb:      skb with the message
+ * @attrtype: attribute type for the bitset nest
+ * @val:      value bitmap (u32 based)
+ * @mask:     mask bitmap (u32 based, optional)
+ * @nbits:    bit length of the bitset
+ * @names:    array of bit names (optional)
+ * @compact:  use compact format for the output
+ *
+ * Compose a nested attribute representing a bitset. If @mask is null, simple
+ * bitmap (bit list) is created, if @mask is provided, represent a value/mask
+ * pair. Bit names are only used in verbose mode and when provided by calller.
+ *
+ * Return: 0 on success, negative error value on error
+ */
+int ethnl_put_bitset32(struct sk_buff *skb, int attrtype, const u32 *val,
+		       const u32 *mask, unsigned int nbits,
+		       ethnl_string_array_t names, bool compact)
+{
+	struct nlattr *nest;
+	struct nlattr *attr;
+
+	nest = nla_nest_start(skb, attrtype);
+	if (!nest)
+		return -EMSGSIZE;
+
+	if (!mask && nla_put_flag(skb, ETHTOOL_A_BITSET_NOMASK))
+		goto nla_put_failure;
+	if (nla_put_u32(skb, ETHTOOL_A_BITSET_SIZE, nbits))
+		goto nla_put_failure;
+	if (compact) {
+		unsigned int nwords = DIV_ROUND_UP(nbits, 32);
+		unsigned int nbytes = nwords * sizeof(u32);
+		u32 *dst;
+
+		attr = nla_reserve(skb, ETHTOOL_A_BITSET_VALUE, nbytes);
+		if (!attr)
+			goto nla_put_failure;
+		dst = nla_data(attr);
+		memcpy(dst, val, nbytes);
+		if (nbits % 32)
+			dst[nwords - 1] &= ethnl_lower_bits(nbits);
+
+		if (mask) {
+			attr = nla_reserve(skb, ETHTOOL_A_BITSET_MASK, nbytes);
+			if (!attr)
+				goto nla_put_failure;
+			dst = nla_data(attr);
+			memcpy(dst, mask, nbytes);
+			if (nbits % 32)
+				dst[nwords - 1] &= ethnl_lower_bits(nbits);
+		}
+	} else {
+		struct nlattr *bits;
+		unsigned int i;
+
+		bits = nla_nest_start(skb, ETHTOOL_A_BITSET_BITS);
+		if (!bits)
+			goto nla_put_failure;
+		for (i = 0; i < nbits; i++) {
+			const char *name = names ? names[i] : NULL;
+
+			if (!ethnl_bitmap32_test_bit(mask ?: val, i))
+				continue;
+			attr = nla_nest_start(skb, ETHTOOL_A_BITSET_BITS_BIT);
+			if (!attr)
+				goto nla_put_failure;
+			if (nla_put_u32(skb, ETHTOOL_A_BITSET_BIT_INDEX, i))
+				goto nla_put_failure;
+			if (name &&
+			    ethnl_put_strz(skb, ETHTOOL_A_BITSET_BIT_NAME, name))
+				goto nla_put_failure;
+			if (mask && ethnl_bitmap32_test_bit(val, i) &&
+			    nla_put_flag(skb, ETHTOOL_A_BITSET_BIT_VALUE))
+				goto nla_put_failure;
+			nla_nest_end(skb, attr);
+		}
+		nla_nest_end(skb, bits);
+	}
+
+	nla_nest_end(skb, nest);
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(skb, nest);
+	return -EMSGSIZE;
+}
+
+static const struct nla_policy bitset_policy[] = {
+	[ETHTOOL_A_BITSET_NOMASK]	= { .type = NLA_FLAG },
+	[ETHTOOL_A_BITSET_SIZE]		= NLA_POLICY_MAX(NLA_U32,
+							 ETHNL_MAX_BITSET_SIZE),
+	[ETHTOOL_A_BITSET_BITS]		= { .type = NLA_NESTED },
+	[ETHTOOL_A_BITSET_VALUE]	= { .type = NLA_BINARY },
+	[ETHTOOL_A_BITSET_MASK]		= { .type = NLA_BINARY },
+};
+
+static const struct nla_policy bit_policy[] = {
+	[ETHTOOL_A_BITSET_BIT_INDEX]	= { .type = NLA_U32 },
+	[ETHTOOL_A_BITSET_BIT_NAME]	= { .type = NLA_NUL_STRING },
+	[ETHTOOL_A_BITSET_BIT_VALUE]	= { .type = NLA_FLAG },
+};
+
+/**
+ * ethnl_bitset_is_compact() - check if bitset attribute represents a compact
+ *			       bitset
+ * @bitset:  nested attribute representing a bitset
+ * @compact: pointer for return value
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+int ethnl_bitset_is_compact(const struct nlattr *bitset, bool *compact)
+{
+	struct nlattr *tb[ARRAY_SIZE(bitset_policy)];
+	int ret;
+
+	ret = nla_parse_nested(tb, ARRAY_SIZE(bitset_policy) - 1, bitset,
+			       bitset_policy, NULL);
+	if (ret < 0)
+		return ret;
+
+	if (tb[ETHTOOL_A_BITSET_BITS]) {
+		if (tb[ETHTOOL_A_BITSET_VALUE] || tb[ETHTOOL_A_BITSET_MASK])
+			return -EINVAL;
+		*compact = false;
+		return 0;
+	}
+	if (!tb[ETHTOOL_A_BITSET_SIZE] || !tb[ETHTOOL_A_BITSET_VALUE])
+		return -EINVAL;
+
+	*compact = true;
+	return 0;
+}
+
+/**
+ * ethnl_name_to_idx() - look up string index for a name
+ * @names:   array of ETH_GSTRING_LEN sized strings
+ * @n_names: number of strings in the array
+ * @name:    name to look up
+ *
+ * Return: index of the string if found, -ENOENT if not found
+ */
+static int ethnl_name_to_idx(ethnl_string_array_t names, unsigned int n_names,
+			     const char *name)
+{
+	unsigned int i;
+
+	if (!names)
+		return -ENOENT;
+
+	for (i = 0; i < n_names; i++) {
+		/* names[i] may not be null terminated */
+		if (!strncmp(names[i], name, ETH_GSTRING_LEN) &&
+		    strlen(name) <= ETH_GSTRING_LEN)
+			return i;
+	}
+
+	return -ENOENT;
+}
+
+static int ethnl_parse_bit(unsigned int *index, bool *val, unsigned int nbits,
+			   const struct nlattr *bit_attr, bool no_mask,
+			   ethnl_string_array_t names,
+			   struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[ARRAY_SIZE(bit_policy)];
+	int ret, idx;
+
+	ret = nla_parse_nested(tb, ARRAY_SIZE(bit_policy) - 1, bit_attr,
+			       bit_policy, extack);
+	if (ret < 0)
+		return ret;
+
+	if (tb[ETHTOOL_A_BITSET_BIT_INDEX]) {
+		const char *name;
+
+		idx = nla_get_u32(tb[ETHTOOL_A_BITSET_BIT_INDEX]);
+		if (idx >= nbits) {
+			NL_SET_ERR_MSG_ATTR(extack,
+					    tb[ETHTOOL_A_BITSET_BIT_INDEX],
+					    "bit index too high");
+			return -EOPNOTSUPP;
+		}
+		name = names ? names[idx] : NULL;
+		if (tb[ETHTOOL_A_BITSET_BIT_NAME] && name &&
+		    strncmp(nla_data(tb[ETHTOOL_A_BITSET_BIT_NAME]), name,
+			    nla_len(tb[ETHTOOL_A_BITSET_BIT_NAME]))) {
+			NL_SET_ERR_MSG_ATTR(extack, bit_attr,
+					    "bit index and name mismatch");
+			return -EINVAL;
+		}
+	} else if (tb[ETHTOOL_A_BITSET_BIT_NAME]) {
+		idx = ethnl_name_to_idx(names, nbits,
+					nla_data(tb[ETHTOOL_A_BITSET_BIT_NAME]));
+		if (idx < 0) {
+			NL_SET_ERR_MSG_ATTR(extack,
+					    tb[ETHTOOL_A_BITSET_BIT_NAME],
+					    "bit name not found");
+			return -EOPNOTSUPP;
+		}
+	} else {
+		NL_SET_ERR_MSG_ATTR(extack, bit_attr,
+				    "neither bit index nor name specified");
+		return -EINVAL;
+	}
+
+	*index = idx;
+	*val = no_mask || tb[ETHTOOL_A_BITSET_BIT_VALUE];
+	return 0;
+}
+
+/**
+ * ethnl_bitmap32_equal() - Compare two bitmaps
+ * @map1:  first bitmap
+ * @map2:  second bitmap
+ * @nbits: bit size to compare
+ *
+ * Return: true if first @nbits are equal, false if not
+ */
+static bool ethnl_bitmap32_equal(const u32 *map1, const u32 *map2,
+				 unsigned int nbits)
+{
+	if (memcmp(map1, map2, nbits / 32 * sizeof(u32)))
+		return false;
+	if (nbits % 32 == 0)
+		return true;
+	return !((map1[nbits / 32] ^ map2[nbits / 32]) &
+		 ethnl_lower_bits(nbits % 32));
+}
+
+static int
+ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits,
+			      const struct nlattr *attr, struct nlattr **tb,
+			      ethnl_string_array_t names,
+			      struct netlink_ext_ack *extack, bool *mod)
+{
+	u32 *saved_bitmap = NULL;
+	struct nlattr *bit_attr;
+	bool no_mask;
+	int rem;
+	int ret;
+
+	if (tb[ETHTOOL_A_BITSET_VALUE]) {
+		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_VALUE],
+				    "value only allowed in compact bitset");
+		return -EINVAL;
+	}
+	if (tb[ETHTOOL_A_BITSET_MASK]) {
+		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
+				    "mask only allowed in compact bitset");
+		return -EINVAL;
+	}
+
+	no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
+	if (no_mask) {
+		unsigned int nwords = DIV_ROUND_UP(nbits, 32);
+		unsigned int nbytes = nwords * sizeof(u32);
+		bool dummy;
+
+		/* The bitmap size is only the size of the map part without
+		 * its mask part.
+		 */
+		saved_bitmap = kcalloc(nwords, sizeof(u32), GFP_KERNEL);
+		if (!saved_bitmap)
+			return -ENOMEM;
+		memcpy(saved_bitmap, bitmap, nbytes);
+		ethnl_bitmap32_clear(bitmap, 0, nbits, &dummy);
+	}
+
+	nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) {
+		bool old_val, new_val;
+		unsigned int idx;
+
+		if (nla_type(bit_attr) != ETHTOOL_A_BITSET_BITS_BIT) {
+			NL_SET_ERR_MSG_ATTR(extack, bit_attr,
+					    "only ETHTOOL_A_BITSET_BITS_BIT allowed in ETHTOOL_A_BITSET_BITS");
+			kfree(saved_bitmap);
+			return -EINVAL;
+		}
+		ret = ethnl_parse_bit(&idx, &new_val, nbits, bit_attr, no_mask,
+				      names, extack);
+		if (ret < 0) {
+			kfree(saved_bitmap);
+			return ret;
+		}
+		old_val = bitmap[idx / 32] & ((u32)1 << (idx % 32));
+		if (new_val != old_val) {
+			if (new_val)
+				bitmap[idx / 32] |= ((u32)1 << (idx % 32));
+			else
+				bitmap[idx / 32] &= ~((u32)1 << (idx % 32));
+			if (!no_mask)
+				*mod = true;
+		}
+	}
+
+	if (no_mask && !ethnl_bitmap32_equal(saved_bitmap, bitmap, nbits))
+		*mod = true;
+
+	kfree(saved_bitmap);
+	return 0;
+}
+
+static int ethnl_compact_sanity_checks(unsigned int nbits,
+				       const struct nlattr *nest,
+				       struct nlattr **tb,
+				       struct netlink_ext_ack *extack)
+{
+	bool no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
+	unsigned int attr_nbits, attr_nwords;
+	const struct nlattr *test_attr;
+
+	if (no_mask && tb[ETHTOOL_A_BITSET_MASK]) {
+		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
+				    "mask not allowed in list bitset");
+		return -EINVAL;
+	}
+	if (!tb[ETHTOOL_A_BITSET_SIZE]) {
+		NL_SET_ERR_MSG_ATTR(extack, nest,
+				    "missing size in compact bitset");
+		return -EINVAL;
+	}
+	if (!tb[ETHTOOL_A_BITSET_VALUE]) {
+		NL_SET_ERR_MSG_ATTR(extack, nest,
+				    "missing value in compact bitset");
+		return -EINVAL;
+	}
+	if (!no_mask && !tb[ETHTOOL_A_BITSET_MASK]) {
+		NL_SET_ERR_MSG_ATTR(extack, nest,
+				    "missing mask in compact nonlist bitset");
+		return -EINVAL;
+	}
+
+	attr_nbits = nla_get_u32(tb[ETHTOOL_A_BITSET_SIZE]);
+	attr_nwords = DIV_ROUND_UP(attr_nbits, 32);
+	if (nla_len(tb[ETHTOOL_A_BITSET_VALUE]) != attr_nwords * sizeof(u32)) {
+		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_VALUE],
+				    "bitset value length does not match size");
+		return -EINVAL;
+	}
+	if (tb[ETHTOOL_A_BITSET_MASK] &&
+	    nla_len(tb[ETHTOOL_A_BITSET_MASK]) != attr_nwords * sizeof(u32)) {
+		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
+				    "bitset mask length does not match size");
+		return -EINVAL;
+	}
+	if (attr_nbits <= nbits)
+		return 0;
+
+	test_attr = no_mask ? tb[ETHTOOL_A_BITSET_VALUE] :
+			      tb[ETHTOOL_A_BITSET_MASK];
+	if (ethnl_bitmap32_not_zero(nla_data(test_attr), nbits, attr_nbits)) {
+		NL_SET_ERR_MSG_ATTR(extack, test_attr,
+				    "cannot modify bits past kernel bitset size");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/**
+ * ethnl_update_bitset32() - Apply a bitset nest to a u32 based bitmap
+ * @bitmap:  bitmap to update
+ * @nbits:   size of the updated bitmap in bits
+ * @attr:    nest attribute to parse and apply
+ * @names:   array of bit names; may be null for compact format
+ * @extack:  extack for error reporting
+ * @mod:     set this to true if bitmap is modified, leave as it is if not
+ *
+ * Apply bitset netsted attribute to a bitmap. If the attribute represents
+ * a bit list, @bitmap is set to its contents; otherwise, bits in mask are
+ * set to values from value. Bitmaps in the attribute may be longer than
+ * @nbits but the message must not request modifying any bits past @nbits.
+ *
+ * Return: negative error code on failure, 0 on success
+ */
+int ethnl_update_bitset32(u32 *bitmap, unsigned int nbits,
+			  const struct nlattr *attr, ethnl_string_array_t names,
+			  struct netlink_ext_ack *extack, bool *mod)
+{
+	struct nlattr *tb[ARRAY_SIZE(bitset_policy)];
+	unsigned int change_bits;
+	bool no_mask;
+	int ret;
+
+	if (!attr)
+		return 0;
+	ret = nla_parse_nested(tb, ARRAY_SIZE(bitset_policy) - 1, attr,
+			       bitset_policy, extack);
+	if (ret < 0)
+		return ret;
+
+	if (tb[ETHTOOL_A_BITSET_BITS])
+		return ethnl_update_bitset32_verbose(bitmap, nbits, attr, tb,
+						     names, extack, mod);
+	ret = ethnl_compact_sanity_checks(nbits, attr, tb, extack);
+	if (ret < 0)
+		return ret;
+
+	no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
+	change_bits = min_t(unsigned int,
+			    nla_get_u32(tb[ETHTOOL_A_BITSET_SIZE]), nbits);
+	ethnl_bitmap32_update(bitmap, change_bits,
+			      nla_data(tb[ETHTOOL_A_BITSET_VALUE]),
+			      no_mask ? NULL :
+					nla_data(tb[ETHTOOL_A_BITSET_MASK]),
+			      mod);
+	if (no_mask && change_bits < nbits)
+		ethnl_bitmap32_clear(bitmap, change_bits, nbits, mod);
+
+	return 0;
+}
+
+/**
+ * ethnl_parse_bitset() - Compute effective value and mask from bitset nest
+ * @val:     unsigned long based bitmap to put value into
+ * @mask:    unsigned long based bitmap to put mask into
+ * @nbits:   size of @val and @mask bitmaps
+ * @attr:    nest attribute to parse and apply
+ * @names:   array of bit names; may be null for compact format
+ * @extack:  extack for error reporting
+ *
+ * Provide @nbits size long bitmaps for value and mask so that
+ * x = (val & mask) | (x & ~mask) would modify any @nbits sized bitmap x
+ * the same way ethnl_update_bitset() with the same bitset attribute would.
+ *
+ * Return:   negative error code on failure, 0 on success
+ */
+int ethnl_parse_bitset(unsigned long *val, unsigned long *mask,
+		       unsigned int nbits, const struct nlattr *attr,
+		       ethnl_string_array_t names,
+		       struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[ARRAY_SIZE(bitset_policy)];
+	const struct nlattr *bit_attr;
+	bool no_mask;
+	int rem;
+	int ret;
+
+	if (!attr)
+		return 0;
+	ret = nla_parse_nested(tb, ARRAY_SIZE(bitset_policy) - 1, attr,
+			       bitset_policy, extack);
+	if (ret < 0)
+		return ret;
+	no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
+
+	if (!tb[ETHTOOL_A_BITSET_BITS]) {
+		unsigned int change_bits;
+
+		ret = ethnl_compact_sanity_checks(nbits, attr, tb, extack);
+		if (ret < 0)
+			return ret;
+
+		change_bits = nla_get_u32(tb[ETHTOOL_A_BITSET_SIZE]);
+		if (change_bits > nbits)
+			change_bits = nbits;
+		bitmap_from_arr32(val, nla_data(tb[ETHTOOL_A_BITSET_VALUE]),
+				  change_bits);
+		if (change_bits < nbits)
+			bitmap_clear(val, change_bits, nbits - change_bits);
+		if (no_mask) {
+			bitmap_fill(mask, nbits);
+		} else {
+			bitmap_from_arr32(mask,
+					  nla_data(tb[ETHTOOL_A_BITSET_MASK]),
+					  change_bits);
+			if (change_bits < nbits)
+				bitmap_clear(mask, change_bits,
+					     nbits - change_bits);
+		}
+
+		return 0;
+	}
+
+	if (tb[ETHTOOL_A_BITSET_VALUE]) {
+		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_VALUE],
+				    "value only allowed in compact bitset");
+		return -EINVAL;
+	}
+	if (tb[ETHTOOL_A_BITSET_MASK]) {
+		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
+				    "mask only allowed in compact bitset");
+		return -EINVAL;
+	}
+
+	bitmap_zero(val, nbits);
+	if (no_mask)
+		bitmap_fill(mask, nbits);
+	else
+		bitmap_zero(mask, nbits);
+
+	nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) {
+		unsigned int idx;
+		bool bit_val;
+
+		ret = ethnl_parse_bit(&idx, &bit_val, nbits, bit_attr, no_mask,
+				      names, extack);
+		if (ret < 0)
+			return ret;
+		if (bit_val)
+			__set_bit(idx, val);
+		if (!no_mask)
+			__set_bit(idx, mask);
+	}
+
+	return 0;
+}
+
+#if BITS_PER_LONG == 64 && defined(__BIG_ENDIAN)
+
+/* 64-bit big endian architectures are the only case when u32 based bitmaps
+ * and unsigned long based bitmaps have different memory layout so that we
+ * cannot simply cast the latter to the former and need actual wrappers
+ * converting the latter to the former.
+ *
+ * To reduce the number of slab allocations, the wrappers use fixed size local
+ * variables for bitmaps up to ETHNL_SMALL_BITMAP_BITS bits which is the
+ * majority of bitmaps used by ethtool.
+ */
+#define ETHNL_SMALL_BITMAP_BITS 128
+#define ETHNL_SMALL_BITMAP_WORDS DIV_ROUND_UP(ETHNL_SMALL_BITMAP_BITS, 32)
+
+int ethnl_bitset_size(const unsigned long *val, const unsigned long *mask,
+		      unsigned int nbits, ethnl_string_array_t names,
+		      bool compact)
+{
+	u32 small_mask32[ETHNL_SMALL_BITMAP_WORDS];
+	u32 small_val32[ETHNL_SMALL_BITMAP_WORDS];
+	u32 *mask32;
+	u32 *val32;
+	int ret;
+
+	if (nbits > ETHNL_SMALL_BITMAP_BITS) {
+		unsigned int nwords = DIV_ROUND_UP(nbits, 32);
+
+		val32 = kmalloc_array(2 * nwords, sizeof(u32), GFP_KERNEL);
+		if (!val32)
+			return -ENOMEM;
+		mask32 = val32 + nwords;
+	} else {
+		val32 = small_val32;
+		mask32 = small_mask32;
+	}
+
+	bitmap_to_arr32(val32, val, nbits);
+	if (mask)
+		bitmap_to_arr32(mask32, mask, nbits);
+	else
+		mask32 = NULL;
+	ret = ethnl_bitset32_size(val32, mask32, nbits, names, compact);
+
+	if (nbits > ETHNL_SMALL_BITMAP_BITS)
+		kfree(val32);
+
+	return ret;
+}
+
+int ethnl_put_bitset(struct sk_buff *skb, int attrtype,
+		     const unsigned long *val, const unsigned long *mask,
+		     unsigned int nbits, ethnl_string_array_t names,
+		     bool compact)
+{
+	u32 small_mask32[ETHNL_SMALL_BITMAP_WORDS];
+	u32 small_val32[ETHNL_SMALL_BITMAP_WORDS];
+	u32 *mask32;
+	u32 *val32;
+	int ret;
+
+	if (nbits > ETHNL_SMALL_BITMAP_BITS) {
+		unsigned int nwords = DIV_ROUND_UP(nbits, 32);
+
+		val32 = kmalloc_array(2 * nwords, sizeof(u32), GFP_KERNEL);
+		if (!val32)
+			return -ENOMEM;
+		mask32 = val32 + nwords;
+	} else {
+		val32 = small_val32;
+		mask32 = small_mask32;
+	}
+
+	bitmap_to_arr32(val32, val, nbits);
+	if (mask)
+		bitmap_to_arr32(mask32, mask, nbits);
+	else
+		mask32 = NULL;
+	ret = ethnl_put_bitset32(skb, attrtype, val32, mask32, nbits, names,
+				 compact);
+
+	if (nbits > ETHNL_SMALL_BITMAP_BITS)
+		kfree(val32);
+
+	return ret;
+}
+
+int ethnl_update_bitset(unsigned long *bitmap, unsigned int nbits,
+			const struct nlattr *attr, ethnl_string_array_t names,
+			struct netlink_ext_ack *extack, bool *mod)
+{
+	u32 small_bitmap32[ETHNL_SMALL_BITMAP_WORDS];
+	u32 *bitmap32 = small_bitmap32;
+	bool u32_mod = false;
+	int ret;
+
+	if (nbits > ETHNL_SMALL_BITMAP_BITS) {
+		unsigned int dst_words = DIV_ROUND_UP(nbits, 32);
+
+		bitmap32 = kmalloc_array(dst_words, sizeof(u32), GFP_KERNEL);
+		if (!bitmap32)
+			return -ENOMEM;
+	}
+
+	bitmap_to_arr32(bitmap32, bitmap, nbits);
+	ret = ethnl_update_bitset32(bitmap32, nbits, attr, names, extack,
+				    &u32_mod);
+	if (u32_mod) {
+		bitmap_from_arr32(bitmap, bitmap32, nbits);
+		*mod = true;
+	}
+
+	if (nbits > ETHNL_SMALL_BITMAP_BITS)
+		kfree(bitmap32);
+
+	return ret;
+}
+
+#else
+
+/* On little endian 64-bit and all 32-bit architectures, an unsigned long
+ * based bitmap can be interpreted as u32 based one using a simple cast.
+ */
+
+int ethnl_bitset_size(const unsigned long *val, const unsigned long *mask,
+		      unsigned int nbits, ethnl_string_array_t names,
+		      bool compact)
+{
+	return ethnl_bitset32_size((const u32 *)val, (const u32 *)mask, nbits,
+				   names, compact);
+}
+
+int ethnl_put_bitset(struct sk_buff *skb, int attrtype,
+		     const unsigned long *val, const unsigned long *mask,
+		     unsigned int nbits, ethnl_string_array_t names,
+		     bool compact)
+{
+	return ethnl_put_bitset32(skb, attrtype, (const u32 *)val,
+				  (const u32 *)mask, nbits, names, compact);
+}
+
+int ethnl_update_bitset(unsigned long *bitmap, unsigned int nbits,
+			const struct nlattr *attr, ethnl_string_array_t names,
+			struct netlink_ext_ack *extack, bool *mod)
+{
+	return ethnl_update_bitset32((u32 *)bitmap, nbits, attr, names, extack,
+				     mod);
+}
+
+#endif /* BITS_PER_LONG == 64 && defined(__BIG_ENDIAN) */