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, 1606 insertions, 0 deletions

diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
new file mode 100644
index 000000000..56bd23059
--- /dev/null
+++ b/lib/test_bitmap.c
@@ -0,0 +1,1606 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test cases for bitmap API.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitmap.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+
+#include "../tools/testing/selftests/kselftest_module.h"
+
+#define EXP1_IN_BITS	(sizeof(exp1) * 8)
+
+KSTM_MODULE_GLOBALS();
+
+static char pbl_buffer[PAGE_SIZE] __initdata;
+static char print_buf[PAGE_SIZE * 2] __initdata;
+
+static const unsigned long exp1[] __initconst = {
+	BITMAP_FROM_U64(1),
+	BITMAP_FROM_U64(2),
+	BITMAP_FROM_U64(0x0000ffff),
+	BITMAP_FROM_U64(0xffff0000),
+	BITMAP_FROM_U64(0x55555555),
+	BITMAP_FROM_U64(0xaaaaaaaa),
+	BITMAP_FROM_U64(0x11111111),
+	BITMAP_FROM_U64(0x22222222),
+	BITMAP_FROM_U64(0xffffffff),
+	BITMAP_FROM_U64(0xfffffffe),
+	BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0xffffffff77777777ULL),
+	BITMAP_FROM_U64(0),
+	BITMAP_FROM_U64(0x00008000),
+	BITMAP_FROM_U64(0x80000000),
+};
+
+static const unsigned long exp2[] __initconst = {
+	BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0xffffffff77777777ULL),
+};
+
+/* Fibonacci sequence */
+static const unsigned long exp2_to_exp3_mask[] __initconst = {
+	BITMAP_FROM_U64(0x008000020020212eULL),
+};
+/* exp3_0_1 = (exp2[0] & ~exp2_to_exp3_mask) | (exp2[1] & exp2_to_exp3_mask) */
+static const unsigned long exp3_0_1[] __initconst = {
+	BITMAP_FROM_U64(0x33b3333311313137ULL),
+};
+/* exp3_1_0 = (exp2[1] & ~exp2_to_exp3_mask) | (exp2[0] & exp2_to_exp3_mask) */
+static const unsigned long exp3_1_0[] __initconst = {
+	BITMAP_FROM_U64(0xff7fffff77575751ULL),
+};
+
+static bool __init
+__check_eq_ulong(const char *srcfile, unsigned int line,
+		 const unsigned long exp_ulong, unsigned long x)
+{
+	if (exp_ulong != x) {
+		pr_err("[%s:%u] expected %lu, got %lu\n",
+			srcfile, line, exp_ulong, x);
+		return false;
+	}
+	return true;
+}
+
+static bool __init
+__check_eq_bitmap(const char *srcfile, unsigned int line,
+		  const unsigned long *exp_bmap, const unsigned long *bmap,
+		  unsigned int nbits)
+{
+	if (!bitmap_equal(exp_bmap, bmap, nbits)) {
+		pr_warn("[%s:%u] bitmaps contents differ: expected \"%*pbl\", got \"%*pbl\"\n",
+			srcfile, line,
+			nbits, exp_bmap, nbits, bmap);
+		return false;
+	}
+	return true;
+}
+
+static bool __init
+__check_eq_pbl(const char *srcfile, unsigned int line,
+	       const char *expected_pbl,
+	       const unsigned long *bitmap, unsigned int nbits)
+{
+	snprintf(pbl_buffer, sizeof(pbl_buffer), "%*pbl", nbits, bitmap);
+	if (strcmp(expected_pbl, pbl_buffer)) {
+		pr_warn("[%s:%u] expected \"%s\", got \"%s\"\n",
+			srcfile, line,
+			expected_pbl, pbl_buffer);
+		return false;
+	}
+	return true;
+}
+
+static bool __init __check_eq_clump8(const char *srcfile, unsigned int line,
+				    const unsigned int offset,
+				    const unsigned int size,
+				    const unsigned char *const clump_exp,
+				    const unsigned long *const clump)
+{
+	unsigned long exp;
+
+	if (offset >= size) {
+		pr_warn("[%s:%u] bit offset for clump out-of-bounds: expected less than %u, got %u\n",
+			srcfile, line, size, offset);
+		return false;
+	}
+
+	exp = clump_exp[offset / 8];
+	if (!exp) {
+		pr_warn("[%s:%u] bit offset for zero clump: expected nonzero clump, got bit offset %u with clump value 0",
+			srcfile, line, offset);
+		return false;
+	}
+
+	if (*clump != exp) {
+		pr_warn("[%s:%u] expected clump value of 0x%lX, got clump value of 0x%lX",
+			srcfile, line, exp, *clump);
+		return false;
+	}
+
+	return true;
+}
+
+static bool __init
+__check_eq_str(const char *srcfile, unsigned int line,
+		const char *exp_str, const char *str,
+		unsigned int len)
+{
+	bool eq;
+
+	eq = strncmp(exp_str, str, len) == 0;
+	if (!eq)
+		pr_err("[%s:%u] expected %s, got %s\n", srcfile, line, exp_str, str);
+
+	return eq;
+}
+
+#define __expect_eq(suffix, ...)					\
+	({								\
+		int result = 0;						\
+		total_tests++;						\
+		if (!__check_eq_ ## suffix(__FILE__, __LINE__,		\
+					   ##__VA_ARGS__)) {		\
+			failed_tests++;					\
+			result = 1;					\
+		}							\
+		result;							\
+	})
+
+#define expect_eq_ulong(...)		__expect_eq(ulong, ##__VA_ARGS__)
+#define expect_eq_uint(x, y)		expect_eq_ulong((unsigned int)(x), (unsigned int)(y))
+#define expect_eq_bitmap(...)		__expect_eq(bitmap, ##__VA_ARGS__)
+#define expect_eq_pbl(...)		__expect_eq(pbl, ##__VA_ARGS__)
+#define expect_eq_u32_array(...)	__expect_eq(u32_array, ##__VA_ARGS__)
+#define expect_eq_clump8(...)		__expect_eq(clump8, ##__VA_ARGS__)
+#define expect_eq_str(...)		__expect_eq(str, ##__VA_ARGS__)
+
+static void __init test_zero_clear(void)
+{
+	DECLARE_BITMAP(bmap, 1024);
+
+	/* Known way to set all bits */
+	memset(bmap, 0xff, 128);
+
+	expect_eq_pbl("0-22", bmap, 23);
+	expect_eq_pbl("0-1023", bmap, 1024);
+
+	/* single-word bitmaps */
+	bitmap_clear(bmap, 0, 9);
+	expect_eq_pbl("9-1023", bmap, 1024);
+
+	bitmap_zero(bmap, 35);
+	expect_eq_pbl("64-1023", bmap, 1024);
+
+	/* cross boundaries operations */
+	bitmap_clear(bmap, 79, 19);
+	expect_eq_pbl("64-78,98-1023", bmap, 1024);
+
+	bitmap_zero(bmap, 115);
+	expect_eq_pbl("128-1023", bmap, 1024);
+
+	/* Zeroing entire area */
+	bitmap_zero(bmap, 1024);
+	expect_eq_pbl("", bmap, 1024);
+}
+
+static void __init test_find_nth_bit(void)
+{
+	unsigned long b, bit, cnt = 0;
+	DECLARE_BITMAP(bmap, 64 * 3);
+
+	bitmap_zero(bmap, 64 * 3);
+	__set_bit(10, bmap);
+	__set_bit(20, bmap);
+	__set_bit(30, bmap);
+	__set_bit(40, bmap);
+	__set_bit(50, bmap);
+	__set_bit(60, bmap);
+	__set_bit(80, bmap);
+	__set_bit(123, bmap);
+
+	expect_eq_uint(10,  find_nth_bit(bmap, 64 * 3, 0));
+	expect_eq_uint(20,  find_nth_bit(bmap, 64 * 3, 1));
+	expect_eq_uint(30,  find_nth_bit(bmap, 64 * 3, 2));
+	expect_eq_uint(40,  find_nth_bit(bmap, 64 * 3, 3));
+	expect_eq_uint(50,  find_nth_bit(bmap, 64 * 3, 4));
+	expect_eq_uint(60,  find_nth_bit(bmap, 64 * 3, 5));
+	expect_eq_uint(80,  find_nth_bit(bmap, 64 * 3, 6));
+	expect_eq_uint(123, find_nth_bit(bmap, 64 * 3, 7));
+	expect_eq_uint(0,   !!(find_nth_bit(bmap, 64 * 3, 8) < 64 * 3));
+
+	expect_eq_uint(10,  find_nth_bit(bmap, 64 * 3 - 1, 0));
+	expect_eq_uint(20,  find_nth_bit(bmap, 64 * 3 - 1, 1));
+	expect_eq_uint(30,  find_nth_bit(bmap, 64 * 3 - 1, 2));
+	expect_eq_uint(40,  find_nth_bit(bmap, 64 * 3 - 1, 3));
+	expect_eq_uint(50,  find_nth_bit(bmap, 64 * 3 - 1, 4));
+	expect_eq_uint(60,  find_nth_bit(bmap, 64 * 3 - 1, 5));
+	expect_eq_uint(80,  find_nth_bit(bmap, 64 * 3 - 1, 6));
+	expect_eq_uint(123, find_nth_bit(bmap, 64 * 3 - 1, 7));
+	expect_eq_uint(0,   !!(find_nth_bit(bmap, 64 * 3 - 1, 8) < 64 * 3 - 1));
+
+	for_each_set_bit(bit, exp1, EXP1_IN_BITS) {
+		b = find_nth_bit(exp1, EXP1_IN_BITS, cnt++);
+		expect_eq_uint(b, bit);
+	}
+}
+
+static void __init
+test_bitmap_find_next_zero_area_off(void)
+{
+	DECLARE_BITMAP(bmap, 192);
+
+	bitmap_set(bmap, 0, 192);
+
+	bitmap_clear(bmap, 0, 8);
+	__clear_bit(50, bmap);
+	bitmap_clear(bmap, 60, 18);
+	__set_bit(69, bmap);
+	__clear_bit(80, bmap);
+	bitmap_clear(bmap, 100, 10);
+	__clear_bit(120, bmap);
+	bitmap_clear(bmap, 145, 8);
+	bitmap_clear(bmap, 160, 32);
+
+	expect_eq_uint(0,
+		bitmap_find_next_zero_area_off(bmap, 192, 0, 8, 0, 0));
+	expect_eq_uint(0,
+		bitmap_find_next_zero_area_off(bmap, 192, 0, 8, 3, 0));
+	expect_eq_uint(163,
+		bitmap_find_next_zero_area_off(bmap, 192, 0, 8, 3, 1));
+	expect_eq_uint(60,
+		bitmap_find_next_zero_area_off(bmap, 192, 1, 8, 0, 0));
+	expect_eq_uint(160,
+		bitmap_find_next_zero_area_off(bmap, 192, 1, 8, 7, 0));
+	expect_eq_uint(60,
+		bitmap_find_next_zero_area_off(bmap, 192, 1, 8, 7, 4));
+	expect_eq_uint(100,
+		bitmap_find_next_zero_area_off(bmap, 192, 0, 10, 0, 0));
+	expect_eq_uint(160,
+		bitmap_find_next_zero_area_off(bmap, 192, 0, 32, 0, 0));
+	expect_eq_uint(1,
+		!!(bitmap_find_next_zero_area_off(bmap, 192, 0, 33, 0, 0) >= 192));
+}
+
+static void __init test_fill_set(void)
+{
+	DECLARE_BITMAP(bmap, 1024);
+
+	/* Known way to clear all bits */
+	memset(bmap, 0x00, 128);
+
+	expect_eq_pbl("", bmap, 23);
+	expect_eq_pbl("", bmap, 1024);
+
+	/* single-word bitmaps */
+	bitmap_set(bmap, 0, 9);
+	expect_eq_pbl("0-8", bmap, 1024);
+
+	bitmap_fill(bmap, 35);
+	expect_eq_pbl("0-63", bmap, 1024);
+
+	/* cross boundaries operations */
+	bitmap_set(bmap, 79, 19);
+	expect_eq_pbl("0-63,79-97", bmap, 1024);
+
+	bitmap_fill(bmap, 115);
+	expect_eq_pbl("0-127", bmap, 1024);
+
+	/* Zeroing entire area */
+	bitmap_fill(bmap, 1024);
+	expect_eq_pbl("0-1023", bmap, 1024);
+}
+
+static void __init test_copy(void)
+{
+	DECLARE_BITMAP(bmap1, 1024);
+	DECLARE_BITMAP(bmap2, 1024);
+
+	bitmap_zero(bmap1, 1024);
+	bitmap_zero(bmap2, 1024);
+
+	/* single-word bitmaps */
+	bitmap_set(bmap1, 0, 19);
+	bitmap_copy(bmap2, bmap1, 23);
+	expect_eq_pbl("0-18", bmap2, 1024);
+
+	bitmap_set(bmap2, 0, 23);
+	bitmap_copy(bmap2, bmap1, 23);
+	expect_eq_pbl("0-18", bmap2, 1024);
+
+	/* multi-word bitmaps */
+	bitmap_set(bmap1, 0, 109);
+	bitmap_copy(bmap2, bmap1, 1024);
+	expect_eq_pbl("0-108", bmap2, 1024);
+
+	bitmap_fill(bmap2, 1024);
+	bitmap_copy(bmap2, bmap1, 1024);
+	expect_eq_pbl("0-108", bmap2, 1024);
+
+	/* the following tests assume a 32- or 64-bit arch (even 128b
+	 * if we care)
+	 */
+
+	bitmap_fill(bmap2, 1024);
+	bitmap_copy(bmap2, bmap1, 109);  /* ... but 0-padded til word length */
+	expect_eq_pbl("0-108,128-1023", bmap2, 1024);
+
+	bitmap_fill(bmap2, 1024);
+	bitmap_copy(bmap2, bmap1, 97);  /* ... but aligned on word length */
+	expect_eq_pbl("0-108,128-1023", bmap2, 1024);
+}
+
+static void __init test_bitmap_region(void)
+{
+	int pos, order;
+
+	DECLARE_BITMAP(bmap, 1000);
+
+	bitmap_zero(bmap, 1000);
+
+	for (order = 0; order < 10; order++) {
+		pos = bitmap_find_free_region(bmap, 1000, order);
+		if (order == 0)
+			expect_eq_uint(pos, 0);
+		else
+			expect_eq_uint(pos, order < 9 ? BIT(order) : -ENOMEM);
+	}
+
+	bitmap_release_region(bmap, 0, 0);
+	for (order = 1; order < 9; order++)
+		bitmap_release_region(bmap, BIT(order), order);
+
+	expect_eq_uint(bitmap_weight(bmap, 1000), 0);
+}
+
+#define EXP2_IN_BITS	(sizeof(exp2) * 8)
+
+static void __init test_replace(void)
+{
+	unsigned int nbits = 64;
+	unsigned int nlongs = DIV_ROUND_UP(nbits, BITS_PER_LONG);
+	DECLARE_BITMAP(bmap, 1024);
+
+	BUILD_BUG_ON(EXP2_IN_BITS < nbits * 2);
+
+	bitmap_zero(bmap, 1024);
+	bitmap_replace(bmap, &exp2[0 * nlongs], &exp2[1 * nlongs], exp2_to_exp3_mask, nbits);
+	expect_eq_bitmap(bmap, exp3_0_1, nbits);
+
+	bitmap_zero(bmap, 1024);
+	bitmap_replace(bmap, &exp2[1 * nlongs], &exp2[0 * nlongs], exp2_to_exp3_mask, nbits);
+	expect_eq_bitmap(bmap, exp3_1_0, nbits);
+
+	bitmap_fill(bmap, 1024);
+	bitmap_replace(bmap, &exp2[0 * nlongs], &exp2[1 * nlongs], exp2_to_exp3_mask, nbits);
+	expect_eq_bitmap(bmap, exp3_0_1, nbits);
+
+	bitmap_fill(bmap, 1024);
+	bitmap_replace(bmap, &exp2[1 * nlongs], &exp2[0 * nlongs], exp2_to_exp3_mask, nbits);
+	expect_eq_bitmap(bmap, exp3_1_0, nbits);
+}
+
+static const unsigned long sg_mask[] __initconst = {
+	BITMAP_FROM_U64(0x000000000000035aULL),
+	BITMAP_FROM_U64(0x0000000000000000ULL),
+};
+
+static const unsigned long sg_src[] __initconst = {
+	BITMAP_FROM_U64(0x0000000000000667ULL),
+	BITMAP_FROM_U64(0x0000000000000000ULL),
+};
+
+static const unsigned long sg_gather_exp[] __initconst = {
+	BITMAP_FROM_U64(0x0000000000000029ULL),
+	BITMAP_FROM_U64(0x0000000000000000ULL),
+};
+
+static const unsigned long sg_scatter_exp[] __initconst = {
+	BITMAP_FROM_U64(0x000000000000021aULL),
+	BITMAP_FROM_U64(0x0000000000000000ULL),
+};
+
+static void __init test_bitmap_sg(void)
+{
+	unsigned int nbits = 64;
+	DECLARE_BITMAP(bmap_gather, 100);
+	DECLARE_BITMAP(bmap_scatter, 100);
+	DECLARE_BITMAP(bmap_tmp, 100);
+	DECLARE_BITMAP(bmap_res, 100);
+
+	/* Simple gather call */
+	bitmap_zero(bmap_gather, 100);
+	bitmap_gather(bmap_gather, sg_src, sg_mask, nbits);
+	expect_eq_bitmap(sg_gather_exp, bmap_gather, 100);
+
+	/* Simple scatter call */
+	bitmap_zero(bmap_scatter, 100);
+	bitmap_scatter(bmap_scatter, sg_src, sg_mask, nbits);
+	expect_eq_bitmap(sg_scatter_exp, bmap_scatter, 100);
+
+	/* Scatter/gather relationship */
+	bitmap_zero(bmap_tmp, 100);
+	bitmap_zero(bmap_res, 100);
+	bitmap_gather(bmap_tmp, bmap_scatter, sg_mask, nbits);
+	bitmap_scatter(bmap_res, bmap_tmp, sg_mask, nbits);
+	expect_eq_bitmap(bmap_scatter, bmap_res, 100);
+}
+
+#define PARSE_TIME	0x1
+#define NO_LEN		0x2
+
+struct test_bitmap_parselist{
+	const int errno;
+	const char *in;
+	const unsigned long *expected;
+	const int nbits;
+	const int flags;
+};
+
+static const struct test_bitmap_parselist parselist_tests[] __initconst = {
+#define step (sizeof(u64) / sizeof(unsigned long))
+
+	{0, "0",			&exp1[0], 8, 0},
+	{0, "1",			&exp1[1 * step], 8, 0},
+	{0, "0-15",			&exp1[2 * step], 32, 0},
+	{0, "16-31",			&exp1[3 * step], 32, 0},
+	{0, "0-31:1/2",			&exp1[4 * step], 32, 0},
+	{0, "1-31:1/2",			&exp1[5 * step], 32, 0},
+	{0, "0-31:1/4",			&exp1[6 * step], 32, 0},
+	{0, "1-31:1/4",			&exp1[7 * step], 32, 0},
+	{0, "0-31:4/4",			&exp1[8 * step], 32, 0},
+	{0, "1-31:4/4",			&exp1[9 * step], 32, 0},
+	{0, "0-31:1/4,32-63:2/4",	&exp1[10 * step], 64, 0},
+	{0, "0-31:3/4,32-63:4/4",	&exp1[11 * step], 64, 0},
+	{0, "  ,,  0-31:3/4  ,, 32-63:4/4  ,,  ",	&exp1[11 * step], 64, 0},
+
+	{0, "0-31:1/4,32-63:2/4,64-95:3/4,96-127:4/4",	exp2, 128, 0},
+
+	{0, "0-2047:128/256", NULL, 2048, PARSE_TIME},
+
+	{0, "",				&exp1[12 * step], 8, 0},
+	{0, "\n",			&exp1[12 * step], 8, 0},
+	{0, ",,  ,,  , ,  ,",		&exp1[12 * step], 8, 0},
+	{0, " ,  ,,  , ,   ",		&exp1[12 * step], 8, 0},
+	{0, " ,  ,,  , ,   \n",		&exp1[12 * step], 8, 0},
+
+	{0, "0-0",			&exp1[0], 32, 0},
+	{0, "1-1",			&exp1[1 * step], 32, 0},
+	{0, "15-15",			&exp1[13 * step], 32, 0},
+	{0, "31-31",			&exp1[14 * step], 32, 0},
+
+	{0, "0-0:0/1",			&exp1[12 * step], 32, 0},
+	{0, "0-0:1/1",			&exp1[0], 32, 0},
+	{0, "0-0:1/31",			&exp1[0], 32, 0},
+	{0, "0-0:31/31",		&exp1[0], 32, 0},
+	{0, "1-1:1/1",			&exp1[1 * step], 32, 0},
+	{0, "0-15:16/31",		&exp1[2 * step], 32, 0},
+	{0, "15-15:1/2",		&exp1[13 * step], 32, 0},
+	{0, "15-15:31/31",		&exp1[13 * step], 32, 0},
+	{0, "15-31:1/31",		&exp1[13 * step], 32, 0},
+	{0, "16-31:16/31",		&exp1[3 * step], 32, 0},
+	{0, "31-31:31/31",		&exp1[14 * step], 32, 0},
+
+	{0, "N-N",			&exp1[14 * step], 32, 0},
+	{0, "0-0:1/N",			&exp1[0], 32, 0},
+	{0, "0-0:N/N",			&exp1[0], 32, 0},
+	{0, "0-15:16/N",		&exp1[2 * step], 32, 0},
+	{0, "15-15:N/N",		&exp1[13 * step], 32, 0},
+	{0, "15-N:1/N",			&exp1[13 * step], 32, 0},
+	{0, "16-N:16/N",		&exp1[3 * step], 32, 0},
+	{0, "N-N:N/N",			&exp1[14 * step], 32, 0},
+
+	{0, "0-N:1/3,1-N:1/3,2-N:1/3",		&exp1[8 * step], 32, 0},
+	{0, "0-31:1/3,1-31:1/3,2-31:1/3",	&exp1[8 * step], 32, 0},
+	{0, "1-10:8/12,8-31:24/29,0-31:0/3",	&exp1[9 * step], 32, 0},
+
+	{0,	  "all",		&exp1[8 * step], 32, 0},
+	{0,	  "0, 1, all,  ",	&exp1[8 * step], 32, 0},
+	{0,	  "all:1/2",		&exp1[4 * step], 32, 0},
+	{0,	  "ALL:1/2",		&exp1[4 * step], 32, 0},
+	{-EINVAL, "al", NULL, 8, 0},
+	{-EINVAL, "alll", NULL, 8, 0},
+
+	{-EINVAL, "-1",	NULL, 8, 0},
+	{-EINVAL, "-0",	NULL, 8, 0},
+	{-EINVAL, "10-1", NULL, 8, 0},
+	{-ERANGE, "8-8", NULL, 8, 0},
+	{-ERANGE, "0-31", NULL, 8, 0},
+	{-EINVAL, "0-31:", NULL, 32, 0},
+	{-EINVAL, "0-31:0", NULL, 32, 0},
+	{-EINVAL, "0-31:0/", NULL, 32, 0},
+	{-EINVAL, "0-31:0/0", NULL, 32, 0},
+	{-EINVAL, "0-31:1/0", NULL, 32, 0},
+	{-EINVAL, "0-31:10/1", NULL, 32, 0},
+	{-EOVERFLOW, "0-98765432123456789:10/1", NULL, 8, 0},
+
+	{-EINVAL, "a-31", NULL, 8, 0},
+	{-EINVAL, "0-a1", NULL, 8, 0},
+	{-EINVAL, "a-31:10/1", NULL, 8, 0},
+	{-EINVAL, "0-31:a/1", NULL, 8, 0},
+	{-EINVAL, "0-\n", NULL, 8, 0},
+
+};
+
+static void __init test_bitmap_parselist(void)
+{
+	int i;
+	int err;
+	ktime_t time;
+	DECLARE_BITMAP(bmap, 2048);
+
+	for (i = 0; i < ARRAY_SIZE(parselist_tests); i++) {
+#define ptest parselist_tests[i]
+
+		time = ktime_get();
+		err = bitmap_parselist(ptest.in, bmap, ptest.nbits);
+		time = ktime_get() - time;
+
+		if (err != ptest.errno) {
+			pr_err("parselist: %d: input is %s, errno is %d, expected %d\n",
+					i, ptest.in, err, ptest.errno);
+			failed_tests++;
+			continue;
+		}
+
+		if (!err && ptest.expected
+			 && !__bitmap_equal(bmap, ptest.expected, ptest.nbits)) {
+			pr_err("parselist: %d: input is %s, result is 0x%lx, expected 0x%lx\n",
+					i, ptest.in, bmap[0],
+					*ptest.expected);
+			failed_tests++;
+			continue;
+		}
+
+		if (ptest.flags & PARSE_TIME)
+			pr_info("parselist('%s'):\t%llu\n", ptest.in, time);
+
+#undef ptest
+	}
+}
+
+static void __init test_bitmap_printlist(void)
+{
+	unsigned long *bmap = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	char expected[256];
+	int ret, slen;
+	ktime_t time;
+
+	if (!buf || !bmap)
+		goto out;
+
+	memset(bmap, -1, PAGE_SIZE);
+	slen = snprintf(expected, 256, "0-%ld", PAGE_SIZE * 8 - 1);
+	if (slen < 0)
+		goto out;
+
+	time = ktime_get();
+	ret = scnprintf(buf, PAGE_SIZE, "%*pbl", (int)PAGE_SIZE * 8, bmap);
+	time = ktime_get() - time;
+
+	if (ret != slen) {
+		pr_err("scnprintf(\"%%*pbl\"): result is %d, expected %d\n", ret, slen);
+		failed_tests++;
+		goto out;
+	}
+
+	if (strncmp(buf, expected, slen)) {
+		pr_err("scnprintf(\"%%*pbl\"): result is %s, expected %s\n", buf, expected);
+		failed_tests++;
+		goto out;
+	}
+
+	pr_info("scnprintf(\"%%*pbl\", '%s'):\t%llu\n", buf, time);
+out:
+	kfree(buf);
+	kfree(bmap);
+}
+
+static const unsigned long parse_test[] __initconst = {
+	BITMAP_FROM_U64(0),
+	BITMAP_FROM_U64(1),
+	BITMAP_FROM_U64(0xdeadbeef),
+	BITMAP_FROM_U64(0x100000000ULL),
+};
+
+static const unsigned long parse_test2[] __initconst = {
+	BITMAP_FROM_U64(0x100000000ULL), BITMAP_FROM_U64(0xdeadbeef),
+	BITMAP_FROM_U64(0x100000000ULL), BITMAP_FROM_U64(0xbaadf00ddeadbeef),
+	BITMAP_FROM_U64(0x100000000ULL), BITMAP_FROM_U64(0x0badf00ddeadbeef),
+};
+
+static const struct test_bitmap_parselist parse_tests[] __initconst = {
+	{0, "",				&parse_test[0 * step], 32, 0},
+	{0, " ",			&parse_test[0 * step], 32, 0},
+	{0, "0",			&parse_test[0 * step], 32, 0},
+	{0, "0\n",			&parse_test[0 * step], 32, 0},
+	{0, "1",			&parse_test[1 * step], 32, 0},
+	{0, "deadbeef",			&parse_test[2 * step], 32, 0},
+	{0, "1,0",			&parse_test[3 * step], 33, 0},
+	{0, "deadbeef,\n,0,1",		&parse_test[2 * step], 96, 0},
+
+	{0, "deadbeef,1,0",		&parse_test2[0 * 2 * step], 96, 0},
+	{0, "baadf00d,deadbeef,1,0",	&parse_test2[1 * 2 * step], 128, 0},
+	{0, "badf00d,deadbeef,1,0",	&parse_test2[2 * 2 * step], 124, 0},
+	{0, "badf00d,deadbeef,1,0",	&parse_test2[2 * 2 * step], 124, NO_LEN},
+	{0, "  badf00d,deadbeef,1,0  ",	&parse_test2[2 * 2 * step], 124, 0},
+	{0, " , badf00d,deadbeef,1,0 , ",	&parse_test2[2 * 2 * step], 124, 0},
+	{0, " , badf00d, ,, ,,deadbeef,1,0 , ",	&parse_test2[2 * 2 * step], 124, 0},
+
+	{-EINVAL,    "goodfood,deadbeef,1,0",	NULL, 128, 0},
+	{-EOVERFLOW, "3,0",			NULL, 33, 0},
+	{-EOVERFLOW, "123badf00d,deadbeef,1,0",	NULL, 128, 0},
+	{-EOVERFLOW, "badf00d,deadbeef,1,0",	NULL, 90, 0},
+	{-EOVERFLOW, "fbadf00d,deadbeef,1,0",	NULL, 95, 0},
+	{-EOVERFLOW, "badf00d,deadbeef,1,0",	NULL, 100, 0},
+#undef step
+};
+
+static void __init test_bitmap_parse(void)
+{
+	int i;
+	int err;
+	ktime_t time;
+	DECLARE_BITMAP(bmap, 2048);
+
+	for (i = 0; i < ARRAY_SIZE(parse_tests); i++) {
+		struct test_bitmap_parselist test = parse_tests[i];
+		size_t len = test.flags & NO_LEN ? UINT_MAX : strlen(test.in);
+
+		time = ktime_get();
+		err = bitmap_parse(test.in, len, bmap, test.nbits);
+		time = ktime_get() - time;
+
+		if (err != test.errno) {
+			pr_err("parse: %d: input is %s, errno is %d, expected %d\n",
+					i, test.in, err, test.errno);
+			failed_tests++;
+			continue;
+		}
+
+		if (!err && test.expected
+			 && !__bitmap_equal(bmap, test.expected, test.nbits)) {
+			pr_err("parse: %d: input is %s, result is 0x%lx, expected 0x%lx\n",
+					i, test.in, bmap[0],
+					*test.expected);
+			failed_tests++;
+			continue;
+		}
+
+		if (test.flags & PARSE_TIME)
+			pr_info("parse: %d: input is '%s' OK, Time: %llu\n",
+					i, test.in, time);
+	}
+}
+
+static void __init test_bitmap_arr32(void)
+{
+	unsigned int nbits, next_bit;
+	u32 arr[EXP1_IN_BITS / 32];
+	DECLARE_BITMAP(bmap2, EXP1_IN_BITS);
+
+	memset(arr, 0xa5, sizeof(arr));
+
+	for (nbits = 1; nbits < EXP1_IN_BITS; ++nbits) {
+		bitmap_to_arr32(arr, exp1, nbits);
+		bitmap_from_arr32(bmap2, arr, nbits);
+		expect_eq_bitmap(bmap2, exp1, nbits);
+
+		next_bit = find_next_bit(bmap2,
+				round_up(nbits, BITS_PER_LONG), nbits);
+		if (next_bit < round_up(nbits, BITS_PER_LONG)) {
+			pr_err("bitmap_copy_arr32(nbits == %d:"
+				" tail is not safely cleared: %d\n",
+				nbits, next_bit);
+			failed_tests++;
+		}
+
+		if (nbits < EXP1_IN_BITS - 32)
+			expect_eq_uint(arr[DIV_ROUND_UP(nbits, 32)],
+								0xa5a5a5a5);
+	}
+}
+
+static void __init test_bitmap_arr64(void)
+{
+	unsigned int nbits, next_bit;
+	u64 arr[EXP1_IN_BITS / 64];
+	DECLARE_BITMAP(bmap2, EXP1_IN_BITS);
+
+	memset(arr, 0xa5, sizeof(arr));
+
+	for (nbits = 1; nbits < EXP1_IN_BITS; ++nbits) {
+		memset(bmap2, 0xff, sizeof(arr));
+		bitmap_to_arr64(arr, exp1, nbits);
+		bitmap_from_arr64(bmap2, arr, nbits);
+		expect_eq_bitmap(bmap2, exp1, nbits);
+
+		next_bit = find_next_bit(bmap2, round_up(nbits, BITS_PER_LONG), nbits);
+		if (next_bit < round_up(nbits, BITS_PER_LONG)) {
+			pr_err("bitmap_copy_arr64(nbits == %d:"
+				" tail is not safely cleared: %d\n", nbits, next_bit);
+			failed_tests++;
+		}
+
+		if ((nbits % 64) &&
+		    (arr[(nbits - 1) / 64] & ~GENMASK_ULL((nbits - 1) % 64, 0))) {
+			pr_err("bitmap_to_arr64(nbits == %d): tail is not safely cleared: 0x%016llx (must be 0x%016llx)\n",
+			       nbits, arr[(nbits - 1) / 64],
+			       GENMASK_ULL((nbits - 1) % 64, 0));
+			failed_tests++;
+		}
+
+		if (nbits < EXP1_IN_BITS - 64)
+			expect_eq_uint(arr[DIV_ROUND_UP(nbits, 64)], 0xa5a5a5a5);
+	}
+}
+
+static void noinline __init test_mem_optimisations(void)
+{
+	DECLARE_BITMAP(bmap1, 1024);
+	DECLARE_BITMAP(bmap2, 1024);
+	unsigned int start, nbits;
+
+	for (start = 0; start < 1024; start += 8) {
+		for (nbits = 1; nbits < 1024 - start; nbits += 8) {
+			memset(bmap1, 0x5a, sizeof(bmap1));
+			memset(bmap2, 0x5a, sizeof(bmap2));
+
+			bitmap_set(bmap1, start, nbits);
+			__bitmap_set(bmap2, start, nbits);
+			if (!bitmap_equal(bmap1, bmap2, 1024)) {
+				printk("set not equal %d %d\n", start, nbits);
+				failed_tests++;
+			}
+			if (!__bitmap_equal(bmap1, bmap2, 1024)) {
+				printk("set not __equal %d %d\n", start, nbits);
+				failed_tests++;
+			}
+
+			bitmap_clear(bmap1, start, nbits);
+			__bitmap_clear(bmap2, start, nbits);
+			if (!bitmap_equal(bmap1, bmap2, 1024)) {
+				printk("clear not equal %d %d\n", start, nbits);
+				failed_tests++;
+			}
+			if (!__bitmap_equal(bmap1, bmap2, 1024)) {
+				printk("clear not __equal %d %d\n", start,
+									nbits);
+				failed_tests++;
+			}
+		}
+	}
+}
+
+static const unsigned char clump_exp[] __initconst = {
+	0x01,	/* 1 bit set */
+	0x02,	/* non-edge 1 bit set */
+	0x00,	/* zero bits set */
+	0x38,	/* 3 bits set across 4-bit boundary */
+	0x38,	/* Repeated clump */
+	0x0F,	/* 4 bits set */
+	0xFF,	/* all bits set */
+	0x05,	/* non-adjacent 2 bits set */
+};
+
+static void __init test_for_each_set_clump8(void)
+{
+#define CLUMP_EXP_NUMBITS 64
+	DECLARE_BITMAP(bits, CLUMP_EXP_NUMBITS);
+	unsigned int start;
+	unsigned long clump;
+
+	/* set bitmap to test case */
+	bitmap_zero(bits, CLUMP_EXP_NUMBITS);
+	bitmap_set(bits, 0, 1);		/* 0x01 */
+	bitmap_set(bits, 9, 1);		/* 0x02 */
+	bitmap_set(bits, 27, 3);	/* 0x28 */
+	bitmap_set(bits, 35, 3);	/* 0x28 */
+	bitmap_set(bits, 40, 4);	/* 0x0F */
+	bitmap_set(bits, 48, 8);	/* 0xFF */
+	bitmap_set(bits, 56, 1);	/* 0x05 - part 1 */
+	bitmap_set(bits, 58, 1);	/* 0x05 - part 2 */
+
+	for_each_set_clump8(start, clump, bits, CLUMP_EXP_NUMBITS)
+		expect_eq_clump8(start, CLUMP_EXP_NUMBITS, clump_exp, &clump);
+}
+
+static void __init test_for_each_set_bit_wrap(void)
+{
+	DECLARE_BITMAP(orig, 500);
+	DECLARE_BITMAP(copy, 500);
+	unsigned int wr, bit;
+
+	bitmap_zero(orig, 500);
+
+	/* Set individual bits */
+	for (bit = 0; bit < 500; bit += 10)
+		bitmap_set(orig, bit, 1);
+
+	/* Set range of bits */
+	bitmap_set(orig, 100, 50);
+
+	for (wr = 0; wr < 500; wr++) {
+		bitmap_zero(copy, 500);
+
+		for_each_set_bit_wrap(bit, orig, 500, wr)
+			bitmap_set(copy, bit, 1);
+
+		expect_eq_bitmap(orig, copy, 500);
+	}
+}
+
+static void __init test_for_each_set_bit(void)
+{
+	DECLARE_BITMAP(orig, 500);
+	DECLARE_BITMAP(copy, 500);
+	unsigned int bit;
+
+	bitmap_zero(orig, 500);
+	bitmap_zero(copy, 500);
+
+	/* Set individual bits */
+	for (bit = 0; bit < 500; bit += 10)
+		bitmap_set(orig, bit, 1);
+
+	/* Set range of bits */
+	bitmap_set(orig, 100, 50);
+
+	for_each_set_bit(bit, orig, 500)
+		bitmap_set(copy, bit, 1);
+
+	expect_eq_bitmap(orig, copy, 500);
+}
+
+static void __init test_for_each_set_bit_from(void)
+{
+	DECLARE_BITMAP(orig, 500);
+	DECLARE_BITMAP(copy, 500);
+	unsigned int wr, bit;
+
+	bitmap_zero(orig, 500);
+
+	/* Set individual bits */
+	for (bit = 0; bit < 500; bit += 10)
+		bitmap_set(orig, bit, 1);
+
+	/* Set range of bits */
+	bitmap_set(orig, 100, 50);
+
+	for (wr = 0; wr < 500; wr++) {
+		DECLARE_BITMAP(tmp, 500);
+
+		bitmap_zero(copy, 500);
+		bit = wr;
+
+		for_each_set_bit_from(bit, orig, 500)
+			bitmap_set(copy, bit, 1);
+
+		bitmap_copy(tmp, orig, 500);
+		bitmap_clear(tmp, 0, wr);
+		expect_eq_bitmap(tmp, copy, 500);
+	}
+}
+
+static void __init test_bitmap_weight(void)
+{
+	unsigned int bit, w1, w2, w;
+	DECLARE_BITMAP(b, 30);
+	DECLARE_BITMAP(b1, 128);
+
+	bitmap_parselist("all:1/2", b, 30);
+
+	/* Test inline implementation */
+	w = bitmap_weight(b, 30);
+	w1 = bitmap_weight(b, 15);
+	w2 = bitmap_weight_from(b, 15, 30);
+
+	expect_eq_uint(15, w);
+	expect_eq_uint(8, w1);
+	expect_eq_uint(7, w2);
+
+	/* Test outline implementation */
+	w = bitmap_weight(exp1, EXP1_IN_BITS);
+	for (bit = 1; bit < EXP1_IN_BITS; bit++) {
+		w1 = bitmap_weight(exp1, bit);
+		w2 = bitmap_weight_from(exp1, bit, EXP1_IN_BITS);
+		expect_eq_uint(w1 + w2, w);
+	}
+
+	/* Test out-of-range */
+	w = bitmap_weight_from(b, 31, 30);
+	expect_eq_uint(0, !!(w < 30));
+
+	/*
+	 * Test bitmap_weight() for correctness in case of some bits set between
+	 * nbits and end of the last word.
+	 */
+	bitmap_fill(b1, 128);
+
+	/* Inline */
+	expect_eq_uint(30, bitmap_weight(b1, 30));
+	expect_eq_uint(100, bitmap_weight(b1, 100));
+
+	/* Outline */
+	for (int i  = 1; i < 128; i++)
+		expect_eq_uint(i, bitmap_weight(b1, i));
+}
+
+static void __init test_for_each_clear_bit(void)
+{
+	DECLARE_BITMAP(orig, 500);
+	DECLARE_BITMAP(copy, 500);
+	unsigned int bit;
+
+	bitmap_fill(orig, 500);
+	bitmap_fill(copy, 500);
+
+	/* Set individual bits */
+	for (bit = 0; bit < 500; bit += 10)
+		bitmap_clear(orig, bit, 1);
+
+	/* Set range of bits */
+	bitmap_clear(orig, 100, 50);
+
+	for_each_clear_bit(bit, orig, 500)
+		bitmap_clear(copy, bit, 1);
+
+	expect_eq_bitmap(orig, copy, 500);
+}
+
+static void __init test_for_each_clear_bit_from(void)
+{
+	DECLARE_BITMAP(orig, 500);
+	DECLARE_BITMAP(copy, 500);
+	unsigned int wr, bit;
+
+	bitmap_fill(orig, 500);
+
+	/* Set individual bits */
+	for (bit = 0; bit < 500; bit += 10)
+		bitmap_clear(orig, bit, 1);
+
+	/* Set range of bits */
+	bitmap_clear(orig, 100, 50);
+
+	for (wr = 0; wr < 500; wr++) {
+		DECLARE_BITMAP(tmp, 500);
+
+		bitmap_fill(copy, 500);
+		bit = wr;
+
+		for_each_clear_bit_from(bit, orig, 500)
+			bitmap_clear(copy, bit, 1);
+
+		bitmap_copy(tmp, orig, 500);
+		bitmap_set(tmp, 0, wr);
+		expect_eq_bitmap(tmp, copy, 500);
+	}
+}
+
+static void __init test_for_each_set_bitrange(void)
+{
+	DECLARE_BITMAP(orig, 500);
+	DECLARE_BITMAP(copy, 500);
+	unsigned int s, e;
+
+	bitmap_zero(orig, 500);
+	bitmap_zero(copy, 500);
+
+	/* Set individual bits */
+	for (s = 0; s < 500; s += 10)
+		bitmap_set(orig, s, 1);
+
+	/* Set range of bits */
+	bitmap_set(orig, 100, 50);
+
+	for_each_set_bitrange(s, e, orig, 500)
+		bitmap_set(copy, s, e-s);
+
+	expect_eq_bitmap(orig, copy, 500);
+}
+
+static void __init test_for_each_clear_bitrange(void)
+{
+	DECLARE_BITMAP(orig, 500);
+	DECLARE_BITMAP(copy, 500);
+	unsigned int s, e;
+
+	bitmap_fill(orig, 500);
+	bitmap_fill(copy, 500);
+
+	/* Set individual bits */
+	for (s = 0; s < 500; s += 10)
+		bitmap_clear(orig, s, 1);
+
+	/* Set range of bits */
+	bitmap_clear(orig, 100, 50);
+
+	for_each_clear_bitrange(s, e, orig, 500)
+		bitmap_clear(copy, s, e-s);
+
+	expect_eq_bitmap(orig, copy, 500);
+}
+
+static void __init test_for_each_set_bitrange_from(void)
+{
+	DECLARE_BITMAP(orig, 500);
+	DECLARE_BITMAP(copy, 500);
+	unsigned int wr, s, e;
+
+	bitmap_zero(orig, 500);
+
+	/* Set individual bits */
+	for (s = 0; s < 500; s += 10)
+		bitmap_set(orig, s, 1);
+
+	/* Set range of bits */
+	bitmap_set(orig, 100, 50);
+
+	for (wr = 0; wr < 500; wr++) {
+		DECLARE_BITMAP(tmp, 500);
+
+		bitmap_zero(copy, 500);
+		s = wr;
+
+		for_each_set_bitrange_from(s, e, orig, 500)
+			bitmap_set(copy, s, e - s);
+
+		bitmap_copy(tmp, orig, 500);
+		bitmap_clear(tmp, 0, wr);
+		expect_eq_bitmap(tmp, copy, 500);
+	}
+}
+
+static void __init test_for_each_clear_bitrange_from(void)
+{
+	DECLARE_BITMAP(orig, 500);
+	DECLARE_BITMAP(copy, 500);
+	unsigned int wr, s, e;
+
+	bitmap_fill(orig, 500);
+
+	/* Set individual bits */
+	for (s = 0; s < 500; s += 10)
+		bitmap_clear(orig, s, 1);
+
+	/* Set range of bits */
+	bitmap_set(orig, 100, 50);
+
+	for (wr = 0; wr < 500; wr++) {
+		DECLARE_BITMAP(tmp, 500);
+
+		bitmap_fill(copy, 500);
+		s = wr;
+
+		for_each_clear_bitrange_from(s, e, orig, 500)
+			bitmap_clear(copy, s, e - s);
+
+		bitmap_copy(tmp, orig, 500);
+		bitmap_set(tmp, 0, wr);
+		expect_eq_bitmap(tmp, copy, 500);
+	}
+}
+
+struct test_bitmap_cut {
+	unsigned int first;
+	unsigned int cut;
+	unsigned int nbits;
+	unsigned long in[4];
+	unsigned long expected[4];
+};
+
+static struct test_bitmap_cut test_cut[] = {
+	{  0,  0,  8, { 0x0000000aUL, }, { 0x0000000aUL, }, },
+	{  0,  0, 32, { 0xdadadeadUL, }, { 0xdadadeadUL, }, },
+	{  0,  3,  8, { 0x000000aaUL, }, { 0x00000015UL, }, },
+	{  3,  3,  8, { 0x000000aaUL, }, { 0x00000012UL, }, },
+	{  0,  1, 32, { 0xa5a5a5a5UL, }, { 0x52d2d2d2UL, }, },
+	{  0,  8, 32, { 0xdeadc0deUL, }, { 0x00deadc0UL, }, },
+	{  1,  1, 32, { 0x5a5a5a5aUL, }, { 0x2d2d2d2cUL, }, },
+	{  0, 15, 32, { 0xa5a5a5a5UL, }, { 0x00014b4bUL, }, },
+	{  0, 16, 32, { 0xa5a5a5a5UL, }, { 0x0000a5a5UL, }, },
+	{ 15, 15, 32, { 0xa5a5a5a5UL, }, { 0x000125a5UL, }, },
+	{ 15, 16, 32, { 0xa5a5a5a5UL, }, { 0x0000a5a5UL, }, },
+	{ 16, 15, 32, { 0xa5a5a5a5UL, }, { 0x0001a5a5UL, }, },
+
+	{ BITS_PER_LONG, BITS_PER_LONG, BITS_PER_LONG,
+		{ 0xa5a5a5a5UL, 0xa5a5a5a5UL, },
+		{ 0xa5a5a5a5UL, 0xa5a5a5a5UL, },
+	},
+	{ 1, BITS_PER_LONG - 1, BITS_PER_LONG,
+		{ 0xa5a5a5a5UL, 0xa5a5a5a5UL, },
+		{ 0x00000001UL, 0x00000001UL, },
+	},
+
+	{ 0, BITS_PER_LONG * 2, BITS_PER_LONG * 2 + 1,
+		{ 0xa5a5a5a5UL, 0x00000001UL, 0x00000001UL, 0x00000001UL },
+		{ 0x00000001UL, },
+	},
+	{ 16, BITS_PER_LONG * 2 + 1, BITS_PER_LONG * 2 + 1 + 16,
+		{ 0x0000ffffUL, 0x5a5a5a5aUL, 0x5a5a5a5aUL, 0x5a5a5a5aUL },
+		{ 0x2d2dffffUL, },
+	},
+};
+
+static void __init test_bitmap_cut(void)
+{
+	unsigned long b[5], *in = &b[1], *out = &b[0];	/* Partial overlap */
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(test_cut); i++) {
+		struct test_bitmap_cut *t = &test_cut[i];
+
+		memcpy(in, t->in, sizeof(t->in));
+
+		bitmap_cut(out, in, t->first, t->cut, t->nbits);
+
+		expect_eq_bitmap(t->expected, out, t->nbits);
+	}
+}
+
+struct test_bitmap_print {
+	const unsigned long *bitmap;
+	unsigned long nbits;
+	const char *mask;
+	const char *list;
+};
+
+static const unsigned long small_bitmap[] __initconst = {
+	BITMAP_FROM_U64(0x3333333311111111ULL),
+};
+
+static const char small_mask[] __initconst = "33333333,11111111\n";
+static const char small_list[] __initconst = "0,4,8,12,16,20,24,28,32-33,36-37,40-41,44-45,48-49,52-53,56-57,60-61\n";
+
+static const unsigned long large_bitmap[] __initconst = {
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+	BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0x3333333311111111ULL),
+};
+
+static const char large_mask[] __initconst = "33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111,"
+					"33333333,11111111,33333333,11111111\n";
+
+static const char large_list[] __initconst = /* more than 4KB */
+	"0,4,8,12,16,20,24,28,32-33,36-37,40-41,44-45,48-49,52-53,56-57,60-61,64,68,72,76,80,84,88,92,96-97,100-101,104-1"
+	"05,108-109,112-113,116-117,120-121,124-125,128,132,136,140,144,148,152,156,160-161,164-165,168-169,172-173,176-1"
+	"77,180-181,184-185,188-189,192,196,200,204,208,212,216,220,224-225,228-229,232-233,236-237,240-241,244-245,248-2"
+	"49,252-253,256,260,264,268,272,276,280,284,288-289,292-293,296-297,300-301,304-305,308-309,312-313,316-317,320,3"
+	"24,328,332,336,340,344,348,352-353,356-357,360-361,364-365,368-369,372-373,376-377,380-381,384,388,392,396,400,4"
+	"04,408,412,416-417,420-421,424-425,428-429,432-433,436-437,440-441,444-445,448,452,456,460,464,468,472,476,480-4"
+	"81,484-485,488-489,492-493,496-497,500-501,504-505,508-509,512,516,520,524,528,532,536,540,544-545,548-549,552-5"
+	"53,556-557,560-561,564-565,568-569,572-573,576,580,584,588,592,596,600,604,608-609,612-613,616-617,620-621,624-6"
+	"25,628-629,632-633,636-637,640,644,648,652,656,660,664,668,672-673,676-677,680-681,684-685,688-689,692-693,696-6"
+	"97,700-701,704,708,712,716,720,724,728,732,736-737,740-741,744-745,748-749,752-753,756-757,760-761,764-765,768,7"
+	"72,776,780,784,788,792,796,800-801,804-805,808-809,812-813,816-817,820-821,824-825,828-829,832,836,840,844,848,8"
+	"52,856,860,864-865,868-869,872-873,876-877,880-881,884-885,888-889,892-893,896,900,904,908,912,916,920,924,928-9"
+	"29,932-933,936-937,940-941,944-945,948-949,952-953,956-957,960,964,968,972,976,980,984,988,992-993,996-997,1000-"
+	"1001,1004-1005,1008-1009,1012-1013,1016-1017,1020-1021,1024,1028,1032,1036,1040,1044,1048,1052,1056-1057,1060-10"
+	"61,1064-1065,1068-1069,1072-1073,1076-1077,1080-1081,1084-1085,1088,1092,1096,1100,1104,1108,1112,1116,1120-1121"
+	",1124-1125,1128-1129,1132-1133,1136-1137,1140-1141,1144-1145,1148-1149,1152,1156,1160,1164,1168,1172,1176,1180,1"
+	"184-1185,1188-1189,1192-1193,1196-1197,1200-1201,1204-1205,1208-1209,1212-1213,1216,1220,1224,1228,1232,1236,124"
+	"0,1244,1248-1249,1252-1253,1256-1257,1260-1261,1264-1265,1268-1269,1272-1273,1276-1277,1280,1284,1288,1292,1296,"
+	"1300,1304,1308,1312-1313,1316-1317,1320-1321,1324-1325,1328-1329,1332-1333,1336-1337,1340-1341,1344,1348,1352,13"
+	"56,1360,1364,1368,1372,1376-1377,1380-1381,1384-1385,1388-1389,1392-1393,1396-1397,1400-1401,1404-1405,1408,1412"
+	",1416,1420,1424,1428,1432,1436,1440-1441,1444-1445,1448-1449,1452-1453,1456-1457,1460-1461,1464-1465,1468-1469,1"
+	"472,1476,1480,1484,1488,1492,1496,1500,1504-1505,1508-1509,1512-1513,1516-1517,1520-1521,1524-1525,1528-1529,153"
+	"2-1533,1536,1540,1544,1548,1552,1556,1560,1564,1568-1569,1572-1573,1576-1577,1580-1581,1584-1585,1588-1589,1592-"
+	"1593,1596-1597,1600,1604,1608,1612,1616,1620,1624,1628,1632-1633,1636-1637,1640-1641,1644-1645,1648-1649,1652-16"
+	"53,1656-1657,1660-1661,1664,1668,1672,1676,1680,1684,1688,1692,1696-1697,1700-1701,1704-1705,1708-1709,1712-1713"
+	",1716-1717,1720-1721,1724-1725,1728,1732,1736,1740,1744,1748,1752,1756,1760-1761,1764-1765,1768-1769,1772-1773,1"
+	"776-1777,1780-1781,1784-1785,1788-1789,1792,1796,1800,1804,1808,1812,1816,1820,1824-1825,1828-1829,1832-1833,183"
+	"6-1837,1840-1841,1844-1845,1848-1849,1852-1853,1856,1860,1864,1868,1872,1876,1880,1884,1888-1889,1892-1893,1896-"
+	"1897,1900-1901,1904-1905,1908-1909,1912-1913,1916-1917,1920,1924,1928,1932,1936,1940,1944,1948,1952-1953,1956-19"
+	"57,1960-1961,1964-1965,1968-1969,1972-1973,1976-1977,1980-1981,1984,1988,1992,1996,2000,2004,2008,2012,2016-2017"
+	",2020-2021,2024-2025,2028-2029,2032-2033,2036-2037,2040-2041,2044-2045,2048,2052,2056,2060,2064,2068,2072,2076,2"
+	"080-2081,2084-2085,2088-2089,2092-2093,2096-2097,2100-2101,2104-2105,2108-2109,2112,2116,2120,2124,2128,2132,213"
+	"6,2140,2144-2145,2148-2149,2152-2153,2156-2157,2160-2161,2164-2165,2168-2169,2172-2173,2176,2180,2184,2188,2192,"
+	"2196,2200,2204,2208-2209,2212-2213,2216-2217,2220-2221,2224-2225,2228-2229,2232-2233,2236-2237,2240,2244,2248,22"
+	"52,2256,2260,2264,2268,2272-2273,2276-2277,2280-2281,2284-2285,2288-2289,2292-2293,2296-2297,2300-2301,2304,2308"
+	",2312,2316,2320,2324,2328,2332,2336-2337,2340-2341,2344-2345,2348-2349,2352-2353,2356-2357,2360-2361,2364-2365,2"
+	"368,2372,2376,2380,2384,2388,2392,2396,2400-2401,2404-2405,2408-2409,2412-2413,2416-2417,2420-2421,2424-2425,242"
+	"8-2429,2432,2436,2440,2444,2448,2452,2456,2460,2464-2465,2468-2469,2472-2473,2476-2477,2480-2481,2484-2485,2488-"
+	"2489,2492-2493,2496,2500,2504,2508,2512,2516,2520,2524,2528-2529,2532-2533,2536-2537,2540-2541,2544-2545,2548-25"
+	"49,2552-2553,2556-2557\n";
+
+static const struct test_bitmap_print test_print[] __initconst = {
+	{ small_bitmap, sizeof(small_bitmap) * BITS_PER_BYTE, small_mask, small_list },
+	{ large_bitmap, sizeof(large_bitmap) * BITS_PER_BYTE, large_mask, large_list },
+};
+
+static void __init test_bitmap_print_buf(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(test_print); i++) {
+		const struct test_bitmap_print *t = &test_print[i];
+		int n;
+
+		n = bitmap_print_bitmask_to_buf(print_buf, t->bitmap, t->nbits,
+						0, 2 * PAGE_SIZE);
+		expect_eq_uint(strlen(t->mask) + 1, n);
+		expect_eq_str(t->mask, print_buf, n);
+
+		n = bitmap_print_list_to_buf(print_buf, t->bitmap, t->nbits,
+					     0, 2 * PAGE_SIZE);
+		expect_eq_uint(strlen(t->list) + 1, n);
+		expect_eq_str(t->list, print_buf, n);
+
+		/* test by non-zero offset */
+		if (strlen(t->list) > PAGE_SIZE) {
+			n = bitmap_print_list_to_buf(print_buf, t->bitmap, t->nbits,
+						     PAGE_SIZE, PAGE_SIZE);
+			expect_eq_uint(strlen(t->list) + 1 - PAGE_SIZE, n);
+			expect_eq_str(t->list + PAGE_SIZE, print_buf, n);
+		}
+	}
+}
+
+/*
+ * FIXME: Clang breaks compile-time evaluations when KASAN and GCOV are enabled.
+ * To workaround it, GCOV is force-disabled in Makefile for this configuration.
+ */
+static void __init test_bitmap_const_eval(void)
+{
+	DECLARE_BITMAP(bitmap, BITS_PER_LONG);
+	unsigned long initvar = BIT(2);
+	unsigned long bitopvar = 0;
+	unsigned long var = 0;
+	int res;
+
+	/*
+	 * Compilers must be able to optimize all of those to compile-time
+	 * constants on any supported optimization level (-O2, -Os) and any
+	 * architecture. Otherwise, trigger a build bug.
+	 * The whole function gets optimized out then, there's nothing to do
+	 * in runtime.
+	 */
+
+	/* Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }` */
+	bitmap_clear(bitmap, 0, BITS_PER_LONG);
+	if (!test_bit(7, bitmap))
+		bitmap_set(bitmap, 5, 2);
+
+	/* Equals to `unsigned long bitopvar = BIT(20)` */
+	__change_bit(31, &bitopvar);
+	bitmap_shift_right(&bitopvar, &bitopvar, 11, BITS_PER_LONG);
+
+	/* Equals to `unsigned long var = BIT(25)` */
+	var |= BIT(25);
+	if (var & BIT(0))
+		var ^= GENMASK(9, 6);
+
+	/* __const_hweight<32|64>(GENMASK(6, 5)) == 2 */
+	res = bitmap_weight(bitmap, 20);
+	BUILD_BUG_ON(!__builtin_constant_p(res));
+	BUILD_BUG_ON(res != 2);
+
+	/* !(BIT(31) & BIT(18)) == 1 */
+	res = !test_bit(18, &bitopvar);
+	BUILD_BUG_ON(!__builtin_constant_p(res));
+	BUILD_BUG_ON(!res);
+
+	/* BIT(2) & GENMASK(14, 8) == 0 */
+	res = initvar & GENMASK(14, 8);
+	BUILD_BUG_ON(!__builtin_constant_p(res));
+	BUILD_BUG_ON(res);
+
+	/* ~BIT(25) */
+	BUILD_BUG_ON(!__builtin_constant_p(~var));
+	BUILD_BUG_ON(~var != ~BIT(25));
+
+	/* ~BIT(25) | BIT(25) == ~0UL */
+	bitmap_complement(&var, &var, BITS_PER_LONG);
+	__assign_bit(25, &var, true);
+
+	/* !(~(~0UL)) == 1 */
+	res = bitmap_full(&var, BITS_PER_LONG);
+	BUILD_BUG_ON(!__builtin_constant_p(res));
+	BUILD_BUG_ON(!res);
+}
+
+/*
+ * Test bitmap should be big enough to include the cases when start is not in
+ * the first word, and start+nbits lands in the following word.
+ */
+#define TEST_BIT_LEN (1000)
+
+/*
+ * Helper function to test bitmap_write() overwriting the chosen byte pattern.
+ */
+static void __init test_bitmap_write_helper(const char *pattern)
+{
+	DECLARE_BITMAP(bitmap, TEST_BIT_LEN);
+	DECLARE_BITMAP(exp_bitmap, TEST_BIT_LEN);
+	DECLARE_BITMAP(pat_bitmap, TEST_BIT_LEN);
+	unsigned long w, r, bit;
+	int i, n, nbits;
+
+	/*
+	 * Only parse the pattern once and store the result in the intermediate
+	 * bitmap.
+	 */
+	bitmap_parselist(pattern, pat_bitmap, TEST_BIT_LEN);
+
+	/*
+	 * Check that writing a single bit does not accidentally touch the
+	 * adjacent bits.
+	 */
+	for (i = 0; i < TEST_BIT_LEN; i++) {
+		bitmap_copy(bitmap, pat_bitmap, TEST_BIT_LEN);
+		bitmap_copy(exp_bitmap, pat_bitmap, TEST_BIT_LEN);
+		for (bit = 0; bit <= 1; bit++) {
+			bitmap_write(bitmap, bit, i, 1);
+			__assign_bit(i, exp_bitmap, bit);
+			expect_eq_bitmap(exp_bitmap, bitmap,
+					 TEST_BIT_LEN);
+		}
+	}
+
+	/* Ensure writing 0 bits does not change anything. */
+	bitmap_copy(bitmap, pat_bitmap, TEST_BIT_LEN);
+	bitmap_copy(exp_bitmap, pat_bitmap, TEST_BIT_LEN);
+	for (i = 0; i < TEST_BIT_LEN; i++) {
+		bitmap_write(bitmap, ~0UL, i, 0);
+		expect_eq_bitmap(exp_bitmap, bitmap, TEST_BIT_LEN);
+	}
+
+	for (nbits = BITS_PER_LONG; nbits >= 1; nbits--) {
+		w = IS_ENABLED(CONFIG_64BIT) ? 0xdeadbeefdeadbeefUL
+					     : 0xdeadbeefUL;
+		w >>= (BITS_PER_LONG - nbits);
+		for (i = 0; i <= TEST_BIT_LEN - nbits; i++) {
+			bitmap_copy(bitmap, pat_bitmap, TEST_BIT_LEN);
+			bitmap_copy(exp_bitmap, pat_bitmap, TEST_BIT_LEN);
+			for (n = 0; n < nbits; n++)
+				__assign_bit(i + n, exp_bitmap, w & BIT(n));
+			bitmap_write(bitmap, w, i, nbits);
+			expect_eq_bitmap(exp_bitmap, bitmap, TEST_BIT_LEN);
+			r = bitmap_read(bitmap, i, nbits);
+			expect_eq_ulong(r, w);
+		}
+	}
+}
+
+static void __init test_bitmap_read_write(void)
+{
+	unsigned char *pattern[3] = {"", "all:1/2", "all"};
+	DECLARE_BITMAP(bitmap, TEST_BIT_LEN);
+	unsigned long zero_bits = 0, bits_per_long = BITS_PER_LONG;
+	unsigned long val;
+	int i, pi;
+
+	/*
+	 * Reading/writing zero bits should not crash the kernel.
+	 * READ_ONCE() prevents constant folding.
+	 */
+	bitmap_write(NULL, 0, 0, READ_ONCE(zero_bits));
+	/* Return value of bitmap_read() is undefined here. */
+	bitmap_read(NULL, 0, READ_ONCE(zero_bits));
+
+	/*
+	 * Reading/writing more than BITS_PER_LONG bits should not crash the
+	 * kernel. READ_ONCE() prevents constant folding.
+	 */
+	bitmap_write(NULL, 0, 0, READ_ONCE(bits_per_long) + 1);
+	/* Return value of bitmap_read() is undefined here. */
+	bitmap_read(NULL, 0, READ_ONCE(bits_per_long) + 1);
+
+	/*
+	 * Ensure that bitmap_read() reads the same value that was previously
+	 * written, and two consequent values are correctly merged.
+	 * The resulting bit pattern is asymmetric to rule out possible issues
+	 * with bit numeration order.
+	 */
+	for (i = 0; i < TEST_BIT_LEN - 7; i++) {
+		bitmap_zero(bitmap, TEST_BIT_LEN);
+
+		bitmap_write(bitmap, 0b10101UL, i, 5);
+		val = bitmap_read(bitmap, i, 5);
+		expect_eq_ulong(0b10101UL, val);
+
+		bitmap_write(bitmap, 0b101UL, i + 5, 3);
+		val = bitmap_read(bitmap, i + 5, 3);
+		expect_eq_ulong(0b101UL, val);
+
+		val = bitmap_read(bitmap, i, 8);
+		expect_eq_ulong(0b10110101UL, val);
+	}
+
+	for (pi = 0; pi < ARRAY_SIZE(pattern); pi++)
+		test_bitmap_write_helper(pattern[pi]);
+}
+
+static void __init test_bitmap_read_perf(void)
+{
+	DECLARE_BITMAP(bitmap, TEST_BIT_LEN);
+	unsigned int cnt, nbits, i;
+	unsigned long val;
+	ktime_t time;
+
+	bitmap_fill(bitmap, TEST_BIT_LEN);
+	time = ktime_get();
+	for (cnt = 0; cnt < 5; cnt++) {
+		for (nbits = 1; nbits <= BITS_PER_LONG; nbits++) {
+			for (i = 0; i < TEST_BIT_LEN; i++) {
+				if (i + nbits > TEST_BIT_LEN)
+					break;
+				/*
+				 * Prevent the compiler from optimizing away the
+				 * bitmap_read() by using its value.
+				 */
+				WRITE_ONCE(val, bitmap_read(bitmap, i, nbits));
+			}
+		}
+	}
+	time = ktime_get() - time;
+	pr_info("%s:\t\t%llu\n", __func__, time);
+}
+
+static void __init test_bitmap_write_perf(void)
+{
+	DECLARE_BITMAP(bitmap, TEST_BIT_LEN);
+	unsigned int cnt, nbits, i;
+	unsigned long val = 0xfeedface;
+	ktime_t time;
+
+	bitmap_zero(bitmap, TEST_BIT_LEN);
+	time = ktime_get();
+	for (cnt = 0; cnt < 5; cnt++) {
+		for (nbits = 1; nbits <= BITS_PER_LONG; nbits++) {
+			for (i = 0; i < TEST_BIT_LEN; i++) {
+				if (i + nbits > TEST_BIT_LEN)
+					break;
+				bitmap_write(bitmap, val, i, nbits);
+			}
+		}
+	}
+	time = ktime_get() - time;
+	pr_info("%s:\t\t%llu\n", __func__, time);
+}
+
+/*
+ * nbits == 0 is most commonly not a valid case. Bitmap users should revisit
+ * the caller logic. Bitmap API doesn't provide any guarantees on returned
+ * value. The pointers are not dereferenced. The return value is intentionally
+ * ignored.
+ */
+static void __init test_zero_nbits(void)
+{
+	static volatile __always_used unsigned long ret __initdata;
+
+	bitmap_clear(NULL, 0, 0);
+	bitmap_complement(NULL, NULL, 0);
+	bitmap_copy(NULL, NULL, 0);
+	bitmap_copy_clear_tail(NULL, NULL, 0);
+	bitmap_fill(NULL, 0);
+	bitmap_from_arr32(NULL, NULL, 0);
+	bitmap_from_arr64(NULL, NULL, 0);
+	bitmap_or(NULL, NULL, NULL, 0);
+	bitmap_set(NULL, 0, 0);
+	bitmap_shift_left(NULL, NULL, 0, 0);
+	bitmap_shift_right(NULL, NULL, 0, 0);
+	bitmap_to_arr32(NULL, NULL, 0);
+	bitmap_to_arr64(NULL, NULL, 0);
+	bitmap_write(NULL, 0, 0, 0);
+	bitmap_xor(NULL, NULL, NULL, 0);
+	bitmap_zero(NULL, 0);
+
+	ret = bitmap_and(NULL, NULL, NULL, 0);
+	ret = bitmap_empty(NULL, 0);
+	ret = bitmap_equal(NULL, NULL, 0);
+	ret = bitmap_full(NULL, 0);
+	ret = bitmap_or_equal(NULL, NULL, NULL, 0);
+	ret = bitmap_read(NULL, 0, 0);
+	ret = bitmap_subset(NULL, NULL, 0);
+	ret = bitmap_weight(NULL, 0);
+	ret = bitmap_weight_and(NULL, NULL, 0);
+	ret = bitmap_weight_andnot(NULL, NULL, 0);
+	ret = bitmap_weight_from(NULL, 0, 0);
+	ret = bitmap_weighted_or(NULL, NULL, NULL, 0);
+
+	ret = find_first_and_and_bit(NULL, NULL, NULL, 0);
+	ret = find_first_and_bit(NULL, NULL, 0);
+	ret = find_first_andnot_bit(NULL, NULL, 0);
+	ret = find_first_bit(NULL, 0);
+	ret = find_first_zero_bit(NULL, 0);
+	ret = find_last_bit(NULL, 0);
+	ret = find_next_and_bit(NULL, NULL, 0, 0);
+	ret = find_next_andnot_bit(NULL, NULL, 0, 0);
+	ret = find_next_bit(NULL, 0, 0);
+	ret = find_next_clump8(NULL, NULL, 0, 0);
+	ret = find_next_zero_bit(NULL, 0, 0);
+	ret = find_nth_and_bit(NULL, NULL, 0, 0);
+	ret = find_nth_bit(NULL, 0, 0);
+	ret = find_random_bit(NULL, 0);
+}
+
+#undef TEST_BIT_LEN
+
+static void __init selftest(void)
+{
+	test_zero_clear();
+	test_fill_set();
+	test_copy();
+	test_bitmap_region();
+	test_replace();
+	test_bitmap_sg();
+	test_bitmap_arr32();
+	test_bitmap_arr64();
+	test_bitmap_parse();
+	test_bitmap_parselist();
+	test_bitmap_printlist();
+	test_mem_optimisations();
+	test_bitmap_cut();
+	test_bitmap_print_buf();
+	test_bitmap_const_eval();
+	test_bitmap_read_write();
+	test_bitmap_read_perf();
+	test_bitmap_weight();
+	test_bitmap_write_perf();
+	test_zero_nbits();
+
+	test_find_nth_bit();
+	test_for_each_set_bit();
+	test_for_each_set_bit_from();
+	test_for_each_clear_bit();
+	test_for_each_clear_bit_from();
+	test_for_each_set_bitrange();
+	test_for_each_clear_bitrange();
+	test_for_each_set_bitrange_from();
+	test_for_each_clear_bitrange_from();
+	test_for_each_set_clump8();
+	test_for_each_set_bit_wrap();
+	test_bitmap_find_next_zero_area_off();
+}
+
+KSTM_MODULE_LOADERS(test_bitmap);
+MODULE_AUTHOR("david decotigny <david.decotigny@googlers.com>");
+MODULE_DESCRIPTION("Test cases for bitmap API");
+MODULE_LICENSE("GPL");