Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "Most of the rest of MM and various other things. Some Kconfig rework
  still awaits merges of dependent trees from linux-next.

  Subsystems affected by this patch series: mm/hotfixes, mm/memcg,
  mm/vmstat, mm/thp, procfs, sysctl, misc, notifiers, core-kernel,
  bitops, lib, checkpatch, epoll, binfmt, init, rapidio, uaccess, kcov,
  ubsan, ipc, bitmap, mm/pagemap"

* akpm: (86 commits)
  mm: remove __ARCH_HAS_4LEVEL_HACK and include/asm-generic/4level-fixup.h
  um: add support for folded p4d page tables
  um: remove unused pxx_offset_proc() and addr_pte() functions
  sparc32: use pgtable-nopud instead of 4level-fixup
  parisc/hugetlb: use pgtable-nopXd instead of 4level-fixup
  parisc: use pgtable-nopXd instead of 4level-fixup
  nds32: use pgtable-nopmd instead of 4level-fixup
  microblaze: use pgtable-nopmd instead of 4level-fixup
  m68k: mm: use pgtable-nopXd instead of 4level-fixup
  m68k: nommu: use pgtable-nopud instead of 4level-fixup
  c6x: use pgtable-nopud instead of 4level-fixup
  arm: nommu: use pgtable-nopud instead of 4level-fixup
  alpha: use pgtable-nopud instead of 4level-fixup
  gpio: pca953x: tighten up indentation
  gpio: pca953x: convert to use bitmap API
  gpio: pca953x: use input from regs structure in pca953x_irq_pending()
  gpio: pca953x: remove redundant variable and check in IRQ handler
  lib/bitmap: introduce bitmap_replace() helper
  lib/test_bitmap: fix comment about this file
  lib/test_bitmap: move exp1 and exp2 upper for others to use
  ...

7 files changed, 275 insertions, 105 deletions

diff --git a/lib/bitmap.c b/lib/bitmap.c
index f9e834841e94..4250519d7d1c 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -222,6 +222,18 @@ int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 }
 EXPORT_SYMBOL(__bitmap_andnot);
 
+void __bitmap_replace(unsigned long *dst,
+		      const unsigned long *old, const unsigned long *new,
+		      const unsigned long *mask, unsigned int nbits)
+{
+	unsigned int k;
+	unsigned int nr = BITS_TO_LONGS(nbits);
+
+	for (k = 0; k < nr; k++)
+		dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]);
+}
+EXPORT_SYMBOL(__bitmap_replace);
+
 int __bitmap_intersects(const unsigned long *bitmap1,
 			const unsigned long *bitmap2, unsigned int bits)
 {
diff --git a/lib/find_bit.c b/lib/find_bit.c
index 5c51eb45178a..e35a76b291e6 100644
--- a/lib/find_bit.c
+++ b/lib/find_bit.c
@@ -214,3 +214,17 @@ EXPORT_SYMBOL(find_next_bit_le);
 #endif
 
 #endif /* __BIG_ENDIAN */
+
+unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr,
+			       unsigned long size, unsigned long offset)
+{
+	offset = find_next_bit(addr, size, offset);
+	if (offset == size)
+		return size;
+
+	offset = round_down(offset, 8);
+	*clump = bitmap_get_value8(addr, offset);
+
+	return offset;
+}
+EXPORT_SYMBOL(find_next_clump8);
diff --git a/lib/genalloc.c b/lib/genalloc.c
index 24d20ca7e91b..7f1244b5294a 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -540,7 +540,7 @@ void gen_pool_for_each_chunk(struct gen_pool *pool,
 EXPORT_SYMBOL(gen_pool_for_each_chunk);
 
 /**
- * addr_in_gen_pool - checks if an address falls within the range of a pool
+ * gen_pool_has_addr - checks if an address falls within the range of a pool
  * @pool:	the generic memory pool
  * @start:	start address
  * @size:	size of the region
@@ -548,7 +548,7 @@ EXPORT_SYMBOL(gen_pool_for_each_chunk);
  * Check if the range of addresses falls within the specified pool. Returns
  * true if the entire range is contained in the pool and false otherwise.
  */
-bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start,
+bool gen_pool_has_addr(struct gen_pool *pool, unsigned long start,
 			size_t size)
 {
 	bool found = false;
@@ -567,6 +567,7 @@ bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start,
 	rcu_read_unlock();
 	return found;
 }
+EXPORT_SYMBOL(gen_pool_has_addr);
 
 /**
  * gen_pool_avail - get available free space of the pool
diff --git a/lib/math/rational.c b/lib/math/rational.c
index ba7443677c90..31fb27db2deb 100644
--- a/lib/math/rational.c
+++ b/lib/math/rational.c
@@ -3,6 +3,7 @@
  * rational fractions
  *
  * Copyright (C) 2009 emlix GmbH, Oskar Schirmer <oskar@scara.com>
+ * Copyright (C) 2019 Trent Piepho <tpiepho@gmail.com>
  *
  * helper functions when coping with rational numbers
  */
@@ -10,6 +11,7 @@
 #include <linux/rational.h>
 #include <linux/compiler.h>
 #include <linux/export.h>
+#include <linux/kernel.h>
 
 /*
  * calculate best rational approximation for a given fraction
@@ -33,30 +35,65 @@ void rational_best_approximation(
 	unsigned long max_numerator, unsigned long max_denominator,
 	unsigned long *best_numerator, unsigned long *best_denominator)
 {
-	unsigned long n, d, n0, d0, n1, d1;
+	/* n/d is the starting rational, which is continually
+	 * decreased each iteration using the Euclidean algorithm.
+	 *
+	 * dp is the value of d from the prior iteration.
+	 *
+	 * n2/d2, n1/d1, and n0/d0 are our successively more accurate
+	 * approximations of the rational.  They are, respectively,
+	 * the current, previous, and two prior iterations of it.
+	 *
+	 * a is current term of the continued fraction.
+	 */
+	unsigned long n, d, n0, d0, n1, d1, n2, d2;
 	n = given_numerator;
 	d = given_denominator;
 	n0 = d1 = 0;
 	n1 = d0 = 1;
+
 	for (;;) {
-		unsigned long t, a;
-		if ((n1 > max_numerator) || (d1 > max_denominator)) {
-			n1 = n0;
-			d1 = d0;
-			break;
-		}
+		unsigned long dp, a;
+
 		if (d == 0)
 			break;
-		t = d;
+		/* Find next term in continued fraction, 'a', via
+		 * Euclidean algorithm.
+		 */
+		dp = d;
 		a = n / d;
 		d = n % d;
-		n = t;
-		t = n0 + a * n1;
+		n = dp;
+
+		/* Calculate the current rational approximation (aka
+		 * convergent), n2/d2, using the term just found and
+		 * the two prior approximations.
+		 */
+		n2 = n0 + a * n1;
+		d2 = d0 + a * d1;
+
+		/* If the current convergent exceeds the maxes, then
+		 * return either the previous convergent or the
+		 * largest semi-convergent, the final term of which is
+		 * found below as 't'.
+		 */
+		if ((n2 > max_numerator) || (d2 > max_denominator)) {
+			unsigned long t = min((max_numerator - n0) / n1,
+					      (max_denominator - d0) / d1);
+
+			/* This tests if the semi-convergent is closer
+			 * than the previous convergent.
+			 */
+			if (2u * t > a || (2u * t == a && d0 * dp > d1 * d)) {
+				n1 = n0 + t * n1;
+				d1 = d0 + t * d1;
+			}
+			break;
+		}
 		n0 = n1;
-		n1 = t;
-		t = d0 + a * d1;
+		n1 = n2;
 		d0 = d1;
-		d1 = t;
+		d1 = d2;
 	}
 	*best_numerator = n1;
 	*best_denominator = d1;
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 51a98f7ee79e..e14a15ac250b 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Test cases for printf facility.
+ * Test cases for bitmap API.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -21,6 +21,39 @@ static unsigned failed_tests __initdata;
 
 static char pbl_buffer[PAGE_SIZE] __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),
+};
+
+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_uint(const char *srcfile, unsigned int line,
@@ -92,6 +125,36 @@ __check_eq_u32_array(const char *srcfile, unsigned int line,
 	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;
+}
+
 #define __expect_eq(suffix, ...)					\
 	({								\
 		int result = 0;						\
@@ -108,6 +171,7 @@ __check_eq_u32_array(const char *srcfile, unsigned int line,
 #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__)
 
 static void __init test_zero_clear(void)
 {
@@ -206,6 +270,30 @@ static void __init test_copy(void)
 	expect_eq_pbl("0-108,128-1023", bmap2, 1024);
 }
 
+#define EXP2_IN_BITS	(sizeof(exp2) * 8)
+
+static void __init test_replace(void)
+{
+	unsigned int nbits = 64;
+	DECLARE_BITMAP(bmap, 1024);
+
+	bitmap_zero(bmap, 1024);
+	bitmap_replace(bmap, &exp2[0], &exp2[1], exp2_to_exp3_mask, nbits);
+	expect_eq_bitmap(bmap, exp3_0_1, nbits);
+
+	bitmap_zero(bmap, 1024);
+	bitmap_replace(bmap, &exp2[1], &exp2[0], exp2_to_exp3_mask, nbits);
+	expect_eq_bitmap(bmap, exp3_1_0, nbits);
+
+	bitmap_fill(bmap, 1024);
+	bitmap_replace(bmap, &exp2[0], &exp2[1], exp2_to_exp3_mask, nbits);
+	expect_eq_bitmap(bmap, exp3_0_1, nbits);
+
+	bitmap_fill(bmap, 1024);
+	bitmap_replace(bmap, &exp2[1], &exp2[0], exp2_to_exp3_mask, nbits);
+	expect_eq_bitmap(bmap, exp3_1_0, nbits);
+}
+
 #define PARSE_TIME 0x1
 
 struct test_bitmap_parselist{
@@ -216,53 +304,32 @@ struct test_bitmap_parselist{
 	const int flags;
 };
 
-static const unsigned long exp[] __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),
-};
-
-static const unsigned long exp2[] __initconst = {
-	BITMAP_FROM_U64(0x3333333311111111ULL),
-	BITMAP_FROM_U64(0xffffffff77777777ULL)
-};
-
 static const struct test_bitmap_parselist parselist_tests[] __initconst = {
 #define step (sizeof(u64) / sizeof(unsigned long))
 
-	{0, "0",			&exp[0], 8, 0},
-	{0, "1",			&exp[1 * step], 8, 0},
-	{0, "0-15",			&exp[2 * step], 32, 0},
-	{0, "16-31",			&exp[3 * step], 32, 0},
-	{0, "0-31:1/2",			&exp[4 * step], 32, 0},
-	{0, "1-31:1/2",			&exp[5 * step], 32, 0},
-	{0, "0-31:1/4",			&exp[6 * step], 32, 0},
-	{0, "1-31:1/4",			&exp[7 * step], 32, 0},
-	{0, "0-31:4/4",			&exp[8 * step], 32, 0},
-	{0, "1-31:4/4",			&exp[9 * step], 32, 0},
-	{0, "0-31:1/4,32-63:2/4",	&exp[10 * step], 64, 0},
-	{0, "0-31:3/4,32-63:4/4",	&exp[11 * step], 64, 0},
-	{0, "  ,,  0-31:3/4  ,, 32-63:4/4  ,,  ",	&exp[11 * step], 64, 0},
+	{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, "",				&exp[12 * step], 8, 0},
-	{0, "\n",			&exp[12 * step], 8, 0},
-	{0, ",,  ,,  , ,  ,",		&exp[12 * step], 8, 0},
-	{0, " ,  ,,  , ,   ",		&exp[12 * step], 8, 0},
-	{0, " ,  ,,  , ,   \n",		&exp[12 * step], 8, 0},
+	{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},
 
 	{-EINVAL, "-1",	NULL, 8, 0},
 	{-EINVAL, "-0",	NULL, 8, 0},
@@ -280,6 +347,8 @@ static const struct test_bitmap_parselist parselist_tests[] __initconst = {
 	{-EINVAL, "a-31:10/1", NULL, 8, 0},
 	{-EINVAL, "0-31:a/1", NULL, 8, 0},
 	{-EINVAL, "0-\n", NULL, 8, 0},
+
+#undef step
 };
 
 static void __init __test_bitmap_parselist(int is_user)
@@ -299,7 +368,7 @@ static void __init __test_bitmap_parselist(int is_user)
 
 			set_fs(KERNEL_DS);
 			time = ktime_get();
-			err = bitmap_parselist_user(ptest.in, len,
+			err = bitmap_parselist_user((__force const char __user *)ptest.in, len,
 						    bmap, ptest.nbits);
 			time = ktime_get() - time;
 			set_fs(orig_fs);
@@ -326,6 +395,8 @@ static void __init __test_bitmap_parselist(int is_user)
 		if (ptest.flags & PARSE_TIME)
 			pr_err("parselist%s: %d: input is '%s' OK, Time: %llu\n",
 					mode, i, ptest.in, time);
+
+#undef ptest
 	}
 }
 
@@ -339,20 +410,20 @@ static void __init test_bitmap_parselist_user(void)
 	__test_bitmap_parselist(1);
 }
 
-#define EXP_BYTES	(sizeof(exp) * 8)
+#define EXP1_IN_BITS	(sizeof(exp1) * 8)
 
 static void __init test_bitmap_arr32(void)
 {
 	unsigned int nbits, next_bit;
-	u32 arr[sizeof(exp) / 4];
-	DECLARE_BITMAP(bmap2, EXP_BYTES);
+	u32 arr[EXP1_IN_BITS / 32];
+	DECLARE_BITMAP(bmap2, EXP1_IN_BITS);
 
 	memset(arr, 0xa5, sizeof(arr));
 
-	for (nbits = 0; nbits < EXP_BYTES; ++nbits) {
-		bitmap_to_arr32(arr, exp, nbits);
+	for (nbits = 0; nbits < EXP1_IN_BITS; ++nbits) {
+		bitmap_to_arr32(arr, exp1, nbits);
 		bitmap_from_arr32(bmap2, arr, nbits);
-		expect_eq_bitmap(bmap2, exp, nbits);
+		expect_eq_bitmap(bmap2, exp1, nbits);
 
 		next_bit = find_next_bit(bmap2,
 				round_up(nbits, BITS_PER_LONG), nbits);
@@ -361,7 +432,7 @@ static void __init test_bitmap_arr32(void)
 				" tail is not safely cleared: %d\n",
 				nbits, next_bit);
 
-		if (nbits < EXP_BYTES - 32)
+		if (nbits < EXP1_IN_BITS - 32)
 			expect_eq_uint(arr[DIV_ROUND_UP(nbits, 32)],
 								0xa5a5a5a5);
 	}
@@ -404,15 +475,50 @@ static void noinline __init test_mem_optimisations(void)
 	}
 }
 
+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 selftest(void)
 {
 	test_zero_clear();
 	test_fill_set();
 	test_copy();
+	test_replace();
 	test_bitmap_arr32();
 	test_bitmap_parselist();
 	test_bitmap_parselist_user();
 	test_mem_optimisations();
+	test_for_each_set_clump8();
 }
 
 KSTM_MODULE_LOADERS(test_bitmap);
diff --git a/lib/test_meminit.c b/lib/test_meminit.c
index 9742e5cb853a..e4f706a404b3 100644
--- a/lib/test_meminit.c
+++ b/lib/test_meminit.c
@@ -183,6 +183,9 @@ static bool __init check_buf(void *buf, int size, bool want_ctor,
 	return fail;
 }
 
+#define BULK_SIZE 100
+static void *bulk_array[BULK_SIZE];
+
 /*
  * Test kmem_cache with given parameters:
  *  want_ctor - use a constructor;
@@ -203,9 +206,24 @@ static int __init do_kmem_cache_size(size_t size, bool want_ctor,
 			      want_rcu ? SLAB_TYPESAFE_BY_RCU : 0,
 			      want_ctor ? test_ctor : NULL);
 	for (iter = 0; iter < 10; iter++) {
+		/* Do a test of bulk allocations */
+		if (!want_rcu && !want_ctor) {
+			int ret;
+
+			ret = kmem_cache_alloc_bulk(c, alloc_mask, BULK_SIZE, bulk_array);
+			if (!ret) {
+				fail = true;
+			} else {
+				int i;
+				for (i = 0; i < ret; i++)
+					fail |= check_buf(bulk_array[i], size, want_ctor, want_rcu, want_zero);
+				kmem_cache_free_bulk(c, ret, bulk_array);
+			}
+		}
+
 		buf = kmem_cache_alloc(c, alloc_mask);
 		/* Check that buf is zeroed, if it must be. */
-		fail = check_buf(buf, size, want_ctor, want_rcu, want_zero);
+		fail |= check_buf(buf, size, want_ctor, want_rcu, want_zero);
 		fill_with_garbage_skip(buf, size, want_ctor ? CTOR_BYTES : 0);
 
 		if (!want_rcu) {
diff --git a/lib/ubsan.c b/lib/ubsan.c
index fc552d524ef7..7b9b58aee72c 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -140,25 +140,21 @@ static void val_to_string(char *str, size_t size, struct type_descriptor *type,
 	}
 }
 
-static DEFINE_SPINLOCK(report_lock);
-
-static void ubsan_prologue(struct source_location *location,
-			unsigned long *flags)
+static void ubsan_prologue(struct source_location *location)
 {
 	current->in_ubsan++;
-	spin_lock_irqsave(&report_lock, *flags);
 
 	pr_err("========================================"
 		"========================================\n");
 	print_source_location("UBSAN: Undefined behaviour in", location);
 }
 
-static void ubsan_epilogue(unsigned long *flags)
+static void ubsan_epilogue(void)
 {
 	dump_stack();
 	pr_err("========================================"
 		"========================================\n");
-	spin_unlock_irqrestore(&report_lock, *flags);
+
 	current->in_ubsan--;
 }
 
@@ -167,14 +163,13 @@ static void handle_overflow(struct overflow_data *data, void *lhs,
 {
 
 	struct type_descriptor *type = data->type;
-	unsigned long flags;
 	char lhs_val_str[VALUE_LENGTH];
 	char rhs_val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
 	val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
@@ -186,7 +181,7 @@ static void handle_overflow(struct overflow_data *data, void *lhs,
 		rhs_val_str,
 		type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 
 void __ubsan_handle_add_overflow(struct overflow_data *data,
@@ -214,20 +209,19 @@ EXPORT_SYMBOL(__ubsan_handle_mul_overflow);
 void __ubsan_handle_negate_overflow(struct overflow_data *data,
 				void *old_val)
 {
-	unsigned long flags;
 	char old_val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);
 
 	pr_err("negation of %s cannot be represented in type %s:\n",
 		old_val_str, data->type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
 
@@ -235,13 +229,12 @@ EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
 void __ubsan_handle_divrem_overflow(struct overflow_data *data,
 				void *lhs, void *rhs)
 {
-	unsigned long flags;
 	char rhs_val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
 
@@ -251,58 +244,52 @@ void __ubsan_handle_divrem_overflow(struct overflow_data *data,
 	else
 		pr_err("division by zero\n");
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);
 
 static void handle_null_ptr_deref(struct type_mismatch_data_common *data)
 {
-	unsigned long flags;
-
 	if (suppress_report(data->location))
 		return;
 
-	ubsan_prologue(data->location, &flags);
+	ubsan_prologue(data->location);
 
 	pr_err("%s null pointer of type %s\n",
 		type_check_kinds[data->type_check_kind],
 		data->type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 
 static void handle_misaligned_access(struct type_mismatch_data_common *data,
 				unsigned long ptr)
 {
-	unsigned long flags;
-
 	if (suppress_report(data->location))
 		return;
 
-	ubsan_prologue(data->location, &flags);
+	ubsan_prologue(data->location);
 
 	pr_err("%s misaligned address %p for type %s\n",
 		type_check_kinds[data->type_check_kind],
 		(void *)ptr, data->type->type_name);
 	pr_err("which requires %ld byte alignment\n", data->alignment);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 
 static void handle_object_size_mismatch(struct type_mismatch_data_common *data,
 					unsigned long ptr)
 {
-	unsigned long flags;
-
 	if (suppress_report(data->location))
 		return;
 
-	ubsan_prologue(data->location, &flags);
+	ubsan_prologue(data->location);
 	pr_err("%s address %p with insufficient space\n",
 		type_check_kinds[data->type_check_kind],
 		(void *) ptr);
 	pr_err("for an object of type %s\n", data->type->type_name);
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 
 static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data,
@@ -351,25 +338,23 @@ EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1);
 
 void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data, void *index)
 {
-	unsigned long flags;
 	char index_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(index_str, sizeof(index_str), data->index_type, index);
 	pr_err("index %s is out of range for type %s\n", index_str,
 		data->array_type->type_name);
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);
 
 void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
 					void *lhs, void *rhs)
 {
-	unsigned long flags;
 	struct type_descriptor *rhs_type = data->rhs_type;
 	struct type_descriptor *lhs_type = data->lhs_type;
 	char rhs_str[VALUE_LENGTH];
@@ -379,7 +364,7 @@ void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
 	if (suppress_report(&data->location))
 		goto out;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
 	val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);
@@ -402,7 +387,7 @@ void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
 			lhs_str, rhs_str,
 			lhs_type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 out:
 	user_access_restore(ua_flags);
 }
@@ -411,11 +396,9 @@ EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);
 
 void __ubsan_handle_builtin_unreachable(struct unreachable_data *data)
 {
-	unsigned long flags;
-
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 	pr_err("calling __builtin_unreachable()\n");
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 	panic("can't return from __builtin_unreachable()");
 }
 EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
@@ -423,19 +406,18 @@ EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
 void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
 				void *val)
 {
-	unsigned long flags;
 	char val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(val_str, sizeof(val_str), data->type, val);
 
 	pr_err("load of value %s is not a valid value for type %s\n",
 		val_str, data->type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);