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-rw-r--r--MAINTAINERS14
-rw-r--r--include/linux/bitops.h19
-rw-r--r--include/linux/compiler_attributes.h13
-rw-r--r--include/linux/cpumask.h10
-rw-r--r--include/linux/find.h2
-rw-r--r--include/linux/wordpart.h7
-rw-r--r--kernel/sched/topology.c6
-rw-r--r--lib/Kconfig.debug1
-rw-r--r--lib/find_bit.c2
-rw-r--r--lib/test_bitmap.c4
-rw-r--r--lib/test_bitops.c28
-rw-r--r--lib/usercopy.c9
12 files changed, 88 insertions, 27 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index 94872dce51ed..f63013898f40 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3725,6 +3725,20 @@ F: tools/include/vdso/bits.h
F: tools/lib/bitmap.c
F: tools/lib/find_bit.c
+BITOPS API
+M: Yury Norov <yury.norov@gmail.com>
+R: Rasmus Villemoes <linux@rasmusvillemoes.dk>
+S: Maintained
+F: arch/*/include/asm/bitops.h
+F: arch/*/include/asm/bitops_32.h
+F: arch/*/include/asm/bitops_64.h
+F: arch/*/lib/bitops.c
+F: include/asm-generic/bitops
+F: include/asm-generic/bitops.h
+F: include/linux/bitops.h
+F: lib/test_bitops.c
+F: tools/*/bitops*
+
BLINKM RGB LED DRIVER
M: Jan-Simon Moeller <jansimon.moeller@gmx.de>
S: Maintained
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 3112ae7d6524..46d4bdc634c0 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -8,13 +8,6 @@
#include <uapi/linux/kernel.h>
-/* Set bits in the first 'n' bytes when loaded from memory */
-#ifdef __LITTLE_ENDIAN
-# define aligned_byte_mask(n) ((1UL << 8*(n))-1)
-#else
-# define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
-#endif
-
#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
#define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
#define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
@@ -257,16 +250,10 @@ static inline unsigned int __ffs64(u64 word)
*/
static inline unsigned int fns(unsigned long word, unsigned int n)
{
- unsigned int bit;
-
- while (word) {
- bit = __ffs(word);
- if (n-- == 0)
- return bit;
- __clear_bit(bit, &word);
- }
+ while (word && n--)
+ word &= word - 1;
- return BITS_PER_LONG;
+ return word ? __ffs(word) : BITS_PER_LONG;
}
/**
diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h
index 8bdf6e0918c1..32284cd26d52 100644
--- a/include/linux/compiler_attributes.h
+++ b/include/linux/compiler_attributes.h
@@ -362,6 +362,19 @@
#define __used __attribute__((__used__))
/*
+ * The __used attribute guarantees that the attributed variable will be
+ * always emitted by a compiler. It doesn't prevent the compiler from
+ * throwing 'unused' warnings when it can't detect how the variable is
+ * actually used. It's a compiler implementation details either emit
+ * the warning in that case or not.
+ *
+ * The combination of both 'used' and 'unused' attributes ensures that
+ * the variable would be emitted, and will not trigger 'unused' warnings.
+ * The attribute is applicable for functions, static and global variables.
+ */
+#define __always_used __used __maybe_unused
+
+/*
* gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-warn_005funused_005fresult-function-attribute
* clang: https://clang.llvm.org/docs/AttributeReference.html#nodiscard-warn-unused-result
*/
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 7600e877908f..4d3bef644add 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -386,6 +386,16 @@ unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int sta
for_each_or_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), small_cpumask_bits)
/**
+ * for_each_cpu_from - iterate over CPUs present in @mask, from @cpu to the end of @mask.
+ * @cpu: the (optionally unsigned) integer iterator
+ * @mask: the cpumask pointer
+ *
+ * After the loop, cpu is >= nr_cpu_ids.
+ */
+#define for_each_cpu_from(cpu, mask) \
+ for_each_set_bit_from(cpu, cpumask_bits(mask), small_cpumask_bits)
+
+/**
* cpumask_any_but - return a "random" in a cpumask, but not this one.
* @mask: the cpumask to search
* @cpu: the cpu to ignore.
diff --git a/include/linux/find.h b/include/linux/find.h
index 28ec5a03393a..5dfca4225fef 100644
--- a/include/linux/find.h
+++ b/include/linux/find.h
@@ -222,7 +222,7 @@ unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
* idx = find_first_bit(addr, size);
*
* Returns the bit number of the N'th set bit.
- * If no such, returns @size.
+ * If no such, returns >= @size.
*/
static inline
unsigned long find_nth_bit(const unsigned long *addr, unsigned long size, unsigned long n)
diff --git a/include/linux/wordpart.h b/include/linux/wordpart.h
index f6f8f83b15b0..4ca1ba66d2f0 100644
--- a/include/linux/wordpart.h
+++ b/include/linux/wordpart.h
@@ -39,4 +39,11 @@
*/
#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
+/* Set bits in the first 'n' bytes when loaded from memory */
+#ifdef __LITTLE_ENDIAN
+# define aligned_byte_mask(n) ((1UL << 8*(n))-1)
+#else
+# define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
+#endif
+
#endif // _LINUX_WORDPART_H
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 329c82faca9b..a6994a1fcc90 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -2353,7 +2353,7 @@ static struct sched_domain *build_sched_domain(struct sched_domain_topology_leve
static bool topology_span_sane(struct sched_domain_topology_level *tl,
const struct cpumask *cpu_map, int cpu)
{
- int i;
+ int i = cpu + 1;
/* NUMA levels are allowed to overlap */
if (tl->flags & SDTL_OVERLAP)
@@ -2365,9 +2365,7 @@ static bool topology_span_sane(struct sched_domain_topology_level *tl,
* breaking the sched_group lists - i.e. a later get_group() pass
* breaks the linking done for an earlier span.
*/
- for_each_cpu(i, cpu_map) {
- if (i == cpu)
- continue;
+ for_each_cpu_from(i, cpu_map) {
/*
* We should 'and' all those masks with 'cpu_map' to exactly
* match the topology we're about to build, but that can only
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c1c1b19525a5..4bcdb2fd17d8 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2482,7 +2482,6 @@ config TEST_LKM
config TEST_BITOPS
tristate "Test module for compilation of bitops operations"
- depends on m
help
This builds the "test_bitops" module that is much like the
TEST_LKM module except that it does a basic exercise of the
diff --git a/lib/find_bit.c b/lib/find_bit.c
index dacadd904250..0836bb3d76c5 100644
--- a/lib/find_bit.c
+++ b/lib/find_bit.c
@@ -87,7 +87,7 @@ out: \
if (sz % BITS_PER_LONG) \
tmp = (FETCH) & BITMAP_LAST_WORD_MASK(sz); \
found: \
- sz = min(idx * BITS_PER_LONG + fns(tmp, nr), sz); \
+ sz = idx * BITS_PER_LONG + fns(tmp, nr); \
out: \
sz; \
})
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 83019beabce4..6dfb8d46a4ff 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -244,7 +244,7 @@ static void __init test_find_nth_bit(void)
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(64 * 3, find_nth_bit(bmap, 64 * 3, 8));
+ 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));
@@ -254,7 +254,7 @@ static void __init test_find_nth_bit(void)
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(64 * 3 - 1, find_nth_bit(bmap, 64 * 3 - 1, 8));
+ 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++);
diff --git a/lib/test_bitops.c b/lib/test_bitops.c
index 3b7bcbee84db..55669624bb28 100644
--- a/lib/test_bitops.c
+++ b/lib/test_bitops.c
@@ -5,9 +5,11 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/cleanup.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/printk.h>
+#include <linux/slab.h>
/* a tiny module only meant to test
*
@@ -50,6 +52,30 @@ static unsigned long order_comb_long[][2] = {
};
#endif
+static int __init test_fns(void)
+{
+ static volatile __always_used unsigned long tmp __initdata;
+ unsigned long *buf __free(kfree) = NULL;
+ unsigned int i, n;
+ ktime_t time;
+
+ buf = kmalloc_array(10000, sizeof(unsigned long), GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ get_random_bytes(buf, 10000 * sizeof(unsigned long));
+ time = ktime_get();
+
+ for (n = 0; n < BITS_PER_LONG; n++)
+ for (i = 0; i < 10000; i++)
+ tmp = fns(buf[i], n);
+
+ time = ktime_get() - time;
+ pr_err("fns: %18llu ns\n", time);
+
+ return 0;
+}
+
static int __init test_bitops_startup(void)
{
int i, bit_set;
@@ -94,6 +120,8 @@ static int __init test_bitops_startup(void)
if (bit_set != BITOPS_LAST)
pr_err("ERROR: FOUND SET BIT %d\n", bit_set);
+ test_fns();
+
pr_info("Completed bitops test\n");
return 0;
diff --git a/lib/usercopy.c b/lib/usercopy.c
index d29fe29c6849..499a7a7d54db 100644
--- a/lib/usercopy.c
+++ b/lib/usercopy.c
@@ -1,9 +1,14 @@
// SPDX-License-Identifier: GPL-2.0
-#include <linux/bitops.h>
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/export.h>
#include <linux/fault-inject-usercopy.h>
#include <linux/instrumented.h>
-#include <linux/uaccess.h>
+#include <linux/kernel.h>
#include <linux/nospec.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/wordpart.h>
/* out-of-line parts */
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-22 07:56:18 +0000