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| author | Kees Cook <kees+treewide@kernel.org> | 2026-09-02 15:31:14 -0700 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2026-09-04 21:37:00 -0700 |
| commit | 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch) | |
| tree | c65086f9bdcd48c6360fb7cb4598bca084da1f32 /lib/hweight.c | |
| download | linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip | |
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci
This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.
Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.
Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'lib/hweight.c')
| -rw-r--r-- | lib/hweight.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/lib/hweight.c b/lib/hweight.c new file mode 100644 index 000000000..0dfcafc3f --- /dev/null +++ b/lib/hweight.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/export.h> +#include <linux/bitops.h> +#include <asm/types.h> + +/** + * DOC: __sw_hweightN - returns the hamming weight of a N-bit word + * @w: the word to weigh + * + * The Hamming Weight of a number is the total number of bits set in it. + */ + +unsigned int __sw_hweight32(unsigned int w) +{ +#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER + w -= (w >> 1) & 0x55555555; + w = (w & 0x33333333) + ((w >> 2) & 0x33333333); + w = (w + (w >> 4)) & 0x0f0f0f0f; + return (w * 0x01010101) >> 24; +#else + unsigned int res = w - ((w >> 1) & 0x55555555); + res = (res & 0x33333333) + ((res >> 2) & 0x33333333); + res = (res + (res >> 4)) & 0x0F0F0F0F; + res = res + (res >> 8); + return (res + (res >> 16)) & 0x000000FF; +#endif +} +EXPORT_SYMBOL(__sw_hweight32); + +unsigned int __sw_hweight16(unsigned int w) +{ + unsigned int res = w - ((w >> 1) & 0x5555); + res = (res & 0x3333) + ((res >> 2) & 0x3333); + res = (res + (res >> 4)) & 0x0F0F; + return (res + (res >> 8)) & 0x00FF; +} +EXPORT_SYMBOL(__sw_hweight16); + +unsigned int __sw_hweight8(unsigned int w) +{ + unsigned int res = w - ((w >> 1) & 0x55); + res = (res & 0x33) + ((res >> 2) & 0x33); + return (res + (res >> 4)) & 0x0F; +} +EXPORT_SYMBOL(__sw_hweight8); + +unsigned long __sw_hweight64(__u64 w) +{ +#if BITS_PER_LONG == 32 + return __sw_hweight32((unsigned int)(w >> 32)) + + __sw_hweight32((unsigned int)w); +#elif BITS_PER_LONG == 64 +#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER + w -= (w >> 1) & 0x5555555555555555ul; + w = (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul); + w = (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful; + return (w * 0x0101010101010101ul) >> 56; +#else + __u64 res = w - ((w >> 1) & 0x5555555555555555ul); + res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul); + res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful; + res = res + (res >> 8); + res = res + (res >> 16); + return (res + (res >> 32)) & 0x00000000000000FFul; +#endif +#endif +} +EXPORT_SYMBOL(__sw_hweight64); |
