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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 /arch/arm64/lib/memcmp.S | |
| 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 'arch/arm64/lib/memcmp.S')
| -rw-r--r-- | arch/arm64/lib/memcmp.S | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/arm64/lib/memcmp.S b/arch/arm64/lib/memcmp.S new file mode 100644 index 000000000..a5ccf2c55 --- /dev/null +++ b/arch/arm64/lib/memcmp.S @@ -0,0 +1,139 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2013-2021, Arm Limited. + * + * Adapted from the original at: + * https://github.com/ARM-software/optimized-routines/blob/e823e3abf5f89ecb/string/aarch64/memcmp.S + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> + +/* Assumptions: + * + * ARMv8-a, AArch64, unaligned accesses. + */ + +#define L(label) .L ## label + +/* Parameters and result. */ +#define src1 x0 +#define src2 x1 +#define limit x2 +#define result w0 + +/* Internal variables. */ +#define data1 x3 +#define data1w w3 +#define data1h x4 +#define data2 x5 +#define data2w w5 +#define data2h x6 +#define tmp1 x7 +#define tmp2 x8 + +SYM_FUNC_START(__pi_memcmp) + subs limit, limit, 8 + b.lo L(less8) + + ldr data1, [src1], 8 + ldr data2, [src2], 8 + cmp data1, data2 + b.ne L(return) + + subs limit, limit, 8 + b.gt L(more16) + + ldr data1, [src1, limit] + ldr data2, [src2, limit] + b L(return) + +L(more16): + ldr data1, [src1], 8 + ldr data2, [src2], 8 + cmp data1, data2 + bne L(return) + + /* Jump directly to comparing the last 16 bytes for 32 byte (or less) + strings. */ + subs limit, limit, 16 + b.ls L(last_bytes) + + /* We overlap loads between 0-32 bytes at either side of SRC1 when we + try to align, so limit it only to strings larger than 128 bytes. */ + cmp limit, 96 + b.ls L(loop16) + + /* Align src1 and adjust src2 with bytes not yet done. */ + and tmp1, src1, 15 + add limit, limit, tmp1 + sub src1, src1, tmp1 + sub src2, src2, tmp1 + + /* Loop performing 16 bytes per iteration using aligned src1. + Limit is pre-decremented by 16 and must be larger than zero. + Exit if <= 16 bytes left to do or if the data is not equal. */ + .p2align 4 +L(loop16): + ldp data1, data1h, [src1], 16 + ldp data2, data2h, [src2], 16 + subs limit, limit, 16 + ccmp data1, data2, 0, hi + ccmp data1h, data2h, 0, eq + b.eq L(loop16) + + cmp data1, data2 + bne L(return) + mov data1, data1h + mov data2, data2h + cmp data1, data2 + bne L(return) + + /* Compare last 1-16 bytes using unaligned access. */ +L(last_bytes): + add src1, src1, limit + add src2, src2, limit + ldp data1, data1h, [src1] + ldp data2, data2h, [src2] + cmp data1, data2 + bne L(return) + mov data1, data1h + mov data2, data2h + cmp data1, data2 + + /* Compare data bytes and set return value to 0, -1 or 1. */ +L(return): +#ifndef __AARCH64EB__ + rev data1, data1 + rev data2, data2 +#endif + cmp data1, data2 +L(ret_eq): + cset result, ne + cneg result, result, lo + ret + + .p2align 4 + /* Compare up to 8 bytes. Limit is [-8..-1]. */ +L(less8): + adds limit, limit, 4 + b.lo L(less4) + ldr data1w, [src1], 4 + ldr data2w, [src2], 4 + cmp data1w, data2w + b.ne L(return) + sub limit, limit, 4 +L(less4): + adds limit, limit, 4 + beq L(ret_eq) +L(byte_loop): + ldrb data1w, [src1], 1 + ldrb data2w, [src2], 1 + subs limit, limit, 1 + ccmp data1w, data2w, 0, ne /* NZCV = 0b0000. */ + b.eq L(byte_loop) + sub result, data1w, data2w + ret +SYM_FUNC_END(__pi_memcmp) +SYM_FUNC_ALIAS_WEAK(memcmp, __pi_memcmp) +EXPORT_SYMBOL_NOKASAN(memcmp) |
