diff options
| author | Eduard Zingerman <eddyz87@gmail.com> | 2026-09-04 17:05:56 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-04 18:17:30 -0700 |
| commit | 506ada89629ec7059b96ecfb0dc7d33ece0103ca (patch) | |
| tree | 0b07297409b68d2333fb4f0eae7f3b072eb68d4c /arch/arm64/lib/strchr.S | |
| download | linux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.tar.gz linux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.zip | |
bpf: mark a NULL kfunc argument precisegrafted
check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.
Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'arch/arm64/lib/strchr.S')
| -rw-r--r-- | arch/arm64/lib/strchr.S | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/arm64/lib/strchr.S b/arch/arm64/lib/strchr.S new file mode 100644 index 000000000..94ee67a6b --- /dev/null +++ b/arch/arm64/lib/strchr.S @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Based on arch/arm/lib/strchr.S + * + * Copyright (C) 1995-2000 Russell King + * Copyright (C) 2013 ARM Ltd. + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> + +/* + * Find the first occurrence of a character in a string. + * + * Parameters: + * x0 - str + * x1 - c + * Returns: + * x0 - address of first occurrence of 'c' or 0 + */ +SYM_FUNC_START(__pi_strchr) + and w1, w1, #0xff +1: ldrb w2, [x0], #1 + cmp w2, w1 + ccmp w2, wzr, #4, ne + b.ne 1b + sub x0, x0, #1 + cmp w2, w1 + csel x0, x0, xzr, eq + ret +SYM_FUNC_END(__pi_strchr) + +SYM_FUNC_ALIAS_WEAK(strchr, __pi_strchr) +EXPORT_SYMBOL_NOKASAN(strchr) |