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1// SPDX-License-Identifier: GPL-2.02/* Copyright (C) 2021. Huawei Technologies Co., Ltd */3#include <linux/types.h>4#include <linux/bpf.h>5#include <bpf/bpf_helpers.h>6#include <bpf/bpf_tracing.h>7 8#define STRNCMP_STR_SZ 40969 10/* Will be updated by benchmark before program loading */11const volatile unsigned int cmp_str_len = 1;12const char target[STRNCMP_STR_SZ];13 14long hits = 0;15char str[STRNCMP_STR_SZ];16 17char _license[] SEC("license") = "GPL";18 19static __always_inline int local_strncmp(const char *s1, unsigned int sz,20 const char *s2)21{22 int ret = 0;23 unsigned int i;24 25 for (i = 0; i < sz; i++) {26 /* E.g. 0xff > 0x31 */27 ret = (unsigned char)s1[i] - (unsigned char)s2[i];28 if (ret || !s1[i])29 break;30 }31 32 return ret;33}34 35SEC("tp/syscalls/sys_enter_getpgid")36int strncmp_no_helper(void *ctx)37{38 if (local_strncmp(str, cmp_str_len + 1, target) < 0)39 __sync_add_and_fetch(&hits, 1);40 return 0;41}42 43SEC("tp/syscalls/sys_enter_getpgid")44int strncmp_helper(void *ctx)45{46 if (bpf_strncmp(str, cmp_str_len + 1, target) < 0)47 __sync_add_and_fetch(&hits, 1);48 return 0;49}50 51