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1// SPDX-License-Identifier: GPL-2.02 3#include <vmlinux.h>4#include <bpf/bpf_tracing.h>5#include <bpf/bpf_helpers.h>6 7struct map_elem {8 struct bpf_timer timer;9 struct bpf_spin_lock lock;10};11 12struct {13 __uint(type, BPF_MAP_TYPE_ARRAY);14 __uint(max_entries, 1);15 __type(key, int);16 __type(value, struct map_elem);17} amap SEC(".maps");18 19struct {20 __uint(type, BPF_MAP_TYPE_HASH);21 __uint(max_entries, 1);22 __type(key, int);23 __type(value, struct map_elem);24} hmap SEC(".maps");25 26int pid = 0;27int crash_map = 0; /* 0 for amap, 1 for hmap */28 29SEC("fentry/do_nanosleep")30int sys_enter(void *ctx)31{32 struct map_elem *e, value = {};33 void *map = crash_map ? (void *)&hmap : (void *)&amap;34 35 if (bpf_get_current_task_btf()->tgid != pid)36 return 0;37 38 *(void **)&value = (void *)0xdeadcaf3;39 40 bpf_map_update_elem(map, &(int){0}, &value, 0);41 /* For array map, doing bpf_map_update_elem will do a42 * check_and_free_timer_in_array, which will trigger the crash if timer43 * pointer was overwritten, for hmap we need to use bpf_timer_cancel.44 */45 if (crash_map == 1) {46 e = bpf_map_lookup_elem(map, &(int){0});47 if (!e)48 return 0;49 bpf_timer_cancel(&e->timer);50 }51 return 0;52}53 54char _license[] SEC("license") = "GPL";55