// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <stdbool.h>
#include "bpf_arena_common.h"

struct {
	__uint(type, BPF_MAP_TYPE_ARENA);
	__uint(map_flags, BPF_F_MMAPABLE);
	__uint(max_entries, 10); /* number of pages */
#ifdef __TARGET_ARCH_arm64
	__ulong(map_extra, 0x1ull << 32); /* start of mmap() region */
#else
	__ulong(map_extra, 0x1ull << 44); /* start of mmap() region */
#endif
} arena SEC(".maps");

#if defined(ENABLE_ATOMICS_TESTS) && defined(__BPF_FEATURE_ADDR_SPACE_CAST)
bool skip_tests __attribute((__section__(".data"))) = false;
#else
bool skip_tests = true;
#endif

__u32 pid = 0;

__u64 __arena_global add64_value = 1;
__u64 __arena_global add64_result = 0;
__u32 __arena_global add32_value = 1;
__u32 __arena_global add32_result = 0;
__u64 __arena_global add_stack_value_copy = 0;
__u64 __arena_global add_stack_result = 0;
__u64 __arena_global add_noreturn_value = 1;

SEC("raw_tp/sys_enter")
int add(const void *ctx)
{
	if (pid != (bpf_get_current_pid_tgid() >> 32))
		return 0;
#ifdef ENABLE_ATOMICS_TESTS
	__u64 add_stack_value = 1;

	add64_result = __sync_fetch_and_add(&add64_value, 2);
	add32_result = __sync_fetch_and_add(&add32_value, 2);
	add_stack_result = __sync_fetch_and_add(&add_stack_value, 2);
	add_stack_value_copy = add_stack_value;
	__sync_fetch_and_add(&add_noreturn_value, 2);
#endif

	return 0;
}

__s64 __arena_global sub64_value = 1;
__s64 __arena_global sub64_result = 0;
__s32 __arena_global sub32_value = 1;
__s32 __arena_global sub32_result = 0;
__s64 __arena_global sub_stack_value_copy = 0;
__s64 __arena_global sub_stack_result = 0;
__s64 __arena_global sub_noreturn_value = 1;

SEC("raw_tp/sys_enter")
int sub(const void *ctx)
{
	if (pid != (bpf_get_current_pid_tgid() >> 32))
		return 0;
#ifdef ENABLE_ATOMICS_TESTS
	__u64 sub_stack_value = 1;

	sub64_result = __sync_fetch_and_sub(&sub64_value, 2);
	sub32_result = __sync_fetch_and_sub(&sub32_value, 2);
	sub_stack_result = __sync_fetch_and_sub(&sub_stack_value, 2);
	sub_stack_value_copy = sub_stack_value;
	__sync_fetch_and_sub(&sub_noreturn_value, 2);
#endif

	return 0;
}

__u64 __arena_global and64_value = (0x110ull << 32);
__u32 __arena_global and32_value = 0x110;

SEC("raw_tp/sys_enter")
int and(const void *ctx)
{
	if (pid != (bpf_get_current_pid_tgid() >> 32))
		return 0;
#ifdef ENABLE_ATOMICS_TESTS

	__sync_fetch_and_and(&and64_value, 0x011ull << 32);
	__sync_fetch_and_and(&and32_value, 0x011);
#endif

	return 0;
}

__u32 __arena_global or32_value = 0x110;
__u64 __arena_global or64_value = (0x110ull << 32);

SEC("raw_tp/sys_enter")
int or(const void *ctx)
{
	if (pid != (bpf_get_current_pid_tgid() >> 32))
		return 0;
#ifdef ENABLE_ATOMICS_TESTS
	__sync_fetch_and_or(&or64_value, 0x011ull << 32);
	__sync_fetch_and_or(&or32_value, 0x011);
#endif

	return 0;
}

__u64 __arena_global xor64_value = (0x110ull << 32);
__u32 __arena_global xor32_value = 0x110;

SEC("raw_tp/sys_enter")
int xor(const void *ctx)
{
	if (pid != (bpf_get_current_pid_tgid() >> 32))
		return 0;
#ifdef ENABLE_ATOMICS_TESTS
	__sync_fetch_and_xor(&xor64_value, 0x011ull << 32);
	__sync_fetch_and_xor(&xor32_value, 0x011);
#endif

	return 0;
}

__u32 __arena_global cmpxchg32_value = 1;
__u32 __arena_global cmpxchg32_result_fail = 0;
__u32 __arena_global cmpxchg32_result_succeed = 0;
__u64 __arena_global cmpxchg64_value = 1;
__u64 __arena_global cmpxchg64_result_fail = 0;
__u64 __arena_global cmpxchg64_result_succeed = 0;

SEC("raw_tp/sys_enter")
int cmpxchg(const void *ctx)
{
	if (pid != (bpf_get_current_pid_tgid() >> 32))
		return 0;
#ifdef ENABLE_ATOMICS_TESTS
	cmpxchg64_result_fail = __sync_val_compare_and_swap(&cmpxchg64_value, 0, 3);
	cmpxchg64_result_succeed = __sync_val_compare_and_swap(&cmpxchg64_value, 1, 2);

	cmpxchg32_result_fail = __sync_val_compare_and_swap(&cmpxchg32_value, 0, 3);
	cmpxchg32_result_succeed = __sync_val_compare_and_swap(&cmpxchg32_value, 1, 2);
#endif

	return 0;
}

__u64 __arena_global xchg64_value = 1;
__u64 __arena_global xchg64_result = 0;
__u32 __arena_global xchg32_value = 1;
__u32 __arena_global xchg32_result = 0;

SEC("raw_tp/sys_enter")
int xchg(const void *ctx)
{
	if (pid != (bpf_get_current_pid_tgid() >> 32))
		return 0;
#ifdef ENABLE_ATOMICS_TESTS
	__u64 val64 = 2;
	__u32 val32 = 2;

	xchg64_result = __sync_lock_test_and_set(&xchg64_value, val64);
	xchg32_result = __sync_lock_test_and_set(&xchg32_value, val32);
#endif

	return 0;
}

__u64 __arena_global uaf_sink;
volatile __u64 __arena_global uaf_recovery_fails;

SEC("syscall")
int uaf(const void *ctx)
{
	if (pid != (bpf_get_current_pid_tgid() >> 32))
		return 0;
#if defined(ENABLE_ATOMICS_TESTS) && !defined(__TARGET_ARCH_arm64) && \
    !defined(__TARGET_ARCH_x86)
	__u32 __arena *page32;
	__u64 __arena *page64;
	void __arena *page;

	page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
	bpf_arena_free_pages(&arena, page, 1);
	uaf_recovery_fails = 24;

	page32 = (__u32 __arena *)page;
	uaf_sink += __sync_fetch_and_add(page32, 1);
	uaf_recovery_fails -= 1;
	__sync_add_and_fetch(page32, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_fetch_and_sub(page32, 1);
	uaf_recovery_fails -= 1;
	__sync_sub_and_fetch(page32, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_fetch_and_and(page32, 1);
	uaf_recovery_fails -= 1;
	__sync_and_and_fetch(page32, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_fetch_and_or(page32, 1);
	uaf_recovery_fails -= 1;
	__sync_or_and_fetch(page32, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_fetch_and_xor(page32, 1);
	uaf_recovery_fails -= 1;
	__sync_xor_and_fetch(page32, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_val_compare_and_swap(page32, 0, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_lock_test_and_set(page32, 1);
	uaf_recovery_fails -= 1;

	page64 = (__u64 __arena *)page;
	uaf_sink += __sync_fetch_and_add(page64, 1);
	uaf_recovery_fails -= 1;
	__sync_add_and_fetch(page64, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_fetch_and_sub(page64, 1);
	uaf_recovery_fails -= 1;
	__sync_sub_and_fetch(page64, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_fetch_and_and(page64, 1);
	uaf_recovery_fails -= 1;
	__sync_and_and_fetch(page64, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_fetch_and_or(page64, 1);
	uaf_recovery_fails -= 1;
	__sync_or_and_fetch(page64, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_fetch_and_xor(page64, 1);
	uaf_recovery_fails -= 1;
	__sync_xor_and_fetch(page64, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_val_compare_and_swap(page64, 0, 1);
	uaf_recovery_fails -= 1;
	uaf_sink += __sync_lock_test_and_set(page64, 1);
	uaf_recovery_fails -= 1;
#endif

	return 0;
}

char _license[] SEC("license") = "GPL";