Contributors: 1
Author Tokens Token Proportion Commits Commit Proportion
Kumar Kartikeya Dwivedi 1088 100.00% 2 100.00%
Total 1088 2 


// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2024-2025 Meta Platforms, Inc. and affiliates. */
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_core_read.h>
#include "bpf_misc.h"
#include "bpf_experimental.h"

struct arr_elem {
	struct bpf_res_spin_lock lock;
};

struct {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__uint(max_entries, 1);
	__type(key, int);
	__type(value, struct arr_elem);
} arrmap SEC(".maps");

long value;

struct bpf_spin_lock lock __hidden SEC(".data.A");
struct bpf_res_spin_lock res_lock __hidden SEC(".data.B");

SEC("?tc")
__failure __msg("point to map value or allocated object")
int res_spin_lock_arg(struct __sk_buff *ctx)
{
	struct arr_elem *elem;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	bpf_res_spin_lock((struct bpf_res_spin_lock *)bpf_core_cast(&elem->lock, struct __sk_buff));
	bpf_res_spin_lock(&elem->lock);
	return 0;
}

SEC("?tc")
__failure __msg("AA deadlock detected")
int res_spin_lock_AA(struct __sk_buff *ctx)
{
	struct arr_elem *elem;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	bpf_res_spin_lock(&elem->lock);
	bpf_res_spin_lock(&elem->lock);
	return 0;
}

SEC("?tc")
__failure __msg("AA deadlock detected")
int res_spin_lock_cond_AA(struct __sk_buff *ctx)
{
	struct arr_elem *elem;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	if (bpf_res_spin_lock(&elem->lock))
		return 0;
	bpf_res_spin_lock(&elem->lock);
	return 0;
}

SEC("?tc")
__failure __msg("unlock of different lock")
int res_spin_lock_mismatch_1(struct __sk_buff *ctx)
{
	struct arr_elem *elem;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	if (bpf_res_spin_lock(&elem->lock))
		return 0;
	bpf_res_spin_unlock(&res_lock);
	return 0;
}

SEC("?tc")
__failure __msg("unlock of different lock")
int res_spin_lock_mismatch_2(struct __sk_buff *ctx)
{
	struct arr_elem *elem;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	if (bpf_res_spin_lock(&res_lock))
		return 0;
	bpf_res_spin_unlock(&elem->lock);
	return 0;
}

SEC("?tc")
__failure __msg("unlock of different lock")
int res_spin_lock_irq_mismatch_1(struct __sk_buff *ctx)
{
	struct arr_elem *elem;
	unsigned long f1;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	bpf_local_irq_save(&f1);
	if (bpf_res_spin_lock(&res_lock))
		return 0;
	bpf_res_spin_unlock_irqrestore(&res_lock, &f1);
	return 0;
}

SEC("?tc")
__failure __msg("unlock of different lock")
int res_spin_lock_irq_mismatch_2(struct __sk_buff *ctx)
{
	struct arr_elem *elem;
	unsigned long f1;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	if (bpf_res_spin_lock_irqsave(&res_lock, &f1))
		return 0;
	bpf_res_spin_unlock(&res_lock);
	return 0;
}

SEC("?tc")
__success
int res_spin_lock_ooo(struct __sk_buff *ctx)
{
	struct arr_elem *elem;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	if (bpf_res_spin_lock(&res_lock))
		return 0;
	if (bpf_res_spin_lock(&elem->lock)) {
		bpf_res_spin_unlock(&res_lock);
		return 0;
	}
	bpf_res_spin_unlock(&elem->lock);
	bpf_res_spin_unlock(&res_lock);
	return 0;
}

SEC("?tc")
__success
int res_spin_lock_ooo_irq(struct __sk_buff *ctx)
{
	struct arr_elem *elem;
	unsigned long f1, f2;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	if (bpf_res_spin_lock_irqsave(&res_lock, &f1))
		return 0;
	if (bpf_res_spin_lock_irqsave(&elem->lock, &f2)) {
		bpf_res_spin_unlock_irqrestore(&res_lock, &f1);
		/* We won't have a unreleased IRQ flag error here. */
		return 0;
	}
	bpf_res_spin_unlock_irqrestore(&elem->lock, &f2);
	bpf_res_spin_unlock_irqrestore(&res_lock, &f1);
	return 0;
}

struct bpf_res_spin_lock lock1 __hidden SEC(".data.OO1");
struct bpf_res_spin_lock lock2 __hidden SEC(".data.OO2");

SEC("?tc")
__failure __msg("bpf_res_spin_unlock cannot be out of order")
int res_spin_lock_ooo_unlock(struct __sk_buff *ctx)
{
	if (bpf_res_spin_lock(&lock1))
		return 0;
	if (bpf_res_spin_lock(&lock2)) {
		bpf_res_spin_unlock(&lock1);
		return 0;
	}
	bpf_res_spin_unlock(&lock1);
	bpf_res_spin_unlock(&lock2);
	return 0;
}

SEC("?tc")
__failure __msg("off 1 doesn't point to 'struct bpf_res_spin_lock' that is at 0")
int res_spin_lock_bad_off(struct __sk_buff *ctx)
{
	struct arr_elem *elem;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem)
		return 0;
	bpf_res_spin_lock((void *)&elem->lock + 1);
	return 0;
}

SEC("?tc")
__failure __msg("R1 doesn't have constant offset. bpf_res_spin_lock has to be at the constant offset")
int res_spin_lock_var_off(struct __sk_buff *ctx)
{
	struct arr_elem *elem;
	u64 val = value;

	elem = bpf_map_lookup_elem(&arrmap, &(int){0});
	if (!elem) {
		// FIXME: Only inline assembly use in assert macro doesn't emit
		//	  BTF definition.
		bpf_throw(0);
		return 0;
	}
	bpf_assert_range(val, 0, 40);
	bpf_res_spin_lock((void *)&value + val);
	return 0;
}

SEC("?tc")
__failure __msg("map 'res_spin.bss' has no valid bpf_res_spin_lock")
int res_spin_lock_no_lock_map(struct __sk_buff *ctx)
{
	bpf_res_spin_lock((void *)&value + 1);
	return 0;
}

SEC("?tc")
__failure __msg("local 'kptr' has no valid bpf_res_spin_lock")
int res_spin_lock_no_lock_kptr(struct __sk_buff *ctx)
{
	struct { int i; } *p = bpf_obj_new(typeof(*p));

	if (!p)
		return 0;
	bpf_res_spin_lock((void *)p);
	return 0;
}

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