tools/testing/selftests/bpf/progs/preempt_lock.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/progs/preempt_lock.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/preempt_lock.c
Extension
.c
Size
4520 bytes
Lines
213
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "bpf_misc.h"
#include "bpf_experimental.h"

extern int bpf_copy_from_user_str(void *dst, u32 dst__sz, const void *unsafe_ptr__ign, u64 flags) __weak __ksym;

SEC("?tc")
__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_1(struct __sk_buff *ctx)
{
	bpf_preempt_disable();
	return 0;
}

SEC("?tc")
__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_2(struct __sk_buff *ctx)
{
	bpf_preempt_disable();
	bpf_preempt_disable();
	return 0;
}

SEC("?tc")
__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_3(struct __sk_buff *ctx)
{
	bpf_preempt_disable();
	bpf_preempt_disable();
	bpf_preempt_disable();
	return 0;
}

SEC("?tc")
__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_3_minus_2(struct __sk_buff *ctx)
{
	bpf_preempt_disable();
	bpf_preempt_disable();
	bpf_preempt_disable();
	bpf_preempt_enable();
	bpf_preempt_enable();
	return 0;
}

static __noinline void preempt_disable(void)
{
	bpf_preempt_disable();
}

static __noinline void preempt_enable(void)
{
	bpf_preempt_enable();
}

SEC("?tc")
__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_1_subprog(struct __sk_buff *ctx)
{
	preempt_disable();
	return 0;
}

SEC("?tc")
__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_2_subprog(struct __sk_buff *ctx)
{
	preempt_disable();
	preempt_disable();
	return 0;
}

SEC("?tc")
__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_2_minus_1_subprog(struct __sk_buff *ctx)
{
	preempt_disable();
	preempt_disable();
	preempt_enable();
	return 0;
}

static __noinline void preempt_balance_subprog(void)
{
	preempt_disable();
	preempt_enable();
}

Annotation

Implementation Notes