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

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

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/verifier_meta_access.c
Extension
.c
Size
7301 bytes
Lines
285
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
/* Converted from tools/testing/selftests/bpf/verifier/meta_access.c */

#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"

SEC("xdp")
__description("meta access, test1")
__success __retval(0)
__naked void meta_access_test1(void)
{
	asm volatile ("					\
	r2 = *(u32*)(r1 + %[xdp_md_data_meta]);		\
	r3 = *(u32*)(r1 + %[xdp_md_data]);		\
	r0 = r2;					\
	r0 += 8;					\
	if r0 > r3 goto l0_%=;				\
	r0 = *(u8*)(r2 + 0);				\
l0_%=:	r0 = 0;						\
	exit;						\
"	:
	: __imm_const(xdp_md_data, offsetof(struct xdp_md, data)),
	  __imm_const(xdp_md_data_meta, offsetof(struct xdp_md, data_meta))
	: __clobber_all);
}

SEC("xdp")
__description("meta access, test2")
__failure __msg("R0 min value is negative")
__naked void meta_access_test2(void)
{
	asm volatile ("					\
	r2 = *(u32*)(r1 + %[xdp_md_data_meta]);		\
	r3 = *(u32*)(r1 + %[xdp_md_data]);		\
	r0 = r2;					\
	r0 -= 8;					\
	r4 = r2;					\
	r4 += 8;					\
	if r4 > r3 goto l0_%=;				\
	r0 = *(u8*)(r0 + 0);				\
l0_%=:	r0 = 0;						\
	exit;						\
"	:
	: __imm_const(xdp_md_data, offsetof(struct xdp_md, data)),
	  __imm_const(xdp_md_data_meta, offsetof(struct xdp_md, data_meta))
	: __clobber_all);
}

SEC("xdp")
__description("meta access, test3")
__failure __msg("invalid access to packet")
__naked void meta_access_test3(void)
{
	asm volatile ("					\
	r2 = *(u32*)(r1 + %[xdp_md_data_meta]);		\
	r3 = *(u32*)(r1 + %[xdp_md_data_end]);		\
	r0 = r2;					\
	r0 += 8;					\
	if r0 > r3 goto l0_%=;				\
	r0 = *(u8*)(r2 + 0);				\
l0_%=:	r0 = 0;						\
	exit;						\
"	:
	: __imm_const(xdp_md_data_end, offsetof(struct xdp_md, data_end)),
	  __imm_const(xdp_md_data_meta, offsetof(struct xdp_md, data_meta))
	: __clobber_all);
}

SEC("xdp")
__description("meta access, test4")
__failure __msg("invalid access to packet")
__naked void meta_access_test4(void)
{
	asm volatile ("					\
	r2 = *(u32*)(r1 + %[xdp_md_data_meta]);		\
	r3 = *(u32*)(r1 + %[xdp_md_data_end]);		\
	r4 = *(u32*)(r1 + %[xdp_md_data]);		\
	r0 = r4;					\
	r0 += 8;					\
	if r0 > r3 goto l0_%=;				\
	r0 = *(u8*)(r2 + 0);				\
l0_%=:	r0 = 0;						\
	exit;						\
"	:
	: __imm_const(xdp_md_data, offsetof(struct xdp_md, data)),
	  __imm_const(xdp_md_data_end, offsetof(struct xdp_md, data_end)),
	  __imm_const(xdp_md_data_meta, offsetof(struct xdp_md, data_meta))
	: __clobber_all);
}

Annotation

Implementation Notes