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

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

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/verifier_ringbuf.c
Extension
.c
Size
3460 bytes
Lines
132
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/ringbuf.c */

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

struct {
	__uint(type, BPF_MAP_TYPE_RINGBUF);
	__uint(max_entries, 4096);
} map_ringbuf SEC(".maps");

SEC("socket")
__description("ringbuf: invalid reservation offset 1")
__failure __msg("R1 must have zero offset when passed to release func")
__failure_unpriv
__naked void ringbuf_invalid_reservation_offset_1(void)
{
	asm volatile ("					\
	/* reserve 8 byte ringbuf memory */		\
	r1 = 0;						\
	*(u64*)(r10 - 8) = r1;				\
	r1 = %[map_ringbuf] ll;				\
	r2 = 8;						\
	r3 = 0;						\
	call %[bpf_ringbuf_reserve];			\
	/* store a pointer to the reserved memory in R6 */\
	r6 = r0;					\
	/* check whether the reservation was successful */\
	if r0 == 0 goto l0_%=;				\
	/* spill R6(mem) into the stack */		\
	*(u64*)(r10 - 8) = r6;				\
	/* fill it back in R7 */			\
	r7 = *(u64*)(r10 - 8);				\
	/* should be able to access *(R7) = 0 */	\
	r1 = 0;						\
	*(u64*)(r7 + 0) = r1;				\
	/* submit the reserved ringbuf memory */	\
	r1 = r7;					\
	/* add invalid offset to reserved ringbuf memory */\
	r1 += 0xcafe;					\
	r2 = 0;						\
	call %[bpf_ringbuf_submit];			\
l0_%=:	r0 = 0;						\
	exit;						\
"	:
	: __imm(bpf_ringbuf_reserve),
	  __imm(bpf_ringbuf_submit),
	  __imm_addr(map_ringbuf)
	: __clobber_all);
}

SEC("socket")
__description("ringbuf: invalid reservation offset 2")
__failure __msg("R7 min value is outside of the allowed memory range")
__failure_unpriv
__naked void ringbuf_invalid_reservation_offset_2(void)
{
	asm volatile ("					\
	/* reserve 8 byte ringbuf memory */		\
	r1 = 0;						\
	*(u64*)(r10 - 8) = r1;				\
	r1 = %[map_ringbuf] ll;				\
	r2 = 8;						\
	r3 = 0;						\
	call %[bpf_ringbuf_reserve];			\
	/* store a pointer to the reserved memory in R6 */\
	r6 = r0;					\
	/* check whether the reservation was successful */\
	if r0 == 0 goto l0_%=;				\
	/* spill R6(mem) into the stack */		\
	*(u64*)(r10 - 8) = r6;				\
	/* fill it back in R7 */			\
	r7 = *(u64*)(r10 - 8);				\
	/* add invalid offset to reserved ringbuf memory */\
	r7 += 0xcafe;					\
	/* should be able to access *(R7) = 0 */	\
	r1 = 0;						\
	*(u64*)(r7 + 0) = r1;				\
	/* submit the reserved ringbuf memory */	\
	r1 = r7;					\
	r2 = 0;						\
	call %[bpf_ringbuf_submit];			\
l0_%=:	r0 = 0;						\
	exit;						\
"	:
	: __imm(bpf_ringbuf_reserve),
	  __imm(bpf_ringbuf_submit),
	  __imm_addr(map_ringbuf)
	: __clobber_all);

Annotation

Implementation Notes