Quelle  verifier_ringbuf.c   Sprache: C

// 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);
}

SEC("xdp")
__description("ringbuf: check passing rb mem to helpers")
__success __retval(0)
__naked void passing_rb_mem_to_helpers(void)
{
 asm volatile (" \
 r6 = r1;     \
 /* reserve 8 byte ringbuf memory */ \
 r1 = 0;      \
 *(u64*)(r10 - 8) = r1;    \
 r1 = %[map_ringbuf] ll;    \
 r2 = 8;      \
 r3 = 0;      \
 call %[bpf_ringbuf_reserve];   \
 r7 = r0;     \
 /* check whether the reservation was successful */\
 if r0 != 0 goto l0_%=;    \
 exit;      \
l0_%=: /* pass allocated ring buffer memory to fib lookup */\
 r1 = r6;     \
 r2 = r0;     \
 r3 = 8;      \
 r4 = 0;      \
 call %[bpf_fib_lookup];    \
 /* submit the ringbuf memory */ \
 r1 = r7;     \
 r2 = 0;      \
 call %[bpf_ringbuf_submit];   \
 r0 = 0;      \
 exit;      \
" :
 : __imm(bpf_fib_lookup),
   __imm(bpf_ringbuf_reserve),
   __imm(bpf_ringbuf_submit),
   __imm_addr(map_ringbuf)
 : __clobber_all);
}

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