Quelle  verifier_map_ptr.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/* Converted from tools/testing/selftests/bpf/verifier/map_ptr.c */

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

#define MAX_ENTRIES 11

struct test_val {
 unsigned int index;
 int foo[MAX_ENTRIES];
};

struct {
 __uint(type, BPF_MAP_TYPE_ARRAY);
 __uint(max_entries, 1);
 __type(key, int);
 __type(value, struct test_val);
} map_array_48b SEC(".maps");

struct other_val {
 long long foo;
 long long bar;
};

struct {
 __uint(type, BPF_MAP_TYPE_HASH);
 __uint(max_entries, 1);
 __type(key, long long);
 __type(value, struct other_val);
} map_hash_16b SEC(".maps");

SEC("socket")
__description("bpf_map_ptr: read with negative offset rejected")
__failure __msg("R1 is bpf_array invalid negative access: off=-8")
__failure_unpriv
__msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
__naked void read_with_negative_offset_rejected(void)
{
 asm volatile (" \
 r1 = r10;     \
 r1 = %[map_array_48b] ll;   \
 r6 = *(u64*)(r1 - 8);    \
 r0 = 1;      \
 exit;      \
" :
 : __imm_addr(map_array_48b)
 : __clobber_all);
}

SEC("socket")
__description("bpf_map_ptr: write rejected")
__failure __msg("only read from bpf_array is supported")
__failure_unpriv
__msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
__naked void bpf_map_ptr_write_rejected(void)
{
 asm volatile (" \
 r0 = 0;      \
 *(u64*)(r10 - 8) = r0;    \
 r2 = r10;     \
 r2 += -8;     \
 r1 = %[map_array_48b] ll;   \
 *(u64*)(r1 + 0) = r2;    \
 r0 = 1;      \
 exit;      \
" :
 : __imm_addr(map_array_48b)
 : __clobber_all);
}

SEC("socket")
__description("bpf_map_ptr: read non-existent field rejected")
__failure
__msg("cannot access ptr member ops with moff 0 in struct bpf_map with off 1 size 4")
__failure_unpriv
__msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
__flag(BPF_F_ANY_ALIGNMENT)
__naked void read_non_existent_field_rejected(void)
{
 asm volatile (" \
 r6 = 0;      \
 r1 = %[map_array_48b] ll;   \
 r6 = *(u32*)(r1 + 1);    \
 r0 = 1;      \
 exit;      \
" :
 : __imm_addr(map_array_48b)
 : __clobber_all);
}

SEC("socket")
__description("bpf_map_ptr: read ops field accepted")
__success __failure_unpriv
__msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
__retval(1)
__naked void ptr_read_ops_field_accepted(void)
{
 asm volatile (" \
 r6 = 0;      \
 r1 = %[map_array_48b] ll;   \
 r6 = *(u64*)(r1 + 0);    \
 r0 = 1;      \
 exit;      \
" :
 : __imm_addr(map_array_48b)
 : __clobber_all);
}

SEC("socket")
__description("bpf_map_ptr: r = 0, map_ptr = map_ptr + r")
__success __failure_unpriv
__msg_unpriv("R1 has pointer with unsupported alu operation")
__retval(0)
__naked void map_ptr_map_ptr_r(void)
{
 asm volatile (" \
 r0 = 0;      \
 *(u64*)(r10 - 8) = r0;    \
 r2 = r10;     \
 r2 += -8;     \
 r0 = 0;      \
 r1 = %[map_hash_16b] ll;   \
 r1 += r0;     \
 call %[bpf_map_lookup_elem];   \
 r0 = 0;      \
 exit;      \
" :
 : __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_16b)
 : __clobber_all);
}

SEC("socket")
__description("bpf_map_ptr: r = 0, r = r + map_ptr")
__success __failure_unpriv
__msg_unpriv("R0 has pointer with unsupported alu operation")
__retval(0)
__naked void _0_r_r_map_ptr(void)
{
 asm volatile (" \
 r0 = 0;      \
 *(u64*)(r10 - 8) = r0;    \
 r2 = r10;     \
 r2 += -8;     \
 r1 = 0;      \
 r0 = %[map_hash_16b] ll;   \
 r1 += r0;     \
 call %[bpf_map_lookup_elem];   \
 r0 = 0;      \
 exit;      \
" :
 : __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_16b)
 : __clobber_all);
}

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