// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
#include <stdbool.h>
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
#include "bpf_compiler.h"
static volatile int zero = 0;
int my_pid;
int arr[256];
int small_arr[16] SEC(".data.small_arr");
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 10);
__type(key, int);
__type(value, int);
} amap SEC(".maps");
#ifdef REAL_TEST
#define MY_PID_GUARD() if (my_pid != (bpf_get_current_pid_tgid() >> 32)) return 0
#else
#define MY_PID_GUARD() ({ })
#endif
SEC("?raw_tp")
__failure __msg("math between map_value pointer and register with unbounded min value is not allowed")
int iter_err_unsafe_c_loop(const void *ctx)
{
struct bpf_iter_num it;
int *v, i = zero; /* obscure initial value of i */
MY_PID_GUARD();
bpf_iter_num_new(&it, 0, 1000);
while ((v = bpf_iter_num_next(&it))) {
i++;
}
bpf_iter_num_destroy(&it);
small_arr[i] = 123; /* invalid */
return 0;
}
SEC("?raw_tp")
__failure __msg("unbounded memory access")
int iter_err_unsafe_asm_loop(const void *ctx)
{
struct bpf_iter_num it;
MY_PID_GUARD();
asm volatile (
"r6 = %[zero];" /* iteration counter */
"r1 = %[it];" /* iterator state */
"r2 = 0;"
"r3 = 1000;"
"r4 = 1;"
"call %[bpf_iter_num_new];"
"loop:"
"r1 = %[it];"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto out;"
"r6 += 1;"
"goto loop;"
"out:"
"r1 = %[it];"
"call %[bpf_iter_num_destroy];"
"r1 = %[small_arr];"
"r2 = r6;"
"r2 <<= 2;"
"r1 += r2;"
"*(u32 *)(r1 + 0) = r6;" /* invalid */
:
: [it]"r"(&it),
[small_arr]"r"(small_arr),
[zero]"r"(zero),
__imm(bpf_iter_num_new),
__imm(bpf_iter_num_next),
__imm(bpf_iter_num_destroy)
: __clobber_common, "r6"
);
return 0;
}
SEC("raw_tp")
__success
int iter_while_loop(const void *ctx)
{
struct bpf_iter_num it;
int *v;
MY_PID_GUARD();
bpf_iter_num_new(&it, 0, 3);
while ((v = bpf_iter_num_next(&it))) {
bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
}
bpf_iter_num_destroy(&it);
return 0;
}
SEC("raw_tp")
__success
int iter_while_loop_auto_cleanup(const void *ctx)
{
__attribute__((cleanup(bpf_iter_num_destroy))) struct bpf_iter_num it;
int *v;
MY_PID_GUARD();
bpf_iter_num_new(&it, 0, 3);
while ((v = bpf_iter_num_next(&it))) {
bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
}
/* (!) no explicit bpf_iter_num_destroy() */
return 0;
}
SEC("raw_tp")
__success
int iter_for_loop(const void *ctx)
{
struct bpf_iter_num it;
int *v;
MY_PID_GUARD();
bpf_iter_num_new(&it, 5, 10);
for (v = bpf_iter_num_next(&it); v; v = bpf_iter_num_next(&it)) {
bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
}
bpf_iter_num_destroy(&it);
return 0;
}
SEC("raw_tp")
__success
int iter_bpf_for_each_macro(const void *ctx)
{
int *v;
MY_PID_GUARD();
bpf_for_each(num, v, 5, 10) {
bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
}
return 0;
}
SEC("raw_tp")
__success
int iter_bpf_for_macro(const void *ctx)
{
int i;
MY_PID_GUARD();
bpf_for(i, 5, 10) {
bpf_printk("ITER_BASIC: E2 VAL: v=%d", i);
}
return 0;
}
SEC("raw_tp")
__success
int iter_pragma_unroll_loop(const void *ctx)
{
struct bpf_iter_num it;
int *v, i;
MY_PID_GUARD();
bpf_iter_num_new(&it, 0, 2);
__pragma_loop_no_unroll
for (i = 0; i < 3; i++) {
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E3 VAL: i=%d v=%d", i, v ? *v : -1);
}
bpf_iter_num_destroy(&it);
return 0;
}
SEC("raw_tp")
__success
int iter_manual_unroll_loop(const void *ctx)
{
struct bpf_iter_num it;
int *v;
MY_PID_GUARD();
bpf_iter_num_new(&it, 100, 200);
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E4 VAL: v=%d\n", v ? *v : -1);
bpf_iter_num_destroy(&it);
return 0;
}
SEC("raw_tp")
__success
int iter_multiple_sequential_loops(const void *ctx)
{
struct bpf_iter_num it;
int *v, i;
MY_PID_GUARD();
bpf_iter_num_new(&it, 0, 3);
while ((v = bpf_iter_num_next(&it))) {
bpf_printk("ITER_BASIC: E1 VAL: v=%d", *v);
}
bpf_iter_num_destroy(&it);
bpf_iter_num_new(&it, 5, 10);
for (v = bpf_iter_num_next(&it); v; v = bpf_iter_num_next(&it)) {
bpf_printk("ITER_BASIC: E2 VAL: v=%d", *v);
}
bpf_iter_num_destroy(&it);
bpf_iter_num_new(&it, 0, 2);
__pragma_loop_no_unroll
for (i = 0; i < 3; i++) {
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E3 VAL: i=%d v=%d", i, v ? *v : -1);
}
bpf_iter_num_destroy(&it);
bpf_iter_num_new(&it, 100, 200);
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E4 VAL: v=%d", v ? *v : -1);
v = bpf_iter_num_next(&it);
bpf_printk("ITER_BASIC: E4 VAL: v=%d\n", v ? *v : -1);
bpf_iter_num_destroy(&it);
return 0;
}
SEC("raw_tp")
__success
int iter_limit_cond_break_loop(const void *ctx)
{
struct bpf_iter_num it;
int *v, i = 0, sum = 0;
MY_PID_GUARD();
bpf_iter_num_new(&it, 0, 10);
while ((v = bpf_iter_num_next(&it))) {
bpf_printk("ITER_SIMPLE: i=%d v=%d", i, *v);
sum += *v;
i++;
if (i > 3)
break;
}
bpf_iter_num_destroy(&it);
bpf_printk("ITER_SIMPLE: sum=%d\n", sum);
return 0;
}
SEC("raw_tp")
__success
int iter_obfuscate_counter(const void *ctx)
{
struct bpf_iter_num it;
int *v, sum = 0;
/* Make i's initial value unknowable for verifier to prevent it from
* pruning if/else branch inside the loop body and marking i as precise.
*/
int i = zero;
MY_PID_GUARD();
bpf_iter_num_new(&it, 0, 10);
while ((v = bpf_iter_num_next(&it))) {
int x;
i += 1;
/* If we initialized i as `int i = 0;` above, verifier would
* track that i becomes 1 on first iteration after increment
* above, and here verifier would eagerly prune else branch
* and mark i as precise, ruining open-coded iterator logic
* completely, as each next iteration would have a different
* *precise* value of i, and thus there would be no
* convergence of state. This would result in reaching maximum
* instruction limit, no matter what the limit is.
*/
if (i == 1)
x = 123;
else
x = i * 3 + 1;
bpf_printk("ITER_OBFUSCATE_COUNTER: i=%d v=%d x=%d", i, *v, x);
sum += x;
}
bpf_iter_num_destroy(&it);
bpf_printk("ITER_OBFUSCATE_COUNTER: sum=%d\n", sum);
return 0;
}
SEC("raw_tp")
__success
int iter_search_loop(const void *ctx)
{
struct bpf_iter_num it;
int *v, *elem = NULL;
bool found = false;
MY_PID_GUARD();
bpf_iter_num_new(&it, 0, 10);
while ((v = bpf_iter_num_next(&it))) {
bpf_printk("ITER_SEARCH_LOOP: v=%d", *v);
if (*v == 2) {
found = true;
elem = v;
barrier_var(elem);
}
}
/* should fail to verify if bpf_iter_num_destroy() is here */
if (found)
/* here found element will be wrong, we should have copied
* value to a variable, but here we want to make sure we can
* access memory after the loop anyways
*/
bpf_printk("ITER_SEARCH_LOOP: FOUND IT = %d!\n", *elem);
else
bpf_printk("ITER_SEARCH_LOOP: NOT FOUND IT!\n");
bpf_iter_num_destroy(&it);
return 0;
}
SEC("raw_tp")
__success
int iter_array_fill(const void *ctx)
{
int sum, i;
MY_PID_GUARD();
bpf_for(i, 0, ARRAY_SIZE(arr)) {
arr[i] = i * 2;
}
sum = 0;
bpf_for(i, 0, ARRAY_SIZE(arr)) {
sum += arr[i];
}
bpf_printk("ITER_ARRAY_FILL: sum=%d (should be %d)\n", sum, 255 * 256);
return 0;
}
static int arr2d[4][5];
static int arr2d_row_sums[4];
static int arr2d_col_sums[5];
SEC("raw_tp")
__success
int iter_nested_iters(const void *ctx)
{
int sum, row, col;
MY_PID_GUARD();
bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
bpf_for( col, 0, ARRAY_SIZE(arr2d[0])) {
arr2d[row][col] = row * col;
}
}
/* zero-initialize sums */
sum = 0;
bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
arr2d_row_sums[row] = 0;
}
bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
arr2d_col_sums[col] = 0;
}
/* calculate sums */
bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
sum += arr2d[row][col];
arr2d_row_sums[row] += arr2d[row][col];
arr2d_col_sums[col] += arr2d[row][col];
}
}
bpf_printk("ITER_NESTED_ITERS: total sum=%d", sum);
bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
bpf_printk("ITER_NESTED_ITERS: row #%d sum=%d", row, arr2d_row_sums[row]);
}
bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
bpf_printk("ITER_NESTED_ITERS: col #%d sum=%d%s",
col, arr2d_col_sums[col],
col == ARRAY_SIZE(arr2d[0]) - 1 ? "\n" : "");
}
return 0;
}
SEC("raw_tp")
__success
int iter_nested_deeply_iters(const void *ctx)
{
int sum = 0;
MY_PID_GUARD();
bpf_repeat(10) {
bpf_repeat(10) {
bpf_repeat(10) {
bpf_repeat(10) {
bpf_repeat(10) {
sum += 1;
}
}
}
}
/* validate that we can break from inside bpf_repeat() */
break;
}
return sum;
}
static __noinline void fill_inner_dimension(int row)
{
int col;
bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
arr2d[row][col] = row * col;
}
}
static __noinline int sum_inner_dimension(int row)
{
int sum = 0, col;
bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
sum += arr2d[row][col];
arr2d_row_sums[row] += arr2d[row][col];
arr2d_col_sums[col] += arr2d[row][col];
}
return sum;
}
SEC("raw_tp")
__success
int iter_subprog_iters(const void *ctx)
{
int sum, row, col;
MY_PID_GUARD();
bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
fill_inner_dimension(row);
}
/* zero-initialize sums */
sum = 0;
bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
arr2d_row_sums[row] = 0;
}
bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
arr2d_col_sums[col] = 0;
}
/* calculate sums */
bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
sum += sum_inner_dimension(row);
}
bpf_printk("ITER_SUBPROG_ITERS: total sum=%d", sum);
bpf_for(row, 0, ARRAY_SIZE(arr2d)) {
bpf_printk("ITER_SUBPROG_ITERS: row #%d sum=%d",
row, arr2d_row_sums[row]);
}
bpf_for(col, 0, ARRAY_SIZE(arr2d[0])) {
bpf_printk("ITER_SUBPROG_ITERS: col #%d sum=%d%s",
col, arr2d_col_sums[col],
col == ARRAY_SIZE(arr2d[0]) - 1 ? "\n" : "");
}
return 0;
}
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, int);
__uint(max_entries, 1000);
} arr_map SEC(".maps");
SEC("?raw_tp")
__failure __msg("invalid mem access 'scalar'")
int iter_err_too_permissive1(const void *ctx)
{
int *map_val = NULL;
int key = 0;
MY_PID_GUARD();
map_val = bpf_map_lookup_elem(&arr_map, &key);
if (!map_val)
return 0;
bpf_repeat(1000000) {
map_val = NULL;
}
*map_val = 123;
return 0;
}
SEC("?raw_tp")
__failure __msg("invalid mem access 'map_value_or_null'")
int iter_err_too_permissive2(const void *ctx)
{
int *map_val = NULL;
int key = 0;
MY_PID_GUARD();
map_val = bpf_map_lookup_elem(&arr_map, &key);
if (!map_val)
return 0;
bpf_repeat(1000000) {
map_val = bpf_map_lookup_elem(&arr_map, &key);
}
*map_val = 123;
return 0;
}
SEC("?raw_tp")
__failure __msg("invalid mem access 'map_value_or_null'")
int iter_err_too_permissive3(const void *ctx)
{
int *map_val = NULL;
int key = 0;
bool found = false;
MY_PID_GUARD();
bpf_repeat(1000000) {
map_val = bpf_map_lookup_elem(&arr_map, &key);
found = true;
}
if (found)
*map_val = 123;
return 0;
}
SEC("raw_tp")
__success
int iter_tricky_but_fine(const void *ctx)
{
int *map_val = NULL;
int key = 0;
bool found = false;
MY_PID_GUARD();
bpf_repeat(1000000) {
map_val = bpf_map_lookup_elem(&arr_map, &key);
if (map_val) {
found = true;
break;
}
}
if (found)
*map_val = 123;
return 0;
}
#define __bpf_memzero(p, sz) bpf_probe_read_kernel((p), (sz), 0)
SEC("raw_tp")
__success
int iter_stack_array_loop(const void *ctx)
{
long arr1[16], arr2[16], sum = 0;
int i;
MY_PID_GUARD();
/* zero-init arr1 and arr2 in such a way that verifier doesn't know
* it's all zeros; if we don't do that, we'll make BPF verifier track
* all combination of zero/non-zero stack slots for arr1/arr2, which
* will lead to O(2^(ARRAY_SIZE(arr1)+ARRAY_SIZE(arr2))) different
* states
*/
__bpf_memzero(arr1, sizeof(arr1));
__bpf_memzero(arr2, sizeof(arr1));
/* validate that we can break and continue when using bpf_for() */
bpf_for(i, 0, ARRAY_SIZE(arr1)) {
if (i & 1) {
arr1[i] = i;
continue;
} else {
arr2[i] = i;
break;
}
}
bpf_for(i, 0, ARRAY_SIZE(arr1)) {
sum += arr1[i] + arr2[i];
}
return sum;
}
static __noinline void fill(struct bpf_iter_num *it, int *arr, __u32 n, int mul)
{
int *t, i;
while ((t = bpf_iter_num_next(it))) {
i = *t;
if (i >= n)
break;
arr[i] = i * mul;
}
}
static __noinline int sum(struct bpf_iter_num *it, int *arr, __u32 n)
{
int *t, i, sum = 0;
while ((t = bpf_iter_num_next(it))) {
i = *t;
if ((__u32)i >= n)
break;
sum += arr[i];
}
return sum;
}
SEC("raw_tp")
__success
int iter_pass_iter_ptr_to_subprog(const void *ctx)
{
int arr1[16], arr2[32];
struct bpf_iter_num it;
int n, sum1, sum2;
MY_PID_GUARD();
/* fill arr1 */
n = ARRAY_SIZE(arr1);
bpf_iter_num_new(&it, 0, n);
fill(&it, arr1, n, 2);
bpf_iter_num_destroy(&it);
/* fill arr2 */
n = ARRAY_SIZE(arr2);
bpf_iter_num_new(&it, 0, n);
fill(&it, arr2, n, 10);
bpf_iter_num_destroy(&it);
/* sum arr1 */
n = ARRAY_SIZE(arr1);
bpf_iter_num_new(&it, 0, n);
sum1 = sum(&it, arr1, n);
bpf_iter_num_destroy(&it);
/* sum arr2 */
n = ARRAY_SIZE(arr2);
bpf_iter_num_new(&it, 0, n);
sum2 = sum(&it, arr2, n);
bpf_iter_num_destroy(&it);
bpf_printk("sum1=%d, sum2=%d", sum1, sum2);
return 0;
}
SEC("?raw_tp")
__failure
__msg("R1 type=scalar expected=fp")
__naked int delayed_read_mark(void)
{
/* This is equivalent to C program below.
* The call to bpf_iter_num_next() is reachable with r7 values &fp[-16] and 0xdead.
* State with r7=&fp[-16] is visited first and follows r6 != 42 ... continue branch.
* At this point iterator next() call is reached with r7 that has no read mark.
* Loop body with r7=0xdead would only be visited if verifier would decide to continue
* with second loop iteration. Absence of read mark on r7 might affect state
* equivalent logic used for iterator convergence tracking.
*
* r7 = &fp[-16]
* fp[-16] = 0
* r6 = bpf_get_prandom_u32()
* bpf_iter_num_new(&fp[-8], 0, 10)
* while (bpf_iter_num_next(&fp[-8])) {
* r6++
* if (r6 != 42) {
* r7 = 0xdead
* continue;
* }
* bpf_probe_read_user(r7, 8, 0xdeadbeef); // this is not safe
* }
* bpf_iter_num_destroy(&fp[-8])
* return 0
*/
asm volatile (
"r7 = r10;"
"r7 += -16;"
"r0 = 0;"
"*(u64 *)(r7 + 0) = r0;"
"call %[bpf_get_prandom_u32];"
"r6 = r0;"
"r1 = r10;"
"r1 += -8;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"1:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto 2f;"
"r6 += 1;"
"if r6 != 42 goto 3f;"
"r7 = 0xdead;"
"goto 1b;"
"3:"
"r1 = r7;"
"r2 = 8;"
"r3 = 0xdeadbeef;"
"call %[bpf_probe_read_user];"
"goto 1b;"
"2:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
"r0 = 0;"
"exit;"
:
: __imm(bpf_get_prandom_u32),
__imm(bpf_iter_num_new),
__imm(bpf_iter_num_next),
__imm(bpf_iter_num_destroy),
__imm(bpf_probe_read_user)
: __clobber_all
);
}
SEC("?raw_tp")
__failure
__msg("math between fp pointer and register with unbounded")
__naked int delayed_precision_mark(void)
{
/* This is equivalent to C program below.
* The test is similar to delayed_iter_mark but verifies that incomplete
* precision don't fool verifier.
* The call to bpf_iter_num_next() is reachable with r7 values -16 and -32.
* State with r7=-16 is visited first and follows r6 != 42 ... continue branch.
* At this point iterator next() call is reached with r7 that has no read
* and precision marks.
* Loop body with r7=-32 would only be visited if verifier would decide to continue
* with second loop iteration. Absence of precision mark on r7 might affect state
* equivalent logic used for iterator convergence tracking.
*
* r8 = 0
* fp[-16] = 0
* r7 = -16
* r6 = bpf_get_prandom_u32()
* bpf_iter_num_new(&fp[-8], 0, 10)
* while (bpf_iter_num_next(&fp[-8])) {
* if (r6 != 42) {
* r7 = -32
* r6 = bpf_get_prandom_u32()
* continue;
* }
* r0 = r10
* r0 += r7
* r8 = *(u64 *)(r0 + 0) // this is not safe
* r6 = bpf_get_prandom_u32()
* }
* bpf_iter_num_destroy(&fp[-8])
* return r8
*/
asm volatile (
"r8 = 0;"
"*(u64 *)(r10 - 16) = r8;"
"r7 = -16;"
"call %[bpf_get_prandom_u32];"
"r6 = r0;"
"r1 = r10;"
"r1 += -8;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"1:"
"r1 = r10;"
"r1 += -8;\n"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto 2f;"
"if r6 != 42 goto 3f;"
"r7 = -33;"
"call %[bpf_get_prandom_u32];"
"r6 = r0;"
"goto 1b;\n"
"3:"
"r0 = r10;"
"r0 += r7;"
"r8 = *(u64 *)(r0 + 0);"
"call %[bpf_get_prandom_u32];"
"r6 = r0;"
"goto 1b;\n"
"2:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
"r0 = r8;"
"exit;"
:
: __imm(bpf_get_prandom_u32),
__imm(bpf_iter_num_new),
__imm(bpf_iter_num_next),
__imm(bpf_iter_num_destroy),
__imm(bpf_probe_read_user)
: __clobber_all
);
}
SEC("?raw_tp")
__failure
__msg("math between fp pointer and register with unbounded")
__flag(BPF_F_TEST_STATE_FREQ)
__naked int loop_state_deps1(void)
{
/* This is equivalent to C program below.
*
* The case turns out to be tricky in a sense that:
* - states with c=-25 are explored only on a second iteration
* of the outer loop;
* - states with read+precise mark on c are explored only on
* second iteration of the inner loop and in a state which
* is pushed to states stack first.
*
* Depending on the details of iterator convergence logic
* verifier might stop states traversal too early and miss
* unsafe c=-25 memory access.
*
* j = iter_new(); // fp[-16]
* a = 0; // r6
* b = 0; // r7
* c = -24; // r8
* while (iter_next(j)) {
* i = iter_new(); // fp[-8]
* a = 0; // r6
* b = 0; // r7
* while (iter_next(i)) {
* if (a == 1) {
* a = 0;
* b = 1;
* } else if (a == 0) {
* a = 1;
* if (random() == 42)
* continue;
* if (b == 1) {
* *(r10 + c) = 7; // this is not safe
* iter_destroy(i);
* iter_destroy(j);
* return;
* }
* }
* }
* iter_destroy(i);
* a = 0;
* b = 0;
* c = -25;
* }
* iter_destroy(j);
* return;
*/
asm volatile (
"r1 = r10;"
"r1 += -16;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"r6 = 0;"
"r7 = 0;"
"r8 = -24;"
"j_loop_%=:"
"r1 = r10;"
"r1 += -16;"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto j_loop_end_%=;"
"r1 = r10;"
"r1 += -8;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"r6 = 0;"
"r7 = 0;"
"i_loop_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto i_loop_end_%=;"
"check_one_r6_%=:"
"if r6 != 1 goto check_zero_r6_%=;"
"r6 = 0;"
"r7 = 1;"
"goto i_loop_%=;"
"check_zero_r6_%=:"
"if r6 != 0 goto i_loop_%=;"
"r6 = 1;"
"call %[bpf_get_prandom_u32];"
"if r0 != 42 goto check_one_r7_%=;"
"goto i_loop_%=;"
"check_one_r7_%=:"
"if r7 != 1 goto i_loop_%=;"
"r0 = r10;"
"r0 += r8;"
"r1 = 7;"
"*(u64 *)(r0 + 0) = r1;"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
"r1 = r10;"
"r1 += -16;"
"call %[bpf_iter_num_destroy];"
"r0 = 0;"
"exit;"
"i_loop_end_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
"r6 = 0;"
"r7 = 0;"
"r8 = -25;"
"goto j_loop_%=;"
"j_loop_end_%=:"
"r1 = r10;"
"r1 += -16;"
"call %[bpf_iter_num_destroy];"
"r0 = 0;"
"exit;"
:
: __imm(bpf_get_prandom_u32),
__imm(bpf_iter_num_new),
__imm(bpf_iter_num_next),
__imm(bpf_iter_num_destroy)
: __clobber_all
);
}
SEC("?raw_tp")
__failure
__msg("math between fp pointer and register with unbounded")
__flag(BPF_F_TEST_STATE_FREQ)
__naked int loop_state_deps2(void)
{
/* This is equivalent to C program below.
*
* The case turns out to be tricky in a sense that:
* - states with read+precise mark on c are explored only on a second
* iteration of the first inner loop and in a state which is pushed to
* states stack first.
* - states with c=-25 are explored only on a second iteration of the
* second inner loop and in a state which is pushed to states stack
* first.
*
* Depending on the details of iterator convergence logic
* verifier might stop states traversal too early and miss
* unsafe c=-25 memory access.
*
* j = iter_new(); // fp[-16]
* a = 0; // r6
* b = 0; // r7
* c = -24; // r8
* while (iter_next(j)) {
* i = iter_new(); // fp[-8]
* a = 0; // r6
* b = 0; // r7
* while (iter_next(i)) {
* if (a == 1) {
* a = 0;
* b = 1;
* } else if (a == 0) {
* a = 1;
* if (random() == 42)
* continue;
* if (b == 1) {
* *(r10 + c) = 7; // this is not safe
* iter_destroy(i);
* iter_destroy(j);
* return;
* }
* }
* }
* iter_destroy(i);
* i = iter_new(); // fp[-8]
* a = 0; // r6
* b = 0; // r7
* while (iter_next(i)) {
* if (a == 1) {
* a = 0;
* b = 1;
* } else if (a == 0) {
* a = 1;
* if (random() == 42)
* continue;
* if (b == 1) {
* a = 0;
* c = -25;
* }
* }
* }
* iter_destroy(i);
* }
* iter_destroy(j);
* return;
*/
asm volatile (
"r1 = r10;"
"r1 += -16;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"r6 = 0;"
"r7 = 0;"
"r8 = -24;"
"j_loop_%=:"
"r1 = r10;"
"r1 += -16;"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto j_loop_end_%=;"
/* first inner loop */
"r1 = r10;"
"r1 += -8;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"r6 = 0;"
"r7 = 0;"
"i_loop_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto i_loop_end_%=;"
"check_one_r6_%=:"
"if r6 != 1 goto check_zero_r6_%=;"
"r6 = 0;"
"r7 = 1;"
"goto i_loop_%=;"
"check_zero_r6_%=:"
"if r6 != 0 goto i_loop_%=;"
"r6 = 1;"
"call %[bpf_get_prandom_u32];"
"if r0 != 42 goto check_one_r7_%=;"
"goto i_loop_%=;"
"check_one_r7_%=:"
"if r7 != 1 goto i_loop_%=;"
"r0 = r10;"
"r0 += r8;"
"r1 = 7;"
"*(u64 *)(r0 + 0) = r1;"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
"r1 = r10;"
"r1 += -16;"
"call %[bpf_iter_num_destroy];"
"r0 = 0;"
"exit;"
"i_loop_end_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
/* second inner loop */
"r1 = r10;"
"r1 += -8;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"r6 = 0;"
"r7 = 0;"
"i2_loop_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto i2_loop_end_%=;"
"check2_one_r6_%=:"
"if r6 != 1 goto check2_zero_r6_%=;"
"r6 = 0;"
"r7 = 1;"
"goto i2_loop_%=;"
"check2_zero_r6_%=:"
"if r6 != 0 goto i2_loop_%=;"
"r6 = 1;"
"call %[bpf_get_prandom_u32];"
"if r0 != 42 goto check2_one_r7_%=;"
"goto i2_loop_%=;"
"check2_one_r7_%=:"
"if r7 != 1 goto i2_loop_%=;"
"r6 = 0;"
"r8 = -25;"
"goto i2_loop_%=;"
"i2_loop_end_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
"r6 = 0;"
"r7 = 0;"
"goto j_loop_%=;"
"j_loop_end_%=:"
"r1 = r10;"
"r1 += -16;"
"call %[bpf_iter_num_destroy];"
"r0 = 0;"
"exit;"
:
: __imm(bpf_get_prandom_u32),
__imm(bpf_iter_num_new),
__imm(bpf_iter_num_next),
__imm(bpf_iter_num_destroy)
: __clobber_all
);
}
SEC("?raw_tp")
__success
__naked int triple_continue(void)
{
/* This is equivalent to C program below.
* High branching factor of the loop body turned out to be
* problematic for one of the iterator convergence tracking
* algorithms explored.
*
* r6 = bpf_get_prandom_u32()
* bpf_iter_num_new(&fp[-8], 0, 10)
* while (bpf_iter_num_next(&fp[-8])) {
* if (bpf_get_prandom_u32() != 42)
* continue;
* if (bpf_get_prandom_u32() != 42)
* continue;
* if (bpf_get_prandom_u32() != 42)
* continue;
* r0 += 0;
* }
* bpf_iter_num_destroy(&fp[-8])
* return 0
*/
asm volatile (
"r1 = r10;"
"r1 += -8;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"loop_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto loop_end_%=;"
"call %[bpf_get_prandom_u32];"
"if r0 != 42 goto loop_%=;"
"call %[bpf_get_prandom_u32];"
"if r0 != 42 goto loop_%=;"
"call %[bpf_get_prandom_u32];"
"if r0 != 42 goto loop_%=;"
"r0 += 0;"
"goto loop_%=;"
"loop_end_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
"r0 = 0;"
"exit;"
:
: __imm(bpf_get_prandom_u32),
__imm(bpf_iter_num_new),
__imm(bpf_iter_num_next),
__imm(bpf_iter_num_destroy)
: __clobber_all
);
}
SEC("?raw_tp")
__success
__naked int widen_spill(void)
{
/* This is equivalent to C program below.
* The counter is stored in fp[-16], if this counter is not widened
* verifier states representing loop iterations would never converge.
*
* fp[-16] = 0
* bpf_iter_num_new(&fp[-8], 0, 10)
* while (bpf_iter_num_next(&fp[-8])) {
* r0 = fp[-16];
* r0 += 1;
* fp[-16] = r0;
* }
* bpf_iter_num_destroy(&fp[-8])
* return 0
*/
asm volatile (
"r0 = 0;"
"*(u64 *)(r10 - 16) = r0;"
"r1 = r10;"
"r1 += -8;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"loop_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto loop_end_%=;"
"r0 = *(u64 *)(r10 - 16);"
"r0 += 1;"
"*(u64 *)(r10 - 16) = r0;"
"goto loop_%=;"
"loop_end_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
"r0 = 0;"
"exit;"
:
: __imm(bpf_iter_num_new),
__imm(bpf_iter_num_next),
__imm(bpf_iter_num_destroy)
: __clobber_all
);
}
SEC("raw_tp")
__success
__naked int checkpoint_states_deletion(void)
{
/* This is equivalent to C program below.
*
* int *a, *b, *c, *d, *e, *f;
* int i, sum = 0;
* bpf_for(i, 0, 10) {
* a = bpf_map_lookup_elem(&amap, &i);
* b = bpf_map_lookup_elem(&amap, &i);
* c = bpf_map_lookup_elem(&amap, &i);
* d = bpf_map_lookup_elem(&amap, &i);
* e = bpf_map_lookup_elem(&amap, &i);
* f = bpf_map_lookup_elem(&amap, &i);
* if (a) sum += 1;
* if (b) sum += 1;
* if (c) sum += 1;
* if (d) sum += 1;
* if (e) sum += 1;
* if (f) sum += 1;
* }
* return 0;
*
* The body of the loop spawns multiple simulation paths
* with different combination of NULL/non-NULL information for a/b/c/d/e/f.
* Each combination is unique from states_equal() point of view.
* Explored states checkpoint is created after each iterator next call.
* Iterator convergence logic expects that eventually current state
* would get equal to one of the explored states and thus loop
* exploration would be finished (at-least for a specific path).
* Verifier evicts explored states with high miss to hit ratio
* to to avoid comparing current state with too many explored
* states per instruction.
* This test is designed to "stress test" eviction policy defined using formula:
*
* sl->miss_cnt > sl->hit_cnt * N + N // if true sl->state is evicted
*
* Currently N is set to 64, which allows for 6 variables in this test.
*/
asm volatile (
"r6 = 0;" /* a */
"r7 = 0;" /* b */
"r8 = 0;" /* c */
"*(u64 *)(r10 - 24) = r6;" /* d */
"*(u64 *)(r10 - 32) = r6;" /* e */
"*(u64 *)(r10 - 40) = r6;" /* f */
"r9 = 0;" /* sum */
"r1 = r10;"
"r1 += -8;"
"r2 = 0;"
"r3 = 10;"
"call %[bpf_iter_num_new];"
"loop_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_next];"
"if r0 == 0 goto loop_end_%=;"
"*(u64 *)(r10 - 16) = r0;"
"r1 = %[amap] ll;"
"r2 = r10;"
"r2 += -16;"
"call %[bpf_map_lookup_elem];"
"r6 = r0;"
"r1 = %[amap] ll;"
"r2 = r10;"
"r2 += -16;"
"call %[bpf_map_lookup_elem];"
"r7 = r0;"
"r1 = %[amap] ll;"
"r2 = r10;"
"r2 += -16;"
"call %[bpf_map_lookup_elem];"
"r8 = r0;"
"r1 = %[amap] ll;"
"r2 = r10;"
"r2 += -16;"
"call %[bpf_map_lookup_elem];"
"*(u64 *)(r10 - 24) = r0;"
"r1 = %[amap] ll;"
"r2 = r10;"
"r2 += -16;"
"call %[bpf_map_lookup_elem];"
"*(u64 *)(r10 - 32) = r0;"
"r1 = %[amap] ll;"
"r2 = r10;"
"r2 += -16;"
"call %[bpf_map_lookup_elem];"
"*(u64 *)(r10 - 40) = r0;"
"if r6 == 0 goto +1;"
"r9 += 1;"
"if r7 == 0 goto +1;"
"r9 += 1;"
"if r8 == 0 goto +1;"
"r9 += 1;"
"r0 = *(u64 *)(r10 - 24);"
"if r0 == 0 goto +1;"
"r9 += 1;"
"r0 = *(u64 *)(r10 - 32);"
"if r0 == 0 goto +1;"
"r9 += 1;"
"r0 = *(u64 *)(r10 - 40);"
"if r0 == 0 goto +1;"
"r9 += 1;"
"goto loop_%=;"
"loop_end_%=:"
"r1 = r10;"
"r1 += -8;"
"call %[bpf_iter_num_destroy];"
"r0 = 0;"
"exit;"
:
: __imm(bpf_map_lookup_elem),
__imm(bpf_iter_num_new),
__imm(bpf_iter_num_next),
__imm(bpf_iter_num_destroy),
__imm_addr(amap)
: __clobber_all
);
}
struct {
int data[32];
int n;
} loop_data;
SEC("raw_tp")
__success
int iter_arr_with_actual_elem_count(const void *ctx)
{
int i, n = loop_data.n, sum = 0;
if (n > ARRAY_SIZE(loop_data.data))
return 0;
bpf_for(i, 0, n) {
/* no rechecking of i against ARRAY_SIZE(loop_data.n) */
sum += loop_data.data[i];
}
return sum;
}
__u32 upper, select_n, result;
__u64 global;
static __noinline bool nest_2(char *str)
{
/* some insns (including branch insns) to ensure stacksafe() is triggered
* in nest_2(). This way, stacksafe() can compare frame associated with nest_1().
*/
if (str[0] == 't')
return true;
if (str[1] == 'e')
return true;
if (str[2] == 's')
return true;
if (str[3] == 't')
return true;
return false;
}
static __noinline bool nest_1(int n)
{
/* case 0: allocate stack, case 1: no allocate stack */
switch (n) {
case 0: {
char comm[16];
if (bpf_get_current_comm(comm, 16))
return false;
return nest_2(comm);
}
case 1:
return nest_2((char *)&global);
default:
return false;
}
}
SEC("raw_tp")
__success
int iter_subprog_check_stacksafe(const void *ctx)
{
long i;
bpf_for(i, 0, upper) {
if (!nest_1(select_n)) {
result = 1;
return 0;
}
}
result = 2;
return 0;
}
char _license[] SEC("license") = "GPL";
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