// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
* Copyright (c) 2016 Facebook
* Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
*/
#include <uapi/linux/btf.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bpf.h>
#include <linux/bpf_verifier.h>
#include <linux/math64.h>
#include <linux/string.h>
#define verbose(env, fmt, args...) bpf_verifier_log_write(env, fmt, ##args)
static bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log)
{
/* ubuf and len_total should both be specified (or not) together */
if (!!log->ubuf != !!log->len_total)
return false;
/* log buf without log_level is meaningless */
if (log->ubuf && log->level == 0)
return false;
if (log->level & ~BPF_LOG_MASK)
return false;
if (log->len_total > UINT_MAX >> 2)
return false;
return true;
}
int bpf_vlog_init(struct bpf_verifier_log *log, u32 log_level,
char __user *log_buf, u32 log_size)
{
log->level = log_level;
log->ubuf = log_buf;
log->len_total = log_size;
/* log attributes have to be sane */
if (!bpf_verifier_log_attr_valid(log))
return -EINVAL;
return 0;
}
static void bpf_vlog_update_len_max(struct bpf_verifier_log *log, u32 add_len)
{
/* add_len includes terminal \0, so no need for +1. */
u64 len = log->end_pos + add_len;
/* log->len_max could be larger than our current len due to
* bpf_vlog_reset() calls, so we maintain the max of any length at any
* previous point
*/
if (len > UINT_MAX)
log->len_max = UINT_MAX;
else if (len > log->len_max)
log->len_max = len;
}
void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
va_list args)
{
u64 cur_pos;
u32 new_n, n;
n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args);
if (log->level == BPF_LOG_KERNEL) {
bool newline = n > 0 && log->kbuf[n - 1] == '\n';
pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n");
return;
}
n += 1; /* include terminating zero */
bpf_vlog_update_len_max(log, n);
if (log->level & BPF_LOG_FIXED) {
/* check if we have at least something to put into user buf */
new_n = 0;
if (log->end_pos < log->len_total) {
new_n = min_t(u32, log->len_total - log->end_pos, n);
log->kbuf[new_n - 1] = '\0';
}
cur_pos = log->end_pos;
log->end_pos += n - 1; /* don't count terminating '\0' */
if (log->ubuf && new_n &&
copy_to_user(log->ubuf + cur_pos, log->kbuf, new_n))
goto fail;
} else {
u64 new_end, new_start;
u32 buf_start, buf_end;
new_end = log->end_pos + n;
if (new_end - log->start_pos >= log->len_total)
new_start = new_end - log->len_total;
else
new_start = log->start_pos;
log->start_pos = new_start;
log->end_pos = new_end - 1; /* don't count terminating '\0' */
if (!log->ubuf)
return;
new_n = min(n, log->len_total);
cur_pos = new_end - new_n;
div_u64_rem(cur_pos, log->len_total, &buf_start);
div_u64_rem(new_end, log->len_total, &buf_end);
/* new_end and buf_end are exclusive indices, so if buf_end is
* exactly zero, then it actually points right to the end of
* ubuf and there is no wrap around
*/
if (buf_end == 0)
buf_end = log->len_total;
/* if buf_start > buf_end, we wrapped around;
* if buf_start == buf_end, then we fill ubuf completely; we
* can't have buf_start == buf_end to mean that there is
* nothing to write, because we always write at least
* something, even if terminal '\0'
*/
if (buf_start < buf_end) {
/* message fits within contiguous chunk of ubuf */
if (copy_to_user(log->ubuf + buf_start,
log->kbuf + n - new_n,
buf_end - buf_start))
goto fail;
} else {
/* message wraps around the end of ubuf, copy in two chunks */
if (copy_to_user(log->ubuf + buf_start,
log->kbuf + n - new_n,
log->len_total - buf_start))
goto fail;
if (copy_to_user(log->ubuf,
log->kbuf + n - buf_end,
buf_end))
goto fail;
}
}
return;
fail:
log->ubuf = NULL;
}
void bpf_vlog_reset(struct bpf_verifier_log *log, u64 new_pos)
{
char zero = 0;
u32 pos;
if (WARN_ON_ONCE(new_pos > log->end_pos))
return;
if (!bpf_verifier_log_needed(log) || log->level == BPF_LOG_KERNEL)
return;
/* if position to which we reset is beyond current log window,
* then we didn't preserve any useful content and should adjust
* start_pos to end up with an empty log (start_pos == end_pos)
*/
log->end_pos = new_pos;
if (log->end_pos < log->start_pos)
log->start_pos = log->end_pos;
if (!log->ubuf)
return;
if (log->level & BPF_LOG_FIXED)
pos = log->end_pos + 1;
else
div_u64_rem(new_pos, log->len_total, &pos);
if (pos < log->len_total && put_user(zero, log->ubuf + pos))
log->ubuf = NULL;
}
static void bpf_vlog_reverse_kbuf(char *buf, int len)
{
int i, j;
for (i = 0, j = len - 1; i < j; i++, j--)
swap(buf[i], buf[j]);
}
static int bpf_vlog_reverse_ubuf(struct bpf_verifier_log *log, int start, int end)
{
/* we split log->kbuf into two equal parts for both ends of array */
int n = sizeof(log->kbuf) / 2, nn;
char *lbuf = log->kbuf, *rbuf = log->kbuf + n;
/* Read ubuf's section [start, end) two chunks at a time, from left
* and right side; within each chunk, swap all the bytes; after that
* reverse the order of lbuf and rbuf and write result back to ubuf.
* This way we'll end up with swapped contents of specified
* [start, end) ubuf segment.
*/
while (end - start > 1) {
nn = min(n, (end - start ) / 2);
if (copy_from_user(lbuf, log->ubuf + start, nn))
return -EFAULT;
if (copy_from_user(rbuf, log->ubuf + end - nn, nn))
return -EFAULT;
bpf_vlog_reverse_kbuf(lbuf, nn);
bpf_vlog_reverse_kbuf(rbuf, nn);
/* we write lbuf to the right end of ubuf, while rbuf to the
* left one to end up with properly reversed overall ubuf
*/
if (copy_to_user(log->ubuf + start, rbuf, nn))
return -EFAULT;
if (copy_to_user(log->ubuf + end - nn, lbuf, nn))
return -EFAULT;
start += nn;
end -= nn;
}
return 0;
}
int bpf_vlog_finalize(struct bpf_verifier_log *log, u32 *log_size_actual)
{
u32 sublen;
int err;
*log_size_actual = 0;
if (!log || log->level == 0 || log->level == BPF_LOG_KERNEL)
return 0;
if (!log->ubuf)
goto skip_log_rotate;
/* If we never truncated log, there is nothing to move around. */
if (log->start_pos == 0)
goto skip_log_rotate;
/* Otherwise we need to rotate log contents to make it start from the
* buffer beginning and be a continuous zero-terminated string. Note
* that if log->start_pos != 0 then we definitely filled up entire log
* buffer with no gaps, and we just need to shift buffer contents to
* the left by (log->start_pos % log->len_total) bytes.
*
* Unfortunately, user buffer could be huge and we don't want to
* allocate temporary kernel memory of the same size just to shift
* contents in a straightforward fashion. Instead, we'll be clever and
* do in-place array rotation. This is a leetcode-style problem, which
* could be solved by three rotations.
*
* Let's say we have log buffer that has to be shifted left by 7 bytes
* (spaces and vertical bar is just for demonstrative purposes):
* E F G H I J K | A B C D
*
* First, we reverse entire array:
* D C B A | K J I H G F E
*
* Then we rotate first 4 bytes (DCBA) and separately last 7 bytes
* (KJIHGFE), resulting in a properly rotated array:
* A B C D | E F G H I J K
*
* We'll utilize log->kbuf to read user memory chunk by chunk, swap
* bytes, and write them back. Doing it byte-by-byte would be
* unnecessarily inefficient. Altogether we are going to read and
* write each byte twice, for total 4 memory copies between kernel and
* user space.
*/
/* length of the chopped off part that will be the beginning;
* len(ABCD) in the example above
*/
div_u64_rem(log->start_pos, log->len_total, &sublen);
sublen = log->len_total - sublen;
err = bpf_vlog_reverse_ubuf(log, 0, log->len_total);
err = err ?: bpf_vlog_reverse_ubuf(log, 0, sublen);
err = err ?: bpf_vlog_reverse_ubuf(log, sublen, log->len_total);
if (err)
log->ubuf = NULL;
skip_log_rotate:
*log_size_actual = log->len_max;
/* properly initialized log has either both ubuf!=NULL and len_total>0
* or ubuf==NULL and len_total==0, so if this condition doesn't hold,
* we got a fault somewhere along the way, so report it back
*/
if (!!log->ubuf != !!log->len_total)
return -EFAULT;
/* did truncation actually happen? */
if (log->ubuf && log->len_max > log->len_total)
return -ENOSPC;
return 0;
}
/* log_level controls verbosity level of eBPF verifier.
* bpf_verifier_log_write() is used to dump the verification trace to the log,
* so the user can figure out what's wrong with the program
*/
__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
const char *fmt, ...)
{
va_list args;
if (!bpf_verifier_log_needed(&env->log))
return;
va_start(args, fmt);
bpf_verifier_vlog(&env->log, fmt, args);
va_end(args);
}
EXPORT_SYMBOL_GPL(bpf_verifier_log_write);
__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
const char *fmt, ...)
{
va_list args;
if (!bpf_verifier_log_needed(log))
return;
va_start(args, fmt);
bpf_verifier_vlog(log, fmt, args);
va_end(args);
}
EXPORT_SYMBOL_GPL(bpf_log);
static const struct bpf_line_info *
find_linfo(const struct bpf_verifier_env *env, u32 insn_off)
{
const struct bpf_line_info *linfo;
const struct bpf_prog *prog;
u32 nr_linfo;
int l, r, m;
prog = env->prog;
nr_linfo = prog->aux->nr_linfo;
if (!nr_linfo || insn_off >= prog->len)
return NULL;
linfo = prog->aux->linfo;
/* Loop invariant: linfo[l].insn_off <= insns_off.
* linfo[0].insn_off == 0 which always satisfies above condition.
* Binary search is searching for rightmost linfo entry that satisfies
* the above invariant, giving us the desired record that covers given
* instruction offset.
*/
l = 0;
r = nr_linfo - 1;
while (l < r) {
/* (r - l + 1) / 2 means we break a tie to the right, so if:
* l=1, r=2, linfo[l].insn_off <= insn_off, linfo[r].insn_off > insn_off,
* then m=2, we see that linfo[m].insn_off > insn_off, and so
* r becomes 1 and we exit the loop with correct l==1.
* If the tie was broken to the left, m=1 would end us up in
* an endless loop where l and m stay at 1 and r stays at 2.
*/
m = l + (r - l + 1) / 2;
if (linfo[m].insn_off <= insn_off)
l = m;
else
r = m - 1;
}
return &linfo[l];
}
static const char *ltrim(const char *s)
{
while (isspace(*s))
s++;
return s;
}
__printf(3, 4) void verbose_linfo(struct bpf_verifier_env *env,
u32 insn_off,
const char *prefix_fmt, ...)
{
const struct bpf_line_info *linfo, *prev_linfo;
const struct btf *btf;
const char *s, *fname;
if (!bpf_verifier_log_needed(&env->log))
return;
prev_linfo = env->prev_linfo;
linfo = find_linfo(env, insn_off);
if (!linfo || linfo == prev_linfo)
return;
/* It often happens that two separate linfo records point to the same
* source code line, but have differing column numbers. Given verifier
* log doesn't emit column information, from user perspective we just
* end up emitting the same source code line twice unnecessarily.
* So instead check that previous and current linfo record point to
* the same file (file_name_offs match) and the same line number, and
* avoid emitting duplicated source code line in such case.
*/
if (prev_linfo && linfo->file_name_off == prev_linfo->file_name_off &&
BPF_LINE_INFO_LINE_NUM(linfo->line_col) == BPF_LINE_INFO_LINE_NUM(prev_linfo->line_col))
return;
if (prefix_fmt) {
va_list args;
va_start(args, prefix_fmt);
bpf_verifier_vlog(&env->log, prefix_fmt, args);
va_end(args);
}
btf = env->prog->aux->btf;
s = ltrim(btf_name_by_offset(btf, linfo->line_off));
verbose(env, "%s", s); /* source code line */
s = btf_name_by_offset(btf, linfo->file_name_off);
/* leave only file name */
fname = strrchr(s, '/');
fname = fname ? fname + 1 : s;
verbose(env, " @ %s:%u\n", fname, BPF_LINE_INFO_LINE_NUM(linfo->line_col));
env->prev_linfo = linfo;
}
static const char *btf_type_name(const struct btf *btf, u32 id)
{
return btf_name_by_offset(btf, btf_type_by_id(btf, id)->name_off);
}
/* string representation of 'enum bpf_reg_type'
*
* Note that reg_type_str() can not appear more than once in a single verbose()
* statement.
*/
const char *reg_type_str(struct bpf_verifier_env *env, enum bpf_reg_type type)
{
char postfix[16] = {0}, prefix[64] = {0};
static const char * const str[] = {
[NOT_INIT] = "?",
[SCALAR_VALUE] = "scalar",
[PTR_TO_CTX] = "ctx",
[CONST_PTR_TO_MAP] = "map_ptr",
[PTR_TO_MAP_VALUE] = "map_value",
[PTR_TO_STACK] = "fp",
[PTR_TO_PACKET] = "pkt",
[PTR_TO_PACKET_META] = "pkt_meta",
[PTR_TO_PACKET_END] = "pkt_end",
[PTR_TO_FLOW_KEYS] = "flow_keys",
[PTR_TO_SOCKET] = "sock",
[PTR_TO_SOCK_COMMON] = "sock_common",
[PTR_TO_TCP_SOCK] = "tcp_sock",
[PTR_TO_TP_BUFFER] = "tp_buffer",
[PTR_TO_XDP_SOCK] = "xdp_sock",
[PTR_TO_BTF_ID] = "ptr_",
[PTR_TO_MEM] = "mem",
[PTR_TO_ARENA] = "arena",
[PTR_TO_BUF] = "buf",
[PTR_TO_FUNC] = "func",
[PTR_TO_MAP_KEY] = "map_key",
[CONST_PTR_TO_DYNPTR] = "dynptr_ptr",
};
if (type & PTR_MAYBE_NULL) {
if (base_type(type) == PTR_TO_BTF_ID)
strscpy(postfix, "or_null_");
else
strscpy(postfix, "_or_null");
}
snprintf(prefix, sizeof(prefix), "%s%s%s%s%s%s%s",
type & MEM_RDONLY ? "rdonly_" : "",
type & MEM_RINGBUF ? "ringbuf_" : "",
type & MEM_USER ? "user_" : "",
type & MEM_PERCPU ? "percpu_" : "",
type & MEM_RCU ? "rcu_" : "",
type & PTR_UNTRUSTED ? "untrusted_" : "",
type & PTR_TRUSTED ? "trusted_" : ""
);
snprintf(env->tmp_str_buf, TMP_STR_BUF_LEN, "%s%s%s",
prefix, str[base_type(type)], postfix);
return env->tmp_str_buf;
}
const char *dynptr_type_str(enum bpf_dynptr_type type)
{
switch (type) {
case BPF_DYNPTR_TYPE_LOCAL:
return "local";
case BPF_DYNPTR_TYPE_RINGBUF:
return "ringbuf";
case BPF_DYNPTR_TYPE_SKB:
return "skb";
case BPF_DYNPTR_TYPE_XDP:
return "xdp";
case BPF_DYNPTR_TYPE_INVALID:
return "<invalid>";
default:
WARN_ONCE(1, "unknown dynptr type %d\n", type);
return "<unknown>";
}
}
const char *iter_type_str(const struct btf *btf, u32 btf_id)
{
if (!btf || btf_id == 0)
return "<invalid>";
/* we already validated that type is valid and has conforming name */
return btf_type_name(btf, btf_id) + sizeof(ITER_PREFIX) - 1;
}
const char *iter_state_str(enum bpf_iter_state state)
{
switch (state) {
case BPF_ITER_STATE_ACTIVE:
return "active";
case BPF_ITER_STATE_DRAINED:
return "drained";
case BPF_ITER_STATE_INVALID:
return "<invalid>";
default:
WARN_ONCE(1, "unknown iter state %d\n", state);
return "<unknown>";
}
}
static char slot_type_char[] = {
[STACK_INVALID] = '?',
[STACK_SPILL] = 'r',
[STACK_MISC] = 'm',
[STACK_ZERO] = '0',
[STACK_DYNPTR] = 'd',
[STACK_ITER] = 'i',
};
static void print_liveness(struct bpf_verifier_env *env,
enum bpf_reg_liveness live)
{
if (live & (REG_LIVE_READ | REG_LIVE_WRITTEN | REG_LIVE_DONE))
verbose(env, "_");
if (live & REG_LIVE_READ)
verbose(env, "r");
if (live & REG_LIVE_WRITTEN)
verbose(env, "w");
if (live & REG_LIVE_DONE)
verbose(env, "D");
}
#define UNUM_MAX_DECIMAL U16_MAX
#define SNUM_MAX_DECIMAL S16_MAX
#define SNUM_MIN_DECIMAL S16_MIN
static bool is_unum_decimal(u64 num)
{
return num <= UNUM_MAX_DECIMAL;
}
static bool is_snum_decimal(s64 num)
{
return num >= SNUM_MIN_DECIMAL && num <= SNUM_MAX_DECIMAL;
}
static void verbose_unum(struct bpf_verifier_env *env, u64 num)
{
if (is_unum_decimal(num))
verbose(env, "%llu", num);
else
verbose(env, "%#llx", num);
}
static void verbose_snum(struct bpf_verifier_env *env, s64 num)
{
if (is_snum_decimal(num))
verbose(env, "%lld", num);
else
verbose(env, "%#llx", num);
}
int tnum_strn(char *str, size_t size, struct tnum a)
{
/* print as a constant, if tnum is fully known */
if (a.mask == 0) {
if (is_unum_decimal(a.value))
return snprintf(str, size, "%llu", a.value);
else
return snprintf(str, size, "%#llx", a.value);
}
return snprintf(str, size, "(%#llx; %#llx)", a.value, a.mask);
}
EXPORT_SYMBOL_GPL(tnum_strn);
static void print_scalar_ranges(struct bpf_verifier_env *env,
const struct bpf_reg_state *reg,
const char **sep)
{
/* For signed ranges, we want to unify 64-bit and 32-bit values in the
* output as much as possible, but there is a bit of a complication.
* If we choose to print values as decimals, this is natural to do,
* because negative 64-bit and 32-bit values >= -S32_MIN have the same
* representation due to sign extension. But if we choose to print
* them in hex format (see is_snum_decimal()), then sign extension is
* misleading.
* E.g., smin=-2 and smin32=-2 are exactly the same in decimal, but in
* hex they will be smin=0xfffffffffffffffe and smin32=0xfffffffe, two
* very different numbers.
* So we avoid sign extension if we choose to print values in hex.
*/
struct {
const char *name;
u64 val;
bool omit;
} minmaxs[] = {
{"smin", reg->smin_value, reg->smin_value == S64_MIN},
{"smax", reg->smax_value, reg->smax_value == S64_MAX},
{"umin", reg->umin_value, reg->umin_value == 0},
{"umax", reg->umax_value, reg->umax_value == U64_MAX},
{"smin32",
is_snum_decimal((s64)reg->s32_min_value)
? (s64)reg->s32_min_value
: (u32)reg->s32_min_value, reg->s32_min_value == S32_MIN},
{"smax32",
is_snum_decimal((s64)reg->s32_max_value)
? (s64)reg->s32_max_value
: (u32)reg->s32_max_value, reg->s32_max_value == S32_MAX},
{"umin32", reg->u32_min_value, reg->u32_min_value == 0},
{"umax32", reg->u32_max_value, reg->u32_max_value == U32_MAX},
}, *m1, *m2, *mend = &minmaxs[ARRAY_SIZE(minmaxs)];
bool neg1, neg2;
for (m1 = &minmaxs[0]; m1 < mend; m1++) {
if (m1->omit)
continue;
neg1 = m1->name[0] == 's' && (s64)m1->val < 0;
verbose(env, "%s%s=", *sep, m1->name);
*sep = ",";
for (m2 = m1 + 2; m2 < mend; m2 += 2) {
if (m2->omit || m2->val != m1->val)
continue;
/* don't mix negatives with positives */
neg2 = m2->name[0] == 's' && (s64)m2->val < 0;
if (neg2 != neg1)
continue;
m2->omit = true;
verbose(env, "%s=", m2->name);
}
if (m1->name[0] == 's')
verbose_snum(env, m1->val);
else
verbose_unum(env, m1->val);
}
}
static bool type_is_map_ptr(enum bpf_reg_type t) {
switch (base_type(t)) {
case CONST_PTR_TO_MAP:
case PTR_TO_MAP_KEY:
case PTR_TO_MAP_VALUE:
return true;
default:
return false;
}
}
/*
* _a stands for append, was shortened to avoid multiline statements below.
* This macro is used to output a comma separated list of attributes.
*/
#define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, ##__VA_ARGS__); sep = ","; })
static void print_reg_state(struct bpf_verifier_env *env,
const struct bpf_func_state *state,
const struct bpf_reg_state *reg)
{
enum bpf_reg_type t;
const char *sep = "";
t = reg->type;
if (t == SCALAR_VALUE && reg->precise)
verbose(env, "P");
if (t == SCALAR_VALUE && tnum_is_const(reg->var_off)) {
/* reg->off should be 0 for SCALAR_VALUE */
verbose_snum(env, reg->var_off.value + reg->off);
return;
}
verbose(env, "%s", reg_type_str(env, t));
if (t == PTR_TO_ARENA)
return;
if (t == PTR_TO_STACK) {
if (state->frameno != reg->frameno)
verbose(env, "[%d]", reg->frameno);
if (tnum_is_const(reg->var_off)) {
verbose_snum(env, reg->var_off.value + reg->off);
return;
}
}
if (base_type(t) == PTR_TO_BTF_ID)
verbose(env, "%s", btf_type_name(reg->btf, reg->btf_id));
verbose(env, "(");
if (reg->id)
verbose_a("id=%d", reg->id & ~BPF_ADD_CONST);
if (reg->id & BPF_ADD_CONST)
verbose(env, "%+d", reg->off);
if (reg->ref_obj_id)
verbose_a("ref_obj_id=%d", reg->ref_obj_id);
if (type_is_non_owning_ref(reg->type))
verbose_a("%s", "non_own_ref");
if (type_is_map_ptr(t)) {
if (reg->map_ptr->name[0])
verbose_a("map=%s", reg->map_ptr->name);
verbose_a("ks=%d,vs=%d",
reg->map_ptr->key_size,
reg->map_ptr->value_size);
}
if (t != SCALAR_VALUE && reg->off) {
verbose_a("off=");
verbose_snum(env, reg->off);
}
if (type_is_pkt_pointer(t)) {
verbose_a("r=");
verbose_unum(env, reg->range);
}
if (base_type(t) == PTR_TO_MEM) {
verbose_a("sz=");
verbose_unum(env, reg->mem_size);
}
if (t == CONST_PTR_TO_DYNPTR)
verbose_a("type=%s", dynptr_type_str(reg->dynptr.type));
if (tnum_is_const(reg->var_off)) {
/* a pointer register with fixed offset */
if (reg->var_off.value) {
verbose_a("imm=");
verbose_snum(env, reg->var_off.value);
}
} else {
print_scalar_ranges(env, reg, &sep);
if (!tnum_is_unknown(reg->var_off)) {
char tn_buf[48];
tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
verbose_a("var_off=%s", tn_buf);
}
}
verbose(env, ")");
}
void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_func_state *state,
bool print_all)
{
const struct bpf_reg_state *reg;
int i;
if (state->frameno)
verbose(env, " frame%d:", state->frameno);
for (i = 0; i < MAX_BPF_REG; i++) {
reg = &state->regs[i];
if (reg->type == NOT_INIT)
continue;
if (!print_all && !reg_scratched(env, i))
continue;
verbose(env, " R%d", i);
print_liveness(env, reg->live);
verbose(env, "=");
print_reg_state(env, state, reg);
}
for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
char types_buf[BPF_REG_SIZE + 1];
const char *sep = "";
bool valid = false;
u8 slot_type;
int j;
if (!print_all && !stack_slot_scratched(env, i))
continue;
for (j = 0; j < BPF_REG_SIZE; j++) {
slot_type = state->stack[i].slot_type[j];
if (slot_type != STACK_INVALID)
valid = true;
types_buf[j] = slot_type_char[slot_type];
}
types_buf[BPF_REG_SIZE] = 0;
if (!valid)
continue;
reg = &state->stack[i].spilled_ptr;
switch (state->stack[i].slot_type[BPF_REG_SIZE - 1]) {
case STACK_SPILL:
/* print MISC/ZERO/INVALID slots above subreg spill */
for (j = 0; j < BPF_REG_SIZE; j++)
if (state->stack[i].slot_type[j] == STACK_SPILL)
break;
types_buf[j] = '\0';
verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
print_liveness(env, reg->live);
verbose(env, "=%s", types_buf);
print_reg_state(env, state, reg);
break;
case STACK_DYNPTR:
/* skip to main dynptr slot */
i += BPF_DYNPTR_NR_SLOTS - 1;
reg = &state->stack[i].spilled_ptr;
verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
print_liveness(env, reg->live);
verbose(env, "=dynptr_%s(", dynptr_type_str(reg->dynptr.type));
if (reg->id)
verbose_a("id=%d", reg->id);
if (reg->ref_obj_id)
verbose_a("ref_id=%d", reg->ref_obj_id);
if (reg->dynptr_id)
verbose_a("dynptr_id=%d", reg->dynptr_id);
verbose(env, ")");
break;
case STACK_ITER:
/* only main slot has ref_obj_id set; skip others */
if (!reg->ref_obj_id)
continue;
verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
print_liveness(env, reg->live);
verbose(env, "=iter_%s(ref_id=%d,state=%s,depth=%u)",
iter_type_str(reg->iter.btf, reg->iter.btf_id),
reg->ref_obj_id, iter_state_str(reg->iter.state),
reg->iter.depth);
break;
case STACK_MISC:
case STACK_ZERO:
default:
verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
print_liveness(env, reg->live);
verbose(env, "=%s", types_buf);
break;
}
}
if (state->acquired_refs && state->refs[0].id) {
verbose(env, " refs=%d", state->refs[0].id);
for (i = 1; i < state->acquired_refs; i++)
if (state->refs[i].id)
verbose(env, ",%d", state->refs[i].id);
}
if (state->in_callback_fn)
verbose(env, " cb");
if (state->in_async_callback_fn)
verbose(env, " async_cb");
verbose(env, "\n");
if (!print_all)
mark_verifier_state_clean(env);
}
static inline u32 vlog_alignment(u32 pos)
{
return round_up(max(pos + BPF_LOG_MIN_ALIGNMENT / 2, BPF_LOG_ALIGNMENT),
BPF_LOG_MIN_ALIGNMENT) - pos - 1;
}
void print_insn_state(struct bpf_verifier_env *env, const struct bpf_func_state *state)
{
if (env->prev_log_pos && env->prev_log_pos == env->log.end_pos) {
/* remove new line character */
bpf_vlog_reset(&env->log, env->prev_log_pos - 1);
verbose(env, "%*c;", vlog_alignment(env->prev_insn_print_pos), ' ');
} else {
verbose(env, "%d:", env->insn_idx);
}
print_verifier_state(env, state, false);
}
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