diff options
Diffstat (limited to 'kernel/bpf/log.c')
| -rw-r--r-- | kernel/bpf/log.c | 880 |
1 files changed, 880 insertions, 0 deletions
diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c new file mode 100644 index 000000000000..38050f4ee400 --- /dev/null +++ b/kernel/bpf/log.c @@ -0,0 +1,880 @@ +// 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', + [STACK_IRQ_FLAG] = 'f' +}; + +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)) { + verbose_snum(env, reg->var_off.value); + 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_verifier_state *vstate, + u32 frameno, bool print_all) +{ + const struct bpf_func_state *state = vstate->frame[frameno]; + 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 (vstate->acquired_refs && vstate->refs[0].id) { + verbose(env, " refs=%d", vstate->refs[0].id); + for (i = 1; i < vstate->acquired_refs; i++) + if (vstate->refs[i].id) + verbose(env, ",%d", vstate->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_verifier_state *vstate, + u32 frameno) +{ + 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, vstate, frameno, false); +} |