diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index e4ceee7f2dff4ca0b594511b405a181c75c28bfd..67ca6c69376cd95a030142ee11f2d66778ddc0ec 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -21,7 +21,7 @@ MAP COMMANDS ============= | **bpftool** **prog { show | list }** [*PROG*] -| **bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes**}] +| **bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes** | **visual**}] | **bpftool** **prog dump jited** *PROG* [{**file** *FILE* | **opcodes**}] | **bpftool** **prog pin** *PROG* *FILE* | **bpftool** **prog load** *OBJ* *FILE* @@ -39,12 +39,18 @@ DESCRIPTION Output will start with program ID followed by program type and zero or more named attributes (depending on kernel version). - **bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** }] - Dump eBPF instructions of the program from the kernel. - If *FILE* is specified image will be written to a file, - otherwise it will be disassembled and printed to stdout. + **bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** }] + Dump eBPF instructions of the program from the kernel. By + default, eBPF will be disassembled and printed to standard + output in human-readable format. In this case, **opcodes** + controls if raw opcodes should be printed as well. - **opcodes** controls if raw opcodes will be printed. + If **file** is specified, the binary image will instead be + written to *FILE*. + + If **visual** is specified, control flow graph (CFG) will be + built instead, and eBPF instructions will be presented with + CFG in DOT format, on standard output. **bpftool prog dump jited** *PROG* [{ **file** *FILE* | **opcodes** }] Dump jited image (host machine code) of the program. diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 08719c54a614a19a9eeafd9048d3bd21dd90b706..490811b45fa75c60a470ee5f626df844d23f9e17 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -147,7 +147,7 @@ _bpftool() # Deal with simplest keywords case $prev in - help|key|opcodes) + help|key|opcodes|visual) return 0 ;; tag) @@ -223,11 +223,16 @@ _bpftool() return 0 ;; *) - _bpftool_once_attr 'file' + _bpftool_once_attr 'file' + if _bpftool_search_list 'xlated'; then + COMPREPLY+=( $( compgen -W 'opcodes visual' -- \ + "$cur" ) ) + else COMPREPLY+=( $( compgen -W 'opcodes' -- \ "$cur" ) ) - return 0 - ;; + fi + return 0 + ;; esac ;; pin) diff --git a/tools/bpf/bpftool/cfg.c b/tools/bpf/bpftool/cfg.c new file mode 100644 index 0000000000000000000000000000000000000000..f30b3a4a840b7c460dff6474223b6857e00d47fc --- /dev/null +++ b/tools/bpf/bpftool/cfg.c @@ -0,0 +1,514 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* + * Copyright (C) 2018 Netronome Systems, Inc. + * + * This software is dual licensed under the GNU General License Version 2, + * June 1991 as shown in the file COPYING in the top-level directory of this + * source tree or the BSD 2-Clause License provided below. You have the + * option to license this software under the complete terms of either license. + * + * The BSD 2-Clause License: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * 1. Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * 2. Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include + +#include "cfg.h" +#include "main.h" +#include "xlated_dumper.h" + +struct cfg { + struct list_head funcs; + int func_num; +}; + +struct func_node { + struct list_head l; + struct list_head bbs; + struct bpf_insn *start; + struct bpf_insn *end; + int idx; + int bb_num; +}; + +struct bb_node { + struct list_head l; + struct list_head e_prevs; + struct list_head e_succs; + struct bpf_insn *head; + struct bpf_insn *tail; + int idx; +}; + +#define EDGE_FLAG_EMPTY 0x0 +#define EDGE_FLAG_FALLTHROUGH 0x1 +#define EDGE_FLAG_JUMP 0x2 +struct edge_node { + struct list_head l; + struct bb_node *src; + struct bb_node *dst; + int flags; +}; + +#define ENTRY_BLOCK_INDEX 0 +#define EXIT_BLOCK_INDEX 1 +#define NUM_FIXED_BLOCKS 2 +#define func_prev(func) list_prev_entry(func, l) +#define func_next(func) list_next_entry(func, l) +#define bb_prev(bb) list_prev_entry(bb, l) +#define bb_next(bb) list_next_entry(bb, l) +#define entry_bb(func) func_first_bb(func) +#define exit_bb(func) func_last_bb(func) +#define cfg_first_func(cfg) \ + list_first_entry(&cfg->funcs, struct func_node, l) +#define cfg_last_func(cfg) \ + list_last_entry(&cfg->funcs, struct func_node, l) +#define func_first_bb(func) \ + list_first_entry(&func->bbs, struct bb_node, l) +#define func_last_bb(func) \ + list_last_entry(&func->bbs, struct bb_node, l) + +static struct func_node *cfg_append_func(struct cfg *cfg, struct bpf_insn *insn) +{ + struct func_node *new_func, *func; + + list_for_each_entry(func, &cfg->funcs, l) { + if (func->start == insn) + return func; + else if (func->start > insn) + break; + } + + func = func_prev(func); + new_func = calloc(1, sizeof(*new_func)); + if (!new_func) { + p_err("OOM when allocating FUNC node"); + return NULL; + } + new_func->start = insn; + new_func->idx = cfg->func_num; + list_add(&new_func->l, &func->l); + cfg->func_num++; + + return new_func; +} + +static struct bb_node *func_append_bb(struct func_node *func, + struct bpf_insn *insn) +{ + struct bb_node *new_bb, *bb; + + list_for_each_entry(bb, &func->bbs, l) { + if (bb->head == insn) + return bb; + else if (bb->head > insn) + break; + } + + bb = bb_prev(bb); + new_bb = calloc(1, sizeof(*new_bb)); + if (!new_bb) { + p_err("OOM when allocating BB node"); + return NULL; + } + new_bb->head = insn; + INIT_LIST_HEAD(&new_bb->e_prevs); + INIT_LIST_HEAD(&new_bb->e_succs); + list_add(&new_bb->l, &bb->l); + + return new_bb; +} + +static struct bb_node *func_insert_dummy_bb(struct list_head *after) +{ + struct bb_node *bb; + + bb = calloc(1, sizeof(*bb)); + if (!bb) { + p_err("OOM when allocating BB node"); + return NULL; + } + + INIT_LIST_HEAD(&bb->e_prevs); + INIT_LIST_HEAD(&bb->e_succs); + list_add(&bb->l, after); + + return bb; +} + +static bool cfg_partition_funcs(struct cfg *cfg, struct bpf_insn *cur, + struct bpf_insn *end) +{ + struct func_node *func, *last_func; + + func = cfg_append_func(cfg, cur); + if (!func) + return true; + + for (; cur < end; cur++) { + if (cur->code != (BPF_JMP | BPF_CALL)) + continue; + if (cur->src_reg != BPF_PSEUDO_CALL) + continue; + func = cfg_append_func(cfg, cur + cur->off + 1); + if (!func) + return true; + } + + last_func = cfg_last_func(cfg); + last_func->end = end - 1; + func = cfg_first_func(cfg); + list_for_each_entry_from(func, &last_func->l, l) { + func->end = func_next(func)->start - 1; + } + + return false; +} + +static bool func_partition_bb_head(struct func_node *func) +{ + struct bpf_insn *cur, *end; + struct bb_node *bb; + + cur = func->start; + end = func->end; + INIT_LIST_HEAD(&func->bbs); + bb = func_append_bb(func, cur); + if (!bb) + return true; + + for (; cur <= end; cur++) { + if (BPF_CLASS(cur->code) == BPF_JMP) { + u8 opcode = BPF_OP(cur->code); + + if (opcode == BPF_EXIT || opcode == BPF_CALL) + continue; + + bb = func_append_bb(func, cur + cur->off + 1); + if (!bb) + return true; + + if (opcode != BPF_JA) { + bb = func_append_bb(func, cur + 1); + if (!bb) + return true; + } + } + } + + return false; +} + +static void func_partition_bb_tail(struct func_node *func) +{ + unsigned int bb_idx = NUM_FIXED_BLOCKS; + struct bb_node *bb, *last; + + last = func_last_bb(func); + last->tail = func->end; + bb = func_first_bb(func); + list_for_each_entry_from(bb, &last->l, l) { + bb->tail = bb_next(bb)->head - 1; + bb->idx = bb_idx++; + } + + last->idx = bb_idx++; + func->bb_num = bb_idx; +} + +static bool func_add_special_bb(struct func_node *func) +{ + struct bb_node *bb; + + bb = func_insert_dummy_bb(&func->bbs); + if (!bb) + return true; + bb->idx = ENTRY_BLOCK_INDEX; + + bb = func_insert_dummy_bb(&func_last_bb(func)->l); + if (!bb) + return true; + bb->idx = EXIT_BLOCK_INDEX; + + return false; +} + +static bool func_partition_bb(struct func_node *func) +{ + if (func_partition_bb_head(func)) + return true; + + func_partition_bb_tail(func); + + return false; +} + +static struct bb_node *func_search_bb_with_head(struct func_node *func, + struct bpf_insn *insn) +{ + struct bb_node *bb; + + list_for_each_entry(bb, &func->bbs, l) { + if (bb->head == insn) + return bb; + } + + return NULL; +} + +static struct edge_node *new_edge(struct bb_node *src, struct bb_node *dst, + int flags) +{ + struct edge_node *e; + + e = calloc(1, sizeof(*e)); + if (!e) { + p_err("OOM when allocating edge node"); + return NULL; + } + + if (src) + e->src = src; + if (dst) + e->dst = dst; + + e->flags |= flags; + + return e; +} + +static bool func_add_bb_edges(struct func_node *func) +{ + struct bpf_insn *insn; + struct edge_node *e; + struct bb_node *bb; + + bb = entry_bb(func); + e = new_edge(bb, bb_next(bb), EDGE_FLAG_FALLTHROUGH); + if (!e) + return true; + list_add_tail(&e->l, &bb->e_succs); + + bb = exit_bb(func); + e = new_edge(bb_prev(bb), bb, EDGE_FLAG_FALLTHROUGH); + if (!e) + return true; + list_add_tail(&e->l, &bb->e_prevs); + + bb = entry_bb(func); + bb = bb_next(bb); + list_for_each_entry_from(bb, &exit_bb(func)->l, l) { + e = new_edge(bb, NULL, EDGE_FLAG_EMPTY); + if (!e) + return true; + e->src = bb; + + insn = bb->tail; + if (BPF_CLASS(insn->code) != BPF_JMP || + BPF_OP(insn->code) == BPF_EXIT) { + e->dst = bb_next(bb); + e->flags |= EDGE_FLAG_FALLTHROUGH; + list_add_tail(&e->l, &bb->e_succs); + continue; + } else if (BPF_OP(insn->code) == BPF_JA) { + e->dst = func_search_bb_with_head(func, + insn + insn->off + 1); + e->flags |= EDGE_FLAG_JUMP; + list_add_tail(&e->l, &bb->e_succs); + continue; + } + + e->dst = bb_next(bb); + e->flags |= EDGE_FLAG_FALLTHROUGH; + list_add_tail(&e->l, &bb->e_succs); + + e = new_edge(bb, NULL, EDGE_FLAG_JUMP); + if (!e) + return true; + e->src = bb; + e->dst = func_search_bb_with_head(func, insn + insn->off + 1); + list_add_tail(&e->l, &bb->e_succs); + } + + return false; +} + +static bool cfg_build(struct cfg *cfg, struct bpf_insn *insn, unsigned int len) +{ + int cnt = len / sizeof(*insn); + struct func_node *func; + + INIT_LIST_HEAD(&cfg->funcs); + + if (cfg_partition_funcs(cfg, insn, insn + cnt)) + return true; + + list_for_each_entry(func, &cfg->funcs, l) { + if (func_partition_bb(func) || func_add_special_bb(func)) + return true; + + if (func_add_bb_edges(func)) + return true; + } + + return false; +} + +static void cfg_destroy(struct cfg *cfg) +{ + struct func_node *func, *func2; + + list_for_each_entry_safe(func, func2, &cfg->funcs, l) { + struct bb_node *bb, *bb2; + + list_for_each_entry_safe(bb, bb2, &func->bbs, l) { + struct edge_node *e, *e2; + + list_for_each_entry_safe(e, e2, &bb->e_prevs, l) { + list_del(&e->l); + free(e); + } + + list_for_each_entry_safe(e, e2, &bb->e_succs, l) { + list_del(&e->l); + free(e); + } + + list_del(&bb->l); + free(bb); + } + + list_del(&func->l); + free(func); + } +} + +static void draw_bb_node(struct func_node *func, struct bb_node *bb) +{ + const char *shape; + + if (bb->idx == ENTRY_BLOCK_INDEX || bb->idx == EXIT_BLOCK_INDEX) + shape = "Mdiamond"; + else + shape = "record"; + + printf("\tfn_%d_bb_%d [shape=%s,style=filled,label=\"", + func->idx, bb->idx, shape); + + if (bb->idx == ENTRY_BLOCK_INDEX) { + printf("ENTRY"); + } else if (bb->idx == EXIT_BLOCK_INDEX) { + printf("EXIT"); + } else { + unsigned int start_idx; + struct dump_data dd = {}; + + printf("{"); + kernel_syms_load(&dd); + start_idx = bb->head - func->start; + dump_xlated_for_graph(&dd, bb->head, bb->tail, start_idx); + kernel_syms_destroy(&dd); + printf("}"); + } + + printf("\"];\n\n"); +} + +static void draw_bb_succ_edges(struct func_node *func, struct bb_node *bb) +{ + const char *style = "\"solid,bold\""; + const char *color = "black"; + int func_idx = func->idx; + struct edge_node *e; + int weight = 10; + + if (list_empty(&bb->e_succs)) + return; + + list_for_each_entry(e, &bb->e_succs, l) { + printf("\tfn_%d_bb_%d:s -> fn_%d_bb_%d:n [style=%s, color=%s, weight=%d, constraint=true", + func_idx, e->src->idx, func_idx, e->dst->idx, + style, color, weight); + printf("];\n"); + } +} + +static void func_output_bb_def(struct func_node *func) +{ + struct bb_node *bb; + + list_for_each_entry(bb, &func->bbs, l) { + draw_bb_node(func, bb); + } +} + +static void func_output_edges(struct func_node *func) +{ + int func_idx = func->idx; + struct bb_node *bb; + + list_for_each_entry(bb, &func->bbs, l) { + draw_bb_succ_edges(func, bb); + } + + /* Add an invisible edge from ENTRY to EXIT, this is to + * improve the graph layout. + */ + printf("\tfn_%d_bb_%d:s -> fn_%d_bb_%d:n [style=\"invis\", constraint=true];\n", + func_idx, ENTRY_BLOCK_INDEX, func_idx, EXIT_BLOCK_INDEX); +} + +static void cfg_dump(struct cfg *cfg) +{ + struct func_node *func; + + printf("digraph \"DOT graph for eBPF program\" {\n"); + list_for_each_entry(func, &cfg->funcs, l) { + printf("subgraph \"cluster_%d\" {\n\tstyle=\"dashed\";\n\tcolor=\"black\";\n\tlabel=\"func_%d ()\";\n", + func->idx, func->idx); + func_output_bb_def(func); + func_output_edges(func); + printf("}\n"); + } + printf("}\n"); +} + +void dump_xlated_cfg(void *buf, unsigned int len) +{ + struct bpf_insn *insn = buf; + struct cfg cfg; + + memset(&cfg, 0, sizeof(cfg)); + if (cfg_build(&cfg, insn, len)) + return; + + cfg_dump(&cfg); + + cfg_destroy(&cfg); +} diff --git a/tools/bpf/bpftool/cfg.h b/tools/bpf/bpftool/cfg.h new file mode 100644 index 0000000000000000000000000000000000000000..2cc9bd990b13cb61979dabd7075db751da741927 --- /dev/null +++ b/tools/bpf/bpftool/cfg.h @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* + * Copyright (C) 2018 Netronome Systems, Inc. + * + * This software is dual licensed under the GNU General License Version 2, + * June 1991 as shown in the file COPYING in the top-level directory of this + * source tree or the BSD 2-Clause License provided below. You have the + * option to license this software under the complete terms of either license. + * + * The BSD 2-Clause License: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * 1. Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * 2. Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef __BPF_TOOL_CFG_H +#define __BPF_TOOL_CFG_H + +void dump_xlated_cfg(void *buf, unsigned int len); + +#endif /* __BPF_TOOL_CFG_H */ diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index e549e329be8216646dbab3c11a6485d85d02f1c6..f7a810897eac4cbfd342eac8f75f1f062a6301f8 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -47,8 +47,9 @@ #include #include +#include "cfg.h" #include "main.h" -#include "disasm.h" +#include "xlated_dumper.h" static const char * const prog_type_name[] = { [BPF_PROG_TYPE_UNSPEC] = "unspec", @@ -407,259 +408,6 @@ static int do_show(int argc, char **argv) return err; } -#define SYM_MAX_NAME 256 - -struct kernel_sym { - unsigned long address; - char name[SYM_MAX_NAME]; -}; - -struct dump_data { - unsigned long address_call_base; - struct kernel_sym *sym_mapping; - __u32 sym_count; - char scratch_buff[SYM_MAX_NAME]; -}; - -static int kernel_syms_cmp(const void *sym_a, const void *sym_b) -{ - return ((struct kernel_sym *)sym_a)->address - - ((struct kernel_sym *)sym_b)->address; -} - -static void kernel_syms_load(struct dump_data *dd) -{ - struct kernel_sym *sym; - char buff[256]; - void *tmp, *address; - FILE *fp; - - fp = fopen("/proc/kallsyms", "r"); - if (!fp) - return; - - while (!feof(fp)) { - if (!fgets(buff, sizeof(buff), fp)) - break; - tmp = realloc(dd->sym_mapping, - (dd->sym_count + 1) * - sizeof(*dd->sym_mapping)); - if (!tmp) { -out: - free(dd->sym_mapping); - dd->sym_mapping = NULL; - fclose(fp); - return; - } - dd->sym_mapping = tmp; - sym = &dd->sym_mapping[dd->sym_count]; - if (sscanf(buff, "%p %*c %s", &address, sym->name) != 2) - continue; - sym->address = (unsigned long)address; - if (!strcmp(sym->name, "__bpf_call_base")) { - dd->address_call_base = sym->address; - /* sysctl kernel.kptr_restrict was set */ - if (!sym->address) - goto out; - } - if (sym->address) - dd->sym_count++; - } - - fclose(fp); - - qsort(dd->sym_mapping, dd->sym_count, - sizeof(*dd->sym_mapping), kernel_syms_cmp); -} - -static void kernel_syms_destroy(struct dump_data *dd) -{ - free(dd->sym_mapping); -} - -static struct kernel_sym *kernel_syms_search(struct dump_data *dd, - unsigned long key) -{ - struct kernel_sym sym = { - .address = key, - }; - - return dd->sym_mapping ? - bsearch(&sym, dd->sym_mapping, dd->sym_count, - sizeof(*dd->sym_mapping), kernel_syms_cmp) : NULL; -} - -static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...) -{ - va_list args; - - va_start(args, fmt); - vprintf(fmt, args); - va_end(args); -} - -static const char *print_call_pcrel(struct dump_data *dd, - struct kernel_sym *sym, - unsigned long address, - const struct bpf_insn *insn) -{ - if (sym) - snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), - "%+d#%s", insn->off, sym->name); - else - snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), - "%+d#0x%lx", insn->off, address); - return dd->scratch_buff; -} - -static const char *print_call_helper(struct dump_data *dd, - struct kernel_sym *sym, - unsigned long address) -{ - if (sym) - snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), - "%s", sym->name); - else - snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), - "0x%lx", address); - return dd->scratch_buff; -} - -static const char *print_call(void *private_data, - const struct bpf_insn *insn) -{ - struct dump_data *dd = private_data; - unsigned long address = dd->address_call_base + insn->imm; - struct kernel_sym *sym; - - sym = kernel_syms_search(dd, address); - if (insn->src_reg == BPF_PSEUDO_CALL) - return print_call_pcrel(dd, sym, address, insn); - else - return print_call_helper(dd, sym, address); -} - -static const char *print_imm(void *private_data, - const struct bpf_insn *insn, - __u64 full_imm) -{ - struct dump_data *dd = private_data; - - if (insn->src_reg == BPF_PSEUDO_MAP_FD) - snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), - "map[id:%u]", insn->imm); - else - snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), - "0x%llx", (unsigned long long)full_imm); - return dd->scratch_buff; -} - -static void dump_xlated_plain(struct dump_data *dd, void *buf, - unsigned int len, bool opcodes) -{ - const struct bpf_insn_cbs cbs = { - .cb_print = print_insn, - .cb_call = print_call, - .cb_imm = print_imm, - .private_data = dd, - }; - struct bpf_insn *insn = buf; - bool double_insn = false; - unsigned int i; - - for (i = 0; i < len / sizeof(*insn); i++) { - if (double_insn) { - double_insn = false; - continue; - } - - double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); - - printf("% 4d: ", i); - print_bpf_insn(&cbs, NULL, insn + i, true); - - if (opcodes) { - printf(" "); - fprint_hex(stdout, insn + i, 8, " "); - if (double_insn && i < len - 1) { - printf(" "); - fprint_hex(stdout, insn + i + 1, 8, " "); - } - printf("\n"); - } - } -} - -static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...) -{ - unsigned int l = strlen(fmt); - char chomped_fmt[l]; - va_list args; - - va_start(args, fmt); - if (l > 0) { - strncpy(chomped_fmt, fmt, l - 1); - chomped_fmt[l - 1] = '\0'; - } - jsonw_vprintf_enquote(json_wtr, chomped_fmt, args); - va_end(args); -} - -static void dump_xlated_json(struct dump_data *dd, void *buf, - unsigned int len, bool opcodes) -{ - const struct bpf_insn_cbs cbs = { - .cb_print = print_insn_json, - .cb_call = print_call, - .cb_imm = print_imm, - .private_data = dd, - }; - struct bpf_insn *insn = buf; - bool double_insn = false; - unsigned int i; - - jsonw_start_array(json_wtr); - for (i = 0; i < len / sizeof(*insn); i++) { - if (double_insn) { - double_insn = false; - continue; - } - double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); - - jsonw_start_object(json_wtr); - jsonw_name(json_wtr, "disasm"); - print_bpf_insn(&cbs, NULL, insn + i, true); - - if (opcodes) { - jsonw_name(json_wtr, "opcodes"); - jsonw_start_object(json_wtr); - - jsonw_name(json_wtr, "code"); - jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code); - - jsonw_name(json_wtr, "src_reg"); - jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg); - - jsonw_name(json_wtr, "dst_reg"); - jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg); - - jsonw_name(json_wtr, "off"); - print_hex_data_json((uint8_t *)(&insn[i].off), 2); - - jsonw_name(json_wtr, "imm"); - if (double_insn && i < len - 1) - print_hex_data_json((uint8_t *)(&insn[i].imm), - 12); - else - print_hex_data_json((uint8_t *)(&insn[i].imm), - 4); - jsonw_end_object(json_wtr); - } - jsonw_end_object(json_wtr); - } - jsonw_end_array(json_wtr); -} - static int do_dump(int argc, char **argv) { struct bpf_prog_info info = {}; @@ -668,6 +416,7 @@ static int do_dump(int argc, char **argv) unsigned int buf_size; char *filepath = NULL; bool opcodes = false; + bool visual = false; unsigned char *buf; __u32 *member_len; __u64 *member_ptr; @@ -706,6 +455,9 @@ static int do_dump(int argc, char **argv) } else if (is_prefix(*argv, "opcodes")) { opcodes = true; NEXT_ARG(); + } else if (is_prefix(*argv, "visual")) { + visual = true; + NEXT_ARG(); } if (argc) { @@ -777,27 +529,30 @@ static int do_dump(int argc, char **argv) if (json_output) jsonw_null(json_wtr); - } else { - if (member_len == &info.jited_prog_len) { - const char *name = NULL; - - if (info.ifindex) { - name = ifindex_to_bfd_name_ns(info.ifindex, - info.netns_dev, - info.netns_ino); - if (!name) - goto err_free; - } - - disasm_print_insn(buf, *member_len, opcodes, name); - } else { - kernel_syms_load(&dd); - if (json_output) - dump_xlated_json(&dd, buf, *member_len, opcodes); - else - dump_xlated_plain(&dd, buf, *member_len, opcodes); - kernel_syms_destroy(&dd); + } else if (member_len == &info.jited_prog_len) { + const char *name = NULL; + + if (info.ifindex) { + name = ifindex_to_bfd_name_ns(info.ifindex, + info.netns_dev, + info.netns_ino); + if (!name) + goto err_free; } + + disasm_print_insn(buf, *member_len, opcodes, name); + } else if (visual) { + if (json_output) + jsonw_null(json_wtr); + else + dump_xlated_cfg(buf, *member_len); + } else { + kernel_syms_load(&dd); + if (json_output) + dump_xlated_json(&dd, buf, *member_len, opcodes); + else + dump_xlated_plain(&dd, buf, *member_len, opcodes); + kernel_syms_destroy(&dd); } free(buf); @@ -851,7 +606,7 @@ static int do_help(int argc, char **argv) fprintf(stderr, "Usage: %s %s { show | list } [PROG]\n" - " %s %s dump xlated PROG [{ file FILE | opcodes }]\n" + " %s %s dump xlated PROG [{ file FILE | opcodes | visual }]\n" " %s %s dump jited PROG [{ file FILE | opcodes }]\n" " %s %s pin PROG FILE\n" " %s %s load OBJ FILE\n" diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c new file mode 100644 index 0000000000000000000000000000000000000000..20da835e9e3833df5b43a0c314e5e946478abc0b --- /dev/null +++ b/tools/bpf/bpftool/xlated_dumper.c @@ -0,0 +1,338 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* + * Copyright (C) 2018 Netronome Systems, Inc. + * + * This software is dual licensed under the GNU General License Version 2, + * June 1991 as shown in the file COPYING in the top-level directory of this + * source tree or the BSD 2-Clause License provided below. You have the + * option to license this software under the complete terms of either license. + * + * The BSD 2-Clause License: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * 1. Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * 2. Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include + +#include "disasm.h" +#include "json_writer.h" +#include "main.h" +#include "xlated_dumper.h" + +static int kernel_syms_cmp(const void *sym_a, const void *sym_b) +{ + return ((struct kernel_sym *)sym_a)->address - + ((struct kernel_sym *)sym_b)->address; +} + +void kernel_syms_load(struct dump_data *dd) +{ + struct kernel_sym *sym; + char buff[256]; + void *tmp, *address; + FILE *fp; + + fp = fopen("/proc/kallsyms", "r"); + if (!fp) + return; + + while (!feof(fp)) { + if (!fgets(buff, sizeof(buff), fp)) + break; + tmp = realloc(dd->sym_mapping, + (dd->sym_count + 1) * + sizeof(*dd->sym_mapping)); + if (!tmp) { +out: + free(dd->sym_mapping); + dd->sym_mapping = NULL; + fclose(fp); + return; + } + dd->sym_mapping = tmp; + sym = &dd->sym_mapping[dd->sym_count]; + if (sscanf(buff, "%p %*c %s", &address, sym->name) != 2) + continue; + sym->address = (unsigned long)address; + if (!strcmp(sym->name, "__bpf_call_base")) { + dd->address_call_base = sym->address; + /* sysctl kernel.kptr_restrict was set */ + if (!sym->address) + goto out; + } + if (sym->address) + dd->sym_count++; + } + + fclose(fp); + + qsort(dd->sym_mapping, dd->sym_count, + sizeof(*dd->sym_mapping), kernel_syms_cmp); +} + +void kernel_syms_destroy(struct dump_data *dd) +{ + free(dd->sym_mapping); +} + +static struct kernel_sym *kernel_syms_search(struct dump_data *dd, + unsigned long key) +{ + struct kernel_sym sym = { + .address = key, + }; + + return dd->sym_mapping ? + bsearch(&sym, dd->sym_mapping, dd->sym_count, + sizeof(*dd->sym_mapping), kernel_syms_cmp) : NULL; +} + +static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + vprintf(fmt, args); + va_end(args); +} + +static void +print_insn_for_graph(struct bpf_verifier_env *env, const char *fmt, ...) +{ + char buf[64], *p; + va_list args; + + va_start(args, fmt); + vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + + p = buf; + while (*p != '\0') { + if (*p == '\n') { + memmove(p + 3, p, strlen(buf) + 1 - (p - buf)); + /* Align each instruction dump row left. */ + *p++ = '\\'; + *p++ = 'l'; + /* Output multiline concatenation. */ + *p++ = '\\'; + } else if (*p == '<' || *p == '>' || *p == '|' || *p == '&') { + memmove(p + 1, p, strlen(buf) + 1 - (p - buf)); + /* Escape special character. */ + *p++ = '\\'; + } + + p++; + } + + printf("%s", buf); +} + +static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...) +{ + unsigned int l = strlen(fmt); + char chomped_fmt[l]; + va_list args; + + va_start(args, fmt); + if (l > 0) { + strncpy(chomped_fmt, fmt, l - 1); + chomped_fmt[l - 1] = '\0'; + } + jsonw_vprintf_enquote(json_wtr, chomped_fmt, args); + va_end(args); +} + +static const char *print_call_pcrel(struct dump_data *dd, + struct kernel_sym *sym, + unsigned long address, + const struct bpf_insn *insn) +{ + if (sym) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%+d#%s", insn->off, sym->name); + else + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%+d#0x%lx", insn->off, address); + return dd->scratch_buff; +} + +static const char *print_call_helper(struct dump_data *dd, + struct kernel_sym *sym, + unsigned long address) +{ + if (sym) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%s", sym->name); + else + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "0x%lx", address); + return dd->scratch_buff; +} + +static const char *print_call(void *private_data, + const struct bpf_insn *insn) +{ + struct dump_data *dd = private_data; + unsigned long address = dd->address_call_base + insn->imm; + struct kernel_sym *sym; + + sym = kernel_syms_search(dd, address); + if (insn->src_reg == BPF_PSEUDO_CALL) + return print_call_pcrel(dd, sym, address, insn); + else + return print_call_helper(dd, sym, address); +} + +static const char *print_imm(void *private_data, + const struct bpf_insn *insn, + __u64 full_imm) +{ + struct dump_data *dd = private_data; + + if (insn->src_reg == BPF_PSEUDO_MAP_FD) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "map[id:%u]", insn->imm); + else + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "0x%llx", (unsigned long long)full_imm); + return dd->scratch_buff; +} + +void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, + bool opcodes) +{ + const struct bpf_insn_cbs cbs = { + .cb_print = print_insn_json, + .cb_call = print_call, + .cb_imm = print_imm, + .private_data = dd, + }; + struct bpf_insn *insn = buf; + bool double_insn = false; + unsigned int i; + + jsonw_start_array(json_wtr); + for (i = 0; i < len / sizeof(*insn); i++) { + if (double_insn) { + double_insn = false; + continue; + } + double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); + + jsonw_start_object(json_wtr); + jsonw_name(json_wtr, "disasm"); + print_bpf_insn(&cbs, NULL, insn + i, true); + + if (opcodes) { + jsonw_name(json_wtr, "opcodes"); + jsonw_start_object(json_wtr); + + jsonw_name(json_wtr, "code"); + jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code); + + jsonw_name(json_wtr, "src_reg"); + jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg); + + jsonw_name(json_wtr, "dst_reg"); + jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg); + + jsonw_name(json_wtr, "off"); + print_hex_data_json((uint8_t *)(&insn[i].off), 2); + + jsonw_name(json_wtr, "imm"); + if (double_insn && i < len - 1) + print_hex_data_json((uint8_t *)(&insn[i].imm), + 12); + else + print_hex_data_json((uint8_t *)(&insn[i].imm), + 4); + jsonw_end_object(json_wtr); + } + jsonw_end_object(json_wtr); + } + jsonw_end_array(json_wtr); +} + +void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, + bool opcodes) +{ + const struct bpf_insn_cbs cbs = { + .cb_print = print_insn, + .cb_call = print_call, + .cb_imm = print_imm, + .private_data = dd, + }; + struct bpf_insn *insn = buf; + bool double_insn = false; + unsigned int i; + + for (i = 0; i < len / sizeof(*insn); i++) { + if (double_insn) { + double_insn = false; + continue; + } + + double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); + + printf("% 4d: ", i); + print_bpf_insn(&cbs, NULL, insn + i, true); + + if (opcodes) { + printf(" "); + fprint_hex(stdout, insn + i, 8, " "); + if (double_insn && i < len - 1) { + printf(" "); + fprint_hex(stdout, insn + i + 1, 8, " "); + } + printf("\n"); + } + } +} + +void dump_xlated_for_graph(struct dump_data *dd, void *buf_start, void *buf_end, + unsigned int start_idx) +{ + const struct bpf_insn_cbs cbs = { + .cb_print = print_insn_for_graph, + .cb_call = print_call, + .cb_imm = print_imm, + .private_data = dd, + }; + struct bpf_insn *insn_start = buf_start; + struct bpf_insn *insn_end = buf_end; + struct bpf_insn *cur = insn_start; + + for (; cur <= insn_end; cur++) { + printf("% 4d: ", (int)(cur - insn_start + start_idx)); + print_bpf_insn(&cbs, NULL, cur, true); + if (cur != insn_end) + printf(" | "); + } +} diff --git a/tools/bpf/bpftool/xlated_dumper.h b/tools/bpf/bpftool/xlated_dumper.h new file mode 100644 index 0000000000000000000000000000000000000000..51c935d38ae2bdfa1bb0bd325e38bfba8ffe1d70 --- /dev/null +++ b/tools/bpf/bpftool/xlated_dumper.h @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* + * Copyright (C) 2018 Netronome Systems, Inc. + * + * This software is dual licensed under the GNU General License Version 2, + * June 1991 as shown in the file COPYING in the top-level directory of this + * source tree or the BSD 2-Clause License provided below. You have the + * option to license this software under the complete terms of either license. + * + * The BSD 2-Clause License: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * 1. Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * 2. Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef __BPF_TOOL_XLATED_DUMPER_H +#define __BPF_TOOL_XLATED_DUMPER_H + +#define SYM_MAX_NAME 256 + +struct kernel_sym { + unsigned long address; + char name[SYM_MAX_NAME]; +}; + +struct dump_data { + unsigned long address_call_base; + struct kernel_sym *sym_mapping; + __u32 sym_count; + char scratch_buff[SYM_MAX_NAME]; +}; + +void kernel_syms_load(struct dump_data *dd); +void kernel_syms_destroy(struct dump_data *dd); +void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, + bool opcodes); +void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, + bool opcodes); +void dump_xlated_for_graph(struct dump_data *dd, void *buf, void *buf_end, + unsigned int start_index); + +#endif