Merge branch 'bpftool-visualization'

Jakub Kicinski says:

====================
Jiong says:

This patch set is an application of CFG information on eBPF program
visualization. It presents some initial code for building CFG information
from eBPF instruction sequences.

After we get eBPF program bytecode, we do sub-program detection and
basic-block partition. These information then are visualized into DOT
graph.

The user could use any DOT graphic tools (xdot, graphviz etc) to view it.

For example:

  bpftool prog dump xlated id 2 visual &>output.dot

  [xdot | dotty] output.dot
  dot -Tpng -o output.png

This initial patch set hasn't tuned much on the dot description layout
nor decoration, we could improve them later once the direction of the patch
set is agreed on. We could also visualize some static analysis performance
data.

v2 (Jakub):
 - update license headers and add SPDX tags.
====================
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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.

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)
@@ -224,8 +224,13 @@ _bpftool()
                             ;;
                     *)
                         _bpftool_once_attr 'file'
+                        if _bpftool_search_list 'xlated'; then
+                            COMPREPLY+=( $( compgen -W 'opcodes visual' -- \
+                                "$cur" ) )
+                        else
                             COMPREPLY+=( $( compgen -W 'opcodes' -- \
                                 "$cur" ) )
+                        fi
                         return 0
                         ;;
                     esac

tools/bpf/bpftool/cfg.c

+// 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 <linux/list.h>
+#include <stdlib.h>
+#include <string.h>
+
+#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);
+}

tools/bpf/bpftool/cfg.h

+// 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 */

tools/bpf/bpftool/prog.c

@@ -47,8 +47,9 @@
 #include <bpf.h>
 #include <libbpf.h>
 
+#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) {
@@ -777,8 +529,7 @@ static int do_dump(int argc, char **argv)
 
 		if (json_output)
 			jsonw_null(json_wtr);
-	} else {
-		if (member_len == &info.jited_prog_len) {
+	} else if (member_len == &info.jited_prog_len) {
 		const char *name = NULL;
 
 		if (info.ifindex) {
@@ -790,6 +541,11 @@ static int do_dump(int argc, char **argv)
 		}
 
 		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)
@@ -798,7 +554,6 @@ static int do_dump(int argc, char **argv)
 			dump_xlated_plain(&dd, buf, *member_len, opcodes);
 		kernel_syms_destroy(&dd);
 	}
-	}
 
 	free(buf);
 	return 0;
@@ -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"

tools/bpf/bpftool/xlated_dumper.c

+// 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 <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#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(" | ");
+	}
+}

tools/bpf/bpftool/xlated_dumper.h

+// 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