tools/bpf/bpftool/xlated_dumper.c - linux - Git at Google

 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 /* Copyright (C) 2018 Netronome Systems, Inc. */

 #define _GNU_SOURCE
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
 #include <bpf/libbpf.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 (fgets(buff, sizeof(buff), fp)) {
 		tmp = reallocarray(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);
 }

 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 __printf(2, 3) print_insn(void *private_data, const char *fmt, ...)
 {
 	va_list args;

 	va_start(args, fmt);
 	vprintf(fmt, args);
 	va_end(args);
 }

 static void __printf(2, 3)
 print_insn_for_graph(void *private_data, 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 __printf(2, 3)
 print_insn_json(void *private_data, 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 (!dd->nr_jited_ksyms)
 		/* Do not show address for interpreted programs */
 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
 			"%+d", insn->off);
 	else 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;

 	if (insn->src_reg == BPF_PSEUDO_CALL &&
 	    (__u32) insn->imm < dd->nr_jited_ksyms && dd->jited_ksyms)
 		address = dd->jited_ksyms[insn->imm];

 	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 if (insn->src_reg == BPF_PSEUDO_MAP_VALUE)
 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
 			 "map[id:%u][0]+%u", insn->imm, (insn + 1)->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, bool linum)
 {
 	const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
 	const struct bpf_insn_cbs cbs = {
 		.cb_print	= print_insn_json,
 		.cb_call	= print_call,
 		.cb_imm		= print_imm,
 		.private_data	= dd,
 	};
 	struct bpf_func_info *record;
 	struct bpf_insn *insn = buf;
 	struct btf *btf = dd->btf;
 	bool double_insn = false;
 	unsigned int nr_skip = 0;
 	char func_sig[1024];
 	unsigned int i;

 	jsonw_start_array(json_wtr);
 	record = dd->func_info;
 	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);

 		if (btf && record) {
 			if (record->insn_off == i) {
 				btf_dumper_type_only(btf, record->type_id,
 						     func_sig,
 						     sizeof(func_sig));
 				if (func_sig[0] != '\0') {
 					jsonw_name(json_wtr, "proto");
 					jsonw_string(json_wtr, func_sig);
 				}
 				record = (void *)record + dd->finfo_rec_size;
 			}
 		}

 		if (prog_linfo) {
 			const struct bpf_line_info *linfo;

 			linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip);
 			if (linfo) {
 				btf_dump_linfo_json(btf, linfo, linum);
 				nr_skip++;
 			}
 		}

 		jsonw_name(json_wtr, "disasm");
 		print_bpf_insn(&cbs, 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, bool linum)
 {
 	const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
 	const struct bpf_insn_cbs cbs = {
 		.cb_print	= print_insn,
 		.cb_call	= print_call,
 		.cb_imm		= print_imm,
 		.private_data	= dd,
 	};
 	struct bpf_func_info *record;
 	struct bpf_insn *insn = buf;
 	struct btf *btf = dd->btf;
 	unsigned int nr_skip = 0;
 	bool double_insn = false;
 	char func_sig[1024];
 	unsigned int i;

 	record = dd->func_info;
 	for (i = 0; i < len / sizeof(*insn); i++) {
 		if (double_insn) {
 			double_insn = false;
 			continue;
 		}

 		if (btf && record) {
 			if (record->insn_off == i) {
 				btf_dumper_type_only(btf, record->type_id,
 						     func_sig,
 						     sizeof(func_sig));
 				if (func_sig[0] != '\0')
 					printf("%s:\n", func_sig);
 				record = (void *)record + dd->finfo_rec_size;
 			}
 		}

 		if (prog_linfo) {
 			const struct bpf_line_info *linfo;

 			linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip);
 			if (linfo) {
 				btf_dump_linfo_plain(btf, linfo, "; ",
 						     linum);
 				nr_skip++;
 			}
 		}

 		double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);

 		printf("% 4d: ", i);
 		print_bpf_insn(&cbs, 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, cur, true);
 		if (cur != insn_end)
 			printf(" | ");
 	}
 }
	// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
	/* Copyright (C) 2018 Netronome Systems, Inc. */

	#define _GNU_SOURCE
	#include <stdarg.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/types.h>
	#include <bpf/libbpf.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 (fgets(buff, sizeof(buff), fp)) {
	tmp = reallocarray(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);
	}

	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 __printf(2, 3) print_insn(void private_data, const char fmt, ...)
	{
	va_list args;

	va_start(args, fmt);
	vprintf(fmt, args);
	va_end(args);
	}

	static void __printf(2, 3)
	print_insn_for_graph(void private_data, 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 __printf(2, 3)
	print_insn_json(void private_data, 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 (!dd->nr_jited_ksyms)
	/* Do not show address for interpreted programs */
	snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
	"%+d", insn->off);
	else 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;

	if (insn->src_reg == BPF_PSEUDO_CALL &&
	(__u32) insn->imm < dd->nr_jited_ksyms && dd->jited_ksyms)
	address = dd->jited_ksyms[insn->imm];

	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 if (insn->src_reg == BPF_PSEUDO_MAP_VALUE)
	snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
	"map[id:%u][0]+%u", insn->imm, (insn + 1)->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, bool linum)
	{
	const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
	const struct bpf_insn_cbs cbs = {
	.cb_print = print_insn_json,
	.cb_call = print_call,
	.cb_imm = print_imm,
	.private_data = dd,
	};
	struct bpf_func_info *record;
	struct bpf_insn *insn = buf;
	struct btf *btf = dd->btf;
	bool double_insn = false;
	unsigned int nr_skip = 0;
	char func_sig[1024];
	unsigned int i;

	jsonw_start_array(json_wtr);
	record = dd->func_info;
	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);

	if (btf && record) {
	if (record->insn_off == i) {
	btf_dumper_type_only(btf, record->type_id,
	func_sig,
	sizeof(func_sig));
	if (func_sig[0] != '\0') {
	jsonw_name(json_wtr, "proto");
	jsonw_string(json_wtr, func_sig);
	}
	record = (void *)record + dd->finfo_rec_size;
	}
	}

	if (prog_linfo) {
	const struct bpf_line_info *linfo;

	linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip);
	if (linfo) {
	btf_dump_linfo_json(btf, linfo, linum);
	nr_skip++;
	}
	}

	jsonw_name(json_wtr, "disasm");
	print_bpf_insn(&cbs, 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, bool linum)
	{
	const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
	const struct bpf_insn_cbs cbs = {
	.cb_print = print_insn,
	.cb_call = print_call,
	.cb_imm = print_imm,
	.private_data = dd,
	};
	struct bpf_func_info *record;
	struct bpf_insn *insn = buf;
	struct btf *btf = dd->btf;
	unsigned int nr_skip = 0;
	bool double_insn = false;
	char func_sig[1024];
	unsigned int i;

	record = dd->func_info;
	for (i = 0; i < len / sizeof(*insn); i++) {
	if (double_insn) {
	double_insn = false;
	continue;
	}

	if (btf && record) {
	if (record->insn_off == i) {
	btf_dumper_type_only(btf, record->type_id,
	func_sig,
	sizeof(func_sig));
	if (func_sig[0] != '\0')
	printf("%s:\n", func_sig);
	record = (void *)record + dd->finfo_rec_size;
	}
	}

	if (prog_linfo) {
	const struct bpf_line_info *linfo;

	linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip);
	if (linfo) {
	btf_dump_linfo_plain(btf, linfo, "; ",
	linum);
	nr_skip++;
	}
	}

	double_insn = insn[i].code == (BPF_LD \| BPF_IMM \| BPF_DW);

	printf("% 4d: ", i);
	print_bpf_insn(&cbs, 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, cur, true);
	if (cur != insn_end)
	printf(" \| ");
	}
	}