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Message-Id: <20171005153422.8947-4-jakub.kicinski@netronome.com>
Date: Thu, 5 Oct 2017 08:34:20 -0700
From: Jakub Kicinski <jakub.kicinski@...ronome.com>
To: netdev@...r.kernel.org
Cc: alexei.starovoitov@...il.com, daniel@...earbox.net,
oss-drivers@...ronome.com,
Jakub Kicinski <jakub.kicinski@...ronome.com>
Subject: [PATCH net-next 3/5] tools: bpftool: use the kernel's instruction printer
Compile the instruction printer from kernel/bpf and use it
for disassembling "translated" eBPF code.
Signed-off-by: Jakub Kicinski <jakub.kicinski@...ronome.com>
Reviewed-by: Simon Horman <simon.horman@...ronome.com>
---
tools/bpf/bpftool/Documentation/bpftool-prog.rst | 11 +++---
tools/bpf/bpftool/Makefile | 7 ++--
tools/bpf/bpftool/main.h | 10 ++----
tools/bpf/bpftool/prog.c | 44 +++++++++++++++++++-----
4 files changed, 51 insertions(+), 21 deletions(-)
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index 57fc4b9924ea..04d12f768f06 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -11,7 +11,7 @@ SYNOPSIS
========
| **bpftool** prog show [*PROG*]
-| **bpftool** prog dump xlated *PROG* file *FILE*
+| **bpftool** prog dump xlated *PROG* [file *FILE*] [opcodes]
| **bpftool** prog dump jited *PROG* [file *FILE*] [opcodes]
| **bpftool** prog pin *PROG* *FILE*
| **bpftool** prog help
@@ -28,9 +28,12 @@ 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*
- Dump eBPF instructions of the program from the kernel to a
- file.
+ **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.
+
+ **opcodes** controls if raw opcodes will be printed.
**bpftool prog dump jited** *PROG* [**file** *FILE*] [**opcodes**]
Dump jited image (host machine code) of the program.
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 8705ee44664d..4f339824ca57 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -51,7 +51,7 @@ CC = gcc
CFLAGS += -O2
CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wshadow
-CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi -I$(srctree)/tools/include -I$(srctree)/tools/lib/bpf
+CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi -I$(srctree)/tools/include -I$(srctree)/tools/lib/bpf -I$(srctree)/kernel/bpf/
LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
include $(wildcard *.d)
@@ -59,7 +59,10 @@ include $(wildcard *.d)
all: $(OUTPUT)bpftool
SRCS=$(wildcard *.c)
-OBJS=$(patsubst %.c,$(OUTPUT)%.o,$(SRCS))
+OBJS=$(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
+
+$(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c
+ $(QUIET_CC)$(COMPILE.c) -MMD -o $@ $<
$(OUTPUT)bpftool: $(OBJS) $(LIBBPF)
$(QUIET_LINK)$(CC) $(CFLAGS) -o $@ $^ $(LIBS)
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 85d2d7870a58..8e809b2bb311 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -36,11 +36,12 @@
#ifndef __BPF_TOOL_H
#define __BPF_TOOL_H
+/* BFD and kernel.h both define GCC_VERSION, differently */
+#undef GCC_VERSION
#include <stdbool.h>
#include <stdio.h>
#include <linux/bpf.h>
-
-#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
+#include <linux/kernel.h>
#define err(msg...) fprintf(stderr, "Error: " msg)
#define warn(msg...) fprintf(stderr, "Warning: " msg)
@@ -48,11 +49,6 @@
#define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr))
-#define min(a, b) \
- ({ typeof(a) _a = (a); typeof(b) _b = (b); _a > _b ? _b : _a; })
-#define max(a, b) \
- ({ typeof(a) _a = (a); typeof(b) _b = (b); _a < _b ? _b : _a; })
-
#define NEXT_ARG() ({ argc--; argv++; if (argc < 0) usage(); })
#define NEXT_ARGP() ({ (*argc)--; (*argv)++; if (*argc < 0) usage(); })
#define BAD_ARG() ({ err("what is '%s'?\n", *argv); -1; })
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 421ba89ce86a..9e2681c83717 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -35,6 +35,7 @@
#include <errno.h>
#include <fcntl.h>
+#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -46,6 +47,7 @@
#include <bpf.h>
#include "main.h"
+#include "disasm.h"
static const char * const prog_type_name[] = {
[BPF_PROG_TYPE_UNSPEC] = "unspec",
@@ -297,11 +299,39 @@ static int do_show(int argc, char **argv)
return 0;
}
+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 dump_xlated(void *buf, unsigned int len, bool opcodes)
+{
+ struct bpf_insn *insn = buf;
+ unsigned int i;
+
+ for (i = 0; i < len / sizeof(*insn); i++) {
+ printf("% 4d: ", i);
+ print_bpf_insn(print_insn, NULL, insn + i, true);
+
+ if (opcodes) {
+ printf(" ");
+ print_hex(insn + i, 8, " ");
+ printf("\n");
+ }
+
+ if (insn[i].code == (BPF_LD | BPF_IMM | BPF_DW))
+ i++;
+ }
+}
+
static int do_dump(int argc, char **argv)
{
struct bpf_prog_info info = {};
__u32 len = sizeof(info);
- bool can_disasm = false;
unsigned int buf_size;
char *filepath = NULL;
bool opcodes = false;
@@ -315,7 +345,6 @@ static int do_dump(int argc, char **argv)
if (is_prefix(*argv, "jited")) {
member_len = &info.jited_prog_len;
member_ptr = &info.jited_prog_insns;
- can_disasm = true;
} else if (is_prefix(*argv, "xlated")) {
member_len = &info.xlated_prog_len;
member_ptr = &info.xlated_prog_insns;
@@ -346,10 +375,6 @@ static int do_dump(int argc, char **argv)
NEXT_ARG();
}
- if (!filepath && !can_disasm) {
- err("expected 'file' got %s\n", *argv);
- return -1;
- }
if (argc) {
usage();
return -1;
@@ -409,7 +434,10 @@ static int do_dump(int argc, char **argv)
goto err_free;
}
} else {
- disasm_print_insn(buf, *member_len, opcodes);
+ if (member_len == &info.jited_prog_len)
+ disasm_print_insn(buf, *member_len, opcodes);
+ else
+ dump_xlated(buf, *member_len, opcodes);
}
free(buf);
@@ -430,7 +458,7 @@ static int do_help(int argc, char **argv)
{
fprintf(stderr,
"Usage: %s %s show [PROG]\n"
- " %s %s dump xlated PROG file FILE\n"
+ " %s %s dump xlated PROG [file FILE] [opcodes]\n"
" %s %s dump jited PROG [file FILE] [opcodes]\n"
" %s %s pin PROG FILE\n"
" %s %s help\n"
--
2.14.1
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