Re: [PATCH bpf-next v4 2/3] bpf: btf: add btf print functionality
From: Jakub Kicinski <hidden>
Date: 2018-07-11 19:10:23
Also in:
lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [tooling] (bpftool), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Quentin Monnet, Linus Torvalds
Thank you for all the changes made so far. On Tue, 10 Jul 2018 20:21:10 -0700, Okash Khawaja wrote:
quoted hunk ↗ jump to hunk
--- /dev/null +++ b/tools/bpf/bpftool/btf_dumper.c@@ -0,0 +1,248 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2018 Facebook */ + +#include <linux/btf.h> +#include <linux/err.h> +#include <stdio.h> /* for (FILE *) used by json_writer */ +#include <linux/bitops.h> +#include <string.h> +#include <ctype.h>
Again, please sort the headers the way I suggested. Otherwise as the list of includes grows it's hard to know what's already there.
+#include "btf.h"
+#include "json_writer.h"
+#include "main.h"
+
+#define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
+#define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
+#define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
+#define BITS_ROUNDUP_BYTES(bits) \
+ (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
+
+static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
+ __u8 bit_offset, const void *data);
+
+static void btf_dumper_ptr(const void *data, json_writer_t *jw,
+ bool is_plain_text)
+{
+ if (is_plain_text)
+ jsonw_printf(jw, "%p", *((unsigned long *)data));
+ else
+ jsonw_printf(jw, "%u", *((unsigned long *)data));Again, please drop the extraneous parens.
+} +
+static void btf_dumper_int_bits(__u32 int_type, __u8 bit_offset,
+ const void *data, json_writer_t *jw,
+ bool is_plain_text)
+{
+ int left_shift_bits, right_shift_bits;
+ int nr_bits = BTF_INT_BITS(int_type);
+ int total_bits_offset;
+ int bytes_to_copy;
+ int bits_to_copy;
+ __u64 print_num;
+
+ total_bits_offset = bit_offset + BTF_INT_OFFSET(int_type);
+ data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
+ bit_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
+ bits_to_copy = bit_offset + nr_bits;
+ bytes_to_copy = BITS_ROUNDUP_BYTES(bits_to_copy);
+
+ print_num = 0;
+ memcpy(&print_num, data, bytes_to_copy);
+#ifdef __BIG_ENDIAN_BITFIELD
+ left_shift_bits = bit_offset;
+#else
+ left_shift_bits = 64 - bits_to_copy;
+#endif
+ right_shift_bits = 64 - nr_bits;Please include <asm/byteorder.h> as I suggested to you previously. This is dead code right now, look: $ git diff
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index c64465094b92..045add07b721 100644
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c@@ -91,7 +91,8 @@ static void btf_dumper_int_bits(__u32 int_type, __u8 bit_offset, print_num = 0; memcpy(&print_num, data, bytes_to_copy); -#ifdef __BIG_ENDIAN_BITFIELD +#ifndef __LITTLE_ENDIAN_BITFIELD +#error "abc" left_shift_bits = bit_offset; #else left_shift_bits = 64 - bits_to_copy;
$ make -C tools/bpf/bpftool/ CC=gcc-8 make: Entering directory '/home/jkicinski/devel/linux/tools/bpf/bpftool' CC btf_dumper.o btf_dumper.c: In function ‘btf_dumper_int_bits’: btf_dumper.c:95:2: error: #error "abc" #error "abc" ^~~~~ Makefile:96: recipe for target 'btf_dumper.o' failed make: *** [btf_dumper.o] Error 1 make: Leaving directory '/home/jkicinski/devel/linux/tools/bpf/bpftool'