Commit a19df713 authored by Mauricio Vásquez's avatar Mauricio Vásquez Committed by Andrii Nakryiko
Browse files

bpftool: Remove usage of reallocarray() 



This commit fixes a compilation error on systems with glibc < 2.26 [0]:

```
In file included from main.h:14:0,
                 from gen.c:24:
linux/tools/include/tools/libc_compat.h:11:21: error: attempt to use poisoned "reallocarray"
 static inline void *reallocarray(void *ptr, size_t nmemb, size_t size)
```

This happens because gen.c pulls <bpf/libbpf_internal.h>, and then
<tools/libc_compat.h> (through main.h). When
COMPAT_NEED_REALLOCARRAY is set, libc_compat.h defines reallocarray()
which libbpf_internal.h poisons with a GCC pragma.

This commit reuses libbpf_reallocarray() implemented in commit
029258d7 ("libbpf: Remove any use of reallocarray() in libbpf").

v1 -> v2:
- reuse libbpf_reallocarray() instead of reimplementing it

Fixes: a9caaba3 ("bpftool: Implement "gen min_core_btf" logic")
Reported-by: default avatarQuentin Monnet <quentin@isovalent.com>
Signed-off-by: default avatarMauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Reviewed-by: default avatarQuentin Monnet <quentin@isovalent.com>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220221125617.39610-1-mauricio@kinvolk.io

[0]: https://lore.kernel.org/bpf/3bf2bd49-9f2d-a2df-5536-bc0dde70a83b@isovalent.com/
parent b4f72786

tools/bpf/bpftool/Makefile

+1 −5
Original line number Diff line number Diff line
@@ -93,7 +93,7 @@ INSTALL ?= install 
RM ?= rm -f



FEATURE_USER = .bpftool

FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib libcap \

FEATURE_TESTS = libbfd disassembler-four-args zlib libcap \

	clang-bpf-co-re

FEATURE_DISPLAY = libbfd disassembler-four-args zlib libcap \

	clang-bpf-co-re
@@ -118,10 +118,6 @@ ifeq ($(feature-disassembler-four-args), 1) 
CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE

endif



ifeq ($(feature-reallocarray), 0)

CFLAGS += -DCOMPAT_NEED_REALLOCARRAY

endif



LIBS = $(LIBBPF) -lelf -lz

LIBS_BOOTSTRAP = $(LIBBPF_BOOTSTRAP) -lelf -lz

ifeq ($(feature-libcap), 1)

tools/bpf/bpftool/main.h

+1 −1
Original line number Diff line number Diff line
@@ -8,10 +8,10 @@ 
#undef GCC_VERSION

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <linux/bpf.h>

#include <linux/compiler.h>

#include <linux/kernel.h>

#include <tools/libc_compat.h>



#include <bpf/hashmap.h>

#include <bpf/libbpf.h>

tools/bpf/bpftool/prog.c

+4 −3
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <bpf/btf.h>

#include <bpf/hashmap.h>

#include <bpf/libbpf.h>

#include <bpf/libbpf_internal.h>

#include <bpf/skel_internal.h>



#include "cfg.h"
@@ -1558,7 +1559,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) 
			if (fd < 0)

				goto err_free_reuse_maps;



			new_map_replace = reallocarray(map_replace,

			new_map_replace = libbpf_reallocarray(map_replace,

							      old_map_fds + 1,

							      sizeof(*map_replace));

			if (!new_map_replace) {

tools/bpf/bpftool/xlated_dumper.c

+3 −2
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <string.h>

#include <sys/types.h>

#include <bpf/libbpf.h>

#include <bpf/libbpf_internal.h>



#include "disasm.h"

#include "json_writer.h"
@@ -32,7 +33,7 @@ void kernel_syms_load(struct dump_data *dd) 
		return;



	while (fgets(buff, sizeof(buff), fp)) {

		tmp = reallocarray(dd->sym_mapping, dd->sym_count + 1,

		tmp = libbpf_reallocarray(dd->sym_mapping, dd->sym_count + 1,

					  sizeof(*dd->sym_mapping));

		if (!tmp) {

out: