Commit 531b014e authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Daniel Borkmann
Browse files

tools: bpf: make use of reallocarray 



reallocarray() is a safer variant of realloc which checks for
multiplication overflow in case of array allocation.  Since it's
not available in Glibc < 2.26 import kernel's overflow.h and
add a static inline implementation when needed.  Use feature
detection to probe for existence of reallocarray.

Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: default avatarJiong Wang <jiong.wang@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 8d13406c

tools/bpf/bpftool/Makefile

+5 −1
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ INSTALL ?= install 
RM ?= rm -f



FEATURE_USER = .bpftool

FEATURE_TESTS = libbfd disassembler-four-args

FEATURE_TESTS = libbfd disassembler-four-args reallocarray

FEATURE_DISPLAY = libbfd disassembler-four-args



check_feat := 1
@@ -75,6 +75,10 @@ ifeq ($(feature-disassembler-four-args), 1) 
CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE

endif



ifeq ($(feature-reallocarray), 0)

CFLAGS += -DCOMPAT_NEED_REALLOCARRAY

endif



include $(wildcard $(OUTPUT)*.d)



all: $(OUTPUT)bpftool

tools/bpf/bpftool/main.h

+1 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 
#include <linux/compiler.h>

#include <linux/kernel.h>

#include <linux/hashtable.h>

#include <tools/libc_compat.h>



#include "json_writer.h"

tools/bpf/bpftool/xlated_dumper.c

+3 −3
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
 * POSSIBILITY OF SUCH DAMAGE.

 */



#define _GNU_SOURCE

#include <stdarg.h>

#include <stdio.h>

#include <stdlib.h>
@@ -66,8 +67,7 @@ void kernel_syms_load(struct dump_data *dd) 
	while (!feof(fp)) {

		if (!fgets(buff, sizeof(buff), fp))

			break;

		tmp = realloc(dd->sym_mapping,

			      (dd->sym_count + 1) *

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

				   sizeof(*dd->sym_mapping));

		if (!tmp) {

out:

tools/build/feature/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ FILES= \ 
         test-libaudit.bin                      \

         test-libbfd.bin                        \

         test-disassembler-four-args.bin        \

         test-reallocarray.bin			\

         test-liberty.bin                       \

         test-liberty-z.bin                     \

         test-cplus-demangle.bin                \
@@ -204,6 +205,9 @@ $(OUTPUT)test-libbfd.bin: 
$(OUTPUT)test-disassembler-four-args.bin:

	$(BUILD) -DPACKAGE='"perf"' -lbfd -lopcodes



$(OUTPUT)test-reallocarray.bin:

	$(BUILD)



$(OUTPUT)test-liberty.bin:

	$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty

tools/build/feature/test-reallocarray.c

0 → 100644
+8 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#define _GNU_SOURCE

#include <stdlib.h>



int main(void)

{

	return !!reallocarray(NULL, 1, 1);

}

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