Commit 19011398 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'bpf-specify-access-type-of-bpf_sysctl_get_name-args' 

Jerome Marchand says:

====================
bpf: Specify access type of bpf_sysctl_get_name args

The second argument of bpf_sysctl_get_name() helper is a pointer to a
buffer that is being written to. However that isn't specify in the
prototype. Until commit 37cce22d ("bpf: verifier: Refactor helper
access type tracking") that mistake was hidden by the way the verifier
treated helper accesses. Since then, the verifier, working on wrong
infromation from the prototype, can make faulty optimization that
would had been caught by the test_sysctl selftests if it was run by
the CI.

The first patch fixes bpf_sysctl_get_name prototype.

The second patch converts the test_sysctl to prog_tests so that it
will be run by the CI and catch similar issues in the future.

Changes in v3:
 - Use ASSERT* macro instead of CHECK_FAIL.
 - Remove useless code.

Changes in v2:
 - Replace ARG_PTR_TO_UNINIT_MEM by ARG_PTR_TO_MEM | MEM_WRITE.
 - Converts test_sysctl to prog_tests.
====================

Link: https://patch.msgid.link/20250619140603.148942-1-jmarchan@redhat.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents aa485e87 b8a20548

kernel/bpf/cgroup.c

+1 −1
Original line number Diff line number Diff line
@@ -2134,7 +2134,7 @@ static const struct bpf_func_proto bpf_sysctl_get_name_proto = { 
	.gpl_only	= false,

	.ret_type	= RET_INTEGER,

	.arg1_type	= ARG_PTR_TO_CTX,

	.arg2_type	= ARG_PTR_TO_MEM,

	.arg2_type	= ARG_PTR_TO_MEM | MEM_WRITE,

	.arg3_type	= ARG_CONST_SIZE,

	.arg4_type	= ARG_ANYTHING,

};

tools/testing/selftests/bpf/.gitignore

+0 −1
Original line number Diff line number Diff line
@@ -21,7 +21,6 @@ test_lirc_mode2_user 
flow_dissector_load

test_tcpnotify_user

test_libbpf

test_sysctl

xdping

test_cpp

*.d

tools/testing/selftests/bpf/Makefile

+2 −3
Original line number Diff line number Diff line
@@ -73,7 +73,7 @@ endif 
# Order correspond to 'make run_tests' order

TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_progs \

	test_sockmap \

	test_tcpnotify_user test_sysctl \

	test_tcpnotify_user \

	test_progs-no_alu32

TEST_INST_SUBDIRS := no_alu32
@@ -220,7 +220,7 @@ ifeq ($(VMLINUX_BTF),) 
$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")

endif



# Define simple and short `make test_progs`, `make test_sysctl`, etc targets

# Define simple and short `make test_progs`, `make test_maps`, etc targets

# to build individual tests.

# NOTE: Semicolon at the end is critical to override lib.mk's default static

# rule for binaries.
@@ -329,7 +329,6 @@ NETWORK_HELPERS := $(OUTPUT)/network_helpers.o 
$(OUTPUT)/test_sockmap: $(CGROUP_HELPERS) $(TESTING_HELPERS)

$(OUTPUT)/test_tcpnotify_user: $(CGROUP_HELPERS) $(TESTING_HELPERS) $(TRACE_HELPERS)

$(OUTPUT)/test_sock_fields: $(CGROUP_HELPERS) $(TESTING_HELPERS)

$(OUTPUT)/test_sysctl: $(CGROUP_HELPERS) $(TESTING_HELPERS)

$(OUTPUT)/test_tag: $(TESTING_HELPERS)

$(OUTPUT)/test_lirc_mode2_user: $(TESTING_HELPERS)

$(OUTPUT)/xdping: $(TESTING_HELPERS)

tools/testing/selftests/bpf/test_sysctl.c→tools/testing/selftests/bpf/prog_tests/test_sysctl.c

+8 −29
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2019 Facebook



#include <fcntl.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>



#include <linux/filter.h>



#include <bpf/bpf.h>

#include <bpf/libbpf.h>



#include <bpf/bpf_endian.h>

#include "bpf_util.h"

#include "test_progs.h"

#include "cgroup_helpers.h"

#include "testing_helpers.h"



#define CG_PATH			"/foo"

#define MAX_INSNS		512
@@ -1608,26 +1594,19 @@ static int run_tests(int cgfd) 
	return fails ? -1 : 0;

}



int main(int argc, char **argv)

void test_sysctl(void)

{

	int cgfd = -1;

	int err = 0;

	int cgfd;



	cgfd = cgroup_setup_and_join(CG_PATH);

	if (cgfd < 0)

		goto err;



	/* Use libbpf 1.0 API mode */

	libbpf_set_strict_mode(LIBBPF_STRICT_ALL);



	if (run_tests(cgfd))

		goto err;

	if (!ASSERT_OK_FD(cgfd < 0, "create_cgroup"))

		goto out;



	if (!ASSERT_OK(run_tests(cgfd), "run_tests"))

		goto out;

err:

	err = -1;



out:

	close(cgfd);

	cleanup_cgroup_environment();

	return err;

	return;

}