Commit 780c6983 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'Access variable length array relaxed for integer type' 



Feng zhou says:

====================

From: Feng Zhou <zhoufeng.zf@bytedance.com>

Add support for integer type of accessing variable length array.
Add a selftest to check it.
====================

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents 2ddade32 5ff54ded

kernel/bpf/btf.c

+5 −3
Original line number Diff line number Diff line
@@ -6157,11 +6157,13 @@ static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, 
		if (off < moff)

			goto error;



		/* Only allow structure for now, can be relaxed for

		 * other types later.

		 */

		/* allow structure and integer */

		t = btf_type_skip_modifiers(btf, array_elem->type,

					    NULL);



		if (btf_type_is_int(t))

			return WALK_SCALAR;



		if (!btf_type_is_struct(t))

			goto error;

tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c

+20 −0
Original line number Diff line number Diff line
@@ -28,6 +28,11 @@ struct bpf_testmod_struct_arg_2 { 
	long b;

};



struct bpf_testmod_struct_arg_3 {

	int a;

	int b[];

};



__diag_push();

__diag_ignore_all("-Wmissing-prototypes",

		  "Global functions as their definitions will be in bpf_testmod.ko BTF");
@@ -63,6 +68,12 @@ bpf_testmod_test_struct_arg_5(void) { 
	return bpf_testmod_test_struct_arg_result;

}



noinline int

bpf_testmod_test_struct_arg_6(struct bpf_testmod_struct_arg_3 *a) {

	bpf_testmod_test_struct_arg_result = a->b[0];

	return bpf_testmod_test_struct_arg_result;

}



__bpf_kfunc void

bpf_testmod_test_mod_kfunc(int i)

{
@@ -195,6 +206,7 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj, 
	};

	struct bpf_testmod_struct_arg_1 struct_arg1 = {10};

	struct bpf_testmod_struct_arg_2 struct_arg2 = {2, 3};

	struct bpf_testmod_struct_arg_3 *struct_arg3;

	int i = 1;



	while (bpf_testmod_return_ptr(i))
@@ -206,6 +218,14 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj, 
	(void)bpf_testmod_test_struct_arg_4(struct_arg1, 1, 2, 3, struct_arg2);

	(void)bpf_testmod_test_struct_arg_5();



	struct_arg3 = kmalloc((sizeof(struct bpf_testmod_struct_arg_3) +

				sizeof(int)), GFP_KERNEL);

	if (struct_arg3 != NULL) {

		struct_arg3->b[0] = 1;

		(void)bpf_testmod_test_struct_arg_6(struct_arg3);

		kfree(struct_arg3);

	}



	/* This is always true. Use the check to make sure the compiler

	 * doesn't remove bpf_testmod_loop_test.

	 */

tools/testing/selftests/bpf/prog_tests/access_variable_array.c

0 → 100644
+16 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2022 Bytedance */



#include <test_progs.h>

#include "test_access_variable_array.skel.h"



void test_access_variable_array(void)

{

	struct test_access_variable_array *skel;



	skel = test_access_variable_array__open_and_load();

	if (!ASSERT_OK_PTR(skel, "test_access_variable_array__open_and_load"))

		return;



	test_access_variable_array__destroy(skel);

}

tools/testing/selftests/bpf/prog_tests/tracing_struct.c

+2 −0
Original line number Diff line number Diff line
@@ -53,6 +53,8 @@ static void test_fentry(void) 


	ASSERT_EQ(skel->bss->t5_ret, 1, "t5 ret");



	ASSERT_EQ(skel->bss->t6, 1, "t6 ret");



	tracing_struct__detach(skel);

destroy_skel:

	tracing_struct__destroy(skel);

tools/testing/selftests/bpf/progs/test_access_variable_array.c

0 → 100644
+19 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2023 Bytedance */



#include "vmlinux.h"

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>



unsigned long span = 0;



SEC("fentry/load_balance")

int BPF_PROG(fentry_fentry, int this_cpu, struct rq *this_rq,

		struct sched_domain *sd)

{

	span = sd->span[0];



	return 0;

}



char _license[] SEC("license") = "GPL";