Commit a90c5845 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Andrii Nakryiko
Browse files

selftests/bpf: Add arena test case for 4Gbyte corner case 



Check that 4Gbyte arena can be allocated and overflow/underflow access in
the first and the last page behaves as expected.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarStanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20240315021834.62988-5-alexei.starovoitov@gmail.com
parent 9a2d5a96

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

+2 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include "cap_helpers.h"

#include "verifier_and.skel.h"

#include "verifier_arena.skel.h"

#include "verifier_arena_large.skel.h"

#include "verifier_array_access.skel.h"

#include "verifier_basic_stack.skel.h"

#include "verifier_bitfield_write.skel.h"
@@ -120,6 +121,7 @@ static void run_tests_aux(const char *skel_name, 


void test_verifier_and(void)                  { RUN(verifier_and); }

void test_verifier_arena(void)                { RUN(verifier_arena); }

void test_verifier_arena_large(void)          { RUN(verifier_arena_large); }

void test_verifier_basic_stack(void)          { RUN(verifier_basic_stack); }

void test_verifier_bitfield_write(void)       { RUN(verifier_bitfield_write); }

void test_verifier_bounds(void)               { RUN(verifier_bounds); }

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

0 → 100644
+68 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */



#include <vmlinux.h>

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#include "bpf_misc.h"

#include "bpf_experimental.h"

#include "bpf_arena_common.h"



#define ARENA_SIZE (1ull << 32)



struct {

	__uint(type, BPF_MAP_TYPE_ARENA);

	__uint(map_flags, BPF_F_MMAPABLE);

	__uint(max_entries, ARENA_SIZE / PAGE_SIZE);

} arena SEC(".maps");



SEC("syscall")

__success __retval(0)

int big_alloc1(void *ctx)

{

#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)

	volatile char __arena *page1, *page2, *no_page, *page3;

	void __arena *base;



	page1 = base = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);

	if (!page1)

		return 1;

	*page1 = 1;

	page2 = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE,

				      1, NUMA_NO_NODE, 0);

	if (!page2)

		return 2;

	*page2 = 2;

	no_page = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE,

					1, NUMA_NO_NODE, 0);

	if (no_page)

		return 3;

	if (*page1 != 1)

		return 4;

	if (*page2 != 2)

		return 5;

	bpf_arena_free_pages(&arena, (void __arena *)page1, 1);

	if (*page2 != 2)

		return 6;

	if (*page1 != 0) /* use-after-free should return 0 */

		return 7;

	page3 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);

	if (!page3)

		return 8;

	*page3 = 3;

	if (page1 != page3)

		return 9;

	if (*page2 != 2)

		return 10;

	if (*(page1 + PAGE_SIZE) != 0)

		return 11;

	if (*(page1 - PAGE_SIZE) != 0)

		return 12;

	if (*(page2 + PAGE_SIZE) != 0)

		return 13;

	if (*(page2 - PAGE_SIZE) != 0)

		return 14;

#endif

	return 0;

}

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