From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1940D223311 for ; Wed, 6 Aug 2025 08:59:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754470755; cv=none; b=IvVKbdUa65PRtyDnb+VsPUjuspOsPJ6m/KeMXRyyNyM2uWOHJZujNuB07ab3O3rNlhbQOBO01BXpVgqlgXpz8u+Rrv8fTdQtC030scYpqlIMe3UTd4Fj66IyNSciesdC6dxCOnuxoi8BKa9ahtTcp7/YQYEIsCRdMSgPqb2ck+s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754470755; c=relaxed/simple; bh=R8DY7B1C60z8T7w/qiuv9BCN8CkV414G/UiSJLimdJs=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ecgMRt9v7l83Xum1RqdC+UIOilOClcci2ndp1wz5V/3DsN8Yk7R/p9xwoKAriC2i0FauoW2aKG8x/rDa3SzX3/gm2PYgNSo2+53zJAKQIjm2CekBWKJueNgok2Knas4jFdRaL/HNe3Xzb+UDwItrVjBZ2o3MwW97EB7hnRDjb6M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uabQIIK8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="uabQIIK8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E003C4CEE7; Wed, 6 Aug 2025 08:59:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754470754; bh=R8DY7B1C60z8T7w/qiuv9BCN8CkV414G/UiSJLimdJs=; h=From:To:Subject:Date:In-Reply-To:References:From; b=uabQIIK8pIywLp3HWWMF61WHDETtShZ3nz3uvtTCS5m4UomMCIWq/UtlVbEnPlnVE kDgvwXg6vJfUf8LqAljnacby4hGdufos78+2cQqeAOZQrlZbG63crTU5mkr0qoXy7A ql8WvHXv+OYD+Cc87ArrTRSSBSk/iPexk2B/v8HUcFSqmIQURQmwH1FLUtFqDu1BD+ /c9pmDierzSUHyV+9lJtE1jOtfwggPJke74tEwBPVCDvjKFAApknFkXF/s2jcjZAqA VX2/vzYCSZ/S9izorvd6xcXqcQWmdcfxr4yyS22HS2Mc/x6RrFL6E9wtnGLp/uA+k3 jDA1AY9SQ4OQw== From: Puranjay Mohan To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Puranjay Mohan , Xu Kuohai , Catalin Marinas , Will Deacon , Kumar Kartikeya Dwivedi , bpf@vger.kernel.org Subject: [PATCH bpf-next 3/3] selftests/bpf: Add tests for arena fault reporting Date: Wed, 6 Aug 2025 08:58:36 +0000 Message-ID: <20250806085847.18633-4-puranjay@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20250806085847.18633-1-puranjay@kernel.org> References: <20250806085847.18633-1-puranjay@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add selftests for testing the reporting of arena page faults through BPF streams. Two new bpf programs are added that read and write to an unmapped arena address and the fault reporting is verified in the userspace through streams. Signed-off-by: Puranjay Mohan --- .../testing/selftests/bpf/prog_tests/stream.c | 24 ++++++++++++ tools/testing/selftests/bpf/progs/stream.c | 37 +++++++++++++++++++ 2 files changed, 61 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/stream.c b/tools/testing/selftests/bpf/prog_tests/stream.c index d9f0185dca61b..4bdde56de35b1 100644 --- a/tools/testing/selftests/bpf/prog_tests/stream.c +++ b/tools/testing/selftests/bpf/prog_tests/stream.c @@ -41,6 +41,22 @@ struct { "([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n" "|[ \t]+[^\n]+\n)*", }, + { + offsetof(struct stream, progs.stream_arena_read_fault), + "ERROR: Arena READ access at unmapped address 0x.*\n" + "CPU: [0-9]+ UID: 0 PID: [0-9]+ Comm: .*\n" + "Call trace:\n" + "([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n" + "|[ \t]+[^\n]+\n)*", + }, + { + offsetof(struct stream, progs.stream_arena_write_fault), + "ERROR: Arena WRITE access at unmapped address 0x.*\n" + "CPU: [0-9]+ UID: 0 PID: [0-9]+ Comm: .*\n" + "Call trace:\n" + "([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n" + "|[ \t]+[^\n]+\n)*", + }, }; static int match_regex(const char *pattern, const char *string) @@ -85,6 +101,14 @@ void test_stream_errors(void) continue; } #endif +#if !defined(__x86_64__) && !defined(__aarch64__) + ASSERT_TRUE(1, "Arena fault reporting unsupported, skip."); + if (i == 2 || i == 3) { + ret = bpf_prog_stream_read(prog_fd, 2, buf, sizeof(buf), &ropts); + ASSERT_EQ(ret, 0, "stream read"); + continue; + } +#endif ret = bpf_prog_stream_read(prog_fd, BPF_STREAM_STDERR, buf, sizeof(buf), &ropts); ASSERT_GT(ret, 0, "stream read"); diff --git a/tools/testing/selftests/bpf/progs/stream.c b/tools/testing/selftests/bpf/progs/stream.c index 35790897dc879..58ebff60cd96a 100644 --- a/tools/testing/selftests/bpf/progs/stream.c +++ b/tools/testing/selftests/bpf/progs/stream.c @@ -1,10 +1,15 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ +#define BPF_NO_KFUNC_PROTOTYPES #include #include #include #include "bpf_misc.h" #include "bpf_experimental.h" +#include "bpf_arena_common.h" + +extern int bpf_res_spin_lock(struct bpf_res_spin_lock *lock) __weak __ksym; +extern void bpf_res_spin_unlock(struct bpf_res_spin_lock *lock) __weak __ksym; struct arr_elem { struct bpf_res_spin_lock lock; @@ -17,6 +22,12 @@ struct { __type(value, struct arr_elem); } arrmap SEC(".maps"); +struct { + __uint(type, BPF_MAP_TYPE_ARENA); + __uint(map_flags, BPF_F_MMAPABLE); + __uint(max_entries, 1); /* number of pages */ +} arena SEC(".maps"); + #define ENOSPC 28 #define _STR "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" @@ -76,4 +87,30 @@ int stream_syscall(void *ctx) return 0; } +SEC("syscall") +__success __retval(0) +int stream_arena_write_fault(void *ctx) +{ + unsigned char __arena *page; + + page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); + bpf_arena_free_pages(&arena, page, 1); + + *(page + 0xbeef) = 1; + + return 0; +} + +SEC("syscall") +__success __retval(0) +int stream_arena_read_fault(void *ctx) +{ + unsigned char __arena *page; + + page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); + bpf_arena_free_pages(&arena, page, 1); + + return *(page + 0xbeef); +} + char _license[] SEC("license") = "GPL"; -- 2.47.3