From nobody Wed Feb 11 00:58:54 2026 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 119879443; Sat, 18 Oct 2025 04:04:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760760287; cv=none; b=o0XuCW+Uh+1dS5aCO5Hva+fykT4u9DOfIhcl5+TlEaFnu2W+1Tjj8chPNAAP/WTSIjYhA0D7afx7CJuSv4UtLbZEyE3IGkwTKpBaSdrPc+ropD9NjrAna3/WVL9zbFefKGvbMSWJ/mz/QJbn8Lw7002bkV6hjgoS11jBXFcY4oM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760760287; c=relaxed/simple; bh=EGot/d/BKG/mhnUls92EnB/ESEjY2JYD89ix94m0Pig=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OaXizK6JZ0dOvTL3Jm1uEXbQq2+tAiWGCofh+dT9cfKLisfmmfRwXcLnWEWaRjYyrjSNuIcoS45PfXTCt9sLCgOfkJcZpJoj8bZfwlvK7SjTd86E1pTNB9yAqQOpQ6LB+iyOgNYb2CBGo5SX4a1dnKuTqST/HaR59entXdLHkdU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4cpSjd3cZBzYQtjF; Sat, 18 Oct 2025 12:03:49 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.75]) by mail.maildlp.com (Postfix) with ESMTP id 906801A0FEE; Sat, 18 Oct 2025 12:04:36 +0800 (CST) Received: from k-arm6401.huawei.com (unknown [7.217.19.243]) by APP2 (Coremail) with SMTP id Syh0CgA32UHPEfNoOeb+Ag--.21556S4; Sat, 18 Oct 2025 12:04:36 +0800 (CST) From: Xu Kuohai To: bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Yonghong Song , Song Liu Subject: [PATCH bpf-next v3 2/3] selftests/bpf: Add overwrite mode test for BPF ring buffer Date: Sat, 18 Oct 2025 11:57:37 +0800 Message-ID: <20251018035738.4039621-3-xukuohai@huaweicloud.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251018035738.4039621-1-xukuohai@huaweicloud.com> References: <20251018035738.4039621-1-xukuohai@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: Syh0CgA32UHPEfNoOeb+Ag--.21556S4 X-Coremail-Antispam: 1UD129KBjvJXoW3Ww18tw4DuF1ruw13uw1ftFb_yoWxuw1kpa yFgryYkryIg3WvgrZ7uFyxZFW8ur4DAw4rKr47Xw18Zr1DCFsxXr1Ikr1UtFn8XrW8Xr1Y k34a9FZ3A3WUKFUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUmab4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2AFwI 0_Jw0_GFylc7CjxVAKzI0EY4vE52x082I5MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCj c4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4 CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1x MIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF 4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsG vfC2KfnxnUUI43ZEXa7IU8go7tUUUUU== X-CM-SenderInfo: 50xn30hkdlqx5xdzvxpfor3voofrz/ Content-Type: text/plain; charset="utf-8" From: Xu Kuohai Add overwrite mode test for BPF ring buffer. The test creates a BPF ring buffer in overwrite mode, then repeatedly reserves and commits records to check if the ring buffer works as expected both before and after overwriting occurs. Signed-off-by: Xu Kuohai --- tools/testing/selftests/bpf/Makefile | 3 +- .../selftests/bpf/prog_tests/ringbuf.c | 64 ++++++++++++ .../bpf/progs/test_ringbuf_overwrite.c | 98 +++++++++++++++++++ 3 files changed, 164 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/progs/test_ringbuf_overwrit= e.c diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests= /bpf/Makefile index f00587d4ede6..43d133bf514d 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -498,7 +498,8 @@ LINKED_SKELS :=3D test_static_linked.skel.h linked_func= s.skel.h \ =20 LSKELS :=3D fexit_sleep.c trace_printk.c trace_vprintk.c map_ptr_kern.c \ core_kern.c core_kern_overflow.c test_ringbuf.c \ - test_ringbuf_n.c test_ringbuf_map_key.c test_ringbuf_write.c + test_ringbuf_n.c test_ringbuf_map_key.c test_ringbuf_write.c \ + test_ringbuf_overwrite.c =20 LSKELS_SIGNED :=3D fentry_test.c fexit_test.c atomics.c =20 diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c b/tools/testi= ng/selftests/bpf/prog_tests/ringbuf.c index d1e4cb28a72c..5264af1dc768 100644 --- a/tools/testing/selftests/bpf/prog_tests/ringbuf.c +++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c @@ -17,6 +17,7 @@ #include "test_ringbuf_n.lskel.h" #include "test_ringbuf_map_key.lskel.h" #include "test_ringbuf_write.lskel.h" +#include "test_ringbuf_overwrite.lskel.h" =20 #define EDONE 7777 =20 @@ -497,6 +498,67 @@ static void ringbuf_map_key_subtest(void) test_ringbuf_map_key_lskel__destroy(skel_map_key); } =20 +static void ringbuf_overwrite_mode_subtest(void) +{ + unsigned long size, len1, len2, len3, len4, len5; + unsigned long expect_avail_data, expect_prod_pos, expect_over_pos; + struct test_ringbuf_overwrite_lskel *skel; + int err; + + skel =3D test_ringbuf_overwrite_lskel__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + size =3D 0x1000; + len1 =3D 0x800; + len2 =3D 0x400; + len3 =3D size - len1 - len2 - BPF_RINGBUF_HDR_SZ * 3; /* 0x3e8 */ + len4 =3D len3 - 8; /* 0x3e0 */ + len5 =3D len3; /* retry with len3 */ + + skel->maps.ringbuf.max_entries =3D size; + skel->rodata->LEN1 =3D len1; + skel->rodata->LEN2 =3D len2; + skel->rodata->LEN3 =3D len3; + skel->rodata->LEN4 =3D len4; + skel->rodata->LEN5 =3D len5; + + skel->bss->pid =3D getpid(); + + err =3D test_ringbuf_overwrite_lskel__load(skel); + if (!ASSERT_OK(err, "skel_load")) + goto cleanup; + + err =3D test_ringbuf_overwrite_lskel__attach(skel); + if (!ASSERT_OK(err, "skel_attach")) + goto cleanup; + + syscall(__NR_getpgid); + + ASSERT_EQ(skel->bss->reserve1_fail, 0, "reserve 1"); + ASSERT_EQ(skel->bss->reserve2_fail, 0, "reserve 2"); + ASSERT_EQ(skel->bss->reserve3_fail, 1, "reserve 3"); + ASSERT_EQ(skel->bss->reserve4_fail, 0, "reserve 4"); + ASSERT_EQ(skel->bss->reserve5_fail, 0, "reserve 5"); + + ASSERT_EQ(skel->bss->ring_size, size, "check_ring_size"); + + expect_avail_data =3D len2 + len4 + len5 + 3 * BPF_RINGBUF_HDR_SZ; + ASSERT_EQ(skel->bss->avail_data, expect_avail_data, "check_avail_size"); + + ASSERT_EQ(skel->bss->cons_pos, 0, "check_cons_pos"); + + expect_prod_pos =3D len1 + len2 + len4 + len5 + 4 * BPF_RINGBUF_HDR_SZ; + ASSERT_EQ(skel->bss->prod_pos, expect_prod_pos, "check_prod_pos"); + + expect_over_pos =3D len1 + BPF_RINGBUF_HDR_SZ; + ASSERT_EQ(skel->bss->over_pos, expect_over_pos, "check_over_pos"); + + test_ringbuf_overwrite_lskel__detach(skel); +cleanup: + test_ringbuf_overwrite_lskel__destroy(skel); +} + void test_ringbuf(void) { if (test__start_subtest("ringbuf")) @@ -507,4 +569,6 @@ void test_ringbuf(void) ringbuf_map_key_subtest(); if (test__start_subtest("ringbuf_write")) ringbuf_write_subtest(); + if (test__start_subtest("ringbuf_overwrite_mode")) + ringbuf_overwrite_mode_subtest(); } diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf_overwrite.c b/t= ools/testing/selftests/bpf/progs/test_ringbuf_overwrite.c new file mode 100644 index 000000000000..ff4aa67ddacc --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_ringbuf_overwrite.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2025. Huawei Technologies Co., Ltd */ + +#include +#include +#include "bpf_misc.h" + +char _license[] SEC("license") =3D "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); + __uint(map_flags, BPF_F_RB_OVERWRITE); +} ringbuf SEC(".maps"); + +int pid; + +const volatile unsigned long LEN1; +const volatile unsigned long LEN2; +const volatile unsigned long LEN3; +const volatile unsigned long LEN4; +const volatile unsigned long LEN5; + +long reserve1_fail =3D 0; +long reserve2_fail =3D 0; +long reserve3_fail =3D 0; +long reserve4_fail =3D 0; +long reserve5_fail =3D 0; + +unsigned long avail_data =3D 0; +unsigned long ring_size =3D 0; +unsigned long cons_pos =3D 0; +unsigned long prod_pos =3D 0; +unsigned long over_pos =3D 0; + +SEC("fentry/" SYS_PREFIX "sys_getpgid") +int test_overwrite_ringbuf(void *ctx) +{ + char *rec1, *rec2, *rec3, *rec4, *rec5; + int cur_pid =3D bpf_get_current_pid_tgid() >> 32; + + if (cur_pid !=3D pid) + return 0; + + rec1 =3D bpf_ringbuf_reserve(&ringbuf, LEN1, 0); + if (!rec1) { + reserve1_fail =3D 1; + return 0; + } + + rec2 =3D bpf_ringbuf_reserve(&ringbuf, LEN2, 0); + if (!rec2) { + bpf_ringbuf_discard(rec1, 0); + reserve2_fail =3D 1; + return 0; + } + + rec3 =3D bpf_ringbuf_reserve(&ringbuf, LEN3, 0); + /* expect failure */ + if (!rec3) { + reserve3_fail =3D 1; + } else { + bpf_ringbuf_discard(rec1, 0); + bpf_ringbuf_discard(rec2, 0); + bpf_ringbuf_discard(rec3, 0); + return 0; + } + + rec4 =3D bpf_ringbuf_reserve(&ringbuf, LEN4, 0); + if (!rec4) { + reserve4_fail =3D 1; + bpf_ringbuf_discard(rec1, 0); + bpf_ringbuf_discard(rec2, 0); + return 0; + } + + bpf_ringbuf_submit(rec1, 0); + bpf_ringbuf_submit(rec2, 0); + bpf_ringbuf_submit(rec4, 0); + + rec5 =3D bpf_ringbuf_reserve(&ringbuf, LEN5, 0); + if (!rec5) { + reserve5_fail =3D 1; + return 0; + } + + for (int i =3D 0; i < LEN3; i++) + rec5[i] =3D 0xdd; + + bpf_ringbuf_submit(rec5, 0); + + ring_size =3D bpf_ringbuf_query(&ringbuf, BPF_RB_RING_SIZE); + avail_data =3D bpf_ringbuf_query(&ringbuf, BPF_RB_AVAIL_DATA); + cons_pos =3D bpf_ringbuf_query(&ringbuf, BPF_RB_CONS_POS); + prod_pos =3D bpf_ringbuf_query(&ringbuf, BPF_RB_PROD_POS); + over_pos =3D bpf_ringbuf_query(&ringbuf, BPF_RB_OVERWRITE_POS); + + return 0; +} --=20 2.43.0