From patchwork Sat Aug 27 10:01:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12956905 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1DC4ECAAD2 for ; Sat, 27 Aug 2022 09:43:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232646AbiH0Jnc (ORCPT ); Sat, 27 Aug 2022 05:43:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230179AbiH0Jnb (ORCPT ); Sat, 27 Aug 2022 05:43:31 -0400 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B05B596FF8 for ; Sat, 27 Aug 2022 02:43:28 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4MFBYT3KMcz6S2r3 for ; Sat, 27 Aug 2022 17:41:49 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP2 (Coremail) with SMTP id Syh0CgDHsb085wljpJSmAw--.1436S4; Sat, 27 Aug 2022 17:43:26 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org, Song Liu , Hao Luo Cc: Hao Sun , Sebastian Andrzej Siewior , Andrii Nakryiko , Yonghong Song , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , KP Singh , "David S . Miller" , Jakub Kicinski , Stanislav Fomichev , Jiri Olsa , John Fastabend , Lorenz Bauer , houtao1@huawei.com Subject: [PATCH bpf-next v2 1/3] bpf: Disable preemption when increasing per-cpu map_locked Date: Sat, 27 Aug 2022 18:01:32 +0800 Message-Id: <20220827100134.1621137-1-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 X-CM-TRANSID: Syh0CgDHsb085wljpJSmAw--.1436S4 X-Coremail-Antispam: 1UD129KBjvJXoWxWFykXFWkCF18GFWxCFy7trb_yoW5ZF18pF 48GF9Yyw48XF9a9a9rXr1Iqr15Jw4xK3yIy3ykGFWUZF45Xr1fXr1IyFySqFyFvr9xArsa vF42qa1Yyr4UAFDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkFb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6r1S6rWUM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I 0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IY c2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s 026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF 0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0x vE42xK8VAvwI8IcIk0rVWrZr1j6s0DMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2 jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07UZ18PUUUUU= X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao Per-cpu htab->map_locked is used to prohibit the concurrent accesses from both NMI and non-NMI contexts. But since commit 74d862b682f5 ("sched: Make migrate_disable/enable() independent of RT"), migrations_disable() is also preemptible under CONFIG_PREEMPT case, so now map_locked also disallows concurrent updates from normal contexts (e.g. userspace processes) unexpectedly as shown below: process A process B htab_map_update_elem() htab_lock_bucket() migrate_disable() /* return 1 */ __this_cpu_inc_return() /* preempted by B */ htab_map_update_elem() /* the same bucket as A */ htab_lock_bucket() migrate_disable() /* return 2, so lock fails */ __this_cpu_inc_return() return -EBUSY A fix that seems feasible is using in_nmi() in htab_lock_bucket() and only checking the value of map_locked for nmi context. But it will re-introduce dead-lock on bucket lock if htab_lock_bucket() is re-entered through non-tracing program (e.g. fentry program). So fixing it by using disable_preempt() instead of migrate_disable() when increasing htab->map_locked. However when htab_use_raw_lock() is false, bucket lock will be a sleepable spin-lock and it breaks disable_preempt(), so still use migrate_disable() for spin-lock case and leave the concurrent map updates problem to BPF memory allocator patchset in which !htab_use_raw_lock() case will be removed. Reviewed-by: Hao Luo Signed-off-by: Hou Tao --- kernel/bpf/hashtab.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index b301a63afa2f..6fb3b7fd1622 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -162,17 +162,25 @@ static inline int htab_lock_bucket(const struct bpf_htab *htab, unsigned long *pflags) { unsigned long flags; + bool use_raw_lock; hash = hash & HASHTAB_MAP_LOCK_MASK; - migrate_disable(); + use_raw_lock = htab_use_raw_lock(htab); + if (use_raw_lock) + preempt_disable(); + else + migrate_disable(); if (unlikely(__this_cpu_inc_return(*(htab->map_locked[hash])) != 1)) { __this_cpu_dec(*(htab->map_locked[hash])); - migrate_enable(); + if (use_raw_lock) + preempt_enable(); + else + migrate_enable(); return -EBUSY; } - if (htab_use_raw_lock(htab)) + if (use_raw_lock) raw_spin_lock_irqsave(&b->raw_lock, flags); else spin_lock_irqsave(&b->lock, flags); @@ -185,13 +193,18 @@ static inline void htab_unlock_bucket(const struct bpf_htab *htab, struct bucket *b, u32 hash, unsigned long flags) { + bool use_raw_lock = htab_use_raw_lock(htab); + hash = hash & HASHTAB_MAP_LOCK_MASK; - if (htab_use_raw_lock(htab)) + if (use_raw_lock) raw_spin_unlock_irqrestore(&b->raw_lock, flags); else spin_unlock_irqrestore(&b->lock, flags); __this_cpu_dec(*(htab->map_locked[hash])); - migrate_enable(); + if (use_raw_lock) + preempt_enable(); + else + migrate_enable(); } static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node); From patchwork Sat Aug 27 10:01:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12956906 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6F65C0502E for ; Sat, 27 Aug 2022 09:43:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230427AbiH0Jnd (ORCPT ); Sat, 27 Aug 2022 05:43:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232615AbiH0Jnb (ORCPT ); Sat, 27 Aug 2022 05:43:31 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D41597510 for ; Sat, 27 Aug 2022 02:43:29 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4MFBYl72ZKzl5f6 for ; Sat, 27 Aug 2022 17:42:03 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP2 (Coremail) with SMTP id Syh0CgDHsb085wljpJSmAw--.1436S5; Sat, 27 Aug 2022 17:43:27 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org, Song Liu , Hao Luo Cc: Hao Sun , Sebastian Andrzej Siewior , Andrii Nakryiko , Yonghong Song , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , KP Singh , "David S . Miller" , Jakub Kicinski , Stanislav Fomichev , Jiri Olsa , John Fastabend , Lorenz Bauer , houtao1@huawei.com Subject: [PATCH bpf-next v2 2/3] bpf: Propagate error from htab_lock_bucket() to userspace Date: Sat, 27 Aug 2022 18:01:33 +0800 Message-Id: <20220827100134.1621137-2-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20220827100134.1621137-1-houtao@huaweicloud.com> References: <20220827100134.1621137-1-houtao@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: Syh0CgDHsb085wljpJSmAw--.1436S5 X-Coremail-Antispam: 1UD129KBjvJXoWruFWfZw48Gry7WFWrtr4Dtwb_yoW8Jryrpa yxK347Kw40qr92yas3XF4xtay5ur95Wr4UGrWDC34Fvr1qqr9a9w18t3sIqFyFqry3Jr4Y vr42vF1Fq345AaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBjb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6r1S6rWUM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUGw A2048vs2IY020Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV WxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx 0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWU JVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCF04k20xvY0x0EwI xGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480 Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_WrylIxkGc2Ij64vIr41lIxAIcVC0I7 IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k2 6cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxV AFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07jn9N3UUUUU= X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao In __htab_map_lookup_and_delete_batch() if htab_lock_bucket() returns -EBUSY, it will go to next bucket. Going to next bucket may not only skip the elements in current bucket silently, but also incur out-of-bound memory access or expose kernel memory to userspace if current bucket_cnt is greater than bucket_size or zero. Fixing it by stopping batch operation and returning -EBUSY when htab_lock_bucket() fails, and the application can retry or skip the busy batch as needed. Reported-by: Hao Sun Signed-off-by: Hou Tao --- kernel/bpf/hashtab.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 6fb3b7fd1622..eb1263f03e9b 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -1704,8 +1704,11 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, /* do not grab the lock unless need it (bucket_cnt > 0). */ if (locked) { ret = htab_lock_bucket(htab, b, batch, &flags); - if (ret) - goto next_batch; + if (ret) { + rcu_read_unlock(); + bpf_enable_instrumentation(); + goto after_loop; + } } bucket_cnt = 0; From patchwork Sat Aug 27 10:01:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12956904 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1546EC0502C for ; Sat, 27 Aug 2022 09:43:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230179AbiH0Jnd (ORCPT ); Sat, 27 Aug 2022 05:43:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230427AbiH0Jnb (ORCPT ); Sat, 27 Aug 2022 05:43:31 -0400 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4A7A97528 for ; Sat, 27 Aug 2022 02:43:29 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4MFBYW03Rcz6S9c9 for ; Sat, 27 Aug 2022 17:41:51 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP2 (Coremail) with SMTP id Syh0CgDHsb085wljpJSmAw--.1436S6; Sat, 27 Aug 2022 17:43:27 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org, Song Liu , Hao Luo Cc: Hao Sun , Sebastian Andrzej Siewior , Andrii Nakryiko , Yonghong Song , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , KP Singh , "David S . Miller" , Jakub Kicinski , Stanislav Fomichev , Jiri Olsa , John Fastabend , Lorenz Bauer , houtao1@huawei.com Subject: [PATCH bpf-next v2 3/3] selftests/bpf: add test cases for htab update Date: Sat, 27 Aug 2022 18:01:34 +0800 Message-Id: <20220827100134.1621137-3-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20220827100134.1621137-1-houtao@huaweicloud.com> References: <20220827100134.1621137-1-houtao@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: Syh0CgDHsb085wljpJSmAw--.1436S6 X-Coremail-Antispam: 1UD129KBjvJXoWxAry8Gr17Jry8Kr17Gr4xXrb_yoWrtw48pa 48Ca4xtr4ftw1DXw1rta17KFWYkF4rXr4Yyrs5WF15Ar4j9rnaqr1xKFyrtF4fJrZ5Zr1r Z3sxtF4UW3yxZF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBYb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6r1S6rWUM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2Ij64 vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8G jcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF0xvE2I x0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4UJwCI42IY6xAI w20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x 0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU1sa9DUUUUU== X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao One test demonstrates the reentrancy of hash map update fails, and another one shows concureently updates of the same hash map bucket succeed. Signed-off-by: Hou Tao --- .../selftests/bpf/prog_tests/htab_update.c | 126 ++++++++++++++++++ .../testing/selftests/bpf/progs/htab_update.c | 29 ++++ 2 files changed, 155 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/htab_update.c create mode 100644 tools/testing/selftests/bpf/progs/htab_update.c diff --git a/tools/testing/selftests/bpf/prog_tests/htab_update.c b/tools/testing/selftests/bpf/prog_tests/htab_update.c new file mode 100644 index 000000000000..e2a4034daa79 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/htab_update.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2022. Huawei Technologies Co., Ltd */ +#define _GNU_SOURCE +#include +#include +#include +#include "htab_update.skel.h" + +struct htab_update_ctx { + int fd; + int loop; + bool stop; +}; + +static void test_reenter_update(void) +{ + struct htab_update *skel; + unsigned int key, value; + int err; + + skel = htab_update__open(); + if (!ASSERT_OK_PTR(skel, "htab_update__open")) + return; + + /* lookup_elem_raw() may be inlined and find_kernel_btf_id() will return -ESRCH */ + bpf_program__set_autoload(skel->progs.lookup_elem_raw, true); + err = htab_update__load(skel); + if (!ASSERT_TRUE(!err || err == -ESRCH, "htab_update__load") || err) + goto out; + + skel->bss->pid = getpid(); + err = htab_update__attach(skel); + if (!ASSERT_OK(err, "htab_update__attach")) + goto out; + + /* Will trigger the reentrancy of bpf_map_update_elem() */ + key = 0; + value = 0; + err = bpf_map_update_elem(bpf_map__fd(skel->maps.htab), &key, &value, 0); + if (!ASSERT_OK(err, "add element")) + goto out; + + ASSERT_EQ(skel->bss->update_err, -EBUSY, "no reentrancy"); +out: + htab_update__destroy(skel); +} + +static void *htab_update_thread(void *arg) +{ + struct htab_update_ctx *ctx = arg; + cpu_set_t cpus; + int i; + + /* Pin on CPU 0 */ + CPU_ZERO(&cpus); + CPU_SET(0, &cpus); + pthread_setaffinity_np(pthread_self(), sizeof(cpus), &cpus); + + i = 0; + while (i++ < ctx->loop && !ctx->stop) { + unsigned int key = 0, value = 0; + int err; + + err = bpf_map_update_elem(ctx->fd, &key, &value, 0); + if (err) { + ctx->stop = true; + return (void *)(long)err; + } + } + + return NULL; +} + +static void test_concurrent_update(void) +{ + struct htab_update_ctx ctx; + struct htab_update *skel; + unsigned int i, nr; + pthread_t *tids; + int err; + + skel = htab_update__open_and_load(); + if (!ASSERT_OK_PTR(skel, "htab_update__open_and_load")) + return; + + ctx.fd = bpf_map__fd(skel->maps.htab); + ctx.loop = 1000; + ctx.stop = false; + + nr = 4; + tids = calloc(nr, sizeof(*tids)); + if (!ASSERT_NEQ(tids, NULL, "no mem")) + goto out; + + for (i = 0; i < nr; i++) { + err = pthread_create(&tids[i], NULL, htab_update_thread, &ctx); + if (!ASSERT_OK(err, "pthread_create")) { + unsigned int j; + + ctx.stop = true; + for (j = 0; j < i; j++) + pthread_join(tids[j], NULL); + goto out; + } + } + + for (i = 0; i < nr; i++) { + void *thread_err = NULL; + + pthread_join(tids[i], &thread_err); + ASSERT_EQ(thread_err, NULL, "update error"); + } + +out: + if (tids) + free(tids); + htab_update__destroy(skel); +} + +void test_htab_update(void) +{ + if (test__start_subtest("reenter_update")) + test_reenter_update(); + if (test__start_subtest("concurrent_update")) + test_concurrent_update(); +} diff --git a/tools/testing/selftests/bpf/progs/htab_update.c b/tools/testing/selftests/bpf/progs/htab_update.c new file mode 100644 index 000000000000..7481bb30b29b --- /dev/null +++ b/tools/testing/selftests/bpf/progs/htab_update.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2022. Huawei Technologies Co., Ltd */ +#include +#include +#include + +char _license[] SEC("license") = "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 1); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u32)); +} htab SEC(".maps"); + +int pid = 0; +int update_err = 0; + +SEC("?fentry/lookup_elem_raw") +int lookup_elem_raw(void *ctx) +{ + __u32 key = 0, value = 1; + + if ((bpf_get_current_pid_tgid() >> 32) != pid) + return 0; + + update_err = bpf_map_update_elem(&htab, &key, &value, 0); + return 0; +}