From mboxrd@z Thu Jan 1 00:00:00 1970 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 90D3BC433F5 for ; Tue, 10 May 2022 03:38:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235728AbiEJDmf (ORCPT ); Mon, 9 May 2022 23:42:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235636AbiEJDkh (ORCPT ); Mon, 9 May 2022 23:40:37 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4425017CC9E; Mon, 9 May 2022 20:35:10 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Axythn3XliaKoPAA--.50059S4; Tue, 10 May 2022 11:35:05 +0800 (CST) From: Tiezhu Yang To: davem@davemloft.net, Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: Xuefeng Li , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next v2 2/2] bpf: Print some info if disable bpf_jit_enable failed Date: Tue, 10 May 2022 11:35:03 +0800 Message-Id: <1652153703-22729-3-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1652153703-22729-1-git-send-email-yangtiezhu@loongson.cn> References: <1652153703-22729-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9Axythn3XliaKoPAA--.50059S4 X-Coremail-Antispam: 1UD129KBjvJXoWxJrW7KF43Cw4UAF45CryrCrg_yoW8XrWfpr 48Jr92krZ0q34xG39rAFnIqr13trWDXF17Cr97Ca1av3WDZr9rJrs5KryUKanF9rWqga43 Zr4IyF9rCaykK37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPE14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jryl82xGYIkIc2 x26xkF7I0E14v26r4j6ryUM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26F4UJVW0 owAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCY02Avz4vE14v_Gr4l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_ Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17 CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0 I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I 8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73 UjIFyTuYvjfUbyxRDUUUU X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A user told me that bpf_jit_enable can be disabled on one system, but he failed to disable bpf_jit_enable on the other system: # echo 0 > /proc/sys/net/core/bpf_jit_enable bash: echo: write error: Invalid argument No useful info is available through the dmesg log, a quick analysis shows that the issue is related with CONFIG_BPF_JIT_ALWAYS_ON. When CONFIG_BPF_JIT_ALWAYS_ON is enabled, bpf_jit_enable is permanently set to 1 and setting any other value than that will return failure. It is better to print some info to tell the user if disable bpf_jit_enable failed. Signed-off-by: Tiezhu Yang --- net/core/sysctl_net_core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index cf00dd7..ca4527f 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -266,6 +266,8 @@ static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write, loff_t *ppos) { int ret, jit_enable = *(int *)table->data; + int min = *(int *)table->extra1; + int max = *(int *)table->extra2; struct ctl_table tmp = *table; if (write && !capable(CAP_SYS_ADMIN)) @@ -283,6 +285,10 @@ static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write, ret = -EPERM; } } + + if (write && ret && min == max) + pr_info_once("CONFIG_BPF_JIT_ALWAYS_ON is enabled, bpf_jit_enable is permanently set to 1.\n"); + return ret; } -- 2.1.0