From patchwork Mon May 9 06:57:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiezhu Yang X-Patchwork-Id: 12843075 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 C2069C433EF for ; Mon, 9 May 2022 07:13:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230226AbiEIHQs (ORCPT ); Mon, 9 May 2022 03:16:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233462AbiEIHCH (ORCPT ); Mon, 9 May 2022 03:02:07 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 63B971A35AA; Sun, 8 May 2022 23:58:13 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Axuth4u3hiwqkOAA--.49630S5; Mon, 09 May 2022 14:58:06 +0800 (CST) From: Tiezhu Yang To: davem@davemloft.net, Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next 3/3] bpf: Print some info if disable bpf_jit_enable failed Date: Mon, 9 May 2022 14:57:55 +0800 Message-Id: <1652079475-16684-4-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1652079475-16684-1-git-send-email-yangtiezhu@loongson.cn> References: <1652079475-16684-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9Axuth4u3hiwqkOAA--.49630S5 X-Coremail-Antispam: 1UD129KBjvJXoWxJrW7KF43Cw4UAF45CryrCrg_yoW8XryUpr 48Gr92krZ8X34xG39rAFnaqr13trWUXF1UCrnrCa15X3WDXr9rJrsYgryUKFZFvrWqga43 Ar4Iyr9ruaykKa7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBFb7Iv0xC_Kw4lb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI 8067AKxVWUWwA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF 64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcV CY1x0267AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280 aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzV Aqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S 6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JMxkIecxEwVAFwVW8AwCF04k20xvY0x 0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E 7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcV C0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF 04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7 CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07bz2NNUUUUU= X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net 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 059352b..f8a1d450 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; tmp.data = &jit_enable; @@ -280,6 +282,10 @@ static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write, ret = -EPERM; } } + + if (write && ret && min == max) + pr_info("CONFIG_BPF_JIT_ALWAYS_ON is enabled, bpf_jit_enable is permanently set to 1.\n"); + return ret; }