From patchwork Wed Apr 4 17:38:48 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 895092 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 40GY9H5k3Rz9ryr; Thu, 5 Apr 2018 03:38:59 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1f3mN3-00039B-5K; Wed, 04 Apr 2018 17:38:53 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1f3mN2-000391-1y for kernel-team@lists.ubuntu.com; Wed, 04 Apr 2018 17:38:52 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1f3mN1-000102-Ma for kernel-team@lists.ubuntu.com; Wed, 04 Apr 2018 17:38:51 +0000 Received: from kamal by fourier with local (Exim 4.86_2) (envelope-from ) id 1f3mMz-0000MQ-Dx for kernel-team@lists.ubuntu.com; Wed, 04 Apr 2018 10:38:49 -0700 From: Kamal Mostafa To: kernel-team@lists.ubuntu.com Subject: [T,X,A][PATCH] UBUNTU: SAUCE: remove ibrs_dump sysctl interface Date: Wed, 4 Apr 2018 10:38:48 -0700 Message-Id: <1522863528-1348-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" BugLink: http://bugs.launchpad.net/bugs/1755627 The ibrs_dump sysctl interface landed in the Ubuntu backport df043b74ba71 ("x86/spec_ctrl: Add sysctl knobs to enable/disable SPEC_CTRL feature") but nothing like it reached mainline. This debug interface spams dmesg with many lines of output each time /proc/sys/kernel/ibrs_dump is accessed (notably, every run of 'sysctl -a') The interface returns only a dummy sysctl value; it has no other purpose aside from generating dmesg output. Remove the interface to squelch the excessive dmesg logging by 'sysctl -a'. Fixes: df043b74ba71 ("x86/spec_ctrl: Add sysctl knobs to enable/disable SPEC_CTRL feature") Signed-off-by: Kamal Mostafa Acked-by: Colin Ian King --- kernel/sysctl.c | 40 ---------------------------------------- 1 file changed, 40 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8a236ed..c642775 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -205,8 +205,6 @@ int proc_dointvec_ibrs_ctrl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); int proc_dointvec_ibpb_ctrl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); -int proc_dointvec_ibrs_dump(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, loff_t *ppos); #endif #ifdef CONFIG_MAGIC_SYSRQ @@ -245,7 +243,6 @@ extern struct ctl_table epoll_table[]; int sysctl_legacy_va_layout; #endif -u32 sysctl_ibrs_dump = 0; u32 sysctl_ibrs_enabled = 0; EXPORT_SYMBOL(sysctl_ibrs_enabled); u32 sysctl_ibpb_enabled = 0; @@ -1254,15 +1251,6 @@ static struct ctl_table kern_table[] = { .extra1 = &zero, .extra2 = &one, }, - { - .procname = "ibrs_dump", - .data = &sysctl_ibrs_dump, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec_ibrs_dump, - .extra1 = &zero, - .extra2 = &one, - }, #endif { } }; @@ -2422,34 +2410,6 @@ int proc_dointvec_minmax(struct ctl_table *table, int write, } #ifdef CONFIG_X86 -int proc_dointvec_ibrs_dump(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, loff_t *ppos) -{ - int ret, orig_inuse; - unsigned int cpu; - - - ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); - printk("sysctl_ibrs_enabled = %u, sysctl_ibpb_enabled = %u\n", sysctl_ibrs_enabled, sysctl_ibpb_enabled); - printk("use_ibrs = %d, use_ibpb = %d\n", use_ibrs, use_ibpb); - mutex_lock(&spec_ctrl_mutex); - orig_inuse = use_ibrs; - /* temporary halt to ibrs usage to dump ibrs values */ - clear_ibrs_inuse(); - for_each_online_cpu(cpu) { - u64 val; - - if (boot_cpu_has(X86_FEATURE_SPEC_CTRL)) - rdmsrl_on_cpu(cpu, MSR_IA32_SPEC_CTRL, &val); - else - val = 0; - printk("read cpu %d ibrs val %lu\n", cpu, (unsigned long) val); - } - use_ibrs = orig_inuse; - mutex_unlock(&spec_ctrl_mutex); - return ret; -} - int proc_dointvec_ibrs_ctrl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) {