From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753544AbdKXJRV (ORCPT ); Fri, 24 Nov 2017 04:17:21 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:46684 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753420AbdKXJP7 (ORCPT ); Fri, 24 Nov 2017 04:15:59 -0500 X-Google-Smtp-Source: AGs4zMb8Gu8anBx2LC5wOtS8FSVIdfsm9n67adCPeMHMzGvAtgIDuyNIdeOybppeIsCd8XULSfJZhw== From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: Dave Hansen , Andy Lutomirski , Thomas Gleixner , "H . Peter Anvin" , Peter Zijlstra , Borislav Petkov , Linus Torvalds Subject: [PATCH 39/43] x86/mm/kaiser: Add debugfs file to turn KAISER on/off at runtime Date: Fri, 24 Nov 2017 10:14:44 +0100 Message-Id: <20171124091448.7649-40-mingo@kernel.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20171124091448.7649-1-mingo@kernel.org> References: <20171124091448.7649-1-mingo@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Hansen This will be used in a few patches. Right now, it's not wired up to do anything useful. Signed-off-by: Dave Hansen Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Daniel Gruss Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Josh Poimboeuf Cc: Kees Cook Cc: Linus Torvalds Cc: Michael Schwarz Cc: Moritz Lipp Cc: Peter Zijlstra Cc: Richard Fellner Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20171123003517.8EAB76E0@viggo.jf.intel.com Signed-off-by: Ingo Molnar --- arch/x86/mm/kaiser.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c index 4665dd724efb..968d5b62d597 100644 --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -470,3 +471,50 @@ void kaiser_remove_mapping(unsigned long start, unsigned long size) */ __native_flush_tlb_global(); } + +int kaiser_enabled = 1; +static ssize_t kaiser_enabled_read_file(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + char buf[32]; + unsigned int len; + + len = sprintf(buf, "%d\n", kaiser_enabled); + return simple_read_from_buffer(user_buf, count, ppos, buf, len); +} + +static ssize_t kaiser_enabled_write_file(struct file *file, + const char __user *user_buf, size_t count, loff_t *ppos) +{ + char buf[32]; + ssize_t len; + unsigned int enable; + + len = min(count, sizeof(buf) - 1); + if (copy_from_user(buf, user_buf, len)) + return -EFAULT; + + buf[len] = '\0'; + if (kstrtoint(buf, 0, &enable)) + return -EINVAL; + + if (enable > 1) + return -EINVAL; + + WRITE_ONCE(kaiser_enabled, enable); + return count; +} + +static const struct file_operations fops_kaiser_enabled = { + .read = kaiser_enabled_read_file, + .write = kaiser_enabled_write_file, + .llseek = default_llseek, +}; + +static int __init create_kaiser_enabled(void) +{ + debugfs_create_file("kaiser-enabled", S_IRUSR | S_IWUSR, + arch_debugfs_dir, NULL, &fops_kaiser_enabled); + return 0; +} +late_initcall(create_kaiser_enabled); -- 2.14.1