From patchwork Mon Aug 26 03:16:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 11113881 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F1D0D1399 for ; Mon, 26 Aug 2019 03:16:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D08782190F for ; Mon, 26 Aug 2019 03:16:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566789373; bh=wXFjl0zCbPJZwn2CEfUDC+aWkXCG/asIDm0k7WxJxXk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XByINzJls9PTggle0I7xV3bJKDYe0fBg5BotZW9fJcL2xaWOBEH902pdPZLGHRlOa da+YF7JEJn3HeWEllUgdU6X7plnpYYOuNV7GG9/iJec5bET2ovBkovcgNI5BHZgB5+ ghekbrXoRrKGPW7JTqm8fOwRLS1rdRmlEoK+Jo6Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729443AbfHZDQJ (ORCPT ); Sun, 25 Aug 2019 23:16:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:35356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726606AbfHZDQJ (ORCPT ); Sun, 25 Aug 2019 23:16:09 -0400 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2274A21744; Mon, 26 Aug 2019 03:16:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566789368; bh=wXFjl0zCbPJZwn2CEfUDC+aWkXCG/asIDm0k7WxJxXk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CrHbAvOKb8sl5AtIIw8tSiWwAZ9CXJtXpmAfUUfZAtvlh5j1VDF5sDwpCTHlGbPuD RRb0XGrjL6SkBuzlQ4DMUaAP0fNmY7nvKHn/ZZH8nlYIrC4ORmzFQPirseye23qfTk 9pmg9mELNZTxjRK3hq2kBZgpG3jVmZkzbq3bTqfw= From: Masami Hiramatsu To: Steven Rostedt , Frank Rowand Cc: Ingo Molnar , Namhyung Kim , Tim Bird , Jiri Olsa , Arnaldo Carvalho de Melo , Tom Zanussi , Rob Herring , Andrew Morton , Thomas Gleixner , Greg Kroah-Hartman , Alexey Dobriyan , Jonathan Corbet , Linus Torvalds , linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v3 02/19] skc: Add /proc/sup_cmdline to show SKC key-value list Date: Mon, 26 Aug 2019 12:16:01 +0900 Message-Id: <156678936178.21459.13301820262182543136.stgit@devnote2> X-Mailer: git-send-email 2.20.1 In-Reply-To: <156678933823.21459.4100380582025186209.stgit@devnote2> References: <156678933823.21459.4100380582025186209.stgit@devnote2> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add /proc/sup_cmdline which shows the list of key-value pairs in SKC data. Since after boot, all SKC data and tree are removed, this interface just keep a copy of key-value pairs in text. Signed-off-by: Masami Hiramatsu --- MAINTAINERS | 1 fs/proc/Makefile | 1 fs/proc/sup_cmdline.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 108 insertions(+) create mode 100644 fs/proc/sup_cmdline.c diff --git a/MAINTAINERS b/MAINTAINERS index 67590c0e37c5..10dd38311d96 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15366,6 +15366,7 @@ SUPPLEMENTAL KERNEL CMDLINE M: Masami Hiramatsu S: Maintained F: lib/skc.c +F: fs/proc/sup_cmdline.c F: include/linux/skc.h SUN3/3X diff --git a/fs/proc/Makefile b/fs/proc/Makefile index ead487e80510..a5d018f9422c 100644 --- a/fs/proc/Makefile +++ b/fs/proc/Makefile @@ -33,3 +33,4 @@ proc-$(CONFIG_PROC_KCORE) += kcore.o proc-$(CONFIG_PROC_VMCORE) += vmcore.o proc-$(CONFIG_PRINTK) += kmsg.o proc-$(CONFIG_PROC_PAGE_MONITOR) += page.o +proc-$(CONFIG_SKC) += sup_cmdline.o diff --git a/fs/proc/sup_cmdline.c b/fs/proc/sup_cmdline.c new file mode 100644 index 000000000000..97bc40f0c9dd --- /dev/null +++ b/fs/proc/sup_cmdline.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * /proc/sup_cmdline - Supplemental kernel command line + */ +#include +#include +#include +#include +#include +#include +#include + +static char *saved_sup_cmdline; + +static int skc_proc_show(struct seq_file *m, void *v) +{ + if (saved_sup_cmdline) + seq_puts(m, saved_sup_cmdline); + else + seq_putc(m, '\n'); + return 0; +} + +static int __init update_snprintf(char **dstp, size_t *sizep, + const char *fmt, ...) +{ + va_list args; + int ret; + + va_start(args, fmt); + ret = vsnprintf(*dstp, *sizep, fmt, args); + va_end(args); + + if (*sizep && ret > 0) { + *sizep -= ret; + *dstp += ret; + } + + return ret; +} + +/* Return the needed total length if @size is 0 */ +static int __init copy_skc_key_value_list(char *dst, size_t size) +{ + struct skc_node *leaf, *vnode; + const char *val; + int len = 0, ret = 0; + char *key; + + key = kzalloc(SKC_KEYLEN_MAX, GFP_KERNEL); + + skc_for_each_key_value(leaf, val) { + ret = skc_node_compose_key(leaf, key, SKC_KEYLEN_MAX); + if (ret < 0) + break; + ret = update_snprintf(&dst, &size, "%s = ", key); + if (ret < 0) + break; + len += ret; + vnode = skc_node_get_child(leaf); + if (vnode && skc_node_is_array(vnode)) { + skc_array_for_each_value(vnode, val) { + ret = update_snprintf(&dst, &size, "\"%s\"%s", + val, vnode->next ? ", " : ";\n"); + if (ret < 0) + goto out; + len += ret; + } + } else { + ret = update_snprintf(&dst, &size, "\"%s\";\n", val); + if (ret < 0) + break; + len += ret; + } + } +out: + kfree(key); + + return ret < 0 ? ret : len; +} + +static int __init proc_skc_init(void) +{ + int len; + + len = copy_skc_key_value_list(NULL, 0); + if (len < 0) + return len; + + if (len > 0) { + saved_sup_cmdline = kzalloc(len + 1, GFP_KERNEL); + if (!saved_sup_cmdline) + return -ENOMEM; + + len = copy_skc_key_value_list(saved_sup_cmdline, len + 1); + if (len < 0) { + kfree(saved_sup_cmdline); + return len; + } + } + + proc_create_single("sup_cmdline", 0, NULL, skc_proc_show); + + return 0; +} +fs_initcall(proc_skc_init);