From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>,
Frank Rowand <frowand.list@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Namhyung Kim <namhyung@kernel.org>, Tim Bird <Tim.Bird@sony.com>,
Jiri Olsa <jolsa@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Tom Zanussi <tom.zanussi@linux.intel.com>,
Rob Herring <robh+dt@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
Jonathan Corbet <corbet@lwn.net>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [RFC PATCH v4 05/22] proc: bootconfig: Add /proc/bootconfig to show boot config list
Date: Mon, 2 Dec 2019 19:14:15 +0900 [thread overview]
Message-ID: <157528165507.22451.6162105840149497154.stgit@devnote2> (raw)
In-Reply-To: <157528159833.22451.14878731055438721716.stgit@devnote2>
Add /proc/bootconfig which shows the list of key-value pairs
in boot config. Since after boot, all boot configs and tree
are removed, this interface just keep a copy of key-value
pairs in text.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
Changes in v4:
- Remove ; in the end of lines.
- Rename /proc/supp_cmdline to /proc/bootconfig
- Simplify code.
---
MAINTAINERS | 1 +
fs/proc/Makefile | 1 +
fs/proc/bootconfig.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 91 insertions(+)
create mode 100644 fs/proc/bootconfig.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 9ea52e87730f..08185de1652b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15693,6 +15693,7 @@ EXTRA BOOT CONFIG
M: Masami Hiramatsu <mhiramat@kernel.org>
S: Maintained
F: lib/bootconfig.c
+F: fs/proc/bootconfig.c
F: include/linux/bootconfig.h
F: tools/bootconfig/*
diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index ead487e80510..bd08616ed8ba 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_BOOT_CONFIG) += bootconfig.o
diff --git a/fs/proc/bootconfig.c b/fs/proc/bootconfig.c
new file mode 100644
index 000000000000..9955d75c0585
--- /dev/null
+++ b/fs/proc/bootconfig.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * /proc/bootconfig - Extra boot configuration
+ */
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/printk.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/bootconfig.h>
+#include <linux/slab.h>
+
+static char *saved_boot_config;
+
+static int boot_config_proc_show(struct seq_file *m, void *v)
+{
+ if (saved_boot_config)
+ seq_puts(m, saved_boot_config);
+ return 0;
+}
+
+/* Rest size of buffer */
+#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
+
+/* Return the needed total length if @size is 0 */
+static int __init copy_xbc_key_value_list(char *dst, size_t size)
+{
+ struct xbc_node *leaf, *vnode;
+ const char *val;
+ char *key, *end = dst + size;
+ int ret = 0;
+
+ key = kzalloc(XBC_KEYLEN_MAX, GFP_KERNEL);
+
+ xbc_for_each_key_value(leaf, val) {
+ ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
+ if (ret < 0)
+ break;
+ ret = snprintf(dst, rest(dst, end), "%s = ", key);
+ if (ret < 0)
+ break;
+ dst += ret;
+ vnode = xbc_node_get_child(leaf);
+ if (vnode && xbc_node_is_array(vnode)) {
+ xbc_array_for_each_value(vnode, val) {
+ ret = snprintf(dst, rest(dst, end), "\"%s\"%s",
+ val, vnode->next ? ", " : "\n");
+ if (ret < 0)
+ goto out;
+ dst += ret;
+ }
+ } else {
+ ret = snprintf(dst, rest(dst, end), "\"%s\"\n", val);
+ if (ret < 0)
+ break;
+ dst += ret;
+ }
+ }
+out:
+ kfree(key);
+
+ return ret < 0 ? ret : dst - (end - size);
+}
+
+static int __init proc_boot_config_init(void)
+{
+ int len;
+
+ len = copy_xbc_key_value_list(NULL, 0);
+ if (len < 0)
+ return len;
+
+ if (len > 0) {
+ saved_boot_config = kzalloc(len + 1, GFP_KERNEL);
+ if (!saved_boot_config)
+ return -ENOMEM;
+
+ len = copy_xbc_key_value_list(saved_boot_config, len + 1);
+ if (len < 0) {
+ kfree(saved_boot_config);
+ return len;
+ }
+ }
+
+ proc_create_single("bootconfig", 0, NULL, boot_config_proc_show);
+
+ return 0;
+}
+fs_initcall(proc_boot_config_init);
next prev parent reply other threads:[~2019-12-02 10:14 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-02 10:13 [RFC PATCH v4 00/22] tracing: bootconfig: Boot-time tracing and Extra boot config Masami Hiramatsu
2019-12-02 10:13 ` [RFC PATCH v4 01/22] bootconfig: Add Extra Boot Config support Masami Hiramatsu
2019-12-08 19:34 ` Randy Dunlap
2019-12-09 5:50 ` Masami Hiramatsu
2019-12-09 15:54 ` Steven Rostedt
2019-12-10 14:15 ` Masami Hiramatsu
2020-02-06 9:08 ` Geert Uytterhoeven
2020-02-06 9:41 ` Masami Hiramatsu
2019-12-02 10:13 ` [RFC PATCH v4 02/22] bootconfig: Load boot config from the tail of initrd Masami Hiramatsu
2019-12-02 10:13 ` [RFC PATCH v4 03/22] tools: bootconfig: Add bootconfig command Masami Hiramatsu
2019-12-02 10:14 ` [RFC PATCH v4 04/22] tools: bootconfig: Add bootconfig test script Masami Hiramatsu
2019-12-02 10:14 ` Masami Hiramatsu [this message]
2019-12-02 10:14 ` [RFC PATCH v4 06/22] init/main.c: Alloc initcall_command_line in do_initcall() and free it Masami Hiramatsu
2019-12-02 10:14 ` [RFC PATCH v4 07/22] bootconfig: init: Allow admin to use bootconfig for kernel command line Masami Hiramatsu
2019-12-02 10:14 ` [RFC PATCH v4 08/22] bootconfig: init: Allow admin to use bootconfig for init " Masami Hiramatsu
2019-12-02 10:14 ` [RFC PATCH v4 09/22] Documentation: bootconfig: Add a doc for extended boot config Masami Hiramatsu
2019-12-02 10:15 ` [RFC PATCH v4 10/22] tracing: Apply soft-disabled and filter to tracepoints printk Masami Hiramatsu
2019-12-02 10:15 ` [RFC PATCH v4 11/22] tracing: kprobes: Output kprobe event to printk buffer Masami Hiramatsu
2019-12-02 10:15 ` [RFC PATCH v4 12/22] tracing: kprobes: Register to dynevent earlier stage Masami Hiramatsu
2019-12-02 10:15 ` [RFC PATCH v4 13/22] tracing: Accept different type for synthetic event fields Masami Hiramatsu
2019-12-02 10:15 ` [RFC PATCH v4 14/22] tracing: Add NULL trace-array check in print_synth_event() Masami Hiramatsu
2019-12-02 10:16 ` [RFC PATCH v4 15/22] tracing/boot: Add boot-time tracing Masami Hiramatsu
2019-12-02 10:16 ` [RFC PATCH v4 16/22] tracing/boot: Add per-event settings Masami Hiramatsu
2019-12-02 10:16 ` [RFC PATCH v4 17/22] tracing/boot Add kprobe event support Masami Hiramatsu
2019-12-02 10:16 ` [RFC PATCH v4 18/22] tracing/boot: Add synthetic " Masami Hiramatsu
2019-12-02 10:16 ` [RFC PATCH v4 19/22] tracing/boot: Add instance node support Masami Hiramatsu
2019-12-02 10:17 ` [RFC PATCH v4 20/22] tracing/boot: Add cpu_mask option support Masami Hiramatsu
2019-12-02 10:17 ` [RFC PATCH v4 21/22] tracing/boot: Add function tracer filter options Masami Hiramatsu
2019-12-02 10:17 ` [RFC PATCH v4 22/22] Documentation: tracing: Add boot-time tracing document Masami Hiramatsu
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