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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Masami Hiramatsu <mhiramat@kernel.org>
Subject: [for-next][PATCH 08/26] proc: bootconfig: Add /proc/bootconfig to show boot config list
Date: Tue, 14 Jan 2020 16:03:24 -0500	[thread overview]
Message-ID: <20200114210336.887523301@goodmis.org> (raw)
In-Reply-To: <20200114210316.450821675@goodmis.org>

From: Masami Hiramatsu <mhiramat@kernel.org>

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.

Link: http://lkml.kernel.org/r/157867225967.17873.12155805787236073787.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 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 06005006de7c..903e8a7ed0bf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15774,6 +15774,7 @@ 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);
-- 
2.24.1



  parent reply	other threads:[~2020-01-14 21:04 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-14 21:03 [for-next][PATCH 00/26] tracing: Updates for 5.6 Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 01/26] perf: Make struct ring_buffer less ambiguous Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 02/26] tracing: Rename trace_buffer to array_buffer Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 03/26] tracing: Make struct ring_buffer less ambiguous Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 04/26] bootconfig: Add Extra Boot Config support Steven Rostedt
2020-02-06 11:54   ` Borislav Petkov
2020-02-06 14:41     ` Masami Hiramatsu
2020-02-06 17:20       ` Geert Uytterhoeven
2020-02-07  0:30         ` Masami Hiramatsu
2020-02-07  8:49           ` Geert Uytterhoeven
2020-02-07 13:17             ` Masami Hiramatsu
2020-02-07 14:28               ` [PATCH] bootconfig: Allocate xbc_nodes array dynamically Masami Hiramatsu
2020-02-06 17:58       ` [for-next][PATCH 04/26] bootconfig: Add Extra Boot Config support Borislav Petkov
2020-02-06 18:10         ` Randy Dunlap
2020-02-06 22:39           ` Steven Rostedt
2020-02-06 22:51             ` Borislav Petkov
2020-02-07  8:59             ` Geert Uytterhoeven
2020-02-07  2:46         ` Masami Hiramatsu
2020-02-07 11:41           ` Borislav Petkov
2020-02-07 15:06             ` Masami Hiramatsu
2020-02-10 11:25               ` Borislav Petkov
2020-02-10 15:10                 ` Masami Hiramatsu
2020-02-10 17:40                   ` Borislav Petkov
2020-02-11  2:02                     ` Masami Hiramatsu
2020-02-18 13:27                       ` Borislav Petkov
2020-02-18 17:57                         ` Steven Rostedt
2020-02-18 19:38                           ` Borislav Petkov
2020-02-19  2:26                             ` Masami Hiramatsu
2020-02-19  2:26                           ` Masami Hiramatsu
2020-02-19  2:26                         ` Masami Hiramatsu
2020-02-11  9:25                     ` Geert Uytterhoeven
2020-01-14 21:03 ` [for-next][PATCH 05/26] bootconfig: Load boot config from the tail of initrd Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 06/26] tools: bootconfig: Add bootconfig command Steven Rostedt
2020-02-07 13:02   ` Michael Ellerman
2020-02-07 13:39     ` Masami Hiramatsu
2020-02-07 13:55     ` [PATCH] tools/bootconfig: Fix wrong __VA_ARGS__ usage Masami Hiramatsu
2020-02-08 11:10       ` Michael Ellerman
2020-02-09  4:09         ` Masami Hiramatsu
2020-02-09 13:05         ` [PATCH] tools/bootconfig: Suppress non-error messages Masami Hiramatsu
2020-02-10  2:06           ` Michael Ellerman
2020-02-10  7:18             ` Masami Hiramatsu
2020-02-10  9:50               ` Michael Ellerman
2020-02-10  9:50       ` [PATCH] tools/bootconfig: Fix wrong __VA_ARGS__ usage Michael Ellerman
2020-02-10 17:07         ` Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 07/26] tools: bootconfig: Add bootconfig test script Steven Rostedt
2020-01-14 21:03 ` Steven Rostedt [this message]
2020-01-14 21:03 ` [for-next][PATCH 09/26] init/main.c: Alloc initcall_command_line in do_initcall() and free it Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 10/26] bootconfig: init: Allow admin to use bootconfig for kernel command line Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 11/26] bootconfig: init: Allow admin to use bootconfig for init " Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 12/26] Documentation: bootconfig: Add a doc for extended boot config Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 13/26] tracing: Apply soft-disabled and filter to tracepoints printk Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 14/26] tracing: kprobes: Output kprobe event to printk buffer Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 15/26] tracing: kprobes: Register to dynevent earlier stage Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 16/26] tracing: Accept different type for synthetic event fields Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 17/26] tracing: Add NULL trace-array check in print_synth_event() Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 18/26] tracing/boot: Add boot-time tracing Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 19/26] tracing/boot: Add per-event settings Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 20/26] tracing/boot Add kprobe event support Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 21/26] tracing/boot: Add synthetic " Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 22/26] tracing/boot: Add instance node support Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 23/26] tracing/boot: Add cpu_mask option support Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 24/26] tracing/boot: Add function tracer filter options Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 25/26] Documentation: tracing: Add boot-time tracing document Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 26/26] tracing: trigger: Replace unneeded RCU-list traversals Steven Rostedt
2020-01-14 22:11   ` Steven Rostedt

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