proc: bootconfig: Add /proc/bootconfig to show boot config list (c1a3c360) · Commits · 戴 / test

MAINTAINERS

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Original line number	Diff line number	Diff line
		@@ -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/*

fs/proc/Makefile

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Original line number	Diff line number	Diff line
		@@ -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

fs/proc/bootconfig.c

0 → 100644

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Original line number	Diff line number	Diff line
		// 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);

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