1 files changed, 141 insertions, 0 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index c4b4996ff1d1..0f92acdd354d 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -42,6 +42,7 @@
 #include <linux/objtool.h>
 #include <linux/kmsg_dump.h>
 #include <linux/dma-map-ops.h>
+#include <linux/sysfs.h>
 
 #include <asm/page.h>
 #include <asm/sections.h>
@@ -1225,3 +1226,143 @@ int kernel_kexec(void)
 	kexec_unlock();
 	return error;
 }
+
+static ssize_t loaded_show(struct kobject *kobj,
+				 struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%d\n", !!kexec_image);
+}
+static struct kobj_attribute loaded_attr = __ATTR_RO(loaded);
+
+#ifdef CONFIG_CRASH_DUMP
+static ssize_t crash_loaded_show(struct kobject *kobj,
+				       struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%d\n", kexec_crash_loaded());
+}
+static struct kobj_attribute crash_loaded_attr = __ATTR_RO(crash_loaded);
+
+#ifdef CONFIG_CRASH_RESERVE
+static ssize_t crash_cma_ranges_show(struct kobject *kobj,
+				     struct kobj_attribute *attr, char *buf)
+{
+
+	ssize_t len = 0;
+	int i;
+
+	for (i = 0; i < crashk_cma_cnt; ++i) {
+		len += sysfs_emit_at(buf, len, "%08llx-%08llx\n",
+				     crashk_cma_ranges[i].start,
+				     crashk_cma_ranges[i].end);
+	}
+	return len;
+}
+static struct kobj_attribute crash_cma_ranges_attr = __ATTR_RO(crash_cma_ranges);
+#endif
+
+static ssize_t crash_size_show(struct kobject *kobj,
+				       struct kobj_attribute *attr, char *buf)
+{
+	ssize_t size = crash_get_memory_size();
+
+	if (size < 0)
+		return size;
+
+	return sysfs_emit(buf, "%zd\n", size);
+}
+static ssize_t crash_size_store(struct kobject *kobj,
+				struct kobj_attribute *attr,
+				const char *buf, size_t count)
+{
+	unsigned long cnt;
+	int ret;
+
+	if (kstrtoul(buf, 0, &cnt))
+		return -EINVAL;
+
+	ret = crash_shrink_memory(cnt);
+	return ret < 0 ? ret : count;
+}
+static struct kobj_attribute crash_size_attr = __ATTR_RW(crash_size);
+
+#ifdef CONFIG_CRASH_HOTPLUG
+static ssize_t crash_elfcorehdr_size_show(struct kobject *kobj,
+			       struct kobj_attribute *attr, char *buf)
+{
+	unsigned int sz = crash_get_elfcorehdr_size();
+
+	return sysfs_emit(buf, "%u\n", sz);
+}
+static struct kobj_attribute crash_elfcorehdr_size_attr = __ATTR_RO(crash_elfcorehdr_size);
+
+#endif /* CONFIG_CRASH_HOTPLUG */
+#endif /* CONFIG_CRASH_DUMP */
+
+static struct attribute *kexec_attrs[] = {
+	&loaded_attr.attr,
+#ifdef CONFIG_CRASH_DUMP
+	&crash_loaded_attr.attr,
+	&crash_size_attr.attr,
+#ifdef CONFIG_CRASH_RESERVE
+	&crash_cma_ranges_attr.attr,
+#endif
+#ifdef CONFIG_CRASH_HOTPLUG
+	&crash_elfcorehdr_size_attr.attr,
+#endif
+#endif
+	NULL
+};
+
+struct kexec_link_entry {
+	const char *target;
+	const char *name;
+};
+
+static struct kexec_link_entry kexec_links[] = {
+	{ "loaded", "kexec_loaded" },
+#ifdef CONFIG_CRASH_DUMP
+	{ "crash_loaded", "kexec_crash_loaded" },
+	{ "crash_size", "kexec_crash_size" },
+#ifdef CONFIG_CRASH_RESERVE
+	{"crash_cma_ranges", "kexec_crash_cma_ranges"},
+#endif
+#ifdef CONFIG_CRASH_HOTPLUG
+	{ "crash_elfcorehdr_size", "crash_elfcorehdr_size" },
+#endif
+#endif
+};
+
+static struct kobject *kexec_kobj;
+ATTRIBUTE_GROUPS(kexec);
+
+static int __init init_kexec_sysctl(void)
+{
+	int error;
+	int i;
+
+	kexec_kobj = kobject_create_and_add("kexec", kernel_kobj);
+	if (!kexec_kobj) {
+		pr_err("failed to create kexec kobject\n");
+		return -ENOMEM;
+	}
+
+	error = sysfs_create_groups(kexec_kobj, kexec_groups);
+	if (error)
+		goto kset_exit;
+
+	for (i = 0; i < ARRAY_SIZE(kexec_links); i++) {
+		error = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, kexec_kobj,
+							     kexec_links[i].target,
+							     kexec_links[i].name);
+		if (error)
+			pr_err("Unable to create %s symlink (%d)", kexec_links[i].name, error);
+	}
+
+	return 0;
+
+kset_exit:
+	kobject_put(kexec_kobj);
+	return error;
+}
+
+subsys_initcall(init_kexec_sysctl);