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-rw-r--r--kernel/ksysfs.c158
1 files changed, 84 insertions, 74 deletions
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 6ada93c23a9a..a9e6354d9e25 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -1,44 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
* are not related to any other subsystem
*
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
- *
- * This file is release under the GPLv2
- *
*/
+#include <asm/byteorder.h>
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/export.h>
#include <linux/init.h>
-#include <linux/kexec.h>
+#include <linux/vmcore_info.h>
#include <linux/profile.h>
#include <linux/stat.h>
#include <linux/sched.h>
#include <linux/capability.h>
+#include <linux/compiler.h>
+
+#include <linux/rcupdate.h> /* rcu_expedited and rcu_normal */
+
+#if defined(__LITTLE_ENDIAN)
+#define CPU_BYTEORDER_STRING "little"
+#elif defined(__BIG_ENDIAN)
+#define CPU_BYTEORDER_STRING "big"
+#else
+#error Unknown byteorder
+#endif
#define KERNEL_ATTR_RO(_name) \
static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
#define KERNEL_ATTR_RW(_name) \
-static struct kobj_attribute _name##_attr = \
- __ATTR(_name, 0644, _name##_show, _name##_store)
+static struct kobj_attribute _name##_attr = __ATTR_RW(_name)
/* current uevent sequence number */
static ssize_t uevent_seqnum_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);
+ return sysfs_emit(buf, "%llu\n", (u64)atomic64_read(&uevent_seqnum));
}
KERNEL_ATTR_RO(uevent_seqnum);
+/* cpu byteorder */
+static ssize_t cpu_byteorder_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%s\n", CPU_BYTEORDER_STRING);
+}
+KERNEL_ATTR_RO(cpu_byteorder);
+
+/* address bits */
+static ssize_t address_bits_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%zu\n", sizeof(void *) * 8 /* CHAR_BIT */);
+}
+KERNEL_ATTR_RO(address_bits);
+
+#ifdef CONFIG_UEVENT_HELPER
/* uevent helper program, used during early boot */
static ssize_t uevent_helper_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%s\n", uevent_helper);
+ return sysfs_emit(buf, "%s\n", uevent_helper);
}
static ssize_t uevent_helper_store(struct kobject *kobj,
struct kobj_attribute *attr,
@@ -53,20 +79,27 @@ static ssize_t uevent_helper_store(struct kobject *kobj,
return count;
}
KERNEL_ATTR_RW(uevent_helper);
-
+#endif
#ifdef CONFIG_PROFILING
static ssize_t profiling_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%d\n", prof_on);
+ return sysfs_emit(buf, "%d\n", prof_on);
}
static ssize_t profiling_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
int ret;
+ static DEFINE_MUTEX(lock);
+ /*
+ * We need serialization, for profile_setup() initializes prof_on
+ * value and profile_init() must not reallocate prof_buffer after
+ * once allocated.
+ */
+ guard(mutex)(&lock);
if (prof_on)
return -EEXIST;
/*
@@ -86,65 +119,33 @@ static ssize_t profiling_store(struct kobject *kobj,
KERNEL_ATTR_RW(profiling);
#endif
-#ifdef CONFIG_KEXEC
-static ssize_t kexec_loaded_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
-{
- return sprintf(buf, "%d\n", !!kexec_image);
-}
-KERNEL_ATTR_RO(kexec_loaded);
-
-static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
-{
- return sprintf(buf, "%d\n", !!kexec_crash_image);
-}
-KERNEL_ATTR_RO(kexec_crash_loaded);
-
-static ssize_t kexec_crash_size_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
-{
- return sprintf(buf, "%zu\n", crash_get_memory_size());
-}
-static ssize_t kexec_crash_size_store(struct kobject *kobj,
- struct kobj_attribute *attr,
- const char *buf, size_t count)
-{
- unsigned long cnt;
- int ret;
-
- if (strict_strtoul(buf, 0, &cnt))
- return -EINVAL;
-
- ret = crash_shrink_memory(cnt);
- return ret < 0 ? ret : count;
-}
-KERNEL_ATTR_RW(kexec_crash_size);
+#ifdef CONFIG_VMCORE_INFO
static ssize_t vmcoreinfo_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%lx %x\n",
- paddr_vmcoreinfo_note(),
- (unsigned int)vmcoreinfo_max_size);
+ phys_addr_t vmcore_base = paddr_vmcoreinfo_note();
+ return sysfs_emit(buf, "%pa %x\n", &vmcore_base,
+ (unsigned int)VMCOREINFO_NOTE_SIZE);
}
KERNEL_ATTR_RO(vmcoreinfo);
-#endif /* CONFIG_KEXEC */
+#endif /* CONFIG_VMCORE_INFO */
/* whether file capabilities are enabled */
static ssize_t fscaps_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%d\n", file_caps_enabled);
+ return sysfs_emit(buf, "%d\n", file_caps_enabled);
}
KERNEL_ATTR_RO(fscaps);
+#ifndef CONFIG_TINY_RCU
int rcu_expedited;
static ssize_t rcu_expedited_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%d\n", rcu_expedited);
+ return sysfs_emit(buf, "%d\n", READ_ONCE(rcu_expedited));
}
static ssize_t rcu_expedited_store(struct kobject *kobj,
struct kobj_attribute *attr,
@@ -157,28 +158,32 @@ static ssize_t rcu_expedited_store(struct kobject *kobj,
}
KERNEL_ATTR_RW(rcu_expedited);
+int rcu_normal;
+static ssize_t rcu_normal_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%d\n", READ_ONCE(rcu_normal));
+}
+static ssize_t rcu_normal_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ if (kstrtoint(buf, 0, &rcu_normal))
+ return -EINVAL;
+
+ return count;
+}
+KERNEL_ATTR_RW(rcu_normal);
+#endif /* #ifndef CONFIG_TINY_RCU */
+
/*
* Make /sys/kernel/notes give the raw contents of our kernel .notes section.
*/
-extern const void __start_notes __attribute__((weak));
-extern const void __stop_notes __attribute__((weak));
+extern const void __start_notes;
+extern const void __stop_notes;
#define notes_size (&__stop_notes - &__start_notes)
-static ssize_t notes_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr,
- char *buf, loff_t off, size_t count)
-{
- memcpy(buf, &__start_notes + off, count);
- return count;
-}
-
-static struct bin_attribute notes_attr = {
- .attr = {
- .name = "notes",
- .mode = S_IRUGO,
- },
- .read = &notes_read,
-};
+static __ro_after_init BIN_ATTR_SIMPLE_RO(notes);
struct kobject *kernel_kobj;
EXPORT_SYMBOL_GPL(kernel_kobj);
@@ -186,21 +191,25 @@ EXPORT_SYMBOL_GPL(kernel_kobj);
static struct attribute * kernel_attrs[] = {
&fscaps_attr.attr,
&uevent_seqnum_attr.attr,
+ &cpu_byteorder_attr.attr,
+ &address_bits_attr.attr,
+#ifdef CONFIG_UEVENT_HELPER
&uevent_helper_attr.attr,
+#endif
#ifdef CONFIG_PROFILING
&profiling_attr.attr,
#endif
-#ifdef CONFIG_KEXEC
- &kexec_loaded_attr.attr,
- &kexec_crash_loaded_attr.attr,
- &kexec_crash_size_attr.attr,
+#ifdef CONFIG_VMCORE_INFO
&vmcoreinfo_attr.attr,
#endif
+#ifndef CONFIG_TINY_RCU
&rcu_expedited_attr.attr,
+ &rcu_normal_attr.attr,
+#endif
NULL
};
-static struct attribute_group kernel_attr_group = {
+static const struct attribute_group kernel_attr_group = {
.attrs = kernel_attrs,
};
@@ -218,8 +227,9 @@ static int __init ksysfs_init(void)
goto kset_exit;
if (notes_size > 0) {
- notes_attr.size = notes_size;
- error = sysfs_create_bin_file(kernel_kobj, &notes_attr);
+ bin_attr_notes.private = (void *)&__start_notes;
+ bin_attr_notes.size = notes_size;
+ error = sysfs_create_bin_file(kernel_kobj, &bin_attr_notes);
if (error)
goto group_exit;
}
generated by cgit (git 2.34.1) at 2025-12-25 03:19:50 +0000