mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-19 02:34:01 +08:00
51be5606d9
- Kexec on panic functionality allocates memory for saving cpu registers in case of system crash event. Address of this allocated memory needs to be exported to user space, which is used by kexec-tools. - Previously, a single /sys/kernel/crash_notes entry was being exported as memory allocated was a single continuous array. Now memory allocation being dyanmic and per cpu based, address of per cpu buffer is exported through "/sys/devices/system/cpu/cpuX/crash_notes" Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
80 lines
1.9 KiB
C
80 lines
1.9 KiB
C
/*
|
|
* 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 <linux/config.h>
|
|
#include <linux/kobject.h>
|
|
#include <linux/string.h>
|
|
#include <linux/sysfs.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
|
|
u64 uevent_seqnum;
|
|
char uevent_helper[UEVENT_HELPER_PATH_LEN] = "/sbin/hotplug";
|
|
|
|
#define KERNEL_ATTR_RO(_name) \
|
|
static struct subsys_attribute _name##_attr = __ATTR_RO(_name)
|
|
|
|
#define KERNEL_ATTR_RW(_name) \
|
|
static struct subsys_attribute _name##_attr = \
|
|
__ATTR(_name, 0644, _name##_show, _name##_store)
|
|
|
|
#ifdef CONFIG_HOTPLUG
|
|
/* current uevent sequence number */
|
|
static ssize_t uevent_seqnum_show(struct subsystem *subsys, char *page)
|
|
{
|
|
return sprintf(page, "%llu\n", (unsigned long long)uevent_seqnum);
|
|
}
|
|
KERNEL_ATTR_RO(uevent_seqnum);
|
|
|
|
/* uevent helper program, used during early boo */
|
|
static ssize_t uevent_helper_show(struct subsystem *subsys, char *page)
|
|
{
|
|
return sprintf(page, "%s\n", uevent_helper);
|
|
}
|
|
static ssize_t uevent_helper_store(struct subsystem *subsys, const char *page, size_t count)
|
|
{
|
|
if (count+1 > UEVENT_HELPER_PATH_LEN)
|
|
return -ENOENT;
|
|
memcpy(uevent_helper, page, count);
|
|
uevent_helper[count] = '\0';
|
|
if (count && uevent_helper[count-1] == '\n')
|
|
uevent_helper[count-1] = '\0';
|
|
return count;
|
|
}
|
|
KERNEL_ATTR_RW(uevent_helper);
|
|
#endif
|
|
|
|
decl_subsys(kernel, NULL, NULL);
|
|
EXPORT_SYMBOL_GPL(kernel_subsys);
|
|
|
|
static struct attribute * kernel_attrs[] = {
|
|
#ifdef CONFIG_HOTPLUG
|
|
&uevent_seqnum_attr.attr,
|
|
&uevent_helper_attr.attr,
|
|
#endif
|
|
NULL
|
|
};
|
|
|
|
static struct attribute_group kernel_attr_group = {
|
|
.attrs = kernel_attrs,
|
|
};
|
|
|
|
static int __init ksysfs_init(void)
|
|
{
|
|
int error = subsystem_register(&kernel_subsys);
|
|
if (!error)
|
|
error = sysfs_create_group(&kernel_subsys.kset.kobj,
|
|
&kernel_attr_group);
|
|
|
|
return error;
|
|
}
|
|
|
|
core_initcall(ksysfs_init);
|