da1a679cde
This patch adds the /sys/kernel/notes magic file. Reading this delivers the contents of the kernel's .notes section. This lets userland easily glean any detailed information about the running kernel's build that was stored there at compile time. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Andi Kleen <ak@suse.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
122 lines
3 KiB
C
122 lines
3 KiB
C
/*
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* kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
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* are not related to any other subsystem
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*
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* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
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*
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* This file is release under the GPLv2
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*
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*/
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#include <linux/kobject.h>
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#include <linux/string.h>
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#include <linux/sysfs.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/kexec.h>
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#define KERNEL_ATTR_RO(_name) \
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static struct subsys_attribute _name##_attr = __ATTR_RO(_name)
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#define KERNEL_ATTR_RW(_name) \
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static struct subsys_attribute _name##_attr = \
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__ATTR(_name, 0644, _name##_show, _name##_store)
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#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
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/* current uevent sequence number */
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static ssize_t uevent_seqnum_show(struct kset *kset, char *page)
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{
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return sprintf(page, "%llu\n", (unsigned long long)uevent_seqnum);
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}
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KERNEL_ATTR_RO(uevent_seqnum);
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/* uevent helper program, used during early boo */
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static ssize_t uevent_helper_show(struct kset *kset, char *page)
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{
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return sprintf(page, "%s\n", uevent_helper);
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}
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static ssize_t uevent_helper_store(struct kset *kset, const char *page, size_t count)
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{
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if (count+1 > UEVENT_HELPER_PATH_LEN)
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return -ENOENT;
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memcpy(uevent_helper, page, count);
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uevent_helper[count] = '\0';
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if (count && uevent_helper[count-1] == '\n')
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uevent_helper[count-1] = '\0';
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return count;
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}
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KERNEL_ATTR_RW(uevent_helper);
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#endif
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#ifdef CONFIG_KEXEC
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static ssize_t kexec_loaded_show(struct kset *kset, char *page)
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{
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return sprintf(page, "%d\n", !!kexec_image);
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}
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KERNEL_ATTR_RO(kexec_loaded);
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static ssize_t kexec_crash_loaded_show(struct kset *kset, char *page)
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{
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return sprintf(page, "%d\n", !!kexec_crash_image);
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}
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KERNEL_ATTR_RO(kexec_crash_loaded);
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#endif /* CONFIG_KEXEC */
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/*
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* Make /sys/kernel/notes give the raw contents of our kernel .notes section.
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*/
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extern const char __start_notes __attribute__((weak));
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extern const char __stop_notes __attribute__((weak));
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#define notes_size (&__stop_notes - &__start_notes)
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static ssize_t notes_read(struct kobject *kobj, struct bin_attribute *bin_attr,
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char *buf, loff_t off, size_t count)
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{
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memcpy(buf, &__start_notes + off, count);
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return count;
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}
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static struct bin_attribute notes_attr = {
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.attr = {
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.name = "notes",
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.mode = S_IRUGO,
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},
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.read = ¬es_read,
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};
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decl_subsys(kernel, NULL, NULL);
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EXPORT_SYMBOL_GPL(kernel_subsys);
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static struct attribute * kernel_attrs[] = {
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#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
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&uevent_seqnum_attr.attr,
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&uevent_helper_attr.attr,
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#endif
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#ifdef CONFIG_KEXEC
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&kexec_loaded_attr.attr,
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&kexec_crash_loaded_attr.attr,
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#endif
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NULL
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};
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static struct attribute_group kernel_attr_group = {
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.attrs = kernel_attrs,
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};
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static int __init ksysfs_init(void)
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{
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int error = subsystem_register(&kernel_subsys);
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if (!error)
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error = sysfs_create_group(&kernel_subsys.kobj,
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&kernel_attr_group);
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if (!error && notes_size > 0) {
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notes_attr.size = notes_size;
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error = sysfs_create_bin_file(&kernel_subsys.kobj,
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¬es_attr);
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}
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return error;
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}
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core_initcall(ksysfs_init);
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