1127 lines
26 KiB
C
1127 lines
26 KiB
C
/*
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* linux/kernel/power/swsusp.c
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*
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* This file is to realize architecture-independent
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* machine suspend feature using pretty near only high-level routines
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*
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* Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
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* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
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*
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* This file is released under the GPLv2.
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*
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* I'd like to thank the following people for their work:
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*
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* Pavel Machek <pavel@ucw.cz>:
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* Modifications, defectiveness pointing, being with me at the very beginning,
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* suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17.
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*
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* Steve Doddi <dirk@loth.demon.co.uk>:
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* Support the possibility of hardware state restoring.
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*
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* Raph <grey.havens@earthling.net>:
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* Support for preserving states of network devices and virtual console
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* (including X and svgatextmode)
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*
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* Kurt Garloff <garloff@suse.de>:
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* Straightened the critical function in order to prevent compilers from
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* playing tricks with local variables.
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*
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* Andreas Mohr <a.mohr@mailto.de>
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*
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* Alex Badea <vampire@go.ro>:
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* Fixed runaway init
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*
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* Andreas Steinmetz <ast@domdv.de>:
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* Added encrypted suspend option
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*
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* More state savers are welcome. Especially for the scsi layer...
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*
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* For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/suspend.h>
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#include <linux/smp_lock.h>
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#include <linux/file.h>
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#include <linux/utsname.h>
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#include <linux/version.h>
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#include <linux/delay.h>
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#include <linux/reboot.h>
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#include <linux/bitops.h>
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#include <linux/vt_kern.h>
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#include <linux/kbd_kern.h>
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#include <linux/keyboard.h>
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#include <linux/spinlock.h>
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#include <linux/genhd.h>
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#include <linux/kernel.h>
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#include <linux/major.h>
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#include <linux/swap.h>
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#include <linux/pm.h>
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#include <linux/device.h>
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#include <linux/buffer_head.h>
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#include <linux/swapops.h>
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#include <linux/bootmem.h>
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#include <linux/syscalls.h>
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#include <linux/console.h>
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#include <linux/highmem.h>
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#include <linux/bio.h>
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#include <linux/mount.h>
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#include <asm/uaccess.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/io.h>
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#include <linux/random.h>
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#include <linux/crypto.h>
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#include <asm/scatterlist.h>
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#include "power.h"
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#define CIPHER "aes"
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#define MAXKEY 32
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#define MAXIV 32
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extern char resume_file[];
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/* Local variables that should not be affected by save */
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unsigned int nr_copy_pages __nosavedata = 0;
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/* Suspend pagedir is allocated before final copy, therefore it
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must be freed after resume
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Warning: this is evil. There are actually two pagedirs at time of
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resume. One is "pagedir_save", which is empty frame allocated at
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time of suspend, that must be freed. Second is "pagedir_nosave",
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allocated at time of resume, that travels through memory not to
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collide with anything.
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Warning: this is even more evil than it seems. Pagedirs this file
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talks about are completely different from page directories used by
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MMU hardware.
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*/
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suspend_pagedir_t *pagedir_nosave __nosavedata = NULL;
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suspend_pagedir_t *pagedir_save;
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#define SWSUSP_SIG "S1SUSPEND"
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static struct swsusp_header {
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char reserved[PAGE_SIZE - 20 - MAXKEY - MAXIV - sizeof(swp_entry_t)];
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u8 key_iv[MAXKEY+MAXIV];
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swp_entry_t swsusp_info;
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char orig_sig[10];
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char sig[10];
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} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
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static struct swsusp_info swsusp_info;
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/*
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* Saving part...
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*/
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/* We memorize in swapfile_used what swap devices are used for suspension */
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#define SWAPFILE_UNUSED 0
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#define SWAPFILE_SUSPEND 1 /* This is the suspending device */
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#define SWAPFILE_IGNORED 2 /* Those are other swap devices ignored for suspension */
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static unsigned short swapfile_used[MAX_SWAPFILES];
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static unsigned short root_swap;
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static int write_page(unsigned long addr, swp_entry_t * loc);
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static int bio_read_page(pgoff_t page_off, void * page);
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static u8 key_iv[MAXKEY+MAXIV];
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#ifdef CONFIG_SWSUSP_ENCRYPT
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static int crypto_init(int mode, void **mem)
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{
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int error = 0;
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int len;
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char *modemsg;
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struct crypto_tfm *tfm;
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modemsg = mode ? "suspend not possible" : "resume not possible";
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tfm = crypto_alloc_tfm(CIPHER, CRYPTO_TFM_MODE_CBC);
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if(!tfm) {
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printk(KERN_ERR "swsusp: no tfm, %s\n", modemsg);
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error = -EINVAL;
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goto out;
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}
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if(MAXKEY < crypto_tfm_alg_min_keysize(tfm)) {
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printk(KERN_ERR "swsusp: key buffer too small, %s\n", modemsg);
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error = -ENOKEY;
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goto fail;
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}
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if (mode)
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get_random_bytes(key_iv, MAXKEY+MAXIV);
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len = crypto_tfm_alg_max_keysize(tfm);
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if (len > MAXKEY)
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len = MAXKEY;
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if (crypto_cipher_setkey(tfm, key_iv, len)) {
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printk(KERN_ERR "swsusp: key setup failure, %s\n", modemsg);
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error = -EKEYREJECTED;
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goto fail;
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}
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len = crypto_tfm_alg_ivsize(tfm);
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if (MAXIV < len) {
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printk(KERN_ERR "swsusp: iv buffer too small, %s\n", modemsg);
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error = -EOVERFLOW;
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goto fail;
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}
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crypto_cipher_set_iv(tfm, key_iv+MAXKEY, len);
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*mem=(void *)tfm;
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goto out;
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fail: crypto_free_tfm(tfm);
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out: return error;
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}
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static __inline__ void crypto_exit(void *mem)
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{
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crypto_free_tfm((struct crypto_tfm *)mem);
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}
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static __inline__ int crypto_write(struct pbe *p, void *mem)
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{
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int error = 0;
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struct scatterlist src, dst;
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src.page = virt_to_page(p->address);
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src.offset = 0;
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src.length = PAGE_SIZE;
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dst.page = virt_to_page((void *)&swsusp_header);
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dst.offset = 0;
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dst.length = PAGE_SIZE;
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error = crypto_cipher_encrypt((struct crypto_tfm *)mem, &dst, &src,
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PAGE_SIZE);
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if (!error)
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error = write_page((unsigned long)&swsusp_header,
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&(p->swap_address));
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return error;
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}
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static __inline__ int crypto_read(struct pbe *p, void *mem)
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{
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int error = 0;
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struct scatterlist src, dst;
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error = bio_read_page(swp_offset(p->swap_address), (void *)p->address);
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if (!error) {
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src.offset = 0;
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src.length = PAGE_SIZE;
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dst.offset = 0;
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dst.length = PAGE_SIZE;
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src.page = dst.page = virt_to_page((void *)p->address);
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error = crypto_cipher_decrypt((struct crypto_tfm *)mem, &dst,
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&src, PAGE_SIZE);
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}
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return error;
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}
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#else
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static __inline__ int crypto_init(int mode, void *mem)
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{
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return 0;
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}
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static __inline__ void crypto_exit(void *mem)
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{
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}
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static __inline__ int crypto_write(struct pbe *p, void *mem)
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{
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return write_page(p->address, &(p->swap_address));
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}
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static __inline__ int crypto_read(struct pbe *p, void *mem)
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{
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return bio_read_page(swp_offset(p->swap_address), (void *)p->address);
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}
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#endif
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static int mark_swapfiles(swp_entry_t prev)
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{
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int error;
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rw_swap_page_sync(READ,
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swp_entry(root_swap, 0),
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virt_to_page((unsigned long)&swsusp_header));
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if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
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!memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
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memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
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memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
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memcpy(swsusp_header.key_iv, key_iv, MAXKEY+MAXIV);
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swsusp_header.swsusp_info = prev;
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error = rw_swap_page_sync(WRITE,
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swp_entry(root_swap, 0),
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virt_to_page((unsigned long)
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&swsusp_header));
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} else {
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pr_debug("swsusp: Partition is not swap space.\n");
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error = -ENODEV;
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}
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return error;
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}
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/*
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* Check whether the swap device is the specified resume
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* device, irrespective of whether they are specified by
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* identical names.
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*
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* (Thus, device inode aliasing is allowed. You can say /dev/hda4
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* instead of /dev/ide/host0/bus0/target0/lun0/part4 [if using devfs]
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* and they'll be considered the same device. This is *necessary* for
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* devfs, since the resume code can only recognize the form /dev/hda4,
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* but the suspend code would see the long name.)
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*/
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static int is_resume_device(const struct swap_info_struct *swap_info)
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{
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struct file *file = swap_info->swap_file;
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struct inode *inode = file->f_dentry->d_inode;
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return S_ISBLK(inode->i_mode) &&
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swsusp_resume_device == MKDEV(imajor(inode), iminor(inode));
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}
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static int swsusp_swap_check(void) /* This is called before saving image */
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{
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int i, len;
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len=strlen(resume_file);
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root_swap = 0xFFFF;
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spin_lock(&swap_lock);
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for (i=0; i<MAX_SWAPFILES; i++) {
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if (!(swap_info[i].flags & SWP_WRITEOK)) {
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swapfile_used[i]=SWAPFILE_UNUSED;
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} else {
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if (!len) {
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printk(KERN_WARNING "resume= option should be used to set suspend device" );
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if (root_swap == 0xFFFF) {
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swapfile_used[i] = SWAPFILE_SUSPEND;
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root_swap = i;
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} else
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swapfile_used[i] = SWAPFILE_IGNORED;
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} else {
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/* we ignore all swap devices that are not the resume_file */
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if (is_resume_device(&swap_info[i])) {
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swapfile_used[i] = SWAPFILE_SUSPEND;
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root_swap = i;
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} else {
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swapfile_used[i] = SWAPFILE_IGNORED;
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}
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}
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}
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}
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spin_unlock(&swap_lock);
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return (root_swap != 0xffff) ? 0 : -ENODEV;
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}
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|
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/**
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* This is called after saving image so modification
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* will be lost after resume... and that's what we want.
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* we make the device unusable. A new call to
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* lock_swapdevices can unlock the devices.
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*/
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static void lock_swapdevices(void)
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{
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int i;
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spin_lock(&swap_lock);
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for (i = 0; i< MAX_SWAPFILES; i++)
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if (swapfile_used[i] == SWAPFILE_IGNORED) {
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swap_info[i].flags ^= SWP_WRITEOK;
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}
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spin_unlock(&swap_lock);
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}
|
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|
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/**
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* write_page - Write one page to a fresh swap location.
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* @addr: Address we're writing.
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* @loc: Place to store the entry we used.
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*
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* Allocate a new swap entry and 'sync' it. Note we discard -EIO
|
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* errors. That is an artifact left over from swsusp. It did not
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* check the return of rw_swap_page_sync() at all, since most pages
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* written back to swap would return -EIO.
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* This is a partial improvement, since we will at least return other
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* errors, though we need to eventually fix the damn code.
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*/
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static int write_page(unsigned long addr, swp_entry_t * loc)
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{
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swp_entry_t entry;
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int error = 0;
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entry = get_swap_page();
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if (swp_offset(entry) &&
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swapfile_used[swp_type(entry)] == SWAPFILE_SUSPEND) {
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error = rw_swap_page_sync(WRITE, entry,
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virt_to_page(addr));
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if (error == -EIO)
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error = 0;
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if (!error)
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*loc = entry;
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} else
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error = -ENOSPC;
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return error;
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}
|
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|
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/**
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* data_free - Free the swap entries used by the saved image.
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*
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* Walk the list of used swap entries and free each one.
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* This is only used for cleanup when suspend fails.
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*/
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static void data_free(void)
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{
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swp_entry_t entry;
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struct pbe * p;
|
|
|
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for_each_pbe(p, pagedir_nosave) {
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entry = p->swap_address;
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if (entry.val)
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swap_free(entry);
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else
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break;
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}
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}
|
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|
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/**
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* data_write - Write saved image to swap.
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*
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* Walk the list of pages in the image and sync each one to swap.
|
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*/
|
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static int data_write(void)
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{
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int error = 0, i = 0;
|
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unsigned int mod = nr_copy_pages / 100;
|
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struct pbe *p;
|
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void *tfm;
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|
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if ((error = crypto_init(1, &tfm)))
|
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return error;
|
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|
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if (!mod)
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mod = 1;
|
|
|
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printk( "Writing data to swap (%d pages)... ", nr_copy_pages );
|
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for_each_pbe (p, pagedir_nosave) {
|
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if (!(i%mod))
|
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printk( "\b\b\b\b%3d%%", i / mod );
|
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if ((error = crypto_write(p, tfm))) {
|
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crypto_exit(tfm);
|
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return error;
|
|
}
|
|
i++;
|
|
}
|
|
printk("\b\b\b\bdone\n");
|
|
crypto_exit(tfm);
|
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return error;
|
|
}
|
|
|
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static void dump_info(void)
|
|
{
|
|
pr_debug(" swsusp: Version: %u\n",swsusp_info.version_code);
|
|
pr_debug(" swsusp: Num Pages: %ld\n",swsusp_info.num_physpages);
|
|
pr_debug(" swsusp: UTS Sys: %s\n",swsusp_info.uts.sysname);
|
|
pr_debug(" swsusp: UTS Node: %s\n",swsusp_info.uts.nodename);
|
|
pr_debug(" swsusp: UTS Release: %s\n",swsusp_info.uts.release);
|
|
pr_debug(" swsusp: UTS Version: %s\n",swsusp_info.uts.version);
|
|
pr_debug(" swsusp: UTS Machine: %s\n",swsusp_info.uts.machine);
|
|
pr_debug(" swsusp: UTS Domain: %s\n",swsusp_info.uts.domainname);
|
|
pr_debug(" swsusp: CPUs: %d\n",swsusp_info.cpus);
|
|
pr_debug(" swsusp: Image: %ld Pages\n",swsusp_info.image_pages);
|
|
pr_debug(" swsusp: Pagedir: %ld Pages\n",swsusp_info.pagedir_pages);
|
|
}
|
|
|
|
static void init_header(void)
|
|
{
|
|
memset(&swsusp_info, 0, sizeof(swsusp_info));
|
|
swsusp_info.version_code = LINUX_VERSION_CODE;
|
|
swsusp_info.num_physpages = num_physpages;
|
|
memcpy(&swsusp_info.uts, &system_utsname, sizeof(system_utsname));
|
|
|
|
swsusp_info.suspend_pagedir = pagedir_nosave;
|
|
swsusp_info.cpus = num_online_cpus();
|
|
swsusp_info.image_pages = nr_copy_pages;
|
|
}
|
|
|
|
static int close_swap(void)
|
|
{
|
|
swp_entry_t entry;
|
|
int error;
|
|
|
|
dump_info();
|
|
error = write_page((unsigned long)&swsusp_info, &entry);
|
|
if (!error) {
|
|
printk( "S" );
|
|
error = mark_swapfiles(entry);
|
|
printk( "|\n" );
|
|
}
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* free_pagedir_entries - Free pages used by the page directory.
|
|
*
|
|
* This is used during suspend for error recovery.
|
|
*/
|
|
|
|
static void free_pagedir_entries(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < swsusp_info.pagedir_pages; i++)
|
|
swap_free(swsusp_info.pagedir[i]);
|
|
}
|
|
|
|
|
|
/**
|
|
* write_pagedir - Write the array of pages holding the page directory.
|
|
* @last: Last swap entry we write (needed for header).
|
|
*/
|
|
|
|
static int write_pagedir(void)
|
|
{
|
|
int error = 0;
|
|
unsigned n = 0;
|
|
struct pbe * pbe;
|
|
|
|
printk( "Writing pagedir...");
|
|
for_each_pb_page (pbe, pagedir_nosave) {
|
|
if ((error = write_page((unsigned long)pbe, &swsusp_info.pagedir[n++])))
|
|
return error;
|
|
}
|
|
|
|
swsusp_info.pagedir_pages = n;
|
|
printk("done (%u pages)\n", n);
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* write_suspend_image - Write entire image and metadata.
|
|
*
|
|
*/
|
|
static int write_suspend_image(void)
|
|
{
|
|
int error;
|
|
|
|
init_header();
|
|
if ((error = data_write()))
|
|
goto FreeData;
|
|
|
|
if ((error = write_pagedir()))
|
|
goto FreePagedir;
|
|
|
|
if ((error = close_swap()))
|
|
goto FreePagedir;
|
|
Done:
|
|
memset(key_iv, 0, MAXKEY+MAXIV);
|
|
return error;
|
|
FreePagedir:
|
|
free_pagedir_entries();
|
|
FreeData:
|
|
data_free();
|
|
goto Done;
|
|
}
|
|
|
|
/**
|
|
* enough_swap - Make sure we have enough swap to save the image.
|
|
*
|
|
* Returns TRUE or FALSE after checking the total amount of swap
|
|
* space avaiable.
|
|
*
|
|
* FIXME: si_swapinfo(&i) returns all swap devices information.
|
|
* We should only consider resume_device.
|
|
*/
|
|
|
|
int enough_swap(void)
|
|
{
|
|
struct sysinfo i;
|
|
|
|
si_swapinfo(&i);
|
|
pr_debug("swsusp: available swap: %lu pages\n", i.freeswap);
|
|
return i.freeswap > (nr_copy_pages + PAGES_FOR_IO +
|
|
nr_copy_pages/PBES_PER_PAGE + !!(nr_copy_pages%PBES_PER_PAGE));
|
|
}
|
|
|
|
|
|
/* It is important _NOT_ to umount filesystems at this point. We want
|
|
* them synced (in case something goes wrong) but we DO not want to mark
|
|
* filesystem clean: it is not. (And it does not matter, if we resume
|
|
* correctly, we'll mark system clean, anyway.)
|
|
*/
|
|
int swsusp_write(void)
|
|
{
|
|
int error;
|
|
device_resume();
|
|
lock_swapdevices();
|
|
error = write_suspend_image();
|
|
/* This will unlock ignored swap devices since writing is finished */
|
|
lock_swapdevices();
|
|
return error;
|
|
|
|
}
|
|
|
|
|
|
|
|
int swsusp_suspend(void)
|
|
{
|
|
int error;
|
|
if ((error = arch_prepare_suspend()))
|
|
return error;
|
|
local_irq_disable();
|
|
/* At this point, device_suspend() has been called, but *not*
|
|
* device_power_down(). We *must* device_power_down() now.
|
|
* Otherwise, drivers for some devices (e.g. interrupt controllers)
|
|
* become desynchronized with the actual state of the hardware
|
|
* at resume time, and evil weirdness ensues.
|
|
*/
|
|
if ((error = device_power_down(PMSG_FREEZE))) {
|
|
printk(KERN_ERR "Some devices failed to power down, aborting suspend\n");
|
|
local_irq_enable();
|
|
return error;
|
|
}
|
|
|
|
if ((error = swsusp_swap_check())) {
|
|
printk(KERN_ERR "swsusp: cannot find swap device, try swapon -a.\n");
|
|
device_power_up();
|
|
local_irq_enable();
|
|
return error;
|
|
}
|
|
|
|
save_processor_state();
|
|
if ((error = swsusp_arch_suspend()))
|
|
printk(KERN_ERR "Error %d suspending\n", error);
|
|
/* Restore control flow magically appears here */
|
|
restore_processor_state();
|
|
restore_highmem();
|
|
device_power_up();
|
|
local_irq_enable();
|
|
return error;
|
|
}
|
|
|
|
int swsusp_resume(void)
|
|
{
|
|
int error;
|
|
local_irq_disable();
|
|
if (device_power_down(PMSG_FREEZE))
|
|
printk(KERN_ERR "Some devices failed to power down, very bad\n");
|
|
/* We'll ignore saved state, but this gets preempt count (etc) right */
|
|
save_processor_state();
|
|
error = swsusp_arch_resume();
|
|
/* Code below is only ever reached in case of failure. Otherwise
|
|
* execution continues at place where swsusp_arch_suspend was called
|
|
*/
|
|
BUG_ON(!error);
|
|
restore_processor_state();
|
|
restore_highmem();
|
|
touch_softlockup_watchdog();
|
|
device_power_up();
|
|
local_irq_enable();
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* On resume, for storing the PBE list and the image,
|
|
* we can only use memory pages that do not conflict with the pages
|
|
* which had been used before suspend.
|
|
*
|
|
* We don't know which pages are usable until we allocate them.
|
|
*
|
|
* Allocated but unusable (ie eaten) memory pages are linked together
|
|
* to create a list, so that we can free them easily
|
|
*
|
|
* We could have used a type other than (void *)
|
|
* for this purpose, but ...
|
|
*/
|
|
static void **eaten_memory = NULL;
|
|
|
|
static inline void eat_page(void *page)
|
|
{
|
|
void **c;
|
|
|
|
c = eaten_memory;
|
|
eaten_memory = page;
|
|
*eaten_memory = c;
|
|
}
|
|
|
|
unsigned long get_usable_page(gfp_t gfp_mask)
|
|
{
|
|
unsigned long m;
|
|
|
|
m = get_zeroed_page(gfp_mask);
|
|
while (!PageNosaveFree(virt_to_page(m))) {
|
|
eat_page((void *)m);
|
|
m = get_zeroed_page(gfp_mask);
|
|
if (!m)
|
|
break;
|
|
}
|
|
return m;
|
|
}
|
|
|
|
void free_eaten_memory(void)
|
|
{
|
|
unsigned long m;
|
|
void **c;
|
|
int i = 0;
|
|
|
|
c = eaten_memory;
|
|
while (c) {
|
|
m = (unsigned long)c;
|
|
c = *c;
|
|
free_page(m);
|
|
i++;
|
|
}
|
|
eaten_memory = NULL;
|
|
pr_debug("swsusp: %d unused pages freed\n", i);
|
|
}
|
|
|
|
/**
|
|
* check_pagedir - We ensure here that pages that the PBEs point to
|
|
* won't collide with pages where we're going to restore from the loaded
|
|
* pages later
|
|
*/
|
|
|
|
static int check_pagedir(struct pbe *pblist)
|
|
{
|
|
struct pbe *p;
|
|
|
|
/* This is necessary, so that we can free allocated pages
|
|
* in case of failure
|
|
*/
|
|
for_each_pbe (p, pblist)
|
|
p->address = 0UL;
|
|
|
|
for_each_pbe (p, pblist) {
|
|
p->address = get_usable_page(GFP_ATOMIC);
|
|
if (!p->address)
|
|
return -ENOMEM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* swsusp_pagedir_relocate - It is possible, that some memory pages
|
|
* occupied by the list of PBEs collide with pages where we're going to
|
|
* restore from the loaded pages later. We relocate them here.
|
|
*/
|
|
|
|
static struct pbe * swsusp_pagedir_relocate(struct pbe *pblist)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long zone_pfn;
|
|
struct pbe *pbpage, *tail, *p;
|
|
void *m;
|
|
int rel = 0, error = 0;
|
|
|
|
if (!pblist) /* a sanity check */
|
|
return NULL;
|
|
|
|
pr_debug("swsusp: Relocating pagedir (%lu pages to check)\n",
|
|
swsusp_info.pagedir_pages);
|
|
|
|
/* Set page flags */
|
|
|
|
for_each_zone (zone) {
|
|
for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
|
|
SetPageNosaveFree(pfn_to_page(zone_pfn +
|
|
zone->zone_start_pfn));
|
|
}
|
|
|
|
/* Clear orig addresses */
|
|
|
|
for_each_pbe (p, pblist)
|
|
ClearPageNosaveFree(virt_to_page(p->orig_address));
|
|
|
|
tail = pblist + PB_PAGE_SKIP;
|
|
|
|
/* Relocate colliding pages */
|
|
|
|
for_each_pb_page (pbpage, pblist) {
|
|
if (!PageNosaveFree(virt_to_page((unsigned long)pbpage))) {
|
|
m = (void *)get_usable_page(GFP_ATOMIC | __GFP_COLD);
|
|
if (!m) {
|
|
error = -ENOMEM;
|
|
break;
|
|
}
|
|
memcpy(m, (void *)pbpage, PAGE_SIZE);
|
|
if (pbpage == pblist)
|
|
pblist = (struct pbe *)m;
|
|
else
|
|
tail->next = (struct pbe *)m;
|
|
|
|
eat_page((void *)pbpage);
|
|
pbpage = (struct pbe *)m;
|
|
|
|
/* We have to link the PBEs again */
|
|
|
|
for (p = pbpage; p < pbpage + PB_PAGE_SKIP; p++)
|
|
if (p->next) /* needed to save the end */
|
|
p->next = p + 1;
|
|
|
|
rel++;
|
|
}
|
|
tail = pbpage + PB_PAGE_SKIP;
|
|
}
|
|
|
|
if (error) {
|
|
printk("\nswsusp: Out of memory\n\n");
|
|
free_pagedir(pblist);
|
|
free_eaten_memory();
|
|
pblist = NULL;
|
|
/* Is this even worth handling? It should never ever happen, and we
|
|
have just lost user's state, anyway... */
|
|
} else
|
|
printk("swsusp: Relocated %d pages\n", rel);
|
|
|
|
return pblist;
|
|
}
|
|
|
|
/*
|
|
* Using bio to read from swap.
|
|
* This code requires a bit more work than just using buffer heads
|
|
* but, it is the recommended way for 2.5/2.6.
|
|
* The following are to signal the beginning and end of I/O. Bios
|
|
* finish asynchronously, while we want them to happen synchronously.
|
|
* A simple atomic_t, and a wait loop take care of this problem.
|
|
*/
|
|
|
|
static atomic_t io_done = ATOMIC_INIT(0);
|
|
|
|
static int end_io(struct bio * bio, unsigned int num, int err)
|
|
{
|
|
if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
|
|
panic("I/O error reading memory image");
|
|
atomic_set(&io_done, 0);
|
|
return 0;
|
|
}
|
|
|
|
static struct block_device * resume_bdev;
|
|
|
|
/**
|
|
* submit - submit BIO request.
|
|
* @rw: READ or WRITE.
|
|
* @off physical offset of page.
|
|
* @page: page we're reading or writing.
|
|
*
|
|
* Straight from the textbook - allocate and initialize the bio.
|
|
* If we're writing, make sure the page is marked as dirty.
|
|
* Then submit it and wait.
|
|
*/
|
|
|
|
static int submit(int rw, pgoff_t page_off, void * page)
|
|
{
|
|
int error = 0;
|
|
struct bio * bio;
|
|
|
|
bio = bio_alloc(GFP_ATOMIC, 1);
|
|
if (!bio)
|
|
return -ENOMEM;
|
|
bio->bi_sector = page_off * (PAGE_SIZE >> 9);
|
|
bio_get(bio);
|
|
bio->bi_bdev = resume_bdev;
|
|
bio->bi_end_io = end_io;
|
|
|
|
if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
|
|
printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
|
|
error = -EFAULT;
|
|
goto Done;
|
|
}
|
|
|
|
if (rw == WRITE)
|
|
bio_set_pages_dirty(bio);
|
|
|
|
atomic_set(&io_done, 1);
|
|
submit_bio(rw | (1 << BIO_RW_SYNC), bio);
|
|
while (atomic_read(&io_done))
|
|
yield();
|
|
|
|
Done:
|
|
bio_put(bio);
|
|
return error;
|
|
}
|
|
|
|
static int bio_read_page(pgoff_t page_off, void * page)
|
|
{
|
|
return submit(READ, page_off, page);
|
|
}
|
|
|
|
static int bio_write_page(pgoff_t page_off, void * page)
|
|
{
|
|
return submit(WRITE, page_off, page);
|
|
}
|
|
|
|
/*
|
|
* Sanity check if this image makes sense with this kernel/swap context
|
|
* I really don't think that it's foolproof but more than nothing..
|
|
*/
|
|
|
|
static const char * sanity_check(void)
|
|
{
|
|
dump_info();
|
|
if (swsusp_info.version_code != LINUX_VERSION_CODE)
|
|
return "kernel version";
|
|
if (swsusp_info.num_physpages != num_physpages)
|
|
return "memory size";
|
|
if (strcmp(swsusp_info.uts.sysname,system_utsname.sysname))
|
|
return "system type";
|
|
if (strcmp(swsusp_info.uts.release,system_utsname.release))
|
|
return "kernel release";
|
|
if (strcmp(swsusp_info.uts.version,system_utsname.version))
|
|
return "version";
|
|
if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
|
|
return "machine";
|
|
#if 0
|
|
/* We can't use number of online CPUs when we use hotplug to remove them ;-))) */
|
|
if (swsusp_info.cpus != num_possible_cpus())
|
|
return "number of cpus";
|
|
#endif
|
|
return NULL;
|
|
}
|
|
|
|
|
|
static int check_header(void)
|
|
{
|
|
const char * reason = NULL;
|
|
int error;
|
|
|
|
if ((error = bio_read_page(swp_offset(swsusp_header.swsusp_info), &swsusp_info)))
|
|
return error;
|
|
|
|
/* Is this same machine? */
|
|
if ((reason = sanity_check())) {
|
|
printk(KERN_ERR "swsusp: Resume mismatch: %s\n",reason);
|
|
return -EPERM;
|
|
}
|
|
nr_copy_pages = swsusp_info.image_pages;
|
|
return error;
|
|
}
|
|
|
|
static int check_sig(void)
|
|
{
|
|
int error;
|
|
|
|
memset(&swsusp_header, 0, sizeof(swsusp_header));
|
|
if ((error = bio_read_page(0, &swsusp_header)))
|
|
return error;
|
|
if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
|
|
memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
|
|
memcpy(key_iv, swsusp_header.key_iv, MAXKEY+MAXIV);
|
|
memset(swsusp_header.key_iv, 0, MAXKEY+MAXIV);
|
|
|
|
/*
|
|
* Reset swap signature now.
|
|
*/
|
|
error = bio_write_page(0, &swsusp_header);
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
if (!error)
|
|
pr_debug("swsusp: Signature found, resuming\n");
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* data_read - Read image pages from swap.
|
|
*
|
|
* You do not need to check for overlaps, check_pagedir()
|
|
* already did that.
|
|
*/
|
|
|
|
static int data_read(struct pbe *pblist)
|
|
{
|
|
struct pbe * p;
|
|
int error = 0;
|
|
int i = 0;
|
|
int mod = swsusp_info.image_pages / 100;
|
|
void *tfm;
|
|
|
|
if ((error = crypto_init(0, &tfm)))
|
|
return error;
|
|
|
|
if (!mod)
|
|
mod = 1;
|
|
|
|
printk("swsusp: Reading image data (%lu pages): ",
|
|
swsusp_info.image_pages);
|
|
|
|
for_each_pbe (p, pblist) {
|
|
if (!(i % mod))
|
|
printk("\b\b\b\b%3d%%", i / mod);
|
|
|
|
if ((error = crypto_read(p, tfm))) {
|
|
crypto_exit(tfm);
|
|
return error;
|
|
}
|
|
|
|
i++;
|
|
}
|
|
printk("\b\b\b\bdone\n");
|
|
crypto_exit(tfm);
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* read_pagedir - Read page backup list pages from swap
|
|
*/
|
|
|
|
static int read_pagedir(struct pbe *pblist)
|
|
{
|
|
struct pbe *pbpage, *p;
|
|
unsigned i = 0;
|
|
int error;
|
|
|
|
if (!pblist)
|
|
return -EFAULT;
|
|
|
|
printk("swsusp: Reading pagedir (%lu pages)\n",
|
|
swsusp_info.pagedir_pages);
|
|
|
|
for_each_pb_page (pbpage, pblist) {
|
|
unsigned long offset = swp_offset(swsusp_info.pagedir[i++]);
|
|
|
|
error = -EFAULT;
|
|
if (offset) {
|
|
p = (pbpage + PB_PAGE_SKIP)->next;
|
|
error = bio_read_page(offset, (void *)pbpage);
|
|
(pbpage + PB_PAGE_SKIP)->next = p;
|
|
}
|
|
if (error)
|
|
break;
|
|
}
|
|
|
|
if (error)
|
|
free_pagedir(pblist);
|
|
else
|
|
BUG_ON(i != swsusp_info.pagedir_pages);
|
|
|
|
return error;
|
|
}
|
|
|
|
|
|
static int check_suspend_image(void)
|
|
{
|
|
int error = 0;
|
|
|
|
if ((error = check_sig()))
|
|
return error;
|
|
|
|
if ((error = check_header()))
|
|
return error;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int read_suspend_image(void)
|
|
{
|
|
int error = 0;
|
|
struct pbe *p;
|
|
|
|
if (!(p = alloc_pagedir(nr_copy_pages)))
|
|
return -ENOMEM;
|
|
|
|
if ((error = read_pagedir(p)))
|
|
return error;
|
|
|
|
create_pbe_list(p, nr_copy_pages);
|
|
|
|
if (!(pagedir_nosave = swsusp_pagedir_relocate(p)))
|
|
return -ENOMEM;
|
|
|
|
/* Allocate memory for the image and read the data from swap */
|
|
|
|
error = check_pagedir(pagedir_nosave);
|
|
|
|
if (!error)
|
|
error = data_read(pagedir_nosave);
|
|
|
|
if (error) { /* We fail cleanly */
|
|
free_eaten_memory();
|
|
for_each_pbe (p, pagedir_nosave)
|
|
if (p->address) {
|
|
free_page(p->address);
|
|
p->address = 0UL;
|
|
}
|
|
free_pagedir(pagedir_nosave);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* swsusp_check - Check for saved image in swap
|
|
*/
|
|
|
|
int swsusp_check(void)
|
|
{
|
|
int error;
|
|
|
|
resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
|
|
if (!IS_ERR(resume_bdev)) {
|
|
set_blocksize(resume_bdev, PAGE_SIZE);
|
|
error = check_suspend_image();
|
|
if (error)
|
|
blkdev_put(resume_bdev);
|
|
} else
|
|
error = PTR_ERR(resume_bdev);
|
|
|
|
if (!error)
|
|
pr_debug("swsusp: resume file found\n");
|
|
else
|
|
pr_debug("swsusp: Error %d check for resume file\n", error);
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* swsusp_read - Read saved image from swap.
|
|
*/
|
|
|
|
int swsusp_read(void)
|
|
{
|
|
int error;
|
|
|
|
if (IS_ERR(resume_bdev)) {
|
|
pr_debug("swsusp: block device not initialised\n");
|
|
return PTR_ERR(resume_bdev);
|
|
}
|
|
|
|
error = read_suspend_image();
|
|
blkdev_put(resume_bdev);
|
|
memset(key_iv, 0, MAXKEY+MAXIV);
|
|
|
|
if (!error)
|
|
pr_debug("swsusp: Reading resume file was successful\n");
|
|
else
|
|
pr_debug("swsusp: Error %d resuming\n", error);
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* swsusp_close - close swap device.
|
|
*/
|
|
|
|
void swsusp_close(void)
|
|
{
|
|
if (IS_ERR(resume_bdev)) {
|
|
pr_debug("swsusp: block device not initialised\n");
|
|
return;
|
|
}
|
|
|
|
blkdev_put(resume_bdev);
|
|
}
|