1 files changed, 181 insertions, 33 deletions

diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index f2bc71b..1cc9ff2 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -31,6 +31,9 @@
  * Alex Badea <vampire@go.ro>:
  * Fixed runaway init
  *
+ * Andreas Steinmetz <ast@domdv.de>:
+ * Added encrypted suspend option
+ *
  * More state savers are welcome. Especially for the scsi layer...
  *
  * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
@@ -71,8 +74,16 @@
 #include <asm/tlbflush.h>
 #include <asm/io.h>
 
+#include <linux/random.h>
+#include <linux/crypto.h>
+#include <asm/scatterlist.h>
+
 #include "power.h"
 
+#define CIPHER "aes"
+#define MAXKEY 32
+#define MAXIV  32
+
 /* References to section boundaries */
 extern const void __nosave_begin, __nosave_end;
 
@@ -103,7 +114,8 @@ static suspend_pagedir_t *pagedir_save;
 #define SWSUSP_SIG	"S1SUSPEND"
 
 static struct swsusp_header {
-	char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)];
+	char reserved[PAGE_SIZE - 20 - MAXKEY - MAXIV - sizeof(swp_entry_t)];
+	u8 key_iv[MAXKEY+MAXIV];
 	swp_entry_t swsusp_info;
 	char	orig_sig[10];
 	char	sig[10];
@@ -129,6 +141,131 @@ static struct swsusp_info swsusp_info;
 static unsigned short swapfile_used[MAX_SWAPFILES];
 static unsigned short root_swap;
 
+static int write_page(unsigned long addr, swp_entry_t * loc);
+static int bio_read_page(pgoff_t page_off, void * page);
+
+static u8 key_iv[MAXKEY+MAXIV];
+
+#ifdef CONFIG_SWSUSP_ENCRYPT
+
+static int crypto_init(int mode, void **mem)
+{
+	int error = 0;
+	int len;
+	char *modemsg;
+	struct crypto_tfm *tfm;
+
+	modemsg = mode ? "suspend not possible" : "resume not possible";
+
+	tfm = crypto_alloc_tfm(CIPHER, CRYPTO_TFM_MODE_CBC);
+	if(!tfm) {
+		printk(KERN_ERR "swsusp: no tfm, %s\n", modemsg);
+		error = -EINVAL;
+		goto out;
+	}
+
+	if(MAXKEY < crypto_tfm_alg_min_keysize(tfm)) {
+		printk(KERN_ERR "swsusp: key buffer too small, %s\n", modemsg);
+		error = -ENOKEY;
+		goto fail;
+	}
+
+	if (mode)
+		get_random_bytes(key_iv, MAXKEY+MAXIV);
+
+	len = crypto_tfm_alg_max_keysize(tfm);
+	if (len > MAXKEY)
+		len = MAXKEY;
+
+	if (crypto_cipher_setkey(tfm, key_iv, len)) {
+		printk(KERN_ERR "swsusp: key setup failure, %s\n", modemsg);
+		error = -EKEYREJECTED;
+		goto fail;
+	}
+
+	len = crypto_tfm_alg_ivsize(tfm);
+
+	if (MAXIV < len) {
+		printk(KERN_ERR "swsusp: iv buffer too small, %s\n", modemsg);
+		error = -EOVERFLOW;
+		goto fail;
+	}
+
+	crypto_cipher_set_iv(tfm, key_iv+MAXKEY, len);
+
+	*mem=(void *)tfm;
+
+	goto out;
+
+fail:	crypto_free_tfm(tfm);
+out:	return error;
+}
+
+static __inline__ void crypto_exit(void *mem)
+{
+	crypto_free_tfm((struct crypto_tfm *)mem);
+}
+
+static __inline__ int crypto_write(struct pbe *p, void *mem)
+{
+	int error = 0;
+	struct scatterlist src, dst;
+
+	src.page   = virt_to_page(p->address);
+	src.offset = 0;
+	src.length = PAGE_SIZE;
+	dst.page   = virt_to_page((void *)&swsusp_header);
+	dst.offset = 0;
+	dst.length = PAGE_SIZE;
+
+	error = crypto_cipher_encrypt((struct crypto_tfm *)mem, &dst, &src,
+					PAGE_SIZE);
+
+	if (!error)
+		error = write_page((unsigned long)&swsusp_header,
+				&(p->swap_address));
+	return error;
+}
+
+static __inline__ int crypto_read(struct pbe *p, void *mem)
+{
+	int error = 0;
+	struct scatterlist src, dst;
+
+	error = bio_read_page(swp_offset(p->swap_address), (void *)p->address);
+	if (!error) {
+		src.offset = 0;
+		src.length = PAGE_SIZE;
+		dst.offset = 0;
+		dst.length = PAGE_SIZE;
+		src.page = dst.page = virt_to_page((void *)p->address);
+
+		error = crypto_cipher_decrypt((struct crypto_tfm *)mem, &dst,
+						&src, PAGE_SIZE);
+	}
+	return error;
+}
+#else
+static __inline__ int crypto_init(int mode, void *mem)
+{
+	return 0;
+}
+
+static __inline__ void crypto_exit(void *mem)
+{
+}
+
+static __inline__ int crypto_write(struct pbe *p, void *mem)
+{
+	return write_page(p->address, &(p->swap_address));
+}
+
+static __inline__ int crypto_read(struct pbe *p, void *mem)
+{
+	return bio_read_page(swp_offset(p->swap_address), (void *)p->address);
+}
+#endif
+
 static int mark_swapfiles(swp_entry_t prev)
 {
 	int error;
@@ -140,6 +277,7 @@ static int mark_swapfiles(swp_entry_t prev)
 	    !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
 		memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
 		memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
+		memcpy(swsusp_header.key_iv, key_iv, MAXKEY+MAXIV);
 		swsusp_header.swsusp_info = prev;
 		error = rw_swap_page_sync(WRITE,
 					  swp_entry(root_swap, 0),
@@ -179,9 +317,9 @@ static int swsusp_swap_check(void) /* This is called before saving image */
 	len=strlen(resume_file);
 	root_swap = 0xFFFF;
 
-	swap_list_lock();
+	spin_lock(&swap_lock);
 	for (i=0; i<MAX_SWAPFILES; i++) {
-		if (swap_info[i].flags == 0) {
+		if (!(swap_info[i].flags & SWP_WRITEOK)) {
 			swapfile_used[i]=SWAPFILE_UNUSED;
 		} else {
 			if (!len) {
@@ -202,7 +340,7 @@ static int swsusp_swap_check(void) /* This is called before saving image */
 			}
 		}
 	}
-	swap_list_unlock();
+	spin_unlock(&swap_lock);
 	return (root_swap != 0xffff) ? 0 : -ENODEV;
 }
 
@@ -216,16 +354,16 @@ static void lock_swapdevices(void)
 {
 	int i;
 
-	swap_list_lock();
+	spin_lock(&swap_lock);
 	for (i = 0; i< MAX_SWAPFILES; i++)
 		if (swapfile_used[i] == SWAPFILE_IGNORED) {
-			swap_info[i].flags ^= 0xFF;
+			swap_info[i].flags ^= SWP_WRITEOK;
 		}
-	swap_list_unlock();
+	spin_unlock(&swap_lock);
 }
 
 /**
- *	write_swap_page - Write one page to a fresh swap location.
+ *	write_page - Write one page to a fresh swap location.
  *	@addr:	Address we're writing.
  *	@loc:	Place to store the entry we used.
  *
@@ -286,6 +424,10 @@ static int data_write(void)
 	int error = 0, i = 0;
 	unsigned int mod = nr_copy_pages / 100;
 	struct pbe *p;
+	void *tfm;
+
+	if ((error = crypto_init(1, &tfm)))
+		return error;
 
 	if (!mod)
 		mod = 1;
@@ -294,11 +436,14 @@ static int data_write(void)
 	for_each_pbe (p, pagedir_nosave) {
 		if (!(i%mod))
 			printk( "\b\b\b\b%3d%%", i / mod );
-		if ((error = write_page(p->address, &(p->swap_address))))
+		if ((error = crypto_write(p, tfm))) {
+			crypto_exit(tfm);
 			return error;
+		}
 		i++;
 	}
 	printk("\b\b\b\bdone\n");
+	crypto_exit(tfm);
 	return error;
 }
 
@@ -385,7 +530,6 @@ static int write_pagedir(void)
  *	write_suspend_image - Write entire image and metadata.
  *
  */
-
 static int write_suspend_image(void)
 {
 	int error;
@@ -400,6 +544,7 @@ static int write_suspend_image(void)
 	if ((error = close_swap()))
 		goto FreePagedir;
  Done:
+	memset(key_iv, 0, MAXKEY+MAXIV);
 	return error;
  FreePagedir:
 	free_pagedir_entries();
@@ -591,18 +736,7 @@ static void copy_data_pages(void)
 
 static int calc_nr(int nr_copy)
 {
-	int extra = 0;
-	int mod = !!(nr_copy % PBES_PER_PAGE);
-	int diff = (nr_copy / PBES_PER_PAGE) + mod;
-
-	do {
-		extra += diff;
-		nr_copy += diff;
-		mod = !!(nr_copy % PBES_PER_PAGE);
-		diff = (nr_copy / PBES_PER_PAGE) + mod - extra;
-	} while (diff > 0);
-
-	return nr_copy;
+	return nr_copy + (nr_copy+PBES_PER_PAGE-2)/(PBES_PER_PAGE-1);
 }
 
 /**
@@ -729,6 +863,9 @@ static int alloc_image_pages(void)
 	return 0;
 }
 
+/* Free pages we allocated for suspend. Suspend pages are alocated
+ * before atomic copy, so we need to free them after resume.
+ */
 void swsusp_free(void)
 {
 	BUG_ON(PageNosave(virt_to_page(pagedir_save)));
@@ -784,6 +921,7 @@ static int swsusp_alloc(void)
 
 	pagedir_nosave = NULL;
 	nr_copy_pages = calc_nr(nr_copy_pages);
+	nr_copy_pages_check = nr_copy_pages;
 
 	pr_debug("suspend: (pages needed: %d + %d free: %d)\n",
 		 nr_copy_pages, PAGES_FOR_IO, nr_free_pages());
@@ -806,7 +944,6 @@ static int swsusp_alloc(void)
 		return error;
 	}
 
-	nr_copy_pages_check = nr_copy_pages;
 	return 0;
 }
 
@@ -886,20 +1023,21 @@ int swsusp_suspend(void)
 	 * 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: FATAL: cannot find swap device, try "
-				"swapon -a!\n");
+		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("Error %d suspending\n", error);
+		printk(KERN_ERR "Error %d suspending\n", error);
 	/* Restore control flow magically appears here */
 	restore_processor_state();
 	BUG_ON (nr_copy_pages_check != nr_copy_pages);
@@ -924,6 +1062,7 @@ int swsusp_resume(void)
 	BUG_ON(!error);
 	restore_processor_state();
 	restore_highmem();
+	touch_softlockup_watchdog();
 	device_power_up();
 	local_irq_enable();
 	return error;
@@ -1077,8 +1216,9 @@ static struct pbe * swsusp_pagedir_relocate(struct pbe *pblist)
 		free_pagedir(pblist);
 		free_eaten_memory();
 		pblist = NULL;
-	}
-	else
+		/* 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;
@@ -1179,7 +1319,8 @@ static const char * sanity_check(void)
 	if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
 		return "machine";
 #if 0
-	if(swsusp_info.cpus != num_online_cpus())
+	/* 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;
@@ -1212,13 +1353,14 @@ static int check_sig(void)
 		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 { 
-		printk(KERN_ERR "swsusp: Suspend partition has wrong signature?\n");
 		return -EINVAL;
 	}
 	if (!error)
@@ -1239,6 +1381,10 @@ static int data_read(struct pbe *pblist)
 	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;
@@ -1250,14 +1396,15 @@ static int data_read(struct pbe *pblist)
 		if (!(i % mod))
 			printk("\b\b\b\b%3d%%", i / mod);
 
-		error = bio_read_page(swp_offset(p->swap_address),
-				  (void *)p->address);
-		if (error)
+		if ((error = crypto_read(p, tfm))) {
+			crypto_exit(tfm);
 			return error;
+		}
 
 		i++;
 	}
 	printk("\b\b\b\bdone\n");
+	crypto_exit(tfm);
 	return error;
 }
 
@@ -1385,6 +1532,7 @@ int swsusp_read(void)
 
 	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");