Merge ../bleed-2.6
[powerpc.git] / kernel / power / swsusp.c
index f2bc71b..10bc5ec 100644 (file)
@@ -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
 #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.
  *
@@ -264,15 +402,14 @@ static int write_page(unsigned long addr, swp_entry_t * loc)
 static void data_free(void)
 {
        swp_entry_t entry;
-       int i;
+       struct pbe * p;
 
-       for (i = 0; i < nr_copy_pages; i++) {
-               entry = (pagedir_nosave + i)->swap_address;
+       for_each_pbe(p, pagedir_nosave) {
+               entry = p->swap_address;
                if (entry.val)
                        swap_free(entry);
                else
                        break;
-               (pagedir_nosave + i)->swap_address = (swp_entry_t){0};
        }
 }
 
@@ -286,6 +423,10 @@ 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 +435,14 @@ 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 +529,6 @@ static int write_pagedir(void)
  *     write_suspend_image - Write entire image and metadata.
  *
  */
-
 static int write_suspend_image(void)
 {
        int error;
@@ -400,6 +543,7 @@ 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 +735,7 @@ 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 +862,9 @@ 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 +920,7 @@ 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());
@@ -794,6 +931,10 @@ static int swsusp_alloc(void)
        if (!enough_swap())
                return -ENOSPC;
 
+       if (MAX_PBES < nr_copy_pages / PBES_PER_PAGE +
+           !!(nr_copy_pages % PBES_PER_PAGE))
+               return -ENOSPC;
+
        if (!(pagedir_save = alloc_pagedir(nr_copy_pages))) {
                printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
                return -ENOMEM;
@@ -806,7 +947,6 @@ static int swsusp_alloc(void)
                return error;
        }
 
-       nr_copy_pages_check = nr_copy_pages;
        return 0;
 }
 
@@ -886,20 +1026,21 @@ 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 +1065,7 @@ int swsusp_resume(void)
        BUG_ON(!error);
        restore_processor_state();
        restore_highmem();
+       touch_softlockup_watchdog();
        device_power_up();
        local_irq_enable();
        return error;
@@ -953,7 +1095,7 @@ static inline void eat_page(void *page)
        *eaten_memory = c;
 }
 
-static unsigned long get_usable_page(unsigned gfp_mask)
+unsigned long get_usable_page(gfp_t gfp_mask)
 {
        unsigned long m;
 
@@ -967,7 +1109,7 @@ static unsigned long get_usable_page(unsigned gfp_mask)
        return m;
 }
 
-static void free_eaten_memory(void)
+void free_eaten_memory(void)
 {
        unsigned long m;
        void **c;
@@ -1077,8 +1219,9 @@ 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 +1322,8 @@ 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 +1356,14 @@ 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 +1384,10 @@ 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 +1399,15 @@ 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;
 }
 
@@ -1291,9 +1441,9 @@ static int read_pagedir(struct pbe *pblist)
        }
 
        if (error)
-               free_page((unsigned long)pblist);
-
-       BUG_ON(i != swsusp_info.pagedir_pages);
+               free_pagedir(pblist);
+       else
+               BUG_ON(i != swsusp_info.pagedir_pages);
 
        return error;
 }
@@ -1331,11 +1481,12 @@ static int read_suspend_image(void)
        /* Allocate memory for the image and read the data from swap */
 
        error = check_pagedir(pagedir_nosave);
-       free_eaten_memory();
+
        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);
@@ -1385,6 +1536,7 @@ 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");