diff options
Diffstat (limited to 'kernel/power/tuxonice_copy_before_write.c')
| -rw-r--r-- | kernel/power/tuxonice_copy_before_write.c | 240 |
1 files changed, 0 insertions, 240 deletions
diff --git a/kernel/power/tuxonice_copy_before_write.c b/kernel/power/tuxonice_copy_before_write.c deleted file mode 100644 index eb627915e..000000000 --- a/kernel/power/tuxonice_copy_before_write.c +++ /dev/null @@ -1,240 +0,0 @@ -/* - * kernel/power/tuxonice_copy_before_write.c - * - * Copyright (C) 2015 Nigel Cunningham (nigel at nigelcunningham com au) - * - * This file is released under the GPLv2. - * - * Routines (apart from the fault handling code) to deal with allocating memory - * for copying pages before they are modified, restoring the contents and getting - * the contents written to disk. - */ - -#include <linux/percpu-defs.h> -#include <linux/sched.h> -#include <linux/tuxonice.h> -#include "tuxonice_alloc.h" -#include "tuxonice_modules.h" -#include "tuxonice_sysfs.h" -#include "tuxonice.h" - -DEFINE_PER_CPU(struct toi_cbw_state, toi_cbw_states); -#define CBWS_PER_PAGE (PAGE_SIZE / sizeof(struct toi_cbw)) -#define toi_cbw_pool_size 100 - -static void _toi_free_cbw_data(struct toi_cbw_state *state) -{ - struct toi_cbw *page_ptr, *ptr, *next; - - page_ptr = ptr = state->first; - - while(ptr) { - next = ptr->next; - - if (ptr->virt) { - toi__free_page(40, virt_to_page(ptr->virt)); - } - if ((((unsigned long) ptr) & PAGE_MASK) != (unsigned long) page_ptr) { - /* Must be on a new page - free the previous one. */ - toi__free_page(40, virt_to_page(page_ptr)); - page_ptr = ptr; - } - ptr = next; - } - - if (page_ptr) { - toi__free_page(40, virt_to_page(page_ptr)); - } - - state->first = state->next = state->last = NULL; - state->size = 0; -} - -void toi_free_cbw_data(void) -{ - int i; - - for_each_online_cpu(i) { - struct toi_cbw_state *state = &per_cpu(toi_cbw_states, i); - - if (!state->first) - continue; - - state->enabled = 0; - - while (state->active) { - schedule(); - } - - _toi_free_cbw_data(state); - } -} - -static int _toi_allocate_cbw_data(struct toi_cbw_state *state) -{ - while(state->size < toi_cbw_pool_size) { - int i; - struct toi_cbw *ptr; - - ptr = (struct toi_cbw *) toi_get_zeroed_page(40, GFP_KERNEL); - - if (!ptr) { - return -ENOMEM; - } - - if (!state->first) { - state->first = state->next = state->last = ptr; - } - - for (i = 0; i < CBWS_PER_PAGE; i++) { - struct toi_cbw *cbw = &ptr[i]; - - cbw->virt = (char *) toi_get_zeroed_page(40, GFP_KERNEL); - if (!cbw->virt) { - state->size += i; - printk("Out of memory allocating CBW pages.\n"); - return -ENOMEM; - } - - if (cbw == state->first) - continue; - - state->last->next = cbw; - state->last = cbw; - } - - state->size += CBWS_PER_PAGE; - } - - state->enabled = 1; - - return 0; -} - - -int toi_allocate_cbw_data(void) -{ - int i, result; - - for_each_online_cpu(i) { - struct toi_cbw_state *state = &per_cpu(toi_cbw_states, i); - - result = _toi_allocate_cbw_data(state); - - if (result) - return result; - } - - return 0; -} - -void toi_cbw_restore(void) -{ - if (!toi_keeping_image) - return; - -} - -void toi_cbw_write(void) -{ - if (!toi_keeping_image) - return; - -} - -/** - * toi_cbw_test_read - Test copy before write on one page - * - * Allocate copy before write buffers, then make one page only copy-before-write - * and attempt to write to it. We should then be able to retrieve the original - * version from the cbw buffer and the modified version from the page itself. - */ -static int toi_cbw_test_read(const char *buffer, int count) -{ - unsigned long virt = toi_get_zeroed_page(40, GFP_KERNEL); - char *original = "Original contents"; - char *modified = "Modified material"; - struct page *page = virt_to_page(virt); - int i, len = 0, found = 0, pfn = page_to_pfn(page); - - if (!page) { - printk("toi_cbw_test_read: Unable to allocate a page for testing.\n"); - return -ENOMEM; - } - - memcpy((char *) virt, original, strlen(original)); - - if (toi_allocate_cbw_data()) { - printk("toi_cbw_test_read: Unable to allocate cbw data.\n"); - return -ENOMEM; - } - - toi_reset_dirtiness_one(pfn, 0); - - SetPageTOI_CBW(page); - - memcpy((char *) virt, modified, strlen(modified)); - - if (strncmp((char *) virt, modified, strlen(modified))) { - len += sprintf((char *) buffer + len, "Failed to write to page after protecting it.\n"); - } - - for_each_online_cpu(i) { - struct toi_cbw_state *state = &per_cpu(toi_cbw_states, i); - struct toi_cbw *ptr = state->first, *last_ptr = ptr; - - if (!found) { - while (ptr) { - if (ptr->pfn == pfn) { - found = 1; - if (strncmp(ptr->virt, original, strlen(original))) { - len += sprintf((char *) buffer + len, "Contents of original buffer are not original.\n"); - } else { - len += sprintf((char *) buffer + len, "Test passed. Buffer changed and original contents preserved.\n"); - } - break; - } - - last_ptr = ptr; - ptr = ptr->next; - } - } - - if (!last_ptr) - len += sprintf((char *) buffer + len, "All available CBW buffers on cpu %d used.\n", i); - } - - if (!found) - len += sprintf((char *) buffer + len, "Copy before write buffer not found.\n"); - - toi_free_cbw_data(); - - return len; -} - -/* - * This array contains entries that are automatically registered at - * boot. Modules and the console code register their own entries separately. - */ -static struct toi_sysfs_data sysfs_params[] = { - SYSFS_CUSTOM("test", SYSFS_RW, toi_cbw_test_read, - NULL, SYSFS_NEEDS_SM_FOR_READ, NULL), -}; - -static struct toi_module_ops toi_cbw_ops = { - .type = MISC_HIDDEN_MODULE, - .name = "copy_before_write debugging", - .directory = "cbw", - .module = THIS_MODULE, - .early = 1, - - .sysfs_data = sysfs_params, - .num_sysfs_entries = sizeof(sysfs_params) / - sizeof(struct toi_sysfs_data), -}; - -int toi_cbw_init(void) -{ - int result = toi_register_module(&toi_cbw_ops); - return result; -} |