aboutsummaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
authorRafael J. Wysocki <rjw@sisk.pl>2006-04-19 01:20:29 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-04-19 12:13:49 -0400
commit4a3b98a422a20dedf3a2a40c44892d6e7e665157 (patch)
tree24387ffda32d2d7a8582116cd39654bf1fac19fe /kernel
parent8db08de4f6ae24e90aedf5125b5ddd52ffff15f4 (diff)
[PATCH] swsusp: prevent possible image corruption on resume
The function free_pagedir() used by swsusp for freeing its internal data structures clears the PG_nosave and PG_nosave_free flags for each page being freed. However, during resume PG_nosave_free set means that the page in question is "unsafe" (ie. it will be overwritten in the process of restoring the saved system state from the image), so it should not be used for the image data. Therefore free_pagedir() should not clear PG_nosave_free if it's called during resume (otherwise "unsafe" pages freed by it may be used for storing the image data and the data may get corrupted later on). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/snapshot.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index c5863d02c89e..3eeedbb13b78 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -240,14 +240,15 @@ static void copy_data_pages(struct pbe *pblist)
240 * free_pagedir - free pages allocated with alloc_pagedir() 240 * free_pagedir - free pages allocated with alloc_pagedir()
241 */ 241 */
242 242
243static void free_pagedir(struct pbe *pblist) 243static void free_pagedir(struct pbe *pblist, int clear_nosave_free)
244{ 244{
245 struct pbe *pbe; 245 struct pbe *pbe;
246 246
247 while (pblist) { 247 while (pblist) {
248 pbe = (pblist + PB_PAGE_SKIP)->next; 248 pbe = (pblist + PB_PAGE_SKIP)->next;
249 ClearPageNosave(virt_to_page(pblist)); 249 ClearPageNosave(virt_to_page(pblist));
250 ClearPageNosaveFree(virt_to_page(pblist)); 250 if (clear_nosave_free)
251 ClearPageNosaveFree(virt_to_page(pblist));
251 free_page((unsigned long)pblist); 252 free_page((unsigned long)pblist);
252 pblist = pbe; 253 pblist = pbe;
253 } 254 }
@@ -389,7 +390,7 @@ struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed
389 pbe->next = alloc_image_page(gfp_mask, safe_needed); 390 pbe->next = alloc_image_page(gfp_mask, safe_needed);
390 } 391 }
391 if (!pbe) { /* get_zeroed_page() failed */ 392 if (!pbe) { /* get_zeroed_page() failed */
392 free_pagedir(pblist); 393 free_pagedir(pblist, 1);
393 pblist = NULL; 394 pblist = NULL;
394 } else 395 } else
395 create_pbe_list(pblist, nr_pages); 396 create_pbe_list(pblist, nr_pages);
@@ -736,7 +737,7 @@ static int create_image(struct snapshot_handle *handle)
736 pblist = alloc_pagedir(nr_copy_pages, GFP_ATOMIC, 1); 737 pblist = alloc_pagedir(nr_copy_pages, GFP_ATOMIC, 1);
737 if (pblist) 738 if (pblist)
738 copy_page_backup_list(pblist, p); 739 copy_page_backup_list(pblist, p);
739 free_pagedir(p); 740 free_pagedir(p, 0);
740 if (!pblist) 741 if (!pblist)
741 error = -ENOMEM; 742 error = -ENOMEM;
742 } 743 }