summaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorLee, Chun-Yi <joeyli.kernel@gmail.com>2014-08-04 23:23:21 +0800
committerJiri Slaby <jslaby@suse.cz>2014-09-02 11:38:08 +0200
commitab73940ae61dd855de2965f0d728b803e9ff0546 (patch)
treeab9dc8bac82b8a65fabae8cbe836e0f2d6cdcd9e /kernel
parent0325fb03fe49b37dfb9a66be6083ce4aebe17df9 (diff)
PM / hibernate: avoid unsafe pages in e820 reserved regions
commit 84c91b7ae07c62cf6dee7fde3277f4be21331f85 upstream. When the machine doesn't well handle the e820 persistent when hibernate resuming, then it may cause page fault when writing image to snapshot buffer: [ 17.929495] BUG: unable to handle kernel paging request at ffff880069d4f000 [ 17.933469] IP: [<ffffffff810a1cf0>] load_image_lzo+0x810/0xe40 [ 17.933469] PGD 2194067 PUD 77ffff067 PMD 2197067 PTE 0 [ 17.933469] Oops: 0002 [#1] SMP ... The ffff880069d4f000 page is in e820 reserved region of resume boot kernel: [ 0.000000] BIOS-e820: [mem 0x0000000069d4f000-0x0000000069e12fff] reserved ... [ 0.000000] PM: Registered nosave memory: [mem 0x69d4f000-0x69e12fff] So snapshot.c mark the pfn to forbidden pages map. But, this page is also in the memory bitmap in snapshot image because it's an original page used by image kernel, so it will also mark as an unsafe(free) page in prepare_image(). That means the page in e820 when resuming mark as "forbidden" and "free", it causes get_buffer() treat it as an allocated unsafe page. Then snapshot_write_next() return this page to load_image, load_image writing content to this address, but this page didn't really allocated . So, we got page fault. Although the root cause is from BIOS, I think aggressive check and significant message in kernel will better then a page fault for issue tracking, especially when serial console unavailable. This patch adds code in mark_unsafe_pages() for check does free pages in nosave region. If so, then it print message and return fault to stop whole S4 resume process: [ 8.166004] PM: Image loading progress: 0% [ 8.658717] PM: 0x6796c000 in e820 nosave region: [mem 0x6796c000-0x6796cfff] [ 8.918737] PM: Read 2511940 kbytes in 1.04 seconds (2415.32 MB/s) [ 8.926633] PM: Error -14 resuming [ 8.933534] PM: Failed to load hibernation image, recovering. Reviewed-by: Takashi Iwai <tiwai@suse.de> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Lee, Chun-Yi <jlee@suse.com> [rjw: Subject] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/snapshot.c21
1 files changed, 20 insertions, 1 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index b38109e204af..5e2bde1adb7c 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -730,6 +730,25 @@ static void mark_nosave_pages(struct memory_bitmap *bm)
}
}
+static bool is_nosave_page(unsigned long pfn)
+{
+ struct nosave_region *region;
+
+ list_for_each_entry(region, &nosave_regions, list) {
+ if (pfn >= region->start_pfn && pfn < region->end_pfn) {
+ pr_err("PM: %#010llx in e820 nosave region: "
+ "[mem %#010llx-%#010llx]\n",
+ (unsigned long long) pfn << PAGE_SHIFT,
+ (unsigned long long) region->start_pfn << PAGE_SHIFT,
+ ((unsigned long long) region->end_pfn << PAGE_SHIFT)
+ - 1);
+ return true;
+ }
+ }
+
+ return false;
+}
+
/**
* create_basic_memory_bitmaps - create bitmaps needed for marking page
* frames that should not be saved and free page frames. The pointers
@@ -1774,7 +1793,7 @@ static int mark_unsafe_pages(struct memory_bitmap *bm)
do {
pfn = memory_bm_next_pfn(bm);
if (likely(pfn != BM_END_OF_MAP)) {
- if (likely(pfn_valid(pfn)))
+ if (likely(pfn_valid(pfn)) && !is_nosave_page(pfn))
swsusp_set_page_free(pfn_to_page(pfn));
else
return -EFAULT;