Hibernation: Fix mark_nosave_pages()
There is a problem in the hibernation code that triggers on some NUMA
systems on which pfn_valid() returns 'true' for some PFNs that don't
belong to any zone. Namely, there is a BUG_ON() in
memory_bm_find_bit() that triggers for PFNs not belonging to any
zone and passing the pfn_valid() test. On the affected systems it
triggers when we mark PFNs reported by the platform as not saveable,
because the PFNs in question belong to a region mapped directly using
iorepam() (i.e. the ACPI data area) and they pass the pfn_valid()
test.
Modify memory_bm_find_bit() so that it returns an error if given PFN
doesn't belong to any zone instead of crashing the kernel and ignore
the result returned by it in mark_nosave_pages(), while marking the
"nosave" memory regions.
This doesn't affect the hibernation functionality, as we won't touch
the PFNs in question anyway.
http://bugzilla.kernel.org/show_bug.cgi?id=9966 .
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 72a020c..5f91a07 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -447,7 +447,7 @@
* of @bm->cur_zone_bm are updated.
*/
-static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
+static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
void **addr, unsigned int *bit_nr)
{
struct zone_bitmap *zone_bm;
@@ -461,7 +461,8 @@
while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
zone_bm = zone_bm->next;
- BUG_ON(!zone_bm);
+ if (!zone_bm)
+ return -EFAULT;
}
bm->cur.zone_bm = zone_bm;
}
@@ -479,23 +480,40 @@
pfn -= bb->start_pfn;
*bit_nr = pfn % BM_BITS_PER_CHUNK;
*addr = bb->data + pfn / BM_BITS_PER_CHUNK;
+ return 0;
}
static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
{
void *addr;
unsigned int bit;
+ int error;
- memory_bm_find_bit(bm, pfn, &addr, &bit);
+ error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+ BUG_ON(error);
set_bit(bit, addr);
}
+static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
+{
+ void *addr;
+ unsigned int bit;
+ int error;
+
+ error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+ if (!error)
+ set_bit(bit, addr);
+ return error;
+}
+
static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
{
void *addr;
unsigned int bit;
+ int error;
- memory_bm_find_bit(bm, pfn, &addr, &bit);
+ error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+ BUG_ON(error);
clear_bit(bit, addr);
}
@@ -503,8 +521,10 @@
{
void *addr;
unsigned int bit;
+ int error;
- memory_bm_find_bit(bm, pfn, &addr, &bit);
+ error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+ BUG_ON(error);
return test_bit(bit, addr);
}
@@ -709,8 +729,15 @@
region->end_pfn << PAGE_SHIFT);
for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
- if (pfn_valid(pfn))
- memory_bm_set_bit(bm, pfn);
+ if (pfn_valid(pfn)) {
+ /*
+ * It is safe to ignore the result of
+ * mem_bm_set_bit_check() here, since we won't
+ * touch the PFNs for which the error is
+ * returned anyway.
+ */
+ mem_bm_set_bit_check(bm, pfn);
+ }
}
}