The patch titled
Subject: bootmem: avoid freeing to bootmem after bootmem is done
has been removed from the -mm tree. Its filename was
bootmem-avoid-freeing-to-bootmem-after-bootmem-is-done.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Subject: bootmem: avoid freeing to bootmem after bootmem is done
Bootmem isn't popular any more, but some architectures still use it, and
freeing to bootmem after calling free_all_bootmem_core() can end up
scribbling over random memory. Instead, make sure the kernel generates a
warning in this case by ensuring the node_bootmem_map field is non-NULL
when are freeing or marking bootmem.
An instance of this bug was just fixed in the tile architecture ("tile:
use free_bootmem_late() for initrd") and catching this case more widely
seems like a good thing.
Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxx>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Paul McQuade <paulmcquad@xxxxxxxxx>
Cc: Tang Chen <tangchen@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/bootmem.c | 7 +++++++
1 file changed, 7 insertions(+)
diff -puN mm/bootmem.c~bootmem-avoid-freeing-to-bootmem-after-bootmem-is-done mm/bootmem.c
--- a/mm/bootmem.c~bootmem-avoid-freeing-to-bootmem-after-bootmem-is-done
+++ a/mm/bootmem.c
@@ -236,6 +236,7 @@ static unsigned long __init free_all_boo
count += pages;
while (pages--)
__free_pages_bootmem(page++, cur++, 0);
+ bdata->node_bootmem_map = NULL;
bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);
@@ -294,6 +295,9 @@ static void __init __free(bootmem_data_t
sidx + bdata->node_min_pfn,
eidx + bdata->node_min_pfn);
+ if (WARN_ON(bdata->node_bootmem_map == NULL))
+ return;
+
if (bdata->hint_idx > sidx)
bdata->hint_idx = sidx;
@@ -314,6 +318,9 @@ static int __init __reserve(bootmem_data
eidx + bdata->node_min_pfn,
flags);
+ if (WARN_ON(bdata->node_bootmem_map == NULL))
+ return 0;
+
for (idx = sidx; idx < eidx; idx++)
if (test_and_set_bit(idx, bdata->node_bootmem_map)) {
if (exclusive) {
_
Patches currently in -mm which might be from cmetcalf@xxxxxxxxxx are
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