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authorChris Metcalf <cmetcalf@ezchip.com>2015-09-08 15:02:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-08 15:35:28 -0700
commit1b4ace4141db1ddc46f6c9915086dd5e18d7154d (patch)
treeb76bfc0fddf6ab377647b0094c70eee83d2365b8
parentc5b4e1b02f2a0c2309ecd58a235a2f5ee4eb0074 (diff)
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@ezchip.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Paul McQuade <paulmcquad@gmail.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/bootmem.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/mm/bootmem.c b/mm/bootmem.c
index a23dd1934654..3b6380784c28 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -236,6 +236,7 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
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 *bdata,
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_t *bdata, unsigned long sidx,
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) {