diff options
| author | Chris Metcalf <cmetcalf@ezchip.com> | 2015-09-08 15:02:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-08 15:35:28 -0700 |
| commit | 1b4ace4141db1ddc46f6c9915086dd5e18d7154d (patch) | |
| tree | b76bfc0fddf6ab377647b0094c70eee83d2365b8 /mm/bootmem.c | |
| parent | c5b4e1b02f2a0c2309ecd58a235a2f5ee4eb0074 (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>
Diffstat (limited to 'mm/bootmem.c')
| -rw-r--r-- | mm/bootmem.c | 7 |
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) { |