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| author | Yinghai Lu <yinghai@kernel.org> | 2010-10-04 14:57:39 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-10-05 21:45:35 -0700 |
| commit | f1af98c7629a1b76fd7336decbc776acdeed2120 (patch) | |
| tree | 4886c7d9469f147a5c3d0ece2c3aa5993ae77ae3 /mm/memblock.c | |
| parent | 1d931264af0f10649b35afa8fbd2e169da51ac08 (diff) | |
| download | lwn-f1af98c7629a1b76fd7336decbc776acdeed2120.tar.gz lwn-f1af98c7629a1b76fd7336decbc776acdeed2120.zip | |
memblock: Fix wraparound in find_region()
When trying to find huge range for crashkernel, get
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: at arch/x86/mm/memblock.c:248 memblock_x86_reserve_range+0x40/0x7a()
[ 0.000000] Hardware name: Sun Fire x4800
[ 0.000000] memblock_x86_reserve_range: wrong range [0xffffffff37000000, 0x137000000)
[ 0.000000] Modules linked in:
[ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.36-rc5-tip-yh-01876-g1cac214-dirty #59
[ 0.000000] Call Trace:
[ 0.000000] [<ffffffff82816f7e>] ? memblock_x86_reserve_range+0x40/0x7a
[ 0.000000] [<ffffffff81078c2d>] warn_slowpath_common+0x85/0x9e
[ 0.000000] [<ffffffff81078d38>] warn_slowpath_fmt+0x6e/0x70
[ 0.000000] [<ffffffff8281e77c>] ? memblock_find_region+0x40/0x78
[ 0.000000] [<ffffffff8281eb1f>] ? memblock_find_base+0x9a/0xb9
[ 0.000000] [<ffffffff82816f7e>] memblock_x86_reserve_range+0x40/0x7a
[ 0.000000] [<ffffffff8280452c>] setup_arch+0x99d/0xb2a
[ 0.000000] [<ffffffff810a3e02>] ? trace_hardirqs_off+0xd/0xf
[ 0.000000] [<ffffffff81cec7d8>] ? _raw_spin_unlock_irqrestore+0x3d/0x4c
[ 0.000000] [<ffffffff827ffcec>] start_kernel+0xde/0x3f1
[ 0.000000] [<ffffffff827ff2d4>] x86_64_start_reservations+0xa0/0xa4
[ 0.000000] [<ffffffff827ff3de>] x86_64_start_kernel+0x106/0x10d
[ 0.000000] ---[ end trace a7919e7f17c0a725 ]---
[ 0.000000] Reserving 8192MB of memory at 17592186041200MB for crashkernel (System RAM: 526336MB)
This is caused by a wraparound in the test due to size > end;
explicitly check for this condition and fail.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4CAA4DD3.1080401@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'mm/memblock.c')
| -rw-r--r-- | mm/memblock.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/memblock.c b/mm/memblock.c index d5d63ac1fd83..9ad39690a2bd 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -105,13 +105,18 @@ static phys_addr_t __init memblock_find_region(phys_addr_t start, phys_addr_t en phys_addr_t base, res_base; long j; + /* In case, huge size is requested */ + if (end < size) + return MEMBLOCK_ERROR; + + base = memblock_align_down((end - size), align); + /* Prevent allocations returning 0 as it's also used to * indicate an allocation failure */ if (start == 0) start = PAGE_SIZE; - base = memblock_align_down((end - size), align); while (start <= base) { j = memblock_overlaps_region(&memblock.reserved, base, size); if (j < 0) |