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| author | Viro <viro@ZenIV.linux.org.uk> | 2014-03-17 16:01:27 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-03-17 16:10:29 -0400 |
| commit | 2f69fa829cb4ca062aaffee9ab9eb44484db75b1 (patch) | |
| tree | a2bc2cf26e8e7907a3270aed8820c8f7c3085d74 /mm/percpu.c | |
| parent | 3d331ad74fa33f0b14a46cf0de8358012d3c1500 (diff) | |
| download | lwn-2f69fa829cb4ca062aaffee9ab9eb44484db75b1.tar.gz lwn-2f69fa829cb4ca062aaffee9ab9eb44484db75b1.zip | |
percpu: allocation size should be even
723ad1d90b56 ("percpu: store offsets instead of lengths in ->map[]")
updated percpu area allocator to use the lowest bit, instead of sign,
to signify whether the area is occupied and forced min align to 2;
unfortunately, it forgot to force the allocation size to be even
causing malfunctions for the very rare odd-sized allocations.
Always force the allocations to be even sized.
tj: Wrote patch description.
Original-patch-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'mm/percpu.c')
| -rw-r--r-- | mm/percpu.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/mm/percpu.c b/mm/percpu.c index c7206d06f8de..202e104df8a7 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -713,11 +713,14 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) /* * We want the lowest bit of offset available for in-use/free - * indicator. + * indicator, so force >= 16bit alignment and make size even. */ if (unlikely(align < 2)) align = 2; + if (unlikely(size & 1)) + size++; + if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { WARN(true, "illegal size (%zu) or align (%zu) for " "percpu allocation\n", size, align); |