Messages in this thread | | | Date | Thu, 21 Feb 2013 12:53:38 -0800 | Subject | Re: [PATCH v3 1/2] memblock: add assertion for zero allocation alignment | From | Tejun Heo <> |
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On Thu, Feb 21, 2013 at 12:52 PM, Vineet Gupta <Vineet.Gupta1@synopsys.com> wrote: > This came to light when calling memblock allocator from arc port (for > copying flattended DT). If a "0" alignment is passed, the allocator > round_up() call incorrectly rounds up the size to 0. > > round_up(num, alignto) => ((num - 1) | (alignto -1)) + 1 > > While the obvious allocation failure causes kernel to panic, it is > better to warn the caller to fix the code. > > Tejun suggested that instead of BUG_ON(!align) - which might be > ineffective due to pending console init and such, it is better to > WARN_ON, and continue the boot with a reasonable default align. > > Caller passing @size need not be handled similarly as the subsequent > panic will indicate that anyhow. > > Signed-off-by: Vineet Gupta <vgupta@synopsys.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Tejun Heo <tj@kernel.org> > Cc: Yinghai Lu <yinghai@kernel.org> > Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org
Acked-by: Tejun Heo <tj@kernel.org>
Thanks.
-- tejun
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