Hey Ray,

That's a good idea, and none too hard to implement. It's on my list.

I'm a bit afraid of what I may find when I turn it on, but anyhow...

Thanks... D.

-----Original Message-----
From: vpp-dev@lists.fd.io <vpp-dev@lists.fd.io> On Behalf Of Ray Kinsella
Sent: Tuesday, May 1, 2018 10:58 AM
To: vpp-dev@lists.fd.io
Subject: Re: [vpp-dev] segfault due to movaps unaligned access

Is it worth to use an assert (or similar) to validate the assumption in the 
debug build at least. Well at least until the compiler bugs get's sorted?

Ray K

On 26/04/2018 17:08, Dave Barach wrote:
> Yes, it’s arguably a compiler bug.
> 
> But, it makes no sense to vec_validate_aligned(…), pool_get_aligned(…) 
> etc. objects whose size is not a multiple of the alignment request. 
> Only the first element will be aligned to the specified boundary.
> 
> __attribute__((aligned(xxx))) is not the same thing as ensuring that 
> objects are _sized_ correctly.
> 
> D.
> 
> *From:*vpp-dev@lists.fd.io <vpp-dev@lists.fd.io> *On Behalf Of *Radu 
> Nicolau
> *Sent:* Thursday, April 26, 2018 4:54 AM
> *To:* Florin Coras <fcoras.li...@gmail.com>
> *Cc:* vpp-dev@lists.fd.io
> *Subject:* Re: [vpp-dev] segfault due to movaps unaligned access
> 
> Hi Florin,
> 
> Thanks! The patch fixes the issue.
> 
> Any idea why is it happening?
> 
> Regards,
> 
> Radu
> 
> *From:*vpp-dev@lists.fd.io <mailto:vpp-dev@lists.fd.io> 
> [mailto:vpp-dev@lists.fd.io] *On Behalf Of *Florin Coras
> *Sent:* Tuesday, April 24, 2018 11:25 PM
> *To:* Nicolau, Radu <radu.nico...@intel.com 
> <mailto:radu.nico...@intel.com>>
> *Cc:* vpp-dev@lists.fd.io <mailto:vpp-dev@lists.fd.io>
> *Subject:* Re: [vpp-dev] segfault due to movaps unaligned access
> 
> Hi Radu,
> 
> Making the crypto_worker_main_t a full cache line in size (see patch
> [1]) seems to solve the issue. Could you confirm?
> 
> Florin
> 
> [1] https://gerrit.fd.io/r/#/c/12086/
> 
>     On Apr 24, 2018, at 9:23 AM, Radu Nicolau <radu.nico...@intel.com
>     <mailto:radu.nico...@intel.com>> wrote:
> 
>     Hello all,
> 
>     We’re seeing a weird issue, that is a segfault that looks to be
>     caused by a movaps instruction that is trying to access an address
>     that is not 16 byte aligned.
> 
>     The call originates from a vec_validate_init_empty_aligned that has
>     the argument aligned to 16 bytes.
> 
>     I have seen something like this in the past, we couldn’t find a root
>     cause and considered it a GCC bug (version 5 then), but now it pops
>     up again on version 7, so probably it isn’t.
> 
>     Any idea? A snapshot of the gdb screen below.
> 
>     gcc (Ubuntu 7.2.0-8ubuntu3.2) 7.2.0
> 
>     https://postimg.cc/image/9jy4p38at/
> 
>     thanks and I will appreciate any help,
> 
>     Radu
> 
> 




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