Thanks for looking into it! In addition, If I understand correctly, using __attribute__((aligned(xxx))) on structs that are only allocated from heap doesn’t actually do anything (but sometimes confuse gcc into generating misaligned accesses).
From: Dave Barach (dbarach) [mailto:dbar...@cisco.com] Sent: Thursday, April 26, 2018 5:08 PM To: Nicolau, Radu <radu.nico...@intel.com>; Florin Coras <fcoras.li...@gmail.com> Cc: vpp-dev@lists.fd.io Subject: RE: [vpp-dev] segfault due to movaps unaligned access 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<mailto:vpp-dev@lists.fd.io> <vpp-dev@lists.fd.io<mailto: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<mailto:fcoras.li...@gmail.com>> Cc: vpp-dev@lists.fd.io<mailto: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
