Date: Fri, 06 Feb 2015 14:43:24 +0100 From: Pieter de Goeje <pieter@degoeje.nl> To: Eivind Evensen <eivinde@terraplane.org>, freebsd-stable@freebsd.org Subject: Re: Buserror when built on FreeBSD 10, not on FreeBSD 8 Message-ID: <54D4C4FC.5000803@degoeje.nl> In-Reply-To: <20150205133653.GA16112@klump.hjerdalen.lokalnett> References: <20150205133653.GA16112@klump.hjerdalen.lokalnett>
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Eivind Evensen schreef op 2015-02-05 om 14:36: > Hello. > > After upgrading from FreeBSD 8 to 10, I have a problem I don't > understand, hopefully somebody here knows what is happening. > > I have a project that uses both assembly and c. I started getting > bus errors after building on FreeBSD 10. I had, and may still have > some objects around from FreeBSD 8 and if I link those, on 10, they work. > I don't have any installations running 8 any longer though. > This is on amd64 platform. The problem is that the stack is not aligned to 16 bytes. Changing to the code to this: asmcode: sub rsp, 8 call cagain add rsp, 8 ret Fixes the problem. It's probably better to just push/pop rbp as that is only one byte per instruction, which will also align the stack for obvious reasons. I believe that gcc on FreeBSD 8 wasn't as strict as clang is on 10 now. - Pieter
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