Re: lib/51363: ubsan (undef behaviour sanitizer) faults

[bch <brad.harder%gmail.com@localhost>]

The following reply was made to PR lib/51363; it has been noted by GNATS.

From: bch <brad.harder%gmail.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: lib-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: lib/51363: ubsan (undef behaviour sanitizer) faults
Date: Mon, 1 Aug 2016 13:59:21 -0700

 I have since also tried w/ in-tree clang, to same effect, so I don't
 see a difference between pkgsrc and the ./src/external/bsd/llvm/*
 distribution.
 
 As a reference, this is the (trimmed) list of ubsan files I see on my system:
 
 kamloops# locate libubsa | grep -v obj | grep -v src/external
 /usr/lib/i386/libubsan.a
 /usr/lib/i386/libubsan.so
 /usr/lib/i386/libubsan.so.0
 /usr/lib/i386/libubsan.so.0.0
 /usr/lib/i386/libubsan_g.a
 /usr/lib/i386/libubsan_p.a
 /usr/lib/i386/libubsan_pic.a
 /usr/lib/libubsan.a
 /usr/lib/libubsan.so
 /usr/lib/libubsan.so.0
 /usr/lib/libubsan.so.0.0
 /usr/lib/libubsan_g.a
 /usr/lib/libubsan_p.a
 /usr/lib/libubsan_pic.a
 /usr/libdata/debug/usr/lib/i386/libubsan.so.0.0.debug
 /usr/libdata/debug/usr/lib/libubsan.so.0.0.debug
 
 
 
 On 8/1/16, Joerg Sonnenberger <joerg%bec.de@localhost> wrote:
 > The following reply was made to PR lib/51363; it has been noted by GNATS.
 >
 > From: Joerg Sonnenberger <joerg%bec.de@localhost>
 > To: gnats-bugs%NetBSD.org@localhost
 > Cc: lib-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
 > 	netbsd-bugs%netbsd.org@localhost, bch <brad.harder%gmail.com@localhost>
 > Subject: Re: lib/51363: ubsan (undef behaviour sanitizer) faults
 > Date: Mon, 1 Aug 2016 21:56:18 +0200
 >
 >  On Mon, Aug 01, 2016 at 06:25:01PM +0000, David Holland wrote:
 >  > The following reply was made to PR lib/51363; it has been noted by
 > GNATS.
 >  >
 >  > From: David Holland <dholland-bugs%netbsd.org@localhost>
 >  > To: gnats-bugs%NetBSD.org@localhost
 >  > Cc:
 >  > Subject: Re: lib/51363: ubsan (undef behaviour sanitizer) faults
 >  > Date: Mon, 1 Aug 2016 18:22:39 +0000
 >  >
 >  >  On Sun, Jul 31, 2016 at 11:10:01PM +0000, bch wrote:
 >  >   >  This is something I don't understand --
 >  >   >
 >  >   >  I'm using clang from pkgsrc, and there are *no* ubsan components
 >  >   >  installed that I can see. The clang documentation says that issuing
 >  >   >  -fsanitize=* might only instrument the code, or require a lib for
 >  >   >  runtime support. W/ the -fsanitize=undefined clang reports that it
 >  >   >  wants to be linked to ubsan, and linking (w/ clang, which is
 > supposed
 >  >   >  to be used to pick the correct ubsan), still links as you see.
 >  >
 >  >  Me either; unfortunately, I don't know much about it. I asked Joerg
 >  >  and the only helpful information I was able to acquire is that it
 >  >  shouldn't be using the gcc library.
 >  >
 >  >  My guess would be that (maybe at config time when you built it) clang
 >  >  detected the gcc libubsan and decided it should use that; or
 >  >  alternatively it's just generating -lubsan and assuming the library
 >  >  that finds is going to be the right one.
 >  >
 >  >  I have no idea how it's supposed to work. Probably the best bet is to
 >  >  find a clang list to ask on :-/
 >
 >  It wasn't even clear from the start that this is about the pkgsrc clang.
 >  That one doesn't include any of the runtime libraries, so no ubsan
 >  either. It is expected to be available, the compiler driver itself
 >  doesn't check. There is currently no upstream support for any of the
 >  sanitizers for NetBSD. I've refrained so far from committing any time to
 >  it as the architecture is questionable (IMO) and the implementation of
 >  the system call stubs via syscall(2) is horrible too.
 >
 >  Joerg
 >
 >