From: Alexander Monakov <amonakov@ispras.ru>
To: musl@lists.openwall.com
Cc: Constantine <iamvfx@gmail.com>
Subject: Re: Commit 01d4274 breaks Clang's LeakSanitizer when used with musl
Date: Thu, 2 Jul 2015 22:57:58 +0300 (MSK) [thread overview]
Message-ID: <alpine.LNX.2.11.1507022248340.27424@monopod.intra.ispras.ru> (raw)
In-Reply-To: <20150702192916.GI32532@port70.net>
> i think the cause is that they intercept all allocation functions
> and if the act of interception calls into the intercepted function
> itself then they have a problem
This should never happen on musl since it links with -Bsymbolic-functions, and
even uses protected visibility now.
> for glibc calloc they have some ugly workaround, maybe similar hack
> is needed for free in musl, but none of this is future proof so
> they will just keep piling hacks..
Re: hacks, I think it doesn't have to be like that. There should be a
reasonable mechanism to wrap library functions in the context of dynamic
linking; static linking is slightly ahead in that game if you count ld
--wrap=symbol functionality.
For dynamic linking it should be doable with a new type of ELF tag and a bit
of support from the dynamic linker. Would you be interested?
(at the moment I don't have an answer why lsan started failing like that; and
even if, hypothetically, there would be a good library wrapping mechanism,
sanitizers would likely need other support from libc, like dynamic tls layout
discovery for memory sanitizer; I hope it can be resolved to everyone's
satisfaction eventually, improving sanitizers usability, rather than ignoring
it and perpetually calling sanitizers a pile of hacks)
Alexander
next prev parent reply other threads:[~2015-07-02 19:57 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-02 18:22 Constantine
2015-07-02 19:00 ` Rich Felker
2015-07-02 19:29 ` Szabolcs Nagy
2015-07-02 19:45 ` Constantine
2015-07-02 21:10 ` Szabolcs Nagy
2015-07-02 19:46 ` Szabolcs Nagy
2015-07-02 19:57 ` Alexander Monakov [this message]
2015-07-02 20:20 ` Rich Felker
2015-07-02 22:11 ` Alexander Monakov
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