On 2023-11-13 02:53, Sam James wrote:
Sam James <s...@gentoo.org> writes:
Alexander Monakov <amona...@ispras.ru> writes:
[...]
I'm very curious what you mean by "this has come up with LLVM []
too": ttbomk,
LLVM doesn't do such lifetime-based optimization yet, which is why
compiling
LLVM with LLVM doesn't break it. Can you share some examples? Or do
you mean
instances when libLLVM-miscompiled-with-GCC was linked elsewhere, and
that
program crashed mysteriously as a result?
Indeed this work is inspired by the LLVM incident in PR 106943.
[...]
I had some vague memories in the back of my head so I went digging
because I enjoy this:
[...]
I ended up stumbling on two more:
* charm (https://github.com/UIUC-PPL/charm/issues/1045)
* firebird (https://github.com/FirebirdSQL/firebird/issues/5384,
starring richi)
Now I'm really done :)
[...]
Alexander
thanks,
sam
Thanks for your prompt response; it is greatly appreciated.
We conducted tests on two packages from your provided list and obtained
some preliminary results:
* crypto++: No violations were detected during their own tests, which
were executed using 'make valgrind' and our custom option
--fvalgrind-emit-annotations.
* firebird: An issue was identified with the global object isqlGlobal.
It
appears that developers are assuming the global object will be
zero-initialized, but the C++ standard guarantees this only for static
initialization. The presence of a non-trivial constructor,
IsqlGlobals(),
means that isqlGlobal has formally uninitialized fields. A snippet from
the Valgrind dump is as follows:
==106087== Conditional jump or move depends on uninitialised value(s)
==106087== at 0x4378F0: create_db(char const*, char*) (isql.cpp:5838)
==106087== by 0x44CBE3: frontend(char const*) (isql.cpp:6699)
==106087== by 0x44EBC1: get_statement (isql.cpp:7638)
==106087== by 0x44EBC1: do_isql() (isql.cpp:6008)
==106087== by 0x45039C: ISQL_main(int, char**) (isql.cpp:1854)
==106087== by 0x4EE1082: (below main) (libc-start.c:308)
==106087== Uninitialised value was created by a client request
==106087== at 0x5A617C: __valgrind_make_mem_undefined (valgrind.c:48)
==106087== by 0x42E365: IsqlGlobals::IsqlGlobals() (isql.cpp:1378)
==106087== by 0x418388: __static_initialization_and_destruction_0
(isql.cpp:1098)
==106087== by 0x418388: _GLOBAL__sub_I_isql.cpp (isql.cpp:11536)
==106087== by 0x5A61DC: __libc_csu_init (in ...)
==106087== by 0x4EE100F: (below main) (libc-start.c:264)
---
With best regards,
Daniil
