[cfe-users] MSAN blacklist
Evgenii Stepanov via cfe-users
cfe-users at lists.llvm.org
Tue Jan 30 17:18:18 PST 2018
Interceptors are defined here:
On Tue, Jan 30, 2018 at 4:17 PM, Bernd Schubert
<bs_lists at aakef.fastmail.fm> wrote:
> Thanks for your help Evgenii!
> This is actually another glibc feature and so internal to glibc (in my
> personal opinion, just bloat, but probably not easy to remove nowadays).
> This is basically the function
> So the argz feature (no idea why this has to be in main glibc)
> It got a bit late (I shouldn't have tried to compile glibc with llvm), I
> will try to overload/LD_PRELOAD argz_create_sep() tomorrow and memset
> the allocated memory.
> Unfortunately I don't have much control over the user of this function
> this is gnu-libtool / libltdl, which is just copied/linked into the
> I will also open an issue on github, as this is glibc, so these argz
> functions probably should be intersepted by llvm.
> I'm not familiar with llvm code at all. Is it
> llvm::inferLibFuncAttributes(), which defines intercepted functions?
> On 01/29/2018 07:56 PM, Evgenii Stepanov wrote:
>> This is a report from an interceptor, it is not affected by blacklist,
>> You could try MSAN_OPTIONS=intercept_strlen=0, but it is likely that
>> something else will pop up instead.
>> Try figuring out what is the actual reason for the report, i.e. what
>> code is supposed to initialize this memory. Is it some other library
>> that can be built with MSan?
>> A better place for such questions is https://github.com/google/sanitizers/issues
>> On Mon, Jan 29, 2018 at 5:59 AM, Bernd Schubert via cfe-users
>> <cfe-users at lists.llvm.org> wrote:
>>> I would like to blacklist some warnings, but everything I tried
>>> so far is ignored.
>>> # cat msan-blacklist.txt
>>> So I tried to blacklist all kind of combinations of the failing
>>> functions and also of the related file - without success. It always
>>> fails with the same issue.
>>> Uninitialized bytes in __interceptor_strlen at offset 0 inside
>>> [0x703000035370, 45)
>>> ==3968020==WARNING: MemorySanitizer: use-of-uninitialized-value
>>> #0 0x7f0f587fa099 in foreach_dirinpath
>>> Uninitialized value was created by a heap allocation
>>> #0 0x453ebd in __interceptor_malloc (/tmp/ime-server-bernd.0+0x453ebd)
>>> #1 0x7f0f568c0f7e in __argz_create_sep (/usr/lib64/libc.so.6+0x90f7e)
>>> #2 0x7f0f585f7775 in _dl_fixup (/lib64/ld-linux-x86-64.so.2+0xe775)
>>> SUMMARY: MemorySanitizer: use-of-uninitialized-value
>>> /home/bschubert/src/cci/gerrit/src/libltdl/ltdl.c:699:18 in
>>> libcci and the main project I'm working on is compiled liked this
>>> libtool: compile: /opt/llvm-5.0.1/bin/clang -DHAVE_CONFIG_H -I.
>>> -DLTDLOPEN=libltdlc "-DLT_CONFIG_H=<config.h>" -DLTDL -I. -I. -Ilibltdl
>>> -I./libltdl -I./libltdl -ggdb3 -O2 -fsanitize=memory
>>> -fsanitize-memory-track-origins -fsanitize-memory-use-after-dtor
>>> -fsanitize-blacklist=msan-blacklist.txt -MT libltdlc_la-lt_dlloader.lo
>>> -MD -MP -MF .deps/libltdlc_la-lt_dlloader.Tpo -c lt_dlloader.c -fPIC
>>> -DPIC -o .libs/libltdlc_la-lt_dlloader.o
>>> Any ideas?
>>> cfe-users mailing list
>>> cfe-users at lists.llvm.org
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