https://bugs.kde.org/show_bug.cgi?id=358980
Bug ID: 358980
Summary: 32 byte leak reported when code uses dlopen and links
against pthread
Product: valgrind
Version: 3.11.0
Platform: Other
OS: Linux
Status: UNCONFIRMED
Severity: normal
Priority: NOR
Component: memcheck
Assignee: jsew...@acm.org
Reporter: kdebugzi...@calmarius.net
Trivial program reports 32 byte memory leak when it's linked against libdl an
libpthread.
Several command outputs:
$ uname -a
Linux Calmarius 3.13.0-77-generic #121-Ubuntu SMP Wed Jan 20 10:50:42 UTC 2016
x86_64 x86_64 x86_64 GNU/Linux
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04.3 LTS
Release: 14.04
Codename: trusty
$ gcc -v
Reading specs from /usr/lib/gcc/x86_64-linux-gnu/4.8/specs
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
4.8.4-2ubuntu1~14.04' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs
--enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.8 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap
--enable-plugin --with-system-zlib --disable-browser-plugin
--enable-java-awt=gtk --enable-gtk-cairo
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre --enable-java-home
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64
--with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686
--with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc driver version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04) executing gcc version
4.8.1
Consider this trivial program:
#include <dlfcn.h>
int main()
{
void* handle = 0;
handle = dlopen("libm.so", RTLD_NOW);
dlclose(handle);
return 0;
}
Compile this program with this command line:
$ gcc -Wl,--no-as-needed -g -fPIC -o stuff main.c -ldl -lpthread
The -Wl,--no-as-needed is crucial as it won't link against the specified
libraries otherwise.
Then just run valgrind:
$ valgrind -v --leak-check=full --show-reachable=yes ./stuff
==4995== Memcheck, a memory error detector
==4995== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==4995== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==4995== Command: ./stuff
==4995==
--4995-- Valgrind options:
--4995-- -v
--4995-- --leak-check=full
--4995-- --show-reachable=yes
--4995-- Contents of /proc/version:
--4995-- Linux version 3.13.0-77-generic (buildd@lcy01-30) (gcc version 4.8.2
(Ubuntu 4.8.2-19ubuntu1) ) #121-Ubuntu SMP Wed Jan 20 10:50:42 UTC 2016
--4995--
--4995-- Arch and hwcaps: AMD64, LittleEndian, amd64-cx16-rdtscp-sse3-avx
--4995-- Page sizes: currently 4096, max supported 4096
--4995-- Valgrind library directory: /usr/local/lib/valgrind
--4995-- Reading syms from /home/dcsirmaz/workdir/crucible/dlopen/stuff
--4995-- Reading syms from /lib/x86_64-linux-gnu/ld-2.19.so
--4995-- Considering /lib/x86_64-linux-gnu/ld-2.19.so ..
--4995-- .. CRC mismatch (computed 4cbae35e wanted 8d683c31)
--4995-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/ld-2.19.so ..
--4995-- .. CRC is valid
--4995-- Reading syms from /usr/local/lib/valgrind/memcheck-amd64-linux
--4995-- object doesn't have a dynamic symbol table
--4995-- Scheduler: using generic scheduler lock implementation.
--4995-- Reading suppressions file: /usr/local/lib/valgrind/default.supp
==4995== embedded gdbserver: reading from
/tmp/vgdb-pipe-from-vgdb-to-4995-by-dcsirmaz-on-???
==4995== embedded gdbserver: writing to
/tmp/vgdb-pipe-to-vgdb-from-4995-by-dcsirmaz-on-???
==4995== embedded gdbserver: shared mem
/tmp/vgdb-pipe-shared-mem-vgdb-4995-by-dcsirmaz-on-???
==4995==
==4995== TO CONTROL THIS PROCESS USING vgdb (which you probably
==4995== don't want to do, unless you know exactly what you're doing,
==4995== or are doing some strange experiment):
==4995== /usr/local/lib/valgrind/../../bin/vgdb --pid=4995 ...command...
==4995==
==4995== TO DEBUG THIS PROCESS USING GDB: start GDB like this
==4995== /path/to/gdb ./stuff
==4995== and then give GDB the following command
==4995== target remote | /usr/local/lib/valgrind/../../bin/vgdb --pid=4995
==4995== --pid is optional if only one valgrind process is running
==4995==
--4995-- REDIR: 0x4019ca0 (ld-linux-x86-64.so.2:strlen) redirected to
0x38056b11 (vgPlain_amd64_linux_REDIR_FOR_strlen)
--4995-- Reading syms from
/usr/local/lib/valgrind/vgpreload_core-amd64-linux.so
--4995-- Reading syms from
/usr/local/lib/valgrind/vgpreload_memcheck-amd64-linux.so
==4995== WARNING: new redirection conflicts with existing -- ignoring it
--4995-- old: 0x04019ca0 (strlen ) R-> (0000.0) 0x38056b11
vgPlain_amd64_linux_REDIR_FOR_strlen
--4995-- new: 0x04019ca0 (strlen ) R-> (2007.0) 0x04c2dc80
strlen
--4995-- REDIR: 0x4019a50 (ld-linux-x86-64.so.2:index) redirected to 0x4c2d830
(index)
--4995-- REDIR: 0x4019c70 (ld-linux-x86-64.so.2:strcmp) redirected to 0x4c2edd0
(strcmp)
--4995-- REDIR: 0x401a9c0 (ld-linux-x86-64.so.2:mempcpy) redirected to
0x4c31e10 (mempcpy)
--4995-- Reading syms from /lib/x86_64-linux-gnu/libdl-2.19.so
--4995-- Considering /lib/x86_64-linux-gnu/libdl-2.19.so ..
--4995-- .. CRC mismatch (computed c1315e8c wanted 37097b60)
--4995-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/libdl-2.19.so ..
--4995-- .. CRC is valid
--4995-- Reading syms from /lib/x86_64-linux-gnu/libpthread-2.19.so
--4995-- Considering /lib/x86_64-linux-gnu/libpthread-2.19.so ..
--4995-- .. CRC mismatch (computed d568bf33 wanted fb00d679)
--4995-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/libpthread-2.19.so
..
--4995-- .. CRC is valid
--4995-- Reading syms from /lib/x86_64-linux-gnu/libc-2.19.so
--4995-- Considering /lib/x86_64-linux-gnu/libc-2.19.so ..
--4995-- .. CRC mismatch (computed dc620abc wanted 148cbd6e)
--4995-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/libc-2.19.so ..
--4995-- .. CRC is valid
--4995-- REDIR: 0x52e5d60 (libc.so.6:strcasecmp) redirected to 0x4a25706
(_vgnU_ifunc_wrapper)
--4995-- REDIR: 0x52e8050 (libc.so.6:strncasecmp) redirected to 0x4a25706
(_vgnU_ifunc_wrapper)
--4995-- REDIR: 0x52e5530 (libc.so.6:memcpy@GLIBC_2.2.5) redirected to
0x4a25706 (_vgnU_ifunc_wrapper)
--4995-- REDIR: 0x52e37c0 (libc.so.6:rindex) redirected to 0x4c2d510 (rindex)
--4995-- REDIR: 0x52dc220 (libc.so.6:calloc) redirected to 0x4c2c8fe (calloc)
--4995-- REDIR: 0x52db750 (libc.so.6:malloc) redirected to 0x4c2ab96 (malloc)
--4995-- Reading syms from /lib/x86_64-linux-gnu/libm-2.19.so
--4995-- Considering /lib/x86_64-linux-gnu/libm-2.19.so ..
--4995-- .. CRC mismatch (computed a46ef660 wanted 767bfa33)
--4995-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/libm-2.19.so ..
--4995-- .. CRC is valid
--4995-- Discarding syms at 0x5a23610-0x5a921b6 in
/lib/x86_64-linux-gnu/libm-2.19.so due to munmap()
--4995-- REDIR: 0x52dbdf0 (libc.so.6:free) redirected to 0x4c2bcb0 (free)
==4995==
==4995== HEAP SUMMARY:
==4995== in use at exit: 32 bytes in 1 blocks
==4995== total heap usage: 6 allocs, 5 frees, 1,524 bytes allocated
==4995==
==4995== Searching for pointers to 1 not-freed blocks
==4995== Checked 102,648 bytes
==4995==
==4995== 32 bytes in 1 blocks are still reachable in loss record 1 of 1
==4995== at 0x4C2C994: calloc (vg_replace_malloc.c:711)
==4995== by 0x4E3868F: _dlerror_run (dlerror.c:141)
==4995== by 0x4E380C0: dlopen@@GLIBC_2.2.5 (dlopen.c:87)
==4995== by 0x40066D: main (main.c:7)
==4995==
==4995== LEAK SUMMARY:
==4995== definitely lost: 0 bytes in 0 blocks
==4995== indirectly lost: 0 bytes in 0 blocks
==4995== possibly lost: 0 bytes in 0 blocks
==4995== still reachable: 32 bytes in 1 blocks
==4995== suppressed: 0 bytes in 0 blocks
==4995==
==4995== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
==4995== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
It looks like it's a regression to me. As this very exact bug was reported
before and fixed:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=700899
--
You are receiving this mail because:
You are watching all bug changes.
