valgrind 3.8.1 warning in jemalloc 3.2

[Daniel Mezzatto Rodrigues]

Hi.

I have just changed part of my system to use jemalloc (version 3.2). 
Running valgrind (version 3.8.1) gave me some errors (that does not 
occur with system malloc). Some of the errors:

==7888== Invalid write of size 8
==7888==    at 0x4C2C404: memcpy (mc_replace_strmem.c:878)
==7888==    by 0x586E324: huge_ralloc (string3.h:52)
==7888==    by 0x585064B: je_realloc (jemalloc_internal.h:986)

==7888== Invalid read of size 8
==7888==    at 0x58582EB: arena_avail_insert (arena.c:259)
==7888==    by 0x5858EB9: arena_chunk_alloc (arena.c:582)
==7888==    by 0x585B90F: arena_malloc_large (arena.c:664)
==7888==    by 0x5850122: je_calloc (arena.h:883)

==7888== Invalid read of size 8
==7888==    at 0x585833B: arena_avail_insert (arena.c:266)
==7888==    by 0x5858EB9: arena_chunk_alloc (arena.c:582)
==7888==    by 0x585B90F: arena_malloc_large (arena.c:664)
==7888==    by 0x5850122: je_calloc (arena.h:883)

==7888== Invalid read of size 8
==7888==    at 0x5858FB9: arena_chunk_alloc (arena.h:661)
==7888==    by 0x585B90F: arena_malloc_large (arena.c:664)
==7888==    by 0x5850122: je_calloc (arena.h:883)

==7888== Invalid write of size 8
==7888==    at 0x5857DDC: arena_avail_tree_insert (arena.c:135)
==7888==    by 0x5858EB9: arena_chunk_alloc (arena.c:582)
==7888==    by 0x585B90F: arena_malloc_large (arena.c:664)
==7888==    by 0x5850122: je_calloc (arena.h:883)

==7888== Invalid read of size 1
==7888==    at 0x585834A: arena_avail_insert (arena.c:269)
==7888==    by 0x5858EB9: arena_chunk_alloc (arena.c:582)
==7888==    by 0x585B90F: arena_malloc_large (arena.c:664)
==7888==    by 0x5850122: je_calloc (arena.h:883)

==7888== Invalid write of size 8
==7888==    at 0x5857DDC: arena_avail_tree_insert (arena.c:135)
==7888==    by 0x5858EB9: arena_chunk_alloc (arena.c:582)
==7888==    by 0x585B90F: arena_malloc_large (arena.c:664)
==7888==    by 0x5850122: je_calloc (arena.h:883)

==7888== Invalid read of size 8
==7888==    at 0x5858494: arena_run_split (arena.h:502)
==7888==    by 0x585B942: arena_malloc_large (arena.c:667)
==7888==    by 0x5850122: je_calloc (arena.h:883)

==7888== Invalid read of size 1
==7888==    at 0x5857CDA: arena_avail_remove (arena.c:303)
==7888==    by 0x58584C2: arena_run_split (arena.c:394)
==7888==    by 0x585B942: arena_malloc_large (arena.c:667)
==7888==    by 0x5850122: je_calloc (arena.h:883)

==7888== Invalid read of size 8
==7888==    at 0x585C5F1: arena_ralloc_no_move (arena.h:502)
==7888==    by 0x585C808: arena_ralloc (arena.c:1982)
==7888==    by 0x58508BC: je_realloc (jemalloc_internal.h:982)

==7888== Invalid read of size 8
==7888==    at 0x5858768: arena_run_split (arena.h:649)
==7888==    by 0x5858E3F: arena_run_alloc_helper (arena.c:637)
==7888==    by 0x585A5EF: arena_bin_malloc_hard (arena.c:657)
==7888==    by 0x585B2D0: arena_malloc_small (arena.c:1449)
==7888==    by 0x585CBA8: arena_ralloc (arena.h:871)
==7888==    by 0x58508BC: je_realloc (jemalloc_internal.h:982)

I compiled jemallod with ./configure --with-jemalloc-prefix=je_ && make 
&& make install.

This code runs inside a custom Apache HTTPD module running with 
mpm_worker, but a single request generated these valgrind errors (no 
concurrent being processed by multiple threads). It basically calls 
je_malloc for many structures and then a bunch of je_realloc for each 
one of these structures.

Some info about my system:

cat /etc/debian_version
wheezy/sid

uname -a
Linux xxx 3.0.0-28-generic #45-Ubuntu SMP Wed Nov 14 21:57:26 UTC 2012 
x86_64 x86_64 x86_64 GNU/Linux

gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6.1/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 
4.6.1-9ubuntu3' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs 
--enable-languages=c,c++,fortran,objc,obj-c++,go --prefix=/usr 
--program-suffix=-4.6 --enable-shared --enable-linker-build-id 
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext 
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu 
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin 
--enable-objc-gc --disable-werror --with-arch-32=i686 
--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 version 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3)

valgrind --version
valgrind-3.8.1

jemalloc 3.2.0-0-g87499f6748eb

httpd -v
Server version: Apache/2.2.23 (Unix)
Server built:   Dec  7 2012 17:55:24

Are these errors expected? Am I doing something wrong? Any thoughts?

best regards,

Daniel Mezzatto