Program will crash after using gcov

[Nan Xiao]

Hi all,

Greetings from me!

I am using the gcov to test my program (add "-fprofile-arcs
-ftest-coverage") on Linux, but the program will crash after start:

(gdb) bt
#0 0x00000034e433386f in __strlen_sse42 () from /lib64/libc.so.6
#1 0x000000000053c57a in __gcov_init ()
#2 0x000000000053c4b9 in _GLOBAL__I_65535_0_g_st_rerun_cmd_param ()
at source/rerun/aicent_ara_rerun.c:963
#3 0x000000000053dc26 in __do_global_ctors_aux ()
#4 0x0000000000403743 in _init ()
#5 0x00007fff6d6b3ce8 in ?? ()
#6 0x000000000053db55 in __libc_csu_init ()
#7 0x00000034e421ecb0 in __libc_start_main () from /lib64/libc.so.6
#8 0x0000000000404449 in _start ()

From __gcov_init() source

(http://www.coreboot.org/~stepan/coreboot-coverage/lib/libgcov.c.gcov.html)
:
......
size_t filename_length = strlen(info->filename);
......

I can see the root cause is the "info->filename" is invalid (After
disassembling the code, the address is 0x57c4ac00000000, and it is
indeed invalid).

I don't know how to analyse this bug, could anyone give any clues?
Thanks very much in advance!

P.S. My Linux environment:
[***@localhost rel_1_3_3_20140902]# uname -a
Linux localhost.localdomain 2.6.32-431.el6.x86_64 #1 SMP Sun Nov 10
22:19:54 EST 2013 x86_64 x86_64 x86_64 GNU/Linux

gcc version:
[***@localhost rel_1_3_3_20140902]# gcc -v
Using built-in specs.
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap
--enable-shared --enable-threads=posix --enable-checking=release
--with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada
--enable-java-awt=gtk --disable-dssi
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
--enable-libgcj-multifile --enable-java-maintainer-mode
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--disable-libjava-multilib --with-ppl --with-cloog --with-tune=generic
--with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 4.4.7 20120313 (Red Hat 4.4.7-4) (GCC)


Best Regards
Nan Xiao

[Brian Budge]

Post by Nan Xiao
......
size_t filename_length = strlen(info->filename);
......
I can see the root cause is the "info->filename" is invalid (After
disassembling the code, the address is 0x57c4ac00000000, and it is
indeed invalid).
I don't know how to analyse this bug, could anyone give any clues?
Thanks very much in advance!

I would consider using valgrind or address-sanitizer/memory-sanitizer
to track down your bug. Note that the latter two options require a
fairly recent version of gcc or clang.

[Nan Xiao]

Hi Brian,

Thanks very much for your kind response!

The root cause of this issue is using `-fpack-struct=4` compile
option on 64-bit Linux. For detailed information, we can refer
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43341.

Best Regards
Nan Xiao

Post by Brian Budge

Post by Nan Xiao
......
size_t filename_length = strlen(info->filename);
......
I can see the root cause is the "info->filename" is invalid (After
disassembling the code, the address is 0x57c4ac00000000, and it is
indeed invalid).
I don't know how to analyse this bug, could anyone give any clues?
Thanks very much in advance!

I would consider using valgrind or address-sanitizer/memory-sanitizer
to track down your bug. Note that the latter two options require a
fairly recent version of gcc or clang.