[X2Go-Dev] running x2goagent under valgrind
Orion Poplawski
orion at cora.nwra.com
Fri Jan 20 19:03:42 CET 2017
On 01/19/2017 02:34 PM, Nable wrote:
> Hi Orion.
> It may be off-topic but did you try using sanitizers? AFAIR, they've
> appeared first in Clang but now you can use these instruments in GCC
> too. Currently I don't see any reason for using Valgrind instead of
> AddressSanitizer (one should specify -fsanitize=address for
> compilation and linking) except the case when you don't have the full
> source code or have limited test environment (such as 32-bit system,
> VZ container or system with some ancient compiler). IMHO this is much
> faster than valgrind and catches more problems.
>
Thanks for this note - didn't know about this. With it I seem to be hitting
the same issue found with valgrind reported here:
https://github.com/ArcticaProject/nx-libs/issues/293
With -fsanitize=address the program exits immediately:
=================================================================
==30566== ERROR: AddressSanitizer: heap-use-after-free on address
0x601c0000bd68 at pc 0xd6d797 bp 0x7ffc3bc161c0 sp 0x7ffc3bc161b0
READ of size 8 at 0x601c0000bd68 thread T0
#0 0xd6d796 (/usr/lib64/nx/bin/nxagent+0xd6d796)
#1 0xd6e455 (/usr/lib64/nx/bin/nxagent+0xd6e455)
#2 0x5c353d (/usr/lib64/nx/bin/nxagent+0x5c353d)
#3 0x5c3ce7 (/usr/lib64/nx/bin/nxagent+0x5c3ce7)
#4 0x5874fd (/usr/lib64/nx/bin/nxagent+0x5874fd)
#5 0x58b621 (/usr/lib64/nx/bin/nxagent+0x58b621)
#6 0x5a9ff6 (/usr/lib64/nx/bin/nxagent+0x5a9ff6)
#7 0x51129d (/usr/lib64/nx/bin/nxagent+0x51129d)
#8 0x53bb2a (/usr/lib64/nx/bin/nxagent+0x53bb2a)
#9 0x485dd9 (/usr/lib64/nx/bin/nxagent+0x485dd9)
#10 0x419fa4 (/usr/lib64/nx/bin/nxagent+0x419fa4)
#11 0x7fb32fc7ab34 (/usr/lib64/libc-2.17.so+0x21b34)
#12 0x41d14d (/usr/lib64/nx/bin/nxagent+0x41d14d)
0x601c0000bd68 is located 40 bytes inside of 152-byte region
[0x601c0000bd40,0x601c0000bdd8)
freed by thread T0 here:
#0 0x7fb332a05009 (/usr/lib64/libasan.so.0.0.0+0x16009)
#1 0xd82478 (/usr/lib64/nx/bin/nxagent+0xd82478)
previously allocated by thread T0 here:
#0 0x7fb332a05129 (/usr/lib64/libasan.so.0.0.0+0x16129)
#1 0xd82896 (/usr/lib64/nx/bin/nxagent+0xd82896)
Shadow bytes around the buggy address:
0x0c03ffff9750: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
0x0c03ffff9760: 00 00 00 00 00 00 04 fa fa fa fa fa fa fa fa fa
0x0c03ffff9770: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x0c03ffff9780: fd fd fd fa fa fa fa fa fa fa fa fa fd fd fd fd
0x0c03ffff9790: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fa
=>0x0c03ffff97a0: fa fa fa fa fa fa fa fa fd fd fd fd fd[fd]fd fd
0x0c03ffff97b0: fd fd fd fd fd fd fd fd fd fd fd fa fa fa fa fa
0x0c03ffff97c0: fa fa fa fa fd fd fd fd fd fd fd fd fd fd fd fd
0x0c03ffff97d0: fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa fa
0x0c03ffff97e0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x0c03ffff97f0: fd fd fd fd fa fa fa fa fa fa fa fa 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Heap righ redzone: fb
Freed Heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
ASan internal: fe
==30566== ABORTING
which makes discovering any additional issues later in the session impossible.
It would be nice to get this fixed.
--
Orion Poplawski
Technical Manager 720-772-5637
NWRA, Boulder/CoRA Office FAX: 303-415-9702
3380 Mitchell Lane orion at nwra.com
Boulder, CO 80301 http://www.nwra.com
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