Get wrong .gnu.hash contents

[wkisme]

Describe the bug
Just parse and write, the content of .gnu.hash is all zero

To Reproduce

cp /lib/x86_64-linux-gnu/libicuuc.so.70 .
python3
Python 3.10.12 (main, Jun 11 2023, 05:26:28) [GCC 11.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import lief
>>> lief.parse('libicuuc.so.70').write('libicuuc.so.70-1')
>>> exit()
objdump -s libicuuc.so.70-1 | grep .gnu.hash -A5
Contents of section .gnu.hash:
 02f0 05080000 59000000 00020000 0f000000  ....Y...........
 0300 00000000 00000000 00000000 00000000  ................
 0310 00000000 00000000 00000000 00000000  ................
 0320 00000000 00000000 00000000 00000000  ................
 0330 00000000 00000000 00000000 00000000  ................

Expected behavior
The content of .gnu.hash should be same as the original version of DSO.

prometheus@courage-machine:~/shrinkwrap/shrinkwrap$ objdump -s libicuuc.so.70 | grep .gnu.hash -A5
Contents of section .gnu.hash:
 02f0 05080000 59000000 00020000 0f000000  ....Y...........
 0300 08121008 3094c901 60a28202 84043028  ....0...`.....0(
 0310 005200c1 09100042 000382c0 10820280  .R.....B........
 0320 00205004 004e1120 00498001 10434808  . P..N. .I...CH.
 0330 1a003519 01460274 51010200 0464c080  ..5..F.tQ....d..

Environment (please complete the following information):

• System and Version : Ubuntu 22.04.1 TLS
• Target format ELF
• LIEF commit version: 0.13.2-2d9855fc
  Additional context

prometheus@courage-machine:~/shrinkwrap/shrinkwrap$ cp /lib/x86_64-linux-gnu/libxml2.so.2 .
prometheus@courage-machine:~/shrinkwrap/shrinkwrap$ python3
Python 3.10.12 (main, Jun 11 2023, 05:26:28) [GCC 11.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import lief
>>> lief.parse('libxml2.so.2').write('libxml2.so.2-1')
>>> exit()
prometheus@courage-machine:~/shrinkwrap/shrinkwrap$ objdump -s libxml2.so.2 | grep .gnu.hash -A5
Contents of section .gnu.hash:
 02f0 07040000 84000000 00010000 0e000000  ................
 0300 1010c520 02080084 000c1008 84420a04  ... .........B..
 0310 22200064 191604c4 01204ba4 4020a110  " .d..... K.@ ..
 0320 00190215 00108404 14045500 80680038  ..........U..h.8
 0330 00018020 08109002 79582160 43002083  ... ....yX!`C. .
prometheus@courage-machine:~/shrinkwrap/shrinkwrap$ objdump -s libxml2.so.2-1 | grep .gnu.hash -A5
Contents of section .gnu.hash:
 02f0 07040000 84000000 00010000 0e000000  ................
 0300 1010c520 02080084 000c1008 84420a04  ... .........B..
 0310 22200064 191604c4 01204ba4 4020a110  " .d..... K.@ ..
 0320 00190215 00108404 14045500 80680038  ..........U..h.8
 0330 00018020 08109002 79582160 43002083  ... ....yX!`C. .

[romainthomas]

Incomplete because: Missing libxml2.so.2 or libicuuc.so.70

[wkisme]

sudo apt install libxml2, and you will get libxml2.so.2 and libicuuc.so.70

[romainthomas]

What about attaching these files to the issue?

[romainthomas]

Other remark: what is wrong by having a different .gnu.hash content?

[wkisme]

Other remark: what is wrong by having a different .gnu.hash content?

The .gnu.hash content is for looking up symbols.
Maybe can't find corrected symbols, if the .gnu.hash content is different.

Following is an example that can't find symbol, which is in libicuuc.so.70 processed by lief.

prometheus@courage-machine:~/shrinkwrap/shrinkwrap$ ./emacs_zeta
./emacs_zeta: symbol lookup error: /home/prometheus/shrinkwrap/shrinkwrap/zeta-emacs/libxml2.so.2: undefined symbol: UCNV_FROM_U_CALLBACK_STOP_70

ldd /home/prometheus/shrinkwrap/shrinkwrap/zeta-emacs/libxml2.so.2 | grep libicuuc.so.70
        /home/prometheus/shrinkwrap/shrinkwrap/zeta-emacs/./libicuuc.so.70 (0x00007f208d205000)

nm -D /home/prometheus/shrinkwrap/shrinkwrap/zeta-emacs/./libicuuc.so.70 | grep UCNV_FROM_U_CALLBACK_STOP_70
00000000000d9610 T UCNV_FROM_U_CALLBACK_STOP_70

[romainthomas]

Duplicated: #969