I am using following command:
echo 'SOME_DATA' > data.file \
&& objcopy \
--input-target binary \
--output-target=elf64-x86-64 \
--rename-section .data=.my_data_section \
--add-symbol DATA_SECTION_START=.my_data_section:0 \
data.file \
elf.o \
&& readelf -a elf.o
to create "elf.o" file from "data.file" binary file.
In this command ".data" section is created and renamed into ".my_data_section".
At the same time, I am adding symbol/variable "DATA_SECTION_START" pointing it to the beginning of the newly created ".my_data_section" section.
Is it legal to do add and rename section + use such name creating new var at the same time?
I found that "llvm-objcopy" generates wrong "DATA_SECTION_START" variable (Ndx is ABS):
Section Headers:
[Nr] Name Type Address Offset
...
[ 1] .my_data_section PROGBITS 0000000000000000 00000040
...
Symbol table '.symtab' contains 6 entries:
Num: Value Size Type Bind Vis Ndx Name
...
5: 000000000000000a 0 NOTYPE GLOBAL DEFAULT ABS DATA_SECTION_START
At the same time, I see no problem when using "objcopy" (GCC):
Section Headers:
[Nr] Name Type Address Offset
...
[ 1] .my_data_section PROGBITS 0000000000000000 00000040
...
Symbol table '.symtab' contains 6 entries:
Num: Value Size Type Bind Vis Ndx Name
...
5: 0000000000000000 0 NOTYPE GLOBAL DEFAULT 1 DATA_SECTION_START
Can we say that "llvm-objcopy" works in a wrong way?
