MirkoBanchi MirkoBanchi - 2 months ago 17
Linux Question

Linking a dynamically linked executable with ld

i'm trying to create a dynamically linked executable (elf_i386) without gcc. The program is very simple (only a printf)...here the commands:

$ gcc -c simple.c
$ ld -o simple -dynamic-linker /lib/ld-linux.so.2 --entry main /usr/lib/crt1.o /usr/lib/crti.o simple.o -lc /usr/lib/crtn.o


The executable is created and also file command and ldd command show the right output...
However when i launch the program after the call to printf i get a segmentation fault...i've examined with objdump the executable and i think the problem is about the dtors...seems that compiling with:

$gcc -o simple simple.c


a section .dtors is present while it is not present inside the executable created directly with ld :(

Any ideas?

Answer

Lose the --entry main. main isn't your entry point, _start is. Try this:

$ gcc -c hello.c
$ ld -o hello -dynamic-linker /lib/ld-linux.so.2 /usr/lib/crt1.o /usr/lib/crti.o hello.o -lc /usr/lib/crtn.o
$ ./hello
hello, world
$ 
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