how is my program executed by bash and the kernel

aheak123 · 08-19-2006, 12:07 PM

Hello all,
I just wanted to know how the program name and arguments are passed to the kernel, are they passed on the stack or registers. I need a detail explanation (under the hood type) of how a program gets executed. I have read the article "How main() is executed on Linux" by Hyouck "Hawk" Kim (great article), but I still have questions on how the stack is setup before
_start gets control.

thanks

XavierP · 08-20-2006, 06:03 AM

Moved: This thread is more suitable in Programming and has been moved accordingly to help your thread/question get the exposure it deserves.

aluser · 08-20-2006, 05:41 PM

Sounds a little homeworky

You can find out by inspecting the source for _start() in libc or by looking at the kernel code.

You can get _start() by downloading glibc here: http://ftp.gnu.org/gnu/glibc/glibc-2.4.tar.gz . The file you want (for i386) is sysdeps/i386/elf/start.S . The function is pretty well commented.

You can browse the kernel code at LXR:
http://lxr.linux.no/source/fs/binfmt_elf.c#L246 . It looks a little harder to grok.