Re: Debugging , Tracing...

[Richard B. Johnson]

On Sun, 6 Jul 2003, Auge Mike wrote:

> Hi all,
>
>       I have asked before few weeks about tracing the execution of the
> kernel or debugging it. Unfortunately, I faced some problems in using Kgdb,
> especially that the patch was not successful on my redhat 7.3.
>      Whatever, lets say that kgdb worked successfully, how can I trace the
> execution of “a specific system call” (lets say printf), so I can see how it
> works internally. Is there any other utility for that? How can I do that
> with kgdb?
>
>      Thanx for your help in advance.
>
> Yours,

printf() is not a system call. It is some procedure within the
'C' runtime library. Eventually, that library makes a call to
write() which is a kernel system call. You can use strace to see
the execution of all the system calls.

If you want to single-step through the 'C' runtime library, you
need to get their sources and compile them with the '-g' parameter
(for debugging). I don't know why you would want to do that, because
you would then have the sources so you can actually read the source
of what happens with a particular call.

Cheers,
Dick Johnson
Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips).
Why is the government concerned about the lunatic fringe? Think about it.