here is a simple example program . I 'm trying to setp into the kernel proc=
of this thread.
int main(int argc, char argv)
(UML) gdb -g -o test test.c
when the test thread is sleeping at "sleep(30);" I prese CTRL+C in
(UML gdb) to stop the tracing linux.
and trying to attach thread test.
(UML gdb) det
(UML gdb) att 16488 (host pid of test : linux [./test])
Attaching to program: /usr/local/bin/linux, process 16488
ptrace: Operation not permitted
this thread is not traced yet, what's the problem?
and when I try to attach any other thread except the orignial linux
tracing thread, the same problem occurs "ptrace: Operation not
I use gentoo linux system kernel 2.6.11 + GNU gdb 6.3 +=20
any idea? should I install a old version of gdb 5.3.90 to solve this prob=
thanks in advance.
On 6/19/05, Blaisorblade <blaisorblade@...> wrote:
> On Saturday 18 June 2005 18:38, John Smith wrote:
> > Hi,
> > I have set up UML kernel 2.6.11 and I can run "linux debug" to step int=
> > kernel boot successfully.
> > I 'm trying to trace into a thread , and I 'm following the instruction
> > in http://user-mode-linux.sourceforge.net/debugging.html
> > CTRL+C in gdb xterm # stop
> > (host) ps aux # get the host pid of uml thread
> > # detach from the current thread
> > (UML gdb) det
> > # attach to the thread you are interested in
> > (UML gdb) att <host pid>
> > problem 1: gdb report: " permission denied" # why???
> Probably the problem is that you can't trace an already traced thread. Th=
> ptrace proxy fixes this but is a bit out of date... IIRC Jeff Dikes works
> successfully with gdb 5.3.90.
> > (UML gdb) det
> > (UML gdb) att 1
> > problem2: gdb report:
> > Attaching to program: /usr/local/bin/linux, process 1
> > 'system-supplied DSO at oxfffe000' has disappeared; keeping its symbols=
> > ...
> This can probably be ignored, it's about symbols for vsyscalls (the
> linux-gate.so.1 =3D> (0xffffe000) line in ldd output).
> > I can not understand what's wrong with these 2 problems.
> > please help me , I have been working on it almost one week.
> Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!".
> Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 2156218=