UML exits? Or just strace? Seems like either a strace or ptrace bug.
Sorry - it was strace that exits - the UML is still running.
How about waiting until UML hangs and then attaching strace to it?
So, there are 5 threads of UML. The main (or the first thread) shows:
==================================================
--- SIGCHLD (Child exited) @ 0 (0) ---
wait4(9078, [{WIFSTOPPED(s) && WSTOPSIG(s) == SIGUSR1}], WSTOPPED, NULL) =
9078
ptrace(PTRACE_SETREGS, 9078, 0, 0x60d0eb08) = 0
ptrace(PTRACE_SETFPREGS, 9078, 0, 0x60d0ebe0) = 0
ptrace(PTRACE_SYSCALL, 9078, 0, SIG_0) = 0
--- SIGCHLD (Child exited) @ 0 (0) ---
wait4(9078, [{WIFSTOPPED(s) && WSTOPSIG(s) == SIGSEGV}], WSTOPPED, NULL) =
9078
ptrace(PTRACE_GETREGS, 9078, 0, 0x60d0eb08) = 0
ptrace(PTRACE_GETFPREGS, 9078, 0, 0x60d0ebe0) = 0
ptrace(PTRACE_CONT, 9078, 0, SIGSEGV) = 0
===================================================
So it seems to be waiting on process ID 9078 which also a UML thread.
However
strace refuses to attach to it even though I am running as root user:
attach: ptrace(PTRACE_ATTACH, ...): Operation not permitted
The other three child threads aren't doing much - each is waiting on a
different event:
Thread 1 - io_getevents(0x2b723ae76000, 0x1, 0x1, 0x6042ffb8, 0
Thread 2 - read(5,
Thread 3 - poll(
I will be back online in a couple of hours. Thank you for your help.
shalb.
From: Jeff Dike <[EMAIL PROTECTED]>
To: S A <[EMAIL PROTECTED]>
CC: [email protected]
Subject: Re: [uml-user] unable to get login prompt with
CONFIG_FRAME_POINTER & x86_64
Date: Fri, 7 Apr 2006 17:40:43 -0400
On Fri, Apr 07, 2006 at 09:40:44PM +0000, S A wrote:
> Is there a way to make strace work with threads? When i run
> uml under strace, it always exits (and it exits doing something
> innocuos like a fcntl or socketpair).
UML exits? Or just strace? Seems like either a strace or ptrace bug.
How about waiting until UML hangs and then attaching strace to it?
> I also tried this under gdb
> and when I interrupt the UML, the backtrace just shows a signal
> handler (included below).
This is normal.
Jeff
-------------------------------------------------------
This SF.Net email is sponsored by xPML, a groundbreaking scripting language
that extends applications into web and mobile media. Attend the live webcast
and join the prime developer group breaking into this new coding territory!
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642
_______________________________________________
User-mode-linux-user mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
