Re: subshell (ctrl-o) not working properly

[Tomasz Chmielewski <mangoo wpkg org>]

Pavel Tsekov wrote:

(...)

> > Pressing ctrl + o shows the background, but I can't execute any shell
> > commands (I return to mc immediately when pressing any key).
> >
> >
> > Strace available at http://wpkg.org/subshell.strace.gz (strace -o
> > subshell.strace) and http://wpkg.org/sub.strace.gz (strace -o sub.strace
> > mc -U).
>
> The strace output suggests that the subshell is being killed by a SIGPWR
> signal. I cannot tell why this signal is being sent to the subshell
> though. Maybe the OS you are running on your embedded device is
> sending this signal for some specific purpose and expects the application
> to deal with it... In any case the fact that the subshell is not working
> on your platform is not a bug in MC.

Perhaps the subshell consumes so much resources on this tiny router that 
 the kernel reports a power failure (that's what SIGPWR is) and kills 
the subshell :)

It's a regular Linux 2.4.30, a major difference is that it's not using 
glibc, but uClibc, and not a x86 processor, but a mipsel one.

In linux-2.4.30/include/asm-i386/signal.h it's:

#define SIGPWR          30

and in linux-2.4.30/include/asm-mips/signal.h it's:

#define SIGPWR          19      /* Power failure restart (System V).  */

and once again in linux-2.4.30/include/asm-mips/offset.h:

#define _SIGPWR     0x13:


Not being a kernel hacker, this tells me that the only way to get 
subshell working for me would be to make it ignore the SIGPWR I guess?


--
Tomasz Chmielewski
WPKG - http://wpkg.org
Software deployment with Samba