sysutils/strace wilderness on 6-CURRENT

Dan Nelson dnelson at
Tue Aug 31 10:24:01 PDT 2004

In the last episode (Aug 31), Gary Jennejohn said:
> Dan Nelson writes:
> > In the last episode (Aug 31), Vladimir Grebenschikov said:
> > > It silmple does nothing - sleeps foreaver in suspended:
> > > 
> > > # strace /bin/ls
> > 
> > This has happened on 5.x for ages.  The quick fix is to ^Z, then
> > fg, or kill -CONT the hung strace process from another vty.  I
> > don't know what strace does different from truss that makes it
> > hang.  Nowadays, truss does almost as good a job as strace, so I
> > don't use it as often as I used to.  The only thing I miss is
> > strace's ability to print the name of blocking syscalls (read or
> > sleep for example) as it waits.
> > 
> I fixed a bug like this in strace for Linux. The SIGCHLD handler was
> being set too late and the child (through some wacky handling of
> SIGCHLD in the Linux kernel) got into a state where it never returned
> the expected status in wait(). Both the child and strace ended up
> hanging. kill -CONT also got things going there. Maybe FreeBSD has a
> similar problem?

Dunno.  Strace is a port built from the sources at sourceforge, so I
assume that any Linux fixes would also be included.  I see the port is
at 4.5.1 but sourceforge is up to 4.5.7.  Maybe a newer version works

	Dan Nelson
	dnelson at

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