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From: Andriy Gapon <avg@FreeBSD.org>
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$ dtrace -n 'blah blah' -c 'touch /'
dtrace: failed to control pid 16473: process exited with status 0

I think that we need the following change:

--- a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c
@@ -1115,7 +1115,7 @@ alloc:
 #if defined(sun)
 	dtp->dt_prcmode = DT_PROC_STOP_PREINIT;
 #else
-	dtp->dt_prcmode = DT_PROC_STOP_MAIN;
+	dtp->dt_prcmode = DT_PROC_STOP_POSTINIT;
 #endif
 	dtp->dt_linkmode = DT_LINK_KERNEL;
 	dtp->dt_linktype = DT_LTYP_ELF;


Rationale:
- we don't use DT_PROC_STOP_PREINIT like solaris does, because for some reason
that I haven't investigated we the following line ifdef-ed out in dt_proc_attach:
dt_proc_rdwatch(dpr, RD_PREINIT, "RD_PREINIT");

- 'main' symbol can't always be reliably resolved:
$ readelf -a -W /usr/bin/touch | fgrep main
$

So, it seems that "postinit" is where we can reliable catch a process.
What do you think?

-- 
Andriy Gapon