Date: Thu, 15 Apr 1999 19:54:33 -0400 (EDT) From: Robert Watson <robert@cyrus.watson.org> To: hackers@freebsd.org Subject: child return in fork--question Message-ID: <Pine.BSF.3.96.990415195038.11607F-100000@fledge.watson.org>
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I'm playing around with process scheduling and doing funky things with
syscalls. I notice that on i386, fork_return() hard codes the return
values from the fork syscall:
frame.tf_eax = 0; /* Child returns zero */
frame.tf_eflags &= ~PSL_C; /* success */
frame.tf_edx = 1;
userret(p, &frame, 0);
Most other places, we copy the p_retval[] fields out of the appropriate
process structure, rather than hard coding. Is there a reason why the
same thing doesn't happen here, and p_retval[] be set in the child proc
structure in fork1()? If not, if I submit patches, would they be put in?
(presumably the same code alpha-side would have to be done also).
I'd like to be able to make a machine independent change to the fork
return values in the fork code without munging into i386/alpha/etc code in
the future if I need to change it.
Robert N Watson
robert@fledge.watson.org http://www.watson.org/~robert/
PGP key fingerprint: 03 01 DD 8E 15 67 48 73 25 6D 10 FC EC 68 C1 1C
Carnegie Mellon University http://www.cmu.edu/
TIS Labs at Network Associates, Inc. http://www.tis.com/
Safeport Network Services http://www.safeport.com/
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