Re: svn commit: r195843 - in head: lib/libkvm sys/kern sys/sys

[Brooks Davis]

On Sat, Aug 29, 2009 at 08:12:28PM +0100, Bruce Cran wrote:
> On Fri, 24 Jul 2009 15:03:10 +0000 (UTC)
> Brooks Davis <bro...@freebsd.org> wrote:
> 
> > Author: brooks
> > Date: Fri Jul 24 15:03:10 2009
> > New Revision: 195843
> > URL: http://svn.freebsd.org/changeset/base/195843
> > 
> > Log:
> >   Revert the changes to struct kinfo_proc in r194498.  Instead, fill
> >   in up to 16 (KI_NGROUPS) values and steal a bit from ki_cr_flags
> >   (all bits currently unused) to indicate overflow with the new flag
> >   KI_CRF_GRP_OVERFLOW.
> >   
> >   This fixes procstat -s.
> >   
> >   Approved by: re (kib)
> 
> Hi Brooks,
> 
> This checkin appears to have broken crash dump support: the bcopy in
> kvm_proc.c crashes when running "ps -ax -M /var/crash/vmcore.x
> -N /boot/kernel/kernel", apparently because ucred.cr_groups isn't valid.
> Does it need converted using KVM_READ first?

Sorry for the delay, I believe you are correct we need to use kvm_read
here instead of the bcopy.  Do you still have a core handy you can test
a patch against?  The following should do it.

-- Brooks

Index: lib/libkvm/kvm_proc.c
===================================================================
--- lib/libkvm/kvm_proc.c       (revision 196736)
+++ lib/libkvm/kvm_proc.c       (working copy)
@@ -151,7 +151,7 @@
                                kp->ki_cr_flags |= KI_CRF_GRP_OVERFLOW;
                        }
                                kp->ki_ngroups = ucred.cr_ngroups;
-                       bcopy(ucred.cr_groups, kp->ki_groups,
+                       kvm_read(kd, (u_long)ucred.cr_groups, kp->ki_groups,
                            kp->ki_ngroups * sizeof(gid_t));
                        kp->ki_uid = ucred.cr_uid;
                        if (ucred.cr_prison != NULL) {

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