[PATCH] kdumpctl: filter 'root' kernel parameter when running in live images

[Tong Li]

Live images are booted with a kernel parameter which looks like
"root=live:CDLABEL=Fedora-WS-Live-25_A-2". This argument can't be
recognized by dracut during kdump process and will cause failure
of kdump. So we should filter 'root' out when we find such a
parameter in /proc/cmdline to make kdump work correctly in live
images.

Signed-off-by: Tong Li 
---
 kdumpctl | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kdumpctl b/kdumpctl
index d0bbb55..66f3ff7 100755
--- a/kdumpctl
+++ b/kdumpctl
@@ -27,6 +27,11 @@ if [ -f /etc/sysconfig/kdump ]; then
 	. /etc/sysconfig/kdump
 fi
 
+# root parameter will result kdump failure in live images
+if [[ $(cat /proc/cmdline) == *"root=live:CDLABEL"* ]]; then
+    KDUMP_COMMANDLINE_REMOVE="${KDUMP_COMMANDLINE_REMOVE} root"
+fi
+
 single_instance_lock()
 {
 	local rc timeout=5
-- 
2.7.4

[Dave Young]

On 10/11/16 at 01:59pm, Tong Li wrote:
> Live images are booted with a kernel parameter which looks like
> "root=live:CDLABEL=Fedora-WS-Live-25_A-2". This argument can't be
> recognized by dracut during kdump process and will cause failure
> of kdump. So we should filter 'root' out when we find such a
> parameter in /proc/cmdline to make kdump work correctly in live
> images.
> Signed-off-by: Tong Li
>
> kdumpctl | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/kdumpctl b/kdumpctl
> index d0bbb55..66f3ff7 100755
> --- a/kdumpctl
> +++ b/kdumpctl
> @@ -27,6 +27,11 @@ if [ -f /etc/sysconfig/kdump ]; then
>  	. /etc/sysconfig/kdump
>  fi
>  
> +# root parameter will result kdump failure in live images
> +if [[ $(cat /proc/cmdline) == *"root=live:CDLABEL"* ]]; then
> +    KDUMP_COMMANDLINE_REMOVE="${KDUMP_COMMANDLINE_REMOVE} root"

It should be in the sysconfig variable instead of in kdumpctl.
Could you update kdump.sysconfig.* instead?

Also match "root=live:" should be better, we do not know if there are
other types of live boot.
> +fi
>
> single_instance_lock()
>  {
>  	local rc timeout=5
> -- 
> 2.7.4
> _______________________________________________
> kexec mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]

Thanks
Dave

[Tong Li]

On 2016年10月12日 16:04, Dave Young wrote:
> On 10/11/16 at 01:59pm, Tong Li wrote:
> > Live images are booted with a kernel parameter which looks like
> > "root=live:CDLABEL=Fedora-WS-Live-25_A-2". This argument can't be
> > recognized by dracut during kdump process and will cause failure
> > of kdump. So we should filter 'root' out when we find such a
> > parameter in /proc/cmdline to make kdump work correctly in live
> > images.
> > Signed-off-by: Tong Li
> >
> > kdumpctl | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git a/kdumpctl b/kdumpctl
> > index d0bbb55..66f3ff7 100755
> > --- a/kdumpctl
> > +++ b/kdumpctl
> > @@ -27,6 +27,11 @@ if [ -f /etc/sysconfig/kdump ]; then
> >    . /etc/sysconfig/kdump
> >   fi
> >
> > +# root parameter will result kdump failure in live images
> > +if [[ $(cat /proc/cmdline) == *"root=live:CDLABEL"* ]]; then
> > KDUMP_COMMANDLINE_REMOVE="${KDUMP_COMMANDLINE_REMOVE} root"
>
> It should be in the sysconfig variable instead of in kdumpctl.
> Could you update kdump.sysconfig.* instead?

kdump.sysconfig.* look like just collections of variables. Is that 
appropriate that we add some logical code into it?
> Also match "root=live:" should be better, we do not know if there are
> other types of live boot.

Sounds good. Thank you for the suggestion.
> > +fi
> > single_instance_lock()
> > {
> >  local rc timeout=5
> >
> > -- 
> > 2.7.4
> > _______________________________________________
> > kexec mailing list -- [e-mail]
> > To unsubscribe send an email to [e-mail]
>
> Thanks
> Dave

Regards,
Tong

[Dave Young]

On 10/12/16 at 04:32pm, Tong Li wrote:
> On 2016年10月12日 16:04, Dave Young wrote:
> > On 10/11/16 at 01:59pm, Tong Li wrote:
> > > Live images are booted with a kernel parameter which looks like
> > > "root=live:CDLABEL=Fedora-WS-Live-25_A-2". This argument can't be
> > > recognized by dracut during kdump process and will cause failure
> > > of kdump. So we should filter 'root' out when we find such a
> > > parameter in /proc/cmdline to make kdump work correctly in live
> > > images.
> > > Signed-off-by: Tong Li
> > >
> > > kdumpctl | 5 +++++
> > >   1 file changed, 5 insertions(+)
> > >
> > > diff --git a/kdumpctl b/kdumpctl
> > > index d0bbb55..66f3ff7 100755
> > > --- a/kdumpctl
> > > +++ b/kdumpctl
> > > @@ -27,6 +27,11 @@ if [ -f /etc/sysconfig/kdump ]; then
> > >    . /etc/sysconfig/kdump
> > >   fi
> > > +# root parameter will result kdump failure in live images
> > > +if [[ $(cat /proc/cmdline) == *"root=live:CDLABEL"* ]]; then
> > > KDUMP_COMMANDLINE_REMOVE="${KDUMP_COMMANDLINE_REMOVE} root"
> >
> > It should be in the sysconfig variable instead of in kdumpctl.
> > Could you update kdump.sysconfig.* instead?
>
> kdump.sysconfig.* look like just collections of variables. Is that
> appropriate that we add some logical code into it?

Sorry, you are right, we have no way to conditionally do that in
sysconfig. So please ignore the comment.
> > Also match "root=live:" should be better, we do not know if there are
> > other types of live boot.
>
> Sounds good. Thank you for the suggestion.
> > > +fi
> > > single_instance_lock()
> > > {
> > >  local rc timeout=5
> > >
> > > -- 
> > > 2.7.4
> > > _______________________________________________
> > > kexec mailing list -- [e-mail]
> > > To unsubscribe send an email to [e-mail]
> >
> > Thanks
> > Dave
>
> Regards,
> Tong
> kexec mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]

[Dave Young]

On 10/12/16 at 04:32pm, Tong Li wrote:
> On 2016年10月12日 16:04, Dave Young wrote:
> > On 10/11/16 at 01:59pm, Tong Li wrote:
> > > Live images are booted with a kernel parameter which looks like
> > > "root=live:CDLABEL=Fedora-WS-Live-25_A-2". This argument can't be
> > > recognized by dracut during kdump process and will cause failure
> > > of kdump. So we should filter 'root' out when we find such a
> > > parameter in /proc/cmdline to make kdump work correctly in live
> > > images.
> > > Signed-off-by: Tong Li
> > >
> > > kdumpctl | 5 +++++
> > >   1 file changed, 5 insertions(+)
> > >
> > > diff --git a/kdumpctl b/kdumpctl
> > > index d0bbb55..66f3ff7 100755
> > > --- a/kdumpctl
> > > +++ b/kdumpctl
> > > @@ -27,6 +27,11 @@ if [ -f /etc/sysconfig/kdump ]; then
> > >    . /etc/sysconfig/kdump
> > >   fi
> > > +# root parameter will result kdump failure in live images
> > > +if [[ $(cat /proc/cmdline) == *"root=live:CDLABEL"* ]]; then
> > > KDUMP_COMMANDLINE_REMOVE="${KDUMP_COMMANDLINE_REMOVE} root"
> >
> > It should be in the sysconfig variable instead of in kdumpctl.
> > Could you update kdump.sysconfig.* instead?
>
> kdump.sysconfig.* look like just collections of variables. Is that
> appropriate that we add some logical code into it?
> > Also match "root=live:" should be better, we do not know if there are
> > other types of live boot.
>
> Sounds good. Thank you for the suggestion.

Looking at the code, could you move the logic only for dropping
/proc/cmdline params? like below:

if [ -z "$KDUMP_COMMANDLINE" ]; then
                cmdline=`cat /proc/cmdline`
[ drop root here ...]
        else
                cmdline=${KDUMP_COMMANDLINE}
        fi
> > > +fi
> > > single_instance_lock()
> > > {
> > >  local rc timeout=5
> > >
> > > -- 
> > > 2.7.4
> > > _______________________________________________
> > > kexec mailing list -- [e-mail]
> > > To unsubscribe send an email to [e-mail]
> >
> > Thanks
> > Dave
>
> Regards,
> Tong
> kexec mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]

[Tong Li]

On Thu, Oct 13, 2016 at 3:49 PM, Dave Young  wrote:
> On 10/12/16 at 04:32pm, Tong Li wrote:
> > On 2016年10月12日 16:04, Dave Young wrote:
> > > On 10/11/16 at 01:59pm, Tong Li wrote:
> > > > Live images are booted with a kernel parameter which looks like
> > > > "root=live:CDLABEL=Fedora-WS-Live-25_A-2". This argument can't be
> > > > recognized by dracut during kdump process and will cause failure
> > > > of kdump. So we should filter 'root' out when we find such a
> > > > parameter in /proc/cmdline to make kdump work correctly in live
> > > > images.
> > > > Signed-off-by: Tong Li
> > > >
> > > > kdumpctl | 5 +++++
> > > >   1 file changed, 5 insertions(+)
> > > >
> > > > diff --git a/kdumpctl b/kdumpctl
> > > > index d0bbb55..66f3ff7 100755
> > > > --- a/kdumpctl
> > > > +++ b/kdumpctl
> > > > @@ -27,6 +27,11 @@ if [ -f /etc/sysconfig/kdump ]; then
> > > >           . /etc/sysconfig/kdump
> > > >   fi
> > > > +# root parameter will result kdump failure in live images
> > > > +if [[ $(cat /proc/cmdline) == *"root=live:CDLABEL"* ]]; then
> > > > KDUMP_COMMANDLINE_REMOVE="${KDUMP_COMMANDLINE_REMOVE} root"
> > >
> > > It should be in the sysconfig variable instead of in kdumpctl.
> > > Could you update kdump.sysconfig.* instead?
> >
> > kdump.sysconfig.* look like just collections of variables. Is that
> > appropriate that we add some logical code into it?
> > > Also match "root=live:" should be better, we do not know if there are
> > > other types of live boot.
> >
> > Sounds good. Thank you for the suggestion.
>
> Looking at the code, could you move the logic only for dropping
> /proc/cmdline params? like below:
>     if [ -z "$KDUMP_COMMANDLINE" ]; then
>             cmdline=`cat /proc/cmdline`
>
> [ drop root here ...]
>         else
>                 cmdline=${KDUMP_COMMANDLINE}
>         fi

It looks like this way is more reasonable. Will do. Thank you for the
suggestion.
> > > > +fi
> > > > single_instance_lock()
> > > > {
> > > >         local rc timeout=5
> > > >
> > > > --
> > > > 2.7.4
> > > > _______________________________________________
> > > > kexec mailing list -- [e-mail]
> > > > To unsubscribe send an email to [e-mail]
> > >
> > > Thanks
> > > Dave
> >
> > Regards,
> > Tong
> > kexec mailing list -- [e-mail]
> > To unsubscribe send an email to [e-mail]

Regards,