Bug 1476219

Created attachment 1305890 [details]
kdumpctl file with spacefunction to detect white space.

sorry for the typo:

3.Crash the kernel and check that the dump is stored in /var/crash and not /tmp/crash.

This is reproducible with RHEL 7.4 kexec-tools:
# rpm -qa kexec-tools
kexec-tools-2.0.0-307.el6.x86_64


Initially it took me some time to reproduce this and I had to confirm this with the reporter as when I used a location inside '/tmp' the issue was NOT reproducible:
   path /tmp/crash  <--- space before path

however, when I used a crash location outside /tmp, I was able to reproduce this issue, for e.g. on beaker machine ibm-x3650m4-01-vm-06.lab.eng.bos.redhat.com with path variable set as:
   path /home/bhsharma  <--- space before path

Will add appropriate handling after observing the default behaviour on other utilities like dracut.

To make clear about the problem, I have some questions about the bug:

1. where is the space? for example "path /tmp/crash", do you mean " patch /tmp/crash" or "path   /tmp/crash"?

2. where is the RHEL6 code to strip the space? I do not find it.


OTOH, in rhel6 code we have below code:
local _save_path=$(grep "^path" /etc/kdump.conf|awk '{print $2}')

So it is assumed that path should not prefixed with extra spaces.

Thanks
Dave

> 1. where is the space? for example "path /tmp/crash", do you mean " patch
s/patch/path

(In reply to Dave Young from comment #7)
> > 1. where is the space? for example "path /tmp/crash", do you mean " patch
> s/patch/path

As I captured in Comment 5, the issue is seen when we have space before path.

    1> space is before the path:

    Example:

    <whitespace>    path /home/crash

    2> RHEL 6 code to deal with white spaces:

    [root@localhost Desktop]# uname -r
    2.6.32-696.el6.x86_64
    [root@localhost Desktop]# rpm -qa | grep kexec
    kexec-tools-2.0.0-307.el6.x86_64
    [root@localhost Desktop]#

    The code is in /sbin/mkdumprd 

    Code Snippet
    ============================================================================
      # deal with indentation
        space_at_front=`echo "$msg" | grep -o "^[[:space:]]\+"`
        msg=`echo "$msg" | sed 's/^\s\+//'`

        msg_printed=0
        while [ $# -gt 0 ]; do
            trace_level=`echo "$1" | grep -o '^[0-9]\+'`
            trace_in_higher_levels=`echo "$1" | grep -o '+'`
            trace=`echo $1 | sed "s/^.*://"`

            if [ -z "$trace_level" ]; then
                trace_level=0
            fi

            insert_trace=0
            if [ -n "$trace_in_higher_levels" ]; then
                if [ "$log_level" -ge "$trace_level" ]; then
                    insert_trace=1
                fi
            else
                if [ "$log_level" -eq "$trace_level" ]; then
                    insert_trace=1
                fi
            fi

            if [ $insert_trace -eq 1 ]; then
                if [ $msg_printed -eq 0 ]; then
                    emit "${space_at_front}echo \"$prefix $msg\""
                    msg_printed=1
                fi
                emit "${space_at_front}$func $trace"
            fi
            shift
        done
    }

    ===========================================================================
      

Thanks 
Kenneth D'souza

(In reply to Kenneth D'souza from comment #9)
> 
>     1> space is before the path:
> 
>     Example:
> 
>     <whitespace>    path /home/crash
> 
>     2> RHEL 6 code to deal with white spaces:
> 
>     [root@localhost Desktop]# uname -r
>     2.6.32-696.el6.x86_64
>     [root@localhost Desktop]# rpm -qa | grep kexec
>     kexec-tools-2.0.0-307.el6.x86_64
>     [root@localhost Desktop]#
> 
>     The code is in /sbin/mkdumprd 
> 
>     Code Snippet
>    
> ============================================================================
>       # deal with indentation
>         space_at_front=`echo "$msg" | grep -o "^[[:space:]]\+"`
>         msg=`echo "$msg" | sed 's/^\s\+//'`
> 
>         msg_printed=0
>         while [ $# -gt 0 ]; do
>             trace_level=`echo "$1" | grep -o '^[0-9]\+'`
>             trace_in_higher_levels=`echo "$1" | grep -o '+'`
>             trace=`echo $1 | sed "s/^.*://"`
> 
>             if [ -z "$trace_level" ]; then
>                 trace_level=0
>             fi
> 
>             insert_trace=0
>             if [ -n "$trace_in_higher_levels" ]; then
>                 if [ "$log_level" -ge "$trace_level" ]; then
>                     insert_trace=1
>                 fi
>             else
>                 if [ "$log_level" -eq "$trace_level" ]; then
>                     insert_trace=1
>                 fi
>             fi
> 
>             if [ $insert_trace -eq 1 ]; then
>                 if [ $msg_printed -eq 0 ]; then
>                     emit "${space_at_front}echo \"$prefix $msg\""
>                     msg_printed=1
>                 fi
>                 emit "${space_at_front}$func $trace"
>             fi
>             shift
>         done
>     }
> 

Thanks for the quick reply.

But above code is not for kdump.conf handling, it is for memory trace related. If so it is clear that it happens to work in RHEL6, but actually we do not support it, as I mentioned in last comment 6, RHEL6 also need "path" without extra spaces from the code.

Thus we'd better to enforce any options in kdump.conf should not start with spaces and close this bug.

Reopening this issue.

As discussed with Dave Young on irc, we need to add proper error handling in kdumpctl and also document this properly, as any user can add a space before a variable in kdump.conf and this should be handled properly.

This makes us go with the option 
 
b> There should be no space before the path by failing the service.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2018:0807