lkml.org 
[lkml]   [2013]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v3 01/21] vmcore: reference e_phoff member explicitly to get position of program header table
    On Thu, Mar 21, 2013 at 11:50:41AM +0900, HATAYAMA Daisuke wrote:
    > From: "Eric W. Biederman" <ebiederm@xmission.com>
    > Subject: Re: [PATCH v3 01/21] vmcore: reference e_phoff member explicitly to get position of program header table
    > Date: Tue, 19 Mar 2013 14:44:16 -0700
    >
    > > HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> writes:
    > >
    > >> Currently, the code assumes that position of program header table is
    > >> next to ELF header. But future change can break the assumption on
    > >> kexec-tools and the 1st kernel. To avoid worst case, reference e_phoff
    > >> member explicitly to get position of program header table in
    > >> file-offset.
    > >
    > > In principle this looks good. However when I read this it looks like
    > > you are going a little too far.
    > >
    > > You are changing not only the reading of the supplied headers, but
    > > you are changing the generation of the new new headers that describe
    > > the data provided by /proc/vmcore.
    > >
    > > I get lost in following this after you mangle merge_note_headers.
    > >
    > > In principle removing silly assumptions seems reasonable, but I think
    > > it is completely orthogonal to the task of maping vmcore mmapable.
    > >
    > > I think it is fine to claim that the assumptions made here in vmcore are
    > > part of the kexec on panic ABI at this point, which would generally make
    > > this change unnecessary.
    >
    > This was suggested by Vivek. He prefers generic one.
    >
    > Vivek, do you agree to this? Or is it better to re-post this and other
    > clean-up patches as another one separately to this patch set?

    Given the fact that current code has been working, I am fine to just
    re-post and take care of mmap() related issues. And we can take care
    of cleaning up of some assumptions about PT_NOTE headers later. Trying
    to club large cleanup with mmap() patches is making it hard to review.

    Thanks
    Vivek


    \
     
     \ /
      Last update: 2013-03-22 03:01    [W:2.435 / U:0.548 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site