lkml.org 
[lkml]   [1999]   [Jul]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: QUESTION: modifying kernel functions in a running kernel
    There was a comment about this a few months ago. Basically someone wanted
    to change a basic function. They changed all references to the function to
    be calls to a function address. The function address was set at init time
    to the common usage. From a module, they could reach in an put a
    different address, which everyone would then call. john

    On Tue, 20 Jul 1999, noupe wrote:

    > Is it possible to change a function (not a syscall) which is public
    > (i.e shown in /proc/ksyms) from a module? Something like changing the
    > address to the function so my function will be called instead of the
    > public one?
    >
    > Let's assume that there's a bug in icmp_send() and that you just can't
    > (i.e don't want to) reboot the machine (as you have to when installing
    > a new kernel) for some reason..
    >
    > If you don't patch it, your machine will crash, sooner or later.
    > If you patch it, you have to reboot the machine.
    > But what if you could load a module that exchange the old icmp_send()
    > with the one present in your module?
    > Instead of rebooting your machine, you could just load a module that
    > fixes the problem.
    >
    > So, my questions are:
    > Is this in any way possible to do a thing like this?
    > If yes, what techniques could one use? And is it possible
    > to change functions that aren't public/exported?
    >
    >
    > Thanks in advance, noupe.
    >
    > -
    > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    > the body of a message to majordomo@vger.rutgers.edu
    > Please read the FAQ at http://www.tux.org/lkml/
    >


    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:53    [W:0.021 / U:0.688 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site