lkml.org 
[lkml]   [1999]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    Subject2.3.26: high_memory and vmalloc()'d stuff (modules in particular)
    Hello David and the World,

    I am trying to enhance your ELF /proc/kcore read routine to deal with the
    kernel virtual addresses corresponding to dynamically loaded modules.

    I managed to successfully dump data structures in gdb vmlinux /proc/kcore
    by making the size very large (260M). Obviously this is not a perfect
    solution but is tied to this particular machine. Besides, I want to be
    able to dd if=/proc/kcore of=kcore.img and dumping 260M of stuff most of
    which is garbage is not very elegant.

    So, the question (to everyone) is:

    How do we determine the value similar to high_memory but one that covers
    modules as well? I.e. currently size is calculated as:

    size = ((size_t)high_memory - PAGE_OFFSET) + PAGE_SIZE;

    so, if high_memory=0xc4000000 and module's data structure is at
    0xc4815a6c we can't dump it in gdb because dhdr->p_memsz/p_filesz are set
    accordingly in the ELF core header.

    Any ideas anyone? Ideally, there would be (or is there already?!)
    something called highvm_memory that would be used instead of high_memory
    and would make /proc/kcore's size lazy-dynamically-adjustable on the fly
    as new modules are loaded. I could hack vmalloc()/vfree() to do that but
    perhaps it is already done, so I am asking you (in the meantime I will go
    and try to find a way of determining it).

    Regards,
    Tigran.

    PS. I don't submit the patch even though it works for me because this
    "solution" is obviously only a temporary workaround - I want a proper
    "highvm_memory" or something...

    -
    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 13:54    [W:0.020 / U:94.136 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site