[lkml]   [2002]   [Aug]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: klibc and logging
    Russell King wrote:
    > On Tue, Aug 13, 2002 at 12:12:10AM -0700, H. Peter Anvin wrote:
    >>However, I'm wondering what to do about logging.
    > While writing my scripts for initramfs, the following thought occurred:
    > 1. We only need the fd for initramfs.
    > 2. We want to log the output from commands executed in initramfs.
    > Currently with an initrd, we set fd 0, 1, 2 to point to /dev/console.
    > Is there any reason we couldn't set fd 0 to /dev/console (maybe from
    > inside initramfs) but always setup fd 1 and 2 from the kernel to point
    > at a special "translate this into printk" fd ?
    > This has several advantages:
    > 1. No need for another "special" device.
    > 2. Once the fd is closed, its gone for good - no security concerns with
    > apps in userland after boot dumping copious amounts of data into the
    > kernel message buffer.
    > 3. initramfs programs/scripts don't need to be aware of any special
    > logging facilities
    > The disadvantages:
    > 1. We need some way to open fd 1 and 2 in the first place; this is
    > likely to be a special case, and initramfs is supposed to remove
    > special cases from the kernel.

    I really think this is a bad idea. The kmsg device has different
    properties -- for example, you're supposed to tag things with the
    message importance. It really matches the syslog(3) interface better.
    Also, the special case makes me nervous.

    The "DoS opportunity" is a complete and utter red herring. If you have
    permission to write /dev/kmsg then you have permission to write
    /dev/kmem too!


    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:28    [W:0.034 / U:7.280 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site