[lkml]   [2004]   [Dec]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: 32-bit syscalls from 64-bit process on x86-64?
    On Fri, 2004-12-03 at 07:15 +0100, Andi Kleen wrote:
    > int 0x80 from 64bit will call 32bit syscalls.

    Hm, that's not what I found. If I run int 0x80 with [re]ax=1, I get
    exit with a 32-bit process and write with a 64-bit one.

    > But some things
    > will not work properly, e.g. signals because they test the 32bit
    > flag in the task_struct. So you would still get 64bit signal frames.

    OK, I can deal with that, since signals are never directly delivered to
    the client.

    > There are some other such tests, but they probably wont affect you.
    > There were some plans at one point to allow to toggle the flag
    > using personality or prctl, but so far it hasn't been implemented.
    > There is also no way to do 64bit calls from a 32bit executable.

    What about my idea of using distinct ranges of syscall numbers to
    disambiguate them?


    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 14:08    [W:0.044 / U:1.768 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site