• Eric W. Biederman's avatar
    signal/alpha: Document a conflict with SI_USER for SIGTRAP · e2bd64d9
    Eric W. Biederman authored
    Setting si_code to __SI_FAULT results in a userspace seeing
    an si_code of 0.  This is the same si_code as SI_USER.  Posix
    and common sense requires that SI_USER not be a signal specific
    si_code.  As such this use of 0 for the si_code is a pretty
    horribly broken ABI.
    
    Given that alpha is on it's last legs I don't know that it is worth
    fixing this, but it is worth documenting what is going on so that
    no one decides to copy this bad decision.
    
    This was introduced during the 2.5 development cycle so this
    mess has had a long time for people to be able to depend upon it.
    
    v2: Added FPE_FIXME for alpha as Helge Deller <deller@gmx.de> pointed out
        with his alternate patch one of the cases is SIGFPE not SIGTRAP.
    
    Cc: Helge Deller <deller@gmx.de>
    Cc: Richard Henderson <rth@twiddle.net>
    Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
    Cc: Matt Turner <mattst88@gmail.com>
    Cc: linux-alpha@vger.kernel.org
    Acked-by: default avatarRichard Henderson <rth@twiddle.net>
    History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
    Ref: 0a635c7a ("Fill in siginfo_t.")
    Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
    e2bd64d9
siginfo.h 431 Bytes