lkml.org 
[lkml]   [2006]   [Jun]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: i386 ABI and the stack
    On 6/23/06, Linus Torvalds <torvalds@osdl.org> wrote:
    > On Fri, 23 Jun 2006, H. Peter Anvin wrote:
    > > >
    > > > The x86-64 ABI has a 128-byte(*) zone that is safe from signals etc, so you
    > > > can use a small amount of stack below the stackpointer safely. Not so on
    > > > x86.
    > >
    > > Adding a small redzone like this to i386 would be easy, though -- just drop
    > > the stack pointer by that much when creating a signal frame. 128 bytes isn't
    > > enough to interfere with libraries.
    >
    > However, any binaries created with that in mind would be
    > buggy-by-definition on older kernels, so I don't think it's worth it.

    Since gcc-2.96 would access 256 bytes below the stack pointer
    (according to the valgrind man page), the kernel needs to allow
    for this in signal handlers anyway.

    I'm pretty sure I saw that code in the kernel in fact, but I
    can't find it now. Perhaps it got lost in a cleanup accident?
    (it sure would be nice to have continuous source control history)
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-06-24 04:47    [W:0.024 / U:92.336 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site