lkml.org 
[lkml]   [2008]   [Nov]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] generic compat_sys_ustat
    Christoph Hellwig wrote:
    > Due to a different size of ino_t ustat needs a compat handler, but
    > currently only x86 and mips provide one. Add a generic compat_sys_ustat
    > and switch all architectures over to it.
    >
    > Found by Eric Sandeen when running xfstests/017 on ppc64, which causes
    > stack smashing warnings on RHEL/Fedora due to the too large amount of
    > data writen by the syscall.

    ...

    > Index: linux-2.6/fs/compat.c
    > ===================================================================
    > --- linux-2.6.orig/fs/compat.c 2008-11-20 20:09:52.000000000 +0100
    > +++ linux-2.6/fs/compat.c 2008-11-20 20:16:05.000000000 +0100
    > @@ -378,6 +378,24 @@ out:
    > return error;
    > }
    >
    > +asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u32)

    Oh, I had also suggested that the use of "u32" here was slightly
    confusing, it at least made me do a double-take with the unsigned 32 bit
    type... not a big deal, but just thought I'd mention it.

    Thanks,
    -Eric

    > +{
    > + struct ustat *u = compat_alloc_user_space(sizeof(*u));
    > + int ret;
    > +
    > + ret = sys_ustat(dev, u);
    > + if (ret < 0)
    > + return ret;
    > +
    > + if (!access_ok(VERIFY_WRITE, u32, sizeof(*u32)) ||
    > + __put_user((compat_daddr_t) u->f_tfree, &u32->f_tfree) ||
    > + __put_user((compat_ino_t) u->f_tinode, &u32->f_tfree) ||
    > + __copy_to_user(&u32->f_fname, u->f_fname, sizeof(u32->f_fname)) ||
    > + __copy_to_user(&u32->f_fpack, u->f_fpack, sizeof(u32->f_fpack)))
    > + return -EFAULT;
    > + return 0;
    > +}
    > +


    \
     
     \ /
      Last update: 2008-11-21 18:41    [W:0.040 / U:0.064 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site