Re: export of sys_call_table

Brian F. G. Bidulock (bidulock@openss7.org)
Fri, 4 Oct 2002 15:44:05 -0600


David,

How many other architecture-specific exported symbols are there?

It appears to me that many of the system calls themselves are
architecture-specific, particularly so where 64-bit machines
are involved. Is that a reason to not make them accessible?

--brian

On Fri, 04 Oct 2002, David S. Miller wrote:

> From: Alan Cox <alan@lxorguk.ukuu.org.uk>
> Date: 03 Oct 2002 23:02:40 +0100
>
> Overwriting syscall table entries is not safe. Its not safe because
> there is no locking mechanism, and its not safe because of the pentium
> III errata.
>
> It is also non-portable, such syscall overwriting requires knowledge
> of the layout of the table on every architecture. On some platforms
> it is a list of pointers + argument count, on some 64-bit platforms
> it is a list of 32-bit truncated pointers to save space.
>
> There is simply no portable way to make changes to the system call
> table, so exporting it makes zero sense.

-- 
Brian F. G. Bidulock    ¦ The reasonable man adapts himself to the ¦
bidulock@openss7.org    ¦ world; the unreasonable one persists in  ¦
http://www.openss7.org/ ¦ trying  to adapt the  world  to himself. ¦
                        ¦ Therefore  all  progress  depends on the ¦
                        ¦ unreasonable man. -- George Bernard Shaw ¦
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