Re: [gentoo-user] Re: bash stopped running python scripts...

[Mike Edenfield <kutulu@kutulu.org>]

On 8/4/2009 7:13 AM, Graham Murray wrote:
> Remy Blank<remy.blank@pobox.com>  writes:
>
>> The whole issue seems to be handled quite strangely IMO. You would think
>> breaking Python for all ~x86 is a major offense...
>
> It did not break for all ~x86. I have 2 systems both running ~x86, both
> have emerged (but not made active) python-3.1, /usr/bin/python is a bash
> script on both yet emerge works with no problems. The only non-standard
> things are that I have unmasked gcc-4.4.1 and am using git 2.6.31-rc
> kernels.

Aha.  I think I've discovered the "problem".  There was a change in the 
kernel execl() call between 2.6.27 and 2.6.28:

--- linux-2.6.27-hardened-r3/fs/binfmt_script.c 2008-10-09 
18:13:53.000000000 -0400
+++ linux-2.6.28-hardened/fs/binfmt_script.c    2008-12-24 
18:26:37.000000000 -0500
@@ -22,14 +22,15 @@
         char interp[BINPRM_BUF_SIZE];
         int retval;

-       if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!') || 
(bprm->sh_bang))
+       if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!') ||
+           (bprm->recursion_depth > BINPRM_MAX_RECURSION))
                 return -ENOEXEC;
         /*
          * This section does the #! interpretation.
          * Sorta complicated, but hopefully it will work.  -TYT
          */

-       bprm->sh_bang = 1;
+       bprm->recursion_depth++;
         allow_write_access(bprm->file);
         fput(bprm->file);
         bprm->file = NULL;


The kernel >= 2.6.28 now supports nesting up to 4 levels of script in 
the #! lines, if I'm reading that right, whereas < 2.6.28 it only 
supported 1 level.  I'll go update the b.g.o entry and try upgrading my 
kernel.  Though I dunno what that means for Gentoo/FreeBSD.

--Mike