Remove the arg+env limit of MAX_ARG_PAGES by copying the strings directly from
the old mm into the new mm.

We create the new mm before the binfmt code runs, and place the new stack at
the very top of the address space.  Once the binfmt code runs and figures out
where the stack should be, we move it downwards.

It is a bit peculiar in that we have one task with two mm's, one of which is
inactive.

[a.p.zijlstra@chello.nl: limit stack size]
Signed-off-by: NOllie Wild <aaw@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <linux-arch@vger.kernel.org>
Cc: Hugh Dickins <hugh@veritas.com>
[bunk@stusta.de: unexport bprm_mm_init]
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The purpose of audit_bprm() is to log the argv array to a userspace daemon at
the end of the execve system call.  Since user-space hasn't had time to run,
this array is still in pristine state on the process' stack; so no need to
copy it, we can just grab it from there.

In order to minimize the damage to audit_log_*() copy each string into a
temporary kernel buffer first.

Currently the audit code requires that the full argument vector fits in a
single packet.  So currently it does clip the argv size to a (sysctl) limit,
but only when execve auditing is enabled.

If the audit protocol gets extended to allow for multiple packets this check
can be removed.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NOllie Wild <aaw@google.com>
Cc: <linux-audit@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make sysctl/kernel/core_pattern and fs/exec.c agree on maximum core
filename size and change it to 128, so that extensive patterns such as
'/local/cores/%e-%h-%s-%t-%p.core' won't result in truncated filename
generation.
Signed-off-by: NDan Aloni <da-x@monatomic.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

and in other strange binfmts. vDSO is not necessarily mapped there.
Signed-off-by: NAndi Kleen <ak@suse.de>

Add a new `suid_dumpable' sysctl:

This value can be used to query and set the core dump mode for setuid
or otherwise protected/tainted binaries. The modes are

0 - (default) - traditional behaviour.  Any process which has changed
    privilege levels or is execute only will not be dumped

1 - (debug) - all processes dump core when possible.  The core dump is
    owned by the current user and no security is applied.  This is intended
    for system debugging situations only.  Ptrace is unchecked.

2 - (suidsafe) - any binary which normally would not be dumped is dumped
    readable by root only.  This allows the end user to remove such a dump but
    not access it directly.  For security reasons core dumps in this mode will
    not overwrite one another or other files.  This mode is appropriate when
    adminstrators are attempting to debug problems in a normal environment.

(akpm:

> > +EXPORT_SYMBOL(suid_dumpable);
>
> EXPORT_SYMBOL_GPL?

No problem to me.

> >  	if (current->euid == current->uid && current->egid == current->gid)
> >  		current->mm->dumpable = 1;
>
> Should this be SUID_DUMP_USER?

Actually the feedback I had from last time was that the SUID_ defines
should go because its clearer to follow the numbers. They can go
everywhere (and there are lots of places where dumpable is tested/used
as a bool in untouched code)

> Maybe this should be renamed to `dump_policy' or something.  Doing that
> would help us catch any code which isn't using the #defines, too.

Fair comment. The patch was designed to be easy to maintain for Red Hat
rather than for merging. Changing that field would create a gigantic
diff because it is used all over the place.

)
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch makes some needlessly global identifiers static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NArjan van de Ven <arjanv@infradead.org>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!