commit bc4cf2bb271b2d557fc510426755da786fc985be upstream.

Previously we were just setting up the "tp" register in the
new task as started by clone() in libc.  However, this is not
quite right, since in principle a signal might be delivered to
the new task before it had its TLS set up.  (Of course, this race
window still exists for resetting the libc getpid() cached value
in the new task, in principle.  But in any case, we are now doing
this exactly the way all other architectures do it.)

This change is important for 2.6.37 since the tile glibc we will
be submitting upstream will not set TLS in user space any more,
so it will only work on a kernel that has this fix.  It should
also be taken for 2.6.36.x in the stable tree if possible.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile: remove dead code from intvec_32.S

This "bpt_code" instruction was killed off in our development line a while
ago (the actual definition of bpt_code that is used is in kernel/traps.c)
but I didn't push it for 2.6.36 because it seemed harmless and I didn't
want to try to push more than absolutely necessary.

However, we recently fixed a bug in our gcc that had been causing
"-gdwarf2" not to be passed to the assembler, and passing this flag causes
an erroneous assembler failure in the presence of code in a data section,
sometimes.  While we'd like to track down the bug in the assembler,
we'd also like to make sure 2.6.36 builds with the current toolchain,
so I'm removing this dead code as well.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile: fix formatting bug in register dumps
  arch/tile: fix memcpy_fromio()/memcpy_toio() signatures
  arch/tile: Save and restore extra user state for tilegx
  arch/tile: Change struct sigcontext to be more useful
  arch/tile: finish const-ifying sys_execve()

This cut-and-paste bug was caused by rewriting the register dump
code to use only a single printk per line of output.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

This tripped up a driver (not yet committed to git).  Fix it now.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

During context switch, save and restore a couple of additional bits of
tilegx user state that can be persistently modified by userspace.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

Rather than just using pt_regs, it now contains the actual saved
state explicitly, similar to pt_regs.  By doing it this way, we
provide a cleaner API for userspace (or equivalently, we avoid the
need for libc to provide its own definition of sigcontext).

While we're at it, move PT_FLAGS_xxx to where they are not visible
from userspace.  And always pass siginfo and mcontext to signal
handlers, even if they claim they don't need it, since sometimes
they actually try to use it anyway in practice.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

The sys_execve() implementation was properly const-ified but not
the declaration, the syscall wrappers, or the compat version.
This change completes the constification process.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

compat_alloc_user_space() expects the caller to independently call
access_ok() to verify the returned area.  A missing call could
introduce problems on some architectures.

This patch incorporates the access_ok() check into
compat_alloc_user_space() and also adds a sanity check on the length.
The existing compat_alloc_user_space() implementations are renamed
arch_compat_alloc_user_space() and are used as part of the
implementation of the new global function.

This patch assumes NULL will cause __get_user()/__put_user() to either
fail or access userspace on all architectures.  This should be
followed by checking the return value of compat_access_user_space()
for NULL in the callers, at which time the access_ok() in the callers
can also be removed.

Reported-by: Ben Hawkes <hawkes@sota.gen.nz>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: James Bottomley <jejb@parisc-linux.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: <stable@kernel.org>