Ensure that kernel_init_freeable() is not inlined into non __init code

Commit d6b2123802d "make sure that we always have a return path from
kernel_execve()" reshuffled kernel_init()/init_post() to ensure that
kernel_execve() has a caller to return to.

It removed __init annotation for kernel_init() and introduced/calls a
new routine kernel_init_freeable(). Latter however is inlined by any
reasonable compiler (ARC gcc 4.4 in this case), causing slight code
bloat.

This patch forces kernel_init_freeable() as noinline reducing the .text

bloat-o-meter vmlinux vmlinux_new
add/remove: 1/0 grow/shrink: 0/1 up/down: 374/-334 (40)
function                        old     new   delta
kernel_init_freeable              -     374    +374 (.init.text)
kernel_init                     628     294    -334 (.text)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
CONFIG_GENERIC_SIGALTSTACK build breakage with asm-generic/syscalls.h

Saner transition plan for GENERIC_SIGALTSTACK conversion - instead of
adding #define sys_sigaltstack sys_sigaltstack in asm/syscalls.h of
architecture if it's pulls asm-generic/syscalls.h, only to have those
defines removed once all architectures are converted, make the
declaration in said asm-generic/syscalls.h conditional on the lack
of GENERIC_SIGALTSTACK.  Less messy in intermediate stages that way...

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: james.hogan@imgtec.com
Cc: arnd@arndb.de
Cc: torvalds@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINE

Makes sigaltstack conversion easier to split into per-architecture
parts.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINE

Strictly speaking, ppc64 needs it for C ABI compliance.  Realistically
I would be very surprised if e.g. passing 0xffffffff as 'options'
argument to waitid() from 32bit task would cause problems, but yes,
it puts us into undefined behaviour territory.  ppc64 expects int
argument to be passed in 64bit register with bits 31..63 containing
the same value.  SYSCALL_DEFINE on ppc provides a wrapper that normalizes
the value passed from userland; so does COMPAT_SYSCALL_DEFINE.  Plain
declaration of compat_sys_something() with an int argument obviously
doesn't.  Again, for wait4 and waitid I would be extremely surprised
if gcc started to produce code depending on that value having been
properly sign-extended - the argument(s) in question end up passed
blindly to sys_wait4 and sys_waitid resp. and normalization for native
syscalls takes care of their use there.  Still, better to use
COMPAT_SYSCALL_DEFINE here than worry about nasal daemons...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
x32: fix waitid()

It needs 64bit rusage and 32bit siginfo.  glibc never calls it with
non-NULL rusage pointer, or we would've seen breakage already...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
x32: fix sigtimedwait

It needs 64bit timespec.  As it is, we end up truncating the timeout
to whole seconds; usually it doesn't matter, but for having all
sub-second timeouts truncated to one jiffy is visibly wrong.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
virtio-blk: Don't free ida when disk is in use

When a file system is mounted on a virtio-blk disk, we then remove it
and then reattach it, the reattached disk gets the same disk name and
ids as the hot removed one.

This leads to very nasty effects - mostly rendering the newly attached
device completely unusable.

Trying what happens when I do the same thing with a USB device, I saw
that the sd node simply doesn't get free'd when a device gets forcefully
removed.

Imitate the same behavior for vd devices. This way broken vd devices
simply are never free'd and newly attached ones keep working just fine.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
module: prevent warning when finit_module a 0 sized file

If we try to finit_module on a file sized 0 bytes vmalloc will
scream and spit out a warning.

Since modules have to be bigger than 0 bytes anyways we can just
check that beforehand and avoid the warning.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
module: add new state MODULE_STATE_UNFORMED.

You should never look at such a module, so it's excised from all paths
which traverse the modules list.

We add the state at the end, to avoid gratuitous ABI break (ksplice).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
module: put modules in list much earlier.

Prarit's excellent bug report:
> In recent Fedora releases (F17 & F18) some users have reported seeing
> messages similar to
>
> [   15.478160] kvm: Could not allocate 304 bytes percpu data
> [   15.478174] PERCPU: allocation failed, size=304 align=32, alloc from
> reserved chunk failed
>
> during system boot.  In some cases, users have also reported seeing this
> message along with a failed load of other modules.
>
> What is happening is systemd is loading an instance of the kvm module for
> each cpu found (see commit e9bda3b).  When the module load occurs the kernel
> currently allocates the modules percpu data area prior to checking to see
> if the module is already loaded or is in the process of being loaded.  If
> the module is already loaded, or finishes load, the module loading code
> releases the current instance's module's percpu data.

Now we have a new state MODULE_STATE_UNFORMED, we can insert the
module into the list (and thus guarantee its uniqueness) before we
allocate the per-cpu region.

Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Prarit Bhargava <prarit@redhat.com>
drm/i915: Record DERRMR, FORCEWAKE and RING_CTL in error-state

These are useful for investigating hangs involving WAIT_FOR_EVENT.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Apply a droplet of Future-Proof in the if-ladder.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/radeon: clear reset flags if engines are idle

Fixes a hard lock in the gpu reset code after the
rework for DMA support (0ecebb9e0d14e9948e0b1529883a776758117d6f
"drm/radeon: switch to a finer grained reset for evergreen")
due to not bailing before the MC shutdown if the relevant engines
are idle.

Discussion:
http://lists.freedesktop.org/archives/dri-devel/2013-January/032985.html

Reported-by: Eldad Zack <eldad@fogrefinery.com>
Tested-by: Eldad Zack <eldad@fogrefinery.com>
Acked-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/radeon: allow FP16 color clear registers on r500

Probably not a candidate for stable kernels because of conflicts
in DRM versioning.

Signed-off-by: Marek Olšák <maraeo@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/radeon: improve semaphore debugging on lockup

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/i915/eDP: do not write power sequence registers for ghost eDP

Some machines detect an eDP port even if it's not really there, and eDP
initialization has a fail path for this. Typically such machines have an
LVDS display instead. A regression introduced in

commit 82ed61fa1a4e08d5f9e86fb1b715b50ed678b6ac
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sat Oct 20 20:57:41 2012 +0200

    drm/i915: make edp panel power sequence setup more robust

updated the power sequence registers PCH_PP_ON_DELAYS, PCH_PP_OFF_DELAYS,
and PCH_PP_DIVISOR also in the ghost eDP case, messing up the LVDS display.

Split the power sequencer initialization into two, delaying the register
updates until after we know the eDP is real.

Note: Keep the PP_CONTROL unlocking in the first part, even if it does not
update registers, per the commit message of the above mentioned commit.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=52601
Reported-and-tested-by: Ryan Coe <ryan@rycomotorsports.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915: Invalidate the relocation presumed_offsets along the slow path

In the slow path, we are forced to copy the relocations prior to
acquiring the struct mutex in order to handle pagefaults. We forgo
copying the new offsets back into the relocation entries in order to
prevent a recursive locking bug should we trigger a pagefault whilst
holding the mutex for the reservations of the execbuffer. Therefore, we
need to reset the presumed_offsets just in case the objects are rebound
back into their old locations after relocating for this exexbuffer - if
that were to happen we would assume the relocations were valid and leave
the actual pointers to the kernels dangling, instant hang.

Fixes regression from commit bcf50e2775bbc3101932d8e4ab8c7902aa4163b4
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sun Nov 21 22:07:12 2010 +0000

    drm/i915: Handle pagefaults in execbuffer user relocations

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=55984
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@fwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915: fix FORCEWAKE posting reads

We stopped reading FORCEWAKE for posting reads in

commit 8dee3eea3ccd3b6c00a8d3a08dd715d6adf737dd
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Sat Sep 1 22:59:50 2012 -0700

    drm/i915: Never read FORCEWAKE

and started using something from the same cacheline instead. On the
bug reporter's machine this broke entering rc6 states after a
suspend/resume cycle. It turns out reading ECOBUS as posting read
worked fine, while GTFIFODBG did not, preventing RC6 states after
suspend/resume per the bug report referenced below. It's not entirely
clear why, but clearly GTFIFODBG was nowhere near the same cacheline
or address range as FORCEWAKE.

Trying out various registers for posting reads showed that all tested
registers for which NEEDS_FORCE_WAKE() (in i915_drv.c) returns true
work. Conversely, most (but not quite all) registers for which
NEEDS_FORCE_WAKE() returns false do not work. Details in the referenced
bug.

Based on the above, add posting reads on ECOBUS where GTFIFODBG was
previously relied on.

In true cargo cult spirit, add posting reads for FORCEWAKE_VLV writes as
well, but instead of ECOBUS, use FORCEWAKE_ACK_VLV which is in the same
address range as FORCEWAKE_VLV.

v2: Add more details to the commit message. No functional changes.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=52411
Reported-and-tested-by: Alexander Bersenev <bay@hackerdom.ru>
CC: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
[danvet: add cc: stable and make the commit message a bit clearer that
this is a regression fix and what exactly broke.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Revert "drm/radeon: do not move bo to different placement at each cs"

This reverts commit d025e9e2b890db679f1246037bf65bd4be512627.

This causes corruption for a number of users and needs further
investigation in the next cycle.
https://bugzilla.kernel.org/show_bug.cgi?id=52491
https://bugs.freedesktop.org/show_bug.cgi?id=58659
http://lists.freedesktop.org/archives/dri-devel/2013-January/032961.html

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
make sure that /linuxrc has std{in,out,err}

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
sys_clone() needs asmlinkage_protect

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>