[ Upstream commit caace6ca4e06f09413fb8f8a63319594cfb7d47d ]

This issue was noticed while debugging a shutdown issue where some
secondary CPUs are not being shutdown correctly.  A fix for that [1] requires
that secondary cpus be offlined using the cpu_online_mask so that the
stop operation is a no-op if CPU HOTPLUG is disabled.  I, like the author in
[1] looked at the architectures and found that alpha is one of two
architectures that executes smp_send_stop() on all possible CPUs.

On alpha, smp_send_stop() sends an IPI to all possible CPUs but only needs
to send them to online CPUs.

Send the stop IPI to only the online CPUs.

[1] https://lkml.org/lkml/2020/1/10/250

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 54505a1e2083fc54cbe8779b97479f969cd30a00 upstream.

The commits cd0e00c10672 and 92d7223a7423 broke boot on the Alpha Avanti
platform. The patches move memory barriers after a write before the write.
The result is that if there's iowrite followed by ioread, there is no
barrier between them.

The Alpha architecture allows reordering of the accesses to the I/O space,
and the missing barrier between write and read causes hang with serial
port and real time clock.

This patch makes barriers confiorm to the specification.

1. We add mb() before readX_relaxed and writeX_relaxed -
   memory-barriers.txt claims that these functions must be ordered w.r.t.
   each other. Alpha doesn't order them, so we need an explicit barrier.
2. We add mb() before reads from the I/O space - so that if there's a
   write followed by a read, there should be a barrier between them.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: cd0e00c10672 ("alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering")
Fixes: 92d7223a7423 ("alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering #2")
Cc: stable@vger.kernel.org      # v4.17+
Acked-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull namespace fixes from Eric Biederman:
 "This is a set of four fairly obvious bug fixes:

   - a switch from d_find_alias to d_find_any_alias because the xattr
     code perversely takes a dentry

   - two mutex vs copy_to_user fixes from Jann Horn

   - a fix to use a sanitized size not the size userspace passed in from
     Christian Brauner"

* 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  getxattr: use correct xattr length
  sys: don't hold uts_sem while accessing userspace memory
  userns: move user access out of the mutex
  cap_inode_getsecurity: use d_find_any_alias() instead of d_find_alias()

Holding uts_sem as a writer while accessing userspace memory allows a
namespace admin to stall all processes that attempt to take uts_sem.
Instead, move data through stack buffers and don't access userspace memory
while uts_sem is held.

Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

kernel_wait4() expects a userland address for status - it's only
rusage that goes as a kernel one (and needs a copyout afterwards)

[ Also, fix the prototype of kernel_wait4() to have that __user
  annotation   - Linus ]

Fixes: 92ebce5ac55d ("osf_wait4: switch to kernel_wait4()")
Cc: stable@kernel.org # v4.13+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull siginfo updates from Eric Biederman:
 "This set of changes close the known issues with setting si_code to an
  invalid value, and with not fully initializing struct siginfo. There
  remains work to do on nds32, arc, unicore32, powerpc, arm, arm64, ia64
  and x86 to get the code that generates siginfo into a simpler and more
  maintainable state. Most of that work involves refactoring the signal
  handling code and thus careful code review.

  Also not included is the work to shrink the in kernel version of
  struct siginfo. That depends on getting the number of places that
  directly manipulate struct siginfo under control, as it requires the
  introduction of struct kernel_siginfo for the in kernel things.

  Overall this set of changes looks like it is making good progress, and
  with a little luck I will be wrapping up the siginfo work next
  development cycle"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  signal/sh: Stop gcc warning about an impossible case in do_divide_error
  signal/mips: Report FPE_FLTUNK for undiagnosed floating point exceptions
  signal/um: More carefully relay signals in relay_signal.
  signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR}
  signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code
  signal/signalfd: Add support for SIGSYS
  signal/signalfd: Remove __put_user from signalfd_copyinfo
  signal/xtensa: Use force_sig_fault where appropriate
  signal/xtensa: Consistenly use SIGBUS in do_unaligned_user
  signal/um: Use force_sig_fault where appropriate
  signal/sparc: Use force_sig_fault where appropriate
  signal/sparc: Use send_sig_fault where appropriate
  signal/sh: Use force_sig_fault where appropriate
  signal/s390: Use force_sig_fault where appropriate
  signal/riscv: Replace do_trap_siginfo with force_sig_fault
  signal/riscv: Use force_sig_fault where appropriate
  signal/parisc: Use force_sig_fault where appropriate
  signal/parisc: Use force_sig_mceerr where appropriate
  signal/openrisc: Use force_sig_fault where appropriate
  signal/nios2: Use force_sig_fault where appropriate
  ...

memory-barriers.txt has been updated with the following requirement.

"When using writel(), a prior wmb() is not needed to guarantee that the
cache coherent memory writes have completed before writing to the MMIO
region."

Current writeX() and iowriteX() implementations on alpha are not
satisfying this requirement as the barrier is after the register write.

Move mb() in writeX() and iowriteX() functions to guarantee that HW
observes memory changes before performing register operations.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Matt Turner <mattst88@gmail.com>

Remove the dma_ops indirection.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matt Turner <mattst88@gmail.com>

The generic dma_direct implementation does the same thing as the alpha
pci-noop implementation, just with more bells and whistles.  And unlike
the current code it at least has a theoretical chance to actually compile.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matt Turner <mattst88@gmail.com>

Filling in struct siginfo before calling force_sig_info a tedious and
error prone process, where once in a great while the wrong fields
are filled out, and siginfo has been inconsistently cleared.

Simplify this process by using the helper force_sig_fault.  Which
takes as a parameters all of the information it needs, ensures
all of the fiddly bits of filling in struct siginfo are done properly
and then calls force_sig_info.

In short about a 5 line reduction in code for every time force_sig_info
is called, which makes the calling function clearer.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: linux-alpha@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>