[ Upstream commit 9e70cbd11b03889c92462cf52edb2bd023c798fa ]

Initialising the hwrng struct with zeros causes a
compile-time sparse warning:

 $ ARCH=um make -j10 W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
 ...
 CHECK   arch/um/drivers/random.c
 arch/um/drivers/random.c:31:31: sparse: warning: Using plain integer as NULL pointer

Fix the warning by not initialising the hwrng struct
with zeros as it is initialised anyway during module
init.

Fixes: 72d3e093afae ("um: random: Register random as hwrng-core device")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christopher Obbard <chris.obbard@collabora.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 0b9ba6135d7f18b82f3d8bebb55ded725ba88e0e upstream.

UML generally does not provide access to special CPU instructions like
RDRAND, and execution tends to be rather deterministic, with no real
hardware interrupts, making good randomness really very hard, if not
all together impossible. Not only is this a security eyebrow raiser, but
it's also quite annoying when trying to do various pieces of UML-based
automation that takes a long time to boot, if ever.

Fix this by trivially calling getrandom() in the host and using that
seed as "bootloader randomness", which initializes the rng immediately
at UML boot.

The old behavior can be restored the same way as on any other arch, by
way of CONFIG_TRUST_BOOTLOADER_RANDOMNESS=n or
random.trust_bootloader=0. So seen from that perspective, this just
makes UML act like other archs, which is positive in its own right.

Additionally, wire up arch_get_random_{int,long}() in the same way, so
that reseeds can also make use of the host RNG, controllable by
CONFIG_TRUST_CPU_RANDOMNESS and random.trust_cpu, per usual.

Cc: stable@vger.kernel.org
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c6496e0a4a90d8149203c16323cff3fa46e422e7 upstream.

Commit e3a33af812c6 ("um: fix and optimize xor select template for CONFIG64 and timetravel mode")
caused a build regression when CONFIG_XOR_BLOCKS and CONFIG_UML_TIME_TRAVEL_SUPPORT
are selected.
Fix it by removing the straying parenthesis.

Cc: stable@vger.kernel.org
Fixes: e3a33af812c6 ("um: fix and optimize xor select template for CONFIG64 and timetravel mode")
Signed-off-by: Benjamin Beichler <benjamin.beichler@uni-rostock.de>
[rw: Added commit message]
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull x86 fixes from Borislav Petkov:

 - Improve the check whether the kernel supports WP mappings so that it
   can accomodate a XenPV guest due to how the latter is setting up the
   PAT machinery

  - Now that the retbleed nightmare is public, here's the first round of
    fallout fixes:

      * Fix a build failure on 32-bit due to missing include

      * Remove an untraining point in espfix64 return path

      * other small cleanups

* tag 'x86_urgent_for_v5.19_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bugs: Remove apostrophe typo
  um: Add missing apply_returns()
  x86/entry: Remove UNTRAIN_RET from native_irq_return_ldt
  x86/bugs: Mark retbleed_strings static
  x86/pat: Fix x86_has_pat_wp()
  x86/asm/32: Fix ANNOTATE_UNRET_SAFE use on 32-bit

The UML function names to_virt() and to_phys() are exposed by UML
headers, and are very generic and may be defined by drivers.  As it
turns out, commit 9409c9b6709e ("pmem: refactor pmem_clear_poison()")
did exactly that.

This results in build errors such as the following when trying to build
um:allmodconfig:

  drivers/nvdimm/pmem.c: In function ‘pmem_dax_zero_page_range’:
  ./arch/um/include/asm/page.h:105:20: error: too few arguments to function ‘to_phys’
    105 | #define __pa(virt) to_phys((void *) (unsigned long) (virt))
        |                    ^~~~~~~

Use less generic function names for the um specific to_phys() and
to_virt() functions to fix the problem and to avoid similar problems in
the future.

Fixes: 9409c9b6709e ("pmem: refactor pmem_clear_poison()")
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Implement apply_returns() stub for UM, just like all the other patching
routines.

Fixes: 15e67227c49a ("x86: Undo return-thunk damage")
Reported-by: Randy Dunlap <rdunlap@infradead.org)
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/Ys%2Ft45l%2FgarIrD0u@worktop.programming.kicks-ass.net

Call virtio_device_ready() to make this driver work after commit
b4ec69d7e09 ("virtio: harden vring IRQ"), since the driver uses the
virtqueues in the probe function.  (The virtio core sets the device
ready when probe returns.)

Fixes: 8b4ec69d7e09 ("virtio: harden vring IRQ")
Fixes: 68f5d3f3b654 ("um: add PCI over virtio emulation driver")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Message-Id: <20220610151203.3492541-1-vincent.whitchurch@axis.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Johannes Berg <johannes@sipsolutions.net>

Pull ptrace_stop cleanups from Eric Biederman:
 "While looking at the ptrace problems with PREEMPT_RT and the problems
  Peter Zijlstra was encountering with ptrace in his freezer rewrite I
  identified some cleanups to ptrace_stop that make sense on their own
  and move make resolving the other problems much simpler.

  The biggest issue is the habit of the ptrace code to change
  task->__state from the tracer to suppress TASK_WAKEKILL from waking up
  the tracee. No other code in the kernel does that and it is straight
  forward to update signal_wake_up and friends to make that unnecessary.

  Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and
  then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying
  on the fact that all stopped states except the special stop states can
  tolerate spurious wake up and recover their state.

  The state of stopped and traced tasked is changed to be stored in
  task->jobctl as well as in task->__state. This makes it possible for
  the freezer to recover tasks in these special states, as well as
  serving as a general cleanup. With a little more work in that
  direction I believe TASK_STOPPED can learn to tolerate spurious wake
  ups and become an ordinary stop state.

  The TASK_TRACED state has to remain a special state as the registers
  for a process are only reliably available when the process is stopped
  in the scheduler. Fundamentally ptrace needs acess to the saved
  register values of a task.

  There are bunch of semi-random ptrace related cleanups that were found
  while looking at these issues.

  One cleanup that deserves to be called out is from commit 57b6de08b5f6
  ("ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs"). This
  makes a change that is technically user space visible, in the handling
  of what happens to a tracee when a tracer dies unexpectedly. According
  to our testing and our understanding of userspace nothing cares that
  spurious SIGTRAPs can be generated in that case"

* tag 'ptrace_stop-cleanup-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state
  ptrace: Always take siglock in ptrace_resume
  ptrace: Don't change __state
  ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs
  ptrace: Document that wait_task_inactive can't fail
  ptrace: Reimplement PTRACE_KILL by always sending SIGKILL
  signal: Use lockdep_assert_held instead of assert_spin_locked
  ptrace: Remove arch_ptrace_attach
  ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP
  ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP
  signal: Replace __group_send_sig_info with send_signal_locked
  signal: Rename send_signal send_signal_locked

Pull kthread updates from Eric Biederman:
 "This updates init and user mode helper tasks to be ordinary user mode
  tasks.

  Commit 40966e316f86 ("kthread: Ensure struct kthread is present for
  all kthreads") caused init and the user mode helper threads that call
  kernel_execve to have struct kthread allocated for them. This struct
  kthread going away during execve in turned made a use after free of
  struct kthread possible.

  Here, commit 343f4c49f243 ("kthread: Don't allocate kthread_struct for
  init and umh") is enough to fix the use after free and is simple
  enough to be backportable.

  The rest of the changes pass struct kernel_clone_args to clean things
  up and cause the code to make sense.

  In making init and the user mode helpers tasks purely user mode tasks
  I ran into two complications. The function task_tick_numa was
  detecting tasks without an mm by testing for the presence of
  PF_KTHREAD. The initramfs code in populate_initrd_image was using
  flush_delayed_fput to ensuere the closing of all it's file descriptors
  was complete, and flush_delayed_fput does not work in a userspace
  thread.

  I have looked and looked and more complications and in my code review
  I have not found any, and neither has anyone else with the code
  sitting in linux-next"

* tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  sched: Update task_tick_numa to ignore tasks without an mm
  fork: Stop allowing kthreads to call execve
  fork: Explicitly set PF_KTHREAD
  init: Deal with the init process being a user mode process
  fork: Generalize PF_IO_WORKER handling
  fork: Explicity test for idle tasks in copy_thread
  fork: Pass struct kernel_clone_args into copy_thread
  kthread: Don't allocate kthread_struct for init and umh

Pull UML updates from Richard Weinberger:

 - Various cleanups and fixes: xterm, serial line, time travel

 - Set ARCH_HAS_GCOV_PROFILE_ALL

* tag 'for-linus-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Fix out-of-bounds read in LDT setup
  um: chan_user: Fix winch_tramp() return value
  um: virtio_uml: Fix broken device handling in time-travel
  um: line: Use separate IRQs per line
  um: Enable ARCH_HAS_GCOV_PROFILE_ALL
  um: Use asm-generic/dma-mapping.h
  um: daemon: Make default socket configurable
  um: xterm: Make default terminal emulator configurable