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  1. 09 9月, 2019 1 次提交
  3. 08 9月, 2019 4 次提交
  5. 07 9月, 2019 8 次提交
  7. 06 9月, 2019 14 次提交
  9. 05 9月, 2019 7 次提交
  11. 04 9月, 2019 6 次提交
    • A
      Merge tag 'renesas-fixes-for-v5.3' of... · d9a2b63c
      由 Arnd Bergmann 提交于 
      Merge tag 'renesas-fixes-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into arm/fixes

Renesas ARM Based SoC Fixes for v5.3

* R-Car D3 (r8a77995) based Draak Board
  - Correct backlight regulator name in device tree

* tag 'renesas-fixes-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  arm64: dts: renesas: r8a77995: draak: Fix backlight regulator name
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      d9a2b63c
    • G
      powerpc/tm: Fix restoring FP/VMX facility incorrectly on interrupts · a8318c13
      由 Gustavo Romero 提交于 
      When in userspace and MSR FP=0 the hardware FP state is unrelated to
the current process. This is extended for transactions where if tbegin
is run with FP=0, the hardware checkpoint FP state will also be
unrelated to the current process. Due to this, we need to ensure this
hardware checkpoint is updated with the correct state before we enable
FP for this process.

Unfortunately we get this wrong when returning to a process from a
hardware interrupt. A process that starts a transaction with FP=0 can
take an interrupt. When the kernel returns back to that process, we
change to FP=1 but with hardware checkpoint FP state not updated. If
this transaction is then rolled back, the FP registers now contain the
wrong state.

The process looks like this:
   Userspace:                      Kernel

               Start userspace
                with MSR FP=0 TM=1
                  < -----
   ...
   tbegin
   bne
               Hardware interrupt
                   ---- >
                                    <do_IRQ...>
                                    ....
                                    ret_from_except
                                      restore_math()
				        /* sees FP=0 */
                                        restore_fp()
                                          tm_active_with_fp()
					    /* sees FP=1 (Incorrect) */
                                          load_fp_state()
                                        FP = 0 -> 1
                  < -----
               Return to userspace
                 with MSR TM=1 FP=1
                 with junk in the FP TM checkpoint
   TM rollback
   reads FP junk

When returning from the hardware exception, tm_active_with_fp() is
incorrectly making restore_fp() call load_fp_state() which is setting
FP=1.

The fix is to remove tm_active_with_fp().

tm_active_with_fp() is attempting to handle the case where FP state
has been changed inside a transaction. In this case the checkpointed
and transactional FP state is different and hence we must restore the
FP state (ie. we can't do lazy FP restore inside a transaction that's
used FP). It's safe to remove tm_active_with_fp() as this case is
handled by restore_tm_state(). restore_tm_state() detects if FP has
been using inside a transaction and will set load_fp and call
restore_math() to ensure the FP state (checkpoint and transaction) is
restored.

This is a data integrity problem for the current process as the FP
registers are corrupted. It's also a security problem as the FP
registers from one process may be leaked to another.

Similarly for VMX.

A simple testcase to replicate this will be posted to
tools/testing/selftests/powerpc/tm/tm-poison.c

This fixes CVE-2019-15031.

Fixes: a7771176 ("powerpc: Don't enable FP/Altivec if not checkpointed")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: NGustavo Romero <gromero@linux.ibm.com>
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190904045529.23002-2-gromero@linux.vnet.ibm.com
      a8318c13
    • G
      powerpc/tm: Fix FP/VMX unavailable exceptions inside a transaction · 8205d5d9
      由 Gustavo Romero 提交于 
      When we take an FP unavailable exception in a transaction we have to
account for the hardware FP TM checkpointed registers being
incorrect. In this case for this process we know the current and
checkpointed FP registers must be the same (since FP wasn't used
inside the transaction) hence in the thread_struct we copy the current
FP registers to the checkpointed ones.

This copy is done in tm_reclaim_thread(). We use thread->ckpt_regs.msr
to determine if FP was on when in userspace. thread->ckpt_regs.msr
represents the state of the MSR when exiting userspace. This is setup
by check_if_tm_restore_required().

Unfortunatley there is an optimisation in giveup_all() which returns
early if tsk->thread.regs->msr (via local variable `usermsr`) has
FP=VEC=VSX=SPE=0. This optimisation means that
check_if_tm_restore_required() is not called and hence
thread->ckpt_regs.msr is not updated and will contain an old value.

This can happen if due to load_fp=255 we start a userspace process
with MSR FP=1 and then we are context switched out. In this case
thread->ckpt_regs.msr will contain FP=1. If that same process is then
context switched in and load_fp overflows, MSR will have FP=0. If that
process now enters a transaction and does an FP instruction, the FP
unavailable will not update thread->ckpt_regs.msr (the bug) and MSR
FP=1 will be retained in thread->ckpt_regs.msr.  tm_reclaim_thread()
will then not perform the required memcpy and the checkpointed FP regs
in the thread struct will contain the wrong values.

The code path for this happening is:

       Userspace:                      Kernel
                   Start userspace
                    with MSR FP/VEC/VSX/SPE=0 TM=1
                      < -----
       ...
       tbegin
       bne
       fp instruction
                   FP unavailable
                       ---- >
                                        fp_unavailable_tm()
					  tm_reclaim_current()
					    tm_reclaim_thread()
					      giveup_all()
					        return early since FP/VMX/VSX=0
						/* ckpt MSR not updated (Incorrect) */
					      tm_reclaim()
					        /* thread_struct ckpt FP regs contain junk (OK) */
                                              /* Sees ckpt MSR FP=1 (Incorrect) */
					      no memcpy() performed
					        /* thread_struct ckpt FP regs not fixed (Incorrect) */
					  tm_recheckpoint()
					     /* Put junk in hardware checkpoint FP regs */
                                         ....
                      < -----
                   Return to userspace
                     with MSR TM=1 FP=1
                     with junk in the FP TM checkpoint
       TM rollback
       reads FP junk

This is a data integrity problem for the current process as the FP
registers are corrupted. It's also a security problem as the FP
registers from one process may be leaked to another.

This patch moves up check_if_tm_restore_required() in giveup_all() to
ensure thread->ckpt_regs.msr is updated correctly.

A simple testcase to replicate this will be posted to
tools/testing/selftests/powerpc/tm/tm-poison.c

Similarly for VMX.

This fixes CVE-2019-15030.

Fixes: f48e91e8 ("powerpc/tm: Fix FP and VMX register corruption")
Cc: stable@vger.kernel.org # 4.12+
Signed-off-by: NGustavo Romero <gromero@linux.vnet.ibm.com>
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190904045529.23002-1-gromero@linux.vnet.ibm.com
      8205d5d9
    • N
      mm/balloon_compaction: suppress allocation warnings · 02fa5d7b
      由 Nadav Amit 提交于 
      There is no reason to print warnings when balloon page allocation fails,
as they are expected and can be handled gracefully.  Since VMware
balloon now uses balloon-compaction infrastructure, and suppressed these
warnings before, it is also beneficial to suppress these warnings to
keep the same behavior that the balloon had before.

Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: NNadav Amit <namit@vmware.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
      02fa5d7b
    • M
      Revert "vhost: access vq metadata through kernel virtual address" · 3d2c7d37
      由 Michael S. Tsirkin 提交于 
      This reverts commit 7f466032 ("vhost: access vq metadata through
kernel virtual address").  The commit caused a bunch of issues, and
while commit 73f628ec ("vhost: disable metadata prefetch
optimization") disabled the optimization it's not nice to keep lots of
dead code around.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      3d2c7d37
    • Y
      vhost: Remove unnecessary variable · 896fc242
      由 Yunsheng Lin 提交于 
      It is unnecessary to use ret variable to return the error
code, just return the error code directly.
Signed-off-by: NYunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      896fc242