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  1. 30 Nov, 2020 2 commits
  3. 23 Nov, 2020 6 commits
    • Heiko Carstens's avatar
      s390/vdso: reimplement getcpu vdso syscall · 80f06306
      Heiko Carstens authored 
      Implement the previously removed getcpu vdso syscall by using the
TOD programmable field to pass the cpu number to user space.
Reviewed-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      80f06306
    • Heiko Carstens's avatar
      s390/mm: add debug user asce support · 062e5279
      Heiko Carstens authored 
      Verify on exit to user space that always
- the primary ASCE (cr1) is set to kernel ASCE
- the secondary ASCE (cr7) is set to user ASCE

If this is not the case: panic since something went terribly wrong.
Reviewed-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      062e5279
    • Heiko Carstens's avatar
      s390/mm: use invalid asce instead of kernel asce · 0290c9e3
      Heiko Carstens authored 
      Create a region 3 page table which contains only invalid entries, and
use that via "s390_invalid_asce" instead of the kernel ASCE whenever
there is either
- no user address space available, e.g. during early startup
- as an intermediate ASCE when address spaces are switched

This makes sure that user space accesses in such situations are
guaranteed to fail.
Reviewed-by: default avatarSven Schnelle <svens@linux.ibm.com>
Reviewed-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      0290c9e3
    • Heiko Carstens's avatar
      s390/mm: remove set_fs / rework address space handling · 87d59863
      Heiko Carstens authored 
      Remove set_fs support from s390. With doing this rework address space
handling and simplify it. As a result address spaces are now setup
like this:

CPU running in              | %cr1 ASCE | %cr7 ASCE | %cr13 ASCE
----------------------------|-----------|-----------|-----------
user space                  |  user     |  user     |  kernel
kernel, normal execution    |  kernel   |  user     |  kernel
kernel, kvm guest execution |  gmap     |  user     |  kernel

To achieve this the getcpu vdso syscall is removed in order to avoid
secondary address mode and a separate vdso address space in for user
space. The getcpu vdso syscall will be implemented differently with a
subsequent patch.

The kernel accesses user space always via secondary address space.
This happens in different ways:
- with mvcos in home space mode and directly read/write to secondary
  address space
- with mvcs/mvcp in primary space mode and copy from primary space to
  secondary space or vice versa
- with e.g. cs in secondary space mode and access secondary space

Switching translation modes happens with sacf before and after
instructions which access user space, like before.

Lazy handling of control register reloading is removed in the hope to
make everything simpler, but at the cost of making kernel entry and
exit a bit slower. That is: on kernel entry the primary asce is always
changed to contain the kernel asce, and on kernel exit the primary
asce is changed again so it contains the user asce.

In kernel mode there is only one exception to the primary asce: when
kvm guests are executed the primary asce contains the gmap asce (which
describes the guest address space). The primary asce is reset to
kernel asce whenever kvm guest execution is interrupted, so that this
doesn't has to be taken into account for any user space accesses.
Reviewed-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      87d59863
    • Heiko Carstens's avatar
      Merge branch 'fixes' into features · 77663819
      Heiko Carstens authored 
      * fixes:
  s390: fix fpu restore in entry.S
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      77663819
    • Sven Schnelle's avatar
      s390: fix fpu restore in entry.S · 1179f170
      Sven Schnelle authored 
      We need to disable interrupts in load_fpu_regs(). Otherwise an
interrupt might come in after the registers are loaded, but before
CIF_FPU is cleared in load_fpu_regs(). When the interrupt returns,
CIF_FPU will be cleared and the registers will never be restored.

The entry.S code usually saves the interrupt state in __SF_EMPTY on the
stack when disabling/restoring interrupts. sie64a however saves the pointer
to the sie control block in __SF_SIE_CONTROL, which references the same
location.  This is non-obvious to the reader. To avoid thrashing the sie
control block pointer in load_fpu_regs(), move the __SIE_* offsets eight
bytes after __SF_EMPTY on the stack.

Cc: <stable@vger.kernel.org> # 5.8
Fixes: 0b0ed657 ("s390: remove critical section cleanup from entry.S")
Reported-by: default avatarPierre Morel <pmorel@linux.ibm.com>
Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      1179f170
  5. 20 Nov, 2020 15 commits
  7. 18 Nov, 2020 4 commits
  9. 12 Nov, 2020 3 commits
  11. 09 Nov, 2020 10 commits
    • Harald Freudenberger's avatar
      s390/zcrypt/pkey: introduce zcrypt_wait_api_operational() function · 43cb5a7c
      Harald Freudenberger authored 
      The zcrypt api provides a new function to wait until the zcrypt
api is operational:

  int zcrypt_wait_api_operational(void);

The AP bus scan and the binding of ap devices to device drivers is
an asynchronous job. This function waits until these initial jobs
are done and so the zcrypt api should be ready to serve crypto
requests - if there are resources available. The function uses an
internal timeout of 60s. The very first caller will either wait for
ap bus bindings complete or the timeout happens. This state will be
remembered for further callers which will only be blocked until a
decision is made (timeout or bindings complete).
Reviewed-by: default avatarIngo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: default avatarHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      43cb5a7c
    • Harald Freudenberger's avatar
      s390/ap: ap bus userspace notifications for some bus conditions · 837cd105
      Harald Freudenberger authored 
      This patch adds notifications to userspace for two important
conditions of the ap bus:

I) Initial ap bus scan done. This indicates that the initial
   scan of all the ap devices (cards, queues) is complete and
   ap devices have been build up for all the hardware found.
   This condition is signaled with
   1) An ap bus change uevent send to userspace with an environment
      key/value pair "INITSCAN=done":
	# udevadm monitor -k -p
	...
	KERNEL[97.830919] change   /devices/ap (ap)
	ACTION=change
	DEVPATH=/devices/ap
	SUBSYSTEM=ap
	INITSCAN=done
	SEQNUM=10421
   2) A sysfs attribute /sys/bus/ap/scans which shows the
      number of completed ap bus scans done since bus init.
      So a value of 1 or greater signals that the initial
      ap bus scan is complete.
   Note: The initial ap bus scan complete condition is fulfilled
   and will be signaled even if there was no ap resource found.

II) APQN driver bindings complete. This indicates that all
    APQNs have been bound to an zcrypt or alternate device
    driver. Only with the help of an device driver an APQN
    can be used for crypto load. So the binding complete
    condition is the starting point for user space to be
    sure all crypto resources on the ap bus are available
    for use.
    This condition is signaled with
    1) An ap bus change uevent send to userspace with an environment
       key/value pair "BINDINGS=complete":
	 # udevadm monitor -k -p
	 ...
	 KERNEL[97.830975] change   /devices/ap (ap)
	 ACTION=change
	 DEVPATH=/devices/ap
	 SUBSYSTEM=ap
	 BINDINGS=complete
	 SEQNUM=10422
    2) A sysfs attribute /sys/bus/ap/bindings showing
	 "<nr of bound apqns>/<total nr of apqns> (complete)"
       when all available apqns have been bound to device drivers, or
	 "<nr of bound apqns>/<total nr of apqns>"
       when there are some apqns not bound to an device driver.
    Note: The binding complete condition is also fulfilled, when
    there are no apqns available to bind any device driver. In
    this case the binding complete will be signaled AFTER init
    scan is done.
    Note: This condition may arise multiple times when after
    initial scan modifications on the bindings take place. For
    example a manual unbind of an APQN switches the binding
    complete condition off. When at a later time the unbound APQNs
    are bound with an device driver the binding is (again) complete
    resulting in another uevent and marking the bindings sysfs
    attribute with '(complete)'.

There is also a new function to be used within the kernel:

  int ap_wait_init_apqn_bindings_complete(unsigned long timeout)

Interface to wait for the AP bus to have done one initial ap bus
scan and all detected APQNs have been bound to device drivers.
If these both conditions are not fulfilled, this function blocks
on a condition with wait_for_completion_interruptible_timeout().
If these both conditions are fulfilled (before the timeout hits)
the return value is 0. If the timeout (in jiffies) hits instead
-ETIME is returned. On failures negative return values are
returned to the caller. Please note that further unbind/bind
actions after initial binding complete is through do not cause this
function to block again.
Reviewed-by: default avatarIngo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: default avatarHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      837cd105
    • Christian Borntraeger's avatar
      s390/trng: set quality to 1024 · d041315e
      Christian Borntraeger authored 
      The s390-trng does provide 100% entropy. The quality value is supported
to be between 1 and 1024 and not 1..1000.  Use 1024 to make this driver
the preferred one. If we ever have a better driver that has the same
quality but is faster we can change this again when merging the new
driver. No need to be conservative.

This makes sure that the hw variant is preferred over things like
virtio-rng, where the hypervisor has a potential to be misconfigured
and thus should have a slightly lower confidence.

Cc: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      d041315e
    • Daniel Vetter's avatar
      s390/pci: remove races against pte updates · a67a88b0
      Daniel Vetter authored 
      Way back it was a reasonable assumptions that iomem mappings never
change the pfn range they point at. But this has changed:

- gpu drivers dynamically manage their memory nowadays, invalidating
ptes with unmap_mapping_range when buffers get moved

- contiguous dma allocations have moved from dedicated carvetouts to
cma regions. This means if we miss the unmap the pfn might contain
pagecache or anon memory (well anything allocated with GFP_MOVEABLE)

- even /dev/mem now invalidates mappings when the kernel requests that
iomem region when CONFIG_IO_STRICT_DEVMEM is set, see
commit 3234ac66 ("/dev/mem: Revoke mappings when a driver claims the
region")

Accessing pfns obtained from ptes without holding all the locks is
therefore no longer a good idea. Fix this.

Since zpci_memcpy_from|toio seems to not do anything nefarious with
locks we just need to open code get_pfn and follow_pfn and make sure
we drop the locks only after we're done. The write function also needs
the copy_from_user move, since we can't take userspace faults while
holding the mmap sem.
Reviewed-by: default avatarGerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      a67a88b0
    • Vasily Gorbik's avatar
      s390/early: rewrite program parameter setup in C · d7e7fbba
      Vasily Gorbik authored 
      And move it earlier in the decompressor.
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      d7e7fbba
    • Vasily Gorbik's avatar
      s390/kasan: move memory needs estimation into a function · 0c4ec024
      Vasily Gorbik authored 
      Also correct rounding downs in estimation calculations.
Reviewed-by: default avatarAlexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      0c4ec024
    • Vasily Gorbik's avatar
      s390/kasan: make kasan header self-contained · e385b550
      Vasily Gorbik authored 
      It is relying on _REGION1_SHIFT / _REGION2_SHIFT values which come from
asm/pgtable.h, so include it.
Reviewed-by: default avatarAlexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      e385b550
    • Vasily Gorbik's avatar
      s390/kasan: remove obvious parameter with the only possible value · 54b52981
      Vasily Gorbik authored 
      Kasan early code is only working on init_mm, remove unneeded pgd
parameter from kasan_copy_shadow and rename it to
kasan_copy_shadow_mapping.
Reviewed-by: default avatarAlexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      54b52981
    • Vasily Gorbik's avatar
      s390/kasan: avoid confusing naming · 92bca2fe
      Vasily Gorbik authored 
      Kasan has nothing to do with vmemmap, strip vmemmap from function names
to avoid confusing people.
Reviewed-by: default avatarAlexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      92bca2fe
    • Vasily Gorbik's avatar
      s390/decompressor: fix build warning · 39f2899b
      Vasily Gorbik authored 
      Fixes the following warning with CONFIG_KERNEL_UNCOMPRESSED=y

arch/s390/boot/compressed/decompressor.h:6:46: warning: non-void function
does not return a value [-Wreturn-type]
static inline void *decompress_kernel(void) {}
                                             ^
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
      39f2899b
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