Commit Graph

825285 Commits

Author SHA1 Message Date
Philipp Rudo e23a8020ce s390/kexec_file: Signature verification prototype
Add kernel signature verification to kexec_file. The verification is based
on module signature verification and works with kernel images signed via
scripts/sign-file.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:44:01 +02:00
Philipp Rudo 653beba24d s390/kexec_file: Load new kernel to absolute 0
The leading 64 kB of a kernel image doesn't contain any data needed to boot
the new kernel when it was loaded via kexec_file. Thus kexec_file currently
strips them off before loading the image. Keep the leading 64 kB in order
to be able to pass a ipl_report to the next kernel.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:44:00 +02:00
Philipp Rudo 8e49642613 s390/kexec_file: Unify loader code
s390_image_load and s390_elf_load have the same code to load the different
components. Combine this functionality in one shared function.

While at it move kexec_file_update_kernel into the new function as well.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:43:59 +02:00
Philipp Rudo d0d249d75d s390/kexec_file: Simplify parmarea access
Access the parmarea in head.S via a struct instead of individual offsets.

While at it make the fields in the parmarea .quads.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:43:57 +02:00
Philipp Rudo 4c0f032d49 s390/purgatory: Omit use of bin2c
Omit use of script/bin2c hack. Directly include into assembler file instead.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:43:55 +02:00
Philipp Rudo 61f3f8fc22 s390/purgatory: Reduce purgatory size
The purgatory is compiled into the vmlinux and keept in memory all the time
during runtime. Thus any section not needed to load the purgatory
unnecessarily bloats up its foot print in file- and memorysize. Reduce the
purgatory size by stripping the unneeded sections from the purgatory.

This reduces the purgatories size by ~33%.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:43:53 +02:00
Philipp Rudo 729829d775 s390/kexec_file: Fix detection of text segment in ELF loader
To register data for the next kernel (command line, oldmem_base, etc.) the
current kernel needs to find the ELF segment that contains head.S. This is
currently done by checking ifor 'phdr->p_paddr == 0'. This works fine for
the current kernel build but in theory the first few pages could be
skipped. Make the detection more robust by checking if the entry point lies
within the segment.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:43:46 +02:00
Philipp Rudo 6339a3889a s390/kexec_file: Fix potential segment overlap in ELF loader
When loading an ELF image via kexec_file the segment alignment is ignored
in the calculation for the load address of the next segment. When there are
multiple segments this can lead to segment overlap and thus load failure.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Fixes: 8be0188271 ("s390/kexec_file: Add ELF loader")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:43:43 +02:00
Philipp Rudo f3df44e7c9 s390/zcore: Rename ipl_block to mitigate name collision
With git commit 1e941d3949
"s390: move ipl block to .boot.preserved.data section" the earl_ipl_block
got renamed to ipl_block and became publicly available via boot_data.h.
This might cause problems with zcore, which has it's own ipl_block
variable. Thus rename the ipl_block in zcore to prevent name collision
and highlight that it's only used locally.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Fixes: 1e941d3949 ("s390: move ipl block to .boot.preserved.data section")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky f678068652 s390/boot: pad bzImage to 4K
In order to be able to sign the bzImage independent of the block size
of the IPL device, align the bzImage to 4096 bytes.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky 937347ac56 s390/ipl: add helper functions to create an IPL report
PR: Adjusted to the use in kexec_file later.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky 9641b8cc73 s390/ipl: read IPL report at early boot
Read the IPL Report block provided by secure-boot, add the entries
of the certificate list to the system key ring and print the list
of components.

PR: Adjust to Vasilys bootdata_preserved patch set. Preserve ipl_cert_list
for later use in kexec_file.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky d29af5b7a8 s390/ipl: add definitions for the IPL report block
To transport the information required for secure boot a new IPL report
will be created at boot time. It will be written to memory right after
the IPL parameter block. To work with the IPL report a couple of
additional structure definitions are added the the uapi/ipl.h header.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky 5f1207fbe7 s390/ipl: provide uapi header for list directed IPL
The IPL parameter block is used as an interface between Linux and
the machine to query and change the boot device and boot options.
To be able to create IPL parameter block in user space and pass it
as segment to kexec provide an uapi header with proper structure
definitions for the block.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky 86c74d869d s390/ipl: make ipl_info less confusing
The ipl_info union in struct ipl_parameter_block has the same name as
the struct ipl_info. This does not help while reading the code and the
union in struct ipl_parameter_block does not need to be named. Drop
the name from the union.

Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky a8fd61688d s390: report new CPU capabilities
Add hardware capability bits and features tags to /proc/cpuinfo
for 4 new CPU features:
  "Vector-Enhancements Facility 2" (tag "vxe2", hwcap 2^15)
  "Vector-Packed-Decimal-Enhancement Facility" (tag "vxp", hwcap 2^16)
  "Enhanced-Sort Facility" (tag "sort", hwcap 2^17)
  "Deflate-Conversion Facility" (tag "dflt", hwcap 2^18)

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-25 15:34:10 +02:00
Harald Freudenberger 769f020b6c s390/crypto: use TRNG for seeding/reseeding
With the z14 machine there came also a CPACF hardware extension
which provides a True Random Number Generator. This TRNG can
be accessed with a new subfunction code within the CPACF prno
instruction and provides random data with very high entropy.

So if there is a TRNG available, let's use it for initial seeding
and reseeding instead of the current implementation which tries
to generate entropy based on stckf (store clock fast) jitters.

For details about the amount of data needed and pulled for
seeding and reseeding there can be explaining comments in the
code found.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-25 15:34:09 +02:00
Harald Freudenberger 23d1aee92b s390/crypto: rework generate_entropy function for pseudo random dd
Here is a rework of the generate_entropy function of the pseudo random
device driver exploiting the prno CPACF instruction.

George Spelvin pointed out some issues with the existing
implementation. One point was, that the buffer used to store the stckf
values is 2 pages which are initially filled with get_random_bytes()
for each 64 byte junk produced by the function. Another point was that
the stckf values only carry entropy in the LSB and thus a buffer of
2 pages is not really needed. Then there was a comment about the use
of the kimd cpacf function without proper initialization.

The rework addresses these points and now one page is used and only
one half of this is filled with get_random_bytes() on each chunk of 64
bytes requested data. The other half of the page is filled with stckf
values exored into with an overlap of 4 bytes. This can be done due to
the fact that only the lower 4 bytes carry entropy we need.  For more
details about the algorithm used, see the header of the function.

The generate_entropy() function now uses the cpacf function klmd with
proper initialization of the parameter block to perform the sha512
hash.

George also pointed out some issues with the internal buffers used for
seeding and reads. These buffers are now zeroed with memzero_implicit
after use.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reported-by: George Spelvin <lkml@sdf.org>
Suggested-by: George Spelvin <lkml@sdf.org>
Reviewed-by: Patrick Steuer <steuer@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-25 15:34:08 +02:00
Martin Schwidefsky 5513bc8eb4 - support for sending halt/clear requests to the device
- various bug fixes
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Merge tag 'vfio-ccw-20190425' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features

Pull vfio-ccw from Cornelia Huck with the following changes:

 - support for sending halt/clear requests to the device

 - various bug fixes
2019-04-25 13:45:09 +02:00
Farhan Ali d1ffa760d2 vfio-ccw: Prevent quiesce function going into an infinite loop
The quiesce function calls cio_cancel_halt_clear() and if we
get an -EBUSY we go into a loop where we:
	- wait for any interrupts
	- flush all I/O in the workqueue
	- retry cio_cancel_halt_clear

During the period where we are waiting for interrupts or
flushing all I/O, the channel subsystem could have completed
a halt/clear action and turned off the corresponding activity
control bits in the subchannel status word. This means the next
time we call cio_cancel_halt_clear(), we will again start by
calling cancel subchannel and so we can be stuck between calling
cancel and halt forever.

Rather than calling cio_cancel_halt_clear() immediately after
waiting, let's try to disable the subchannel. If we succeed in
disabling the subchannel then we know nothing else can happen
with the device.

Suggested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <4d5a4b98ab1b41ac6131b5c36de18b76c5d66898.1555449329.git.alifm@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00
Farhan Ali b49bdc8602 vfio-ccw: Release any channel program when releasing/removing vfio-ccw mdev
When releasing the vfio-ccw mdev, we currently do not release
any existing channel program and its pinned pages. This can
lead to the following warning:

[1038876.561565] WARNING: CPU: 2 PID: 144727 at drivers/vfio/vfio_iommu_type1.c:1494 vfio_sanity_check_pfn_list+0x40/0x70 [vfio_iommu_type1]

....

1038876.561921] Call Trace:
[1038876.561935] ([<00000009897fb870>] 0x9897fb870)
[1038876.561949]  [<000003ff8013bf62>] vfio_iommu_type1_detach_group+0xda/0x2f0 [vfio_iommu_type1]
[1038876.561965]  [<000003ff8007b634>] __vfio_group_unset_container+0x64/0x190 [vfio]
[1038876.561978]  [<000003ff8007b87e>] vfio_group_put_external_user+0x26/0x38 [vfio]
[1038876.562024]  [<000003ff806fc608>] kvm_vfio_group_put_external_user+0x40/0x60 [kvm]
[1038876.562045]  [<000003ff806fcb9e>] kvm_vfio_destroy+0x5e/0xd0 [kvm]
[1038876.562065]  [<000003ff806f63fc>] kvm_put_kvm+0x2a4/0x3d0 [kvm]
[1038876.562083]  [<000003ff806f655e>] kvm_vm_release+0x36/0x48 [kvm]
[1038876.562098]  [<00000000003c2dc4>] __fput+0x144/0x228
[1038876.562113]  [<000000000016ee82>] task_work_run+0x8a/0xd8
[1038876.562125]  [<000000000014c7a8>] do_exit+0x5d8/0xd90
[1038876.562140]  [<000000000014d084>] do_group_exit+0xc4/0xc8
[1038876.562155]  [<000000000015c046>] get_signal+0x9ae/0xa68
[1038876.562169]  [<0000000000108d66>] do_signal+0x66/0x768
[1038876.562185]  [<0000000000b9e37e>] system_call+0x1ea/0x2d8
[1038876.562195] 2 locks held by qemu-system-s39/144727:
[1038876.562205]  #0: 00000000537abaf9 (&container->group_lock){++++}, at: __vfio_group_unset_container+0x3c/0x190 [vfio]
[1038876.562230]  #1: 00000000670008b5 (&iommu->lock){+.+.}, at: vfio_iommu_type1_detach_group+0x36/0x2f0 [vfio_iommu_type1]
[1038876.562250] Last Breaking-Event-Address:
[1038876.562262]  [<000003ff8013aa24>] vfio_sanity_check_pfn_list+0x3c/0x70 [vfio_iommu_type1]
[1038876.562272] irq event stamp: 4236481
[1038876.562287] hardirqs last  enabled at (4236489): [<00000000001cee7a>] console_unlock+0x6d2/0x740
[1038876.562299] hardirqs last disabled at (4236496): [<00000000001ce87e>] console_unlock+0xd6/0x740
[1038876.562311] softirqs last  enabled at (4234162): [<0000000000b9fa1e>] __do_softirq+0x556/0x598
[1038876.562325] softirqs last disabled at (4234153): [<000000000014e4cc>] irq_exit+0xac/0x108
[1038876.562337] ---[ end trace 6c96d467b1c3ca06 ]---

Similarly we do not free the channel program when we are removing
the vfio-ccw device. Let's fix this by resetting the device and freeing
the channel program and pinned pages in the release path. For the remove
path we can just quiesce the device, since in the remove path the mediated
device is going away for good and so we don't need to do a full reset.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <ae9f20dc8873f2027f7b3c5d2aaa0bdfe06850b8.1554756534.git.alifm@linux.ibm.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00
Farhan Ali cea5dde42a vfio-ccw: Do not call flush_workqueue while holding the spinlock
Currently we call flush_workqueue while holding the subchannel
spinlock. But flush_workqueue function can go to sleep, so
do not call the function while holding the spinlock.

Fixes the following bug:

[  285.203430] BUG: scheduling while atomic: bash/14193/0x00000002
[  285.203434] INFO: lockdep is turned off.
....
[  285.203485] Preemption disabled at:
[  285.203488] [<000003ff80243e5c>] vfio_ccw_sch_quiesce+0xbc/0x120 [vfio_ccw]
[  285.203496] CPU: 7 PID: 14193 Comm: bash Tainted: G        W
....
[  285.203504] Call Trace:
[  285.203510] ([<0000000000113772>] show_stack+0x82/0xd0)
[  285.203514]  [<0000000000b7a102>] dump_stack+0x92/0xd0
[  285.203518]  [<000000000017b8be>] __schedule_bug+0xde/0xf8
[  285.203524]  [<0000000000b95b5a>] __schedule+0x7a/0xc38
[  285.203528]  [<0000000000b9678a>] schedule+0x72/0xb0
[  285.203533]  [<0000000000b9bfbc>] schedule_timeout+0x34/0x528
[  285.203538]  [<0000000000b97608>] wait_for_common+0x118/0x1b0
[  285.203544]  [<0000000000166d6a>] flush_workqueue+0x182/0x548
[  285.203550]  [<000003ff80243e6e>] vfio_ccw_sch_quiesce+0xce/0x120 [vfio_ccw]
[  285.203556]  [<000003ff80245278>] vfio_ccw_mdev_reset+0x38/0x70 [vfio_ccw]
[  285.203562]  [<000003ff802458b0>] vfio_ccw_mdev_remove+0x40/0x78 [vfio_ccw]
[  285.203567]  [<000003ff801a499c>] mdev_device_remove_ops+0x3c/0x80 [mdev]
[  285.203573]  [<000003ff801a4d5c>] mdev_device_remove+0xc4/0x130 [mdev]
[  285.203578]  [<000003ff801a5074>] remove_store+0x6c/0xa8 [mdev]
[  285.203582]  [<000000000046f494>] kernfs_fop_write+0x14c/0x1f8
[  285.203588]  [<00000000003c1530>] __vfs_write+0x38/0x1a8
[  285.203593]  [<00000000003c187c>] vfs_write+0xb4/0x198
[  285.203597]  [<00000000003c1af2>] ksys_write+0x5a/0xb0
[  285.203601]  [<0000000000b9e270>] system_call+0xdc/0x2d8

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <626bab8bb2958ae132452e1ddaf1b20882ad5a9d.1554756534.git.alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00
Cornelia Huck d5afd5d135 vfio-ccw: add handling for async channel instructions
Add a region to the vfio-ccw device that can be used to submit
asynchronous I/O instructions. ssch continues to be handled by the
existing I/O region; the new region handles hsch and csch.

Interrupt status continues to be reported through the same channels
as for ssch.

Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00
Cornelia Huck b094085737 s390/cio: export hsch to modules
The vfio-ccw code will need this, and it matches treatment of ssch
and csch.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00
Cornelia Huck db8e5d17ac vfio-ccw: add capabilities chain
Allow to extend the regions used by vfio-ccw. The first user will be
handling of halt and clear subchannel.

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00
Cornelia Huck 4f76617378 vfio-ccw: protect the I/O region
Introduce a mutex to disallow concurrent reads or writes to the
I/O region. This makes sure that the data the kernel or user
space see is always consistent.

The same mutex will be used to protect the async region as well.

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00
Cornelia Huck 690f6a1581 vfio-ccw: rework ssch state handling
The flow for processing ssch requests can be improved by splitting
the BUSY state:

- CP_PROCESSING: We reject any user space requests while we are in
  the process of translating a channel program and submitting it to
  the hardware. Use -EAGAIN to signal user space that it should
  retry the request.
- CP_PENDING: We have successfully submitted a request with ssch and
  are now expecting an interrupt. As we can't handle more than one
  channel program being processed, reject any further requests with
  -EBUSY. A final interrupt will move us out of this state.
  By making this a separate state, we make it possible to issue a
  halt or a clear while we're still waiting for the final interrupt
  for the ssch (in a follow-on patch).

It also makes a lot of sense not to preemptively filter out writes to
the io_region if we're in an incorrect state: the state machine will
handle this correctly.

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00
Cornelia Huck 71189f263f vfio-ccw: make it safe to access channel programs
When we get a solicited interrupt, the start function may have
been cleared by a csch, but we still have a channel program
structure allocated. Make it safe to call the cp accessors in
any case, so we can call them unconditionally.

While at it, also make sure that functions called from other parts
of the code return gracefully if the channel program structure
has not been initialized (even though that is a bug in the caller).

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00
Martin Schwidefsky c9f621524e s390/mm: fix pxd_bad with folded page tables
With git commit d1874a0c28
"s390/mm: make the pxd_offset functions more robust" and a 2-level page
table it can now happen that pgd_bad() gets asked to verify a large
segment table entry. If the entry is marked as dirty pgd_bad() will
incorrectly return true.

Change the pgd_bad(), p4d_bad(), pud_bad() and pmd_bad() functions to
first verify the table type, return false if the table level is lower
than what the function is suppossed to check, return true if the table
level is too high, and otherwise check the relevant region and segment
table bits. pmd_bad() has to check against ~SEGMENT_ENTRY_BITS for
normal page table pointers or ~SEGMENT_ENTRY_BITS_LARGE for large
segment table entries. Same for pud_bad() which has to check against
~_REGION_ENTRY_BITS or ~_REGION_ENTRY_BITS_LARGE.

Fixes: d1874a0c28 ("s390/mm: make the pxd_offset functions more robust")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-24 13:28:50 +02:00
Vasily Gorbik 01eb42afb4 s390/kasan: fix strncpy_from_user kasan checks
arch/s390/lib/uaccess.c is built without kasan instrumentation. Kasan
checks are performed explicitly in copy_from_user/copy_to_user
functions. But since those functions could be inlined, calls from
files like uaccess.c with instrumentation disabled won't generate
kasan reports. This is currently the case with strncpy_from_user
function which was revealed by newly added kasan test. Avoid inlining of
copy_from_user/copy_to_user when the kernel is built with kasan support
to make sure kasan checks are fully functional.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-24 13:28:46 +02:00
Thomas-Mich Richter 1c410fd6a5 s390/cpum_cf_diag: Add support for CPU-MF SVN 6
Add support for the CPU-Measurement Facility counter
second version number 6. This number is used to detect some
more counters in the crypto counter set and the extended
counter set.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-23 16:30:06 +02:00
Martin Schwidefsky 1a42010cdc s390/mm: convert to the generic get_user_pages_fast code
Define the gup_fast_permitted to check against the asce_limit of the
mm attached to the current task, then replace the s390 specific gup
code with the generic implementation in mm/gup.c.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-23 16:30:04 +02:00
Martin Schwidefsky d1874a0c28 s390/mm: make the pxd_offset functions more robust
Change the way how pgd_offset, p4d_offset, pud_offset and pmd_offset
walk the page tables. pgd_offset now always calculates the index for
the top-level page table and adds it to the pgd, this is either a
segment table offset for a 2-level setup, a region-3 offset for 3-levels,
region-2 offset for 4-levels, or a region-1 offset for a 5-level setup.
The other three functions p4d_offset, pud_offset and pmd_offset will
only add the respective offset if they dereference the passed pointer.

With the new way of walking the page tables a sequence like this from
mm/gup.c now works:

     pgdp = pgd_offset(current->mm, addr);
     pgd = READ_ONCE(*pgdp);
     p4dp = p4d_offset(&pgd, addr);
     p4d = READ_ONCE(*p4dp);
     pudp = pud_offset(&p4d, addr);
     pud = READ_ONCE(*pudp);
     pmdp = pmd_offset(&pud, addr);
     pmd = READ_ONCE(*pmdp);

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-23 16:30:03 +02:00
Julian Wiedmann 6bcf74e2d1 s390/qdio: consolidate index tracking for queue scan
qdio.ko offers a small number of high-level functions to drive the
scanning of a QDIO queue for ready-to-process SBALs:
qdio_get_next_buffers(), __[ti]qdio_inbound_processing() and
__qdio_outbound_processing().

Let each of those functions maintain the 'start' index for their current
scan, and pass it to lower-level helpers as needed. This improves the
code's overall layering, and allows us to eliminate the additional
first_to_kick cursor with a follow-on patch.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-18 10:10:32 +02:00
Julian Wiedmann 5b2ad27052 s390/qdio: limit direct access to first_to_check cursor
Refactor all the low-level helpers to take the first_to_check cursor as
parameter, rather than accessing it directly.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-18 10:10:31 +02:00
Arnd Bergmann 913140e221 s390: zcrypt: initialize variables before_use
The 'func_code' variable gets printed in debug statements without
a prior initialization in multiple functions, as reported when building
with clang:

drivers/s390/crypto/zcrypt_api.c:659:6: warning: variable 'func_code' is used uninitialized whenever 'if' condition is true
      [-Wsometimes-uninitialized]
        if (mex->outputdatalength < mex->inputdatalength) {
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/s390/crypto/zcrypt_api.c:725:29: note: uninitialized use occurs here
        trace_s390_zcrypt_rep(mex, func_code, rc,
                                   ^~~~~~~~~
drivers/s390/crypto/zcrypt_api.c:659:2: note: remove the 'if' if its condition is always false
        if (mex->outputdatalength < mex->inputdatalength) {
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/s390/crypto/zcrypt_api.c:654:24: note: initialize the variable 'func_code' to silence this warning
        unsigned int func_code;
                              ^

Add initializations to all affected code paths to shut up the warning
and make the warning output consistent.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:37:30 +02:00
Arnd Bergmann 6e042492a2 s390: avoid __builtin_return_address(n) on clang
llvm on s390 has problems with __builtin_return_address(n), with n>0,
this results in a somewhat cryptic error message:

fatal error: error in backend: Unsupported stack frame traversal count

To work around it, use the direct return address directly. This
is probably not ideal here, but gets things to compile and should
only lead to inferior reporting, not to misbehavior of the generated
code.

Link: https://bugs.llvm.org/show_bug.cgi?id=41424
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:37:29 +02:00
Joe Perches 475c8e9e89 s390: Convert IS_ENABLED uses to __is_defined
IS_ENABLED should be reserved for CONFIG_<FOO> uses so convert
the uses of IS_ENABLED with a #define to __is_defined.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:36:53 +02:00
Arnd Bergmann 9a0ceb9cfb s390: make chkbss work with clang
llvm skips an empty .bss section entirely, which makes
the check fail with an unexpected error:

/tmp/binutils-multi-test/bin/s390x-linux-gnu-objdump: section '.bss' mentioned in a -j option, but not found in any input file
error: arch/s390/boot/compressed/decompressor.o .bss section is not empty
../arch/s390/scripts/Makefile.chkbss:20: recipe for target 'arch/s390/boot/compressed/decompressor.o.chkbss' failed

Change the check so we first see if a .bss section exists
before trying to read its size.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:36:52 +02:00
Arnd Bergmann 0a113efc3b s390: make __load_psw_mask work with clang
clang fails to use the %O and %R inline assembly modifiers
the same way as gcc, leading to build failures with every use
of __load_psw_mask():

/tmp/nmi-4a9f80.s: Assembler messages:
/tmp/nmi-4a9f80.s:571: Error: junk at end of line: `+8(160(%r11))'
/tmp/nmi-4a9f80.s:626: Error: junk at end of line: `+8(160(%r11))'

Replace these with a more conventional way of passing the addresses
that should work with both clang and gcc.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:36:52 +02:00
Arnd Bergmann efb150df1d s390: syscall_wrapper: avoid clang warning
Building system calls with clang results in a warning
about an alias from a global function to a static one:

../fs/namei.c:3847:1: warning: unused function '__se_sys_mkdirat' [-Wunused-function]
SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode)
^
../include/linux/syscalls.h:219:36: note: expanded from macro 'SYSCALL_DEFINE3'
 #define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__)
                                   ^
../include/linux/syscalls.h:228:2: note: expanded from macro 'SYSCALL_DEFINEx'
        __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
        ^
../arch/s390/include/asm/syscall_wrapper.h:126:18: note: expanded from macro '__SYSCALL_DEFINEx'
        asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))          \
                        ^
<scratch space>:31:1: note: expanded from here
__se_sys_mkdirat
^

The only reference to the static __se_sys_mkdirat() here is the alias, but
this only gets evaluated later. Making this function global as well avoids
the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:36:51 +02:00
Arnd Bergmann 96ca7674ea s390: don't build vdso32 with clang
clang does not support 31 bit object files on s390, so skip
the 32-bit vdso here, and only build it when using gcc to compile
the kernel.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:36:49 +02:00
Arnd Bergmann c1afcaec2a s390: remove -fno-strength-reduce flag
This was added as a workaround for really old compilers, and it prevents
building with clang now. I can see no reason for keeping it, as it has
already been removed for most architectures in the pre-git era, so
let's remove it everywhere, rather than only for clang.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:36:46 +02:00
Martin Schwidefsky 7aa0055e06 s390: fine-tune stack switch helper
The CALL_ON_STACK helper currently does not work with clang and for
calls without arguments. It does not initialize r2 although the constraint
is "+&d". Rework the CALL_FMT_x and the CALL_ON_STACK macros to work
with clang and produce optimal code in all cases.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:36:45 +02:00
Martin Schwidefsky e24e4712ef s390/rseq: use trap4 for RSEQ_SIG
Use trap4 as the guard instruction for the restartable sequence abort
handler.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:48:34 +02:00
Arnd Bergmann e91012ee85 s390: cio: fix cio_irb declaration
clang points out that the declaration of cio_irb does not match the
definition exactly, it is missing the alignment attribute:

../drivers/s390/cio/cio.c:50:1: warning: section does not match previous declaration [-Wsection]
DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
^
../include/linux/percpu-defs.h:150:2: note: expanded from macro 'DEFINE_PER_CPU_ALIGNED'
        DEFINE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION)     \
        ^
../include/linux/percpu-defs.h:93:9: note: expanded from macro 'DEFINE_PER_CPU_SECTION'
        extern __PCPU_ATTRS(sec) __typeof__(type) name;                 \
               ^
../include/linux/percpu-defs.h:49:26: note: expanded from macro '__PCPU_ATTRS'
        __percpu __attribute__((section(PER_CPU_BASE_SECTION sec)))     \
                                ^
../drivers/s390/cio/cio.h:118:1: note: previous attribute is here
DECLARE_PER_CPU(struct irb, cio_irb);
^
../include/linux/percpu-defs.h:111:2: note: expanded from macro 'DECLARE_PER_CPU'
        DECLARE_PER_CPU_SECTION(type, name, "")
        ^
../include/linux/percpu-defs.h:87:9: note: expanded from macro 'DECLARE_PER_CPU_SECTION'
        extern __PCPU_ATTRS(sec) __typeof__(type) name
               ^
../include/linux/percpu-defs.h:49:26: note: expanded from macro '__PCPU_ATTRS'
        __percpu __attribute__((section(PER_CPU_BASE_SECTION sec)))     \
                                ^
Use DECLARE_PER_CPU_ALIGNED() here, to make the two match.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:48:33 +02:00
Thomas Huth 81a8f2beb3 s390/mm: silence compiler warning when compiling without CONFIG_PGSTE
If CONFIG_PGSTE is not set (e.g. when compiling without KVM), GCC complains:

  CC      arch/s390/mm/pgtable.o
arch/s390/mm/pgtable.c:413:15: warning: ‘pmd_alloc_map’ defined but not
 used [-Wunused-function]
 static pmd_t *pmd_alloc_map(struct mm_struct *mm, unsigned long addr)
               ^~~~~~~~~~~~~

Wrap the function with "#ifdef CONFIG_PGSTE" to silence the warning.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:48:28 +02:00
Julian Wiedmann dccbbaff17 s390/qdio: eliminate queue's last_move cursor
This cursor is used for debugging only. But since
commit "s390/qdio: pass up count of ready-to-process SBALs" it effectively
duplicates the first_to_check cursor, diverging for just a short moment
when get_*_buffer_frontier() updates q->first_to_check.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:47:26 +02:00
Julian Wiedmann 65e4f77638 s390/qdio: simplify SBAL range calculation
When passing a range of ready-to-process SBALs to the upper-layer
driver, use the available 'count' instead of calculating the distance
between the first_to_check and first_to_kick cursors.

This simplifies the logic of the queue-scan path, and opens up the
possibility of scanning all 128 SBALs in one go (as determining the
reported count no longer requires wrap-around safe arithmetic on the
queue's cursors).

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:47:25 +02:00
Julian Wiedmann b39544c6e0 s390/qdio: pass up count of ready-to-process SBALs
When qdio_{in,out}bound_q_moved() scans a queue for pending work, it
currently only returns a boolean to its caller. The interface to the
upper-layer-drivers (qdio_kick_handler() and qdio_get_next_buffers())
then re-calculates the number of pending SBALs from the
q->first_to_check and q->first_to_kick cursors.

Refactor this so that whenever get_{in,out}bound_buffer_frontier()
adjusted the queue's first_to_check cursor, it also returns the
corresponding count of ready-to-process SBALs (and 0 else).
A subsequent patch will then make use of this additional information.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:47:24 +02:00