Allow to configure the command line to an arbitrary length, with a
default of 4096 bytes. Also remove COMMAND_LINE_SIZE from
include/uapi/asm/setup.h as this is dynamic now and doesn't tell
anything about the command line size limitations of a new kernel
that might be loaded.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Currently s390 supports a fixed maximum command line length of 896
bytes. This isn't enough as some installers are trying to pass all
configuration data via kernel command line, and even with zfcp alone
it is easy to generate really long command lines. Therefore extend
the command line to 4 kbytes.
In the parm area where the command line is stored there is no indication
of the maximum allowed length, so a new field which contains the maximum
length is added.
The parm area has always been initialized to zero, so with old kernels
this field would read zero. This is important because tools like zipl
could read this field. If it contains a number larger than zero zipl
knows the maximum length that can be stored in the parm area, otherwise
it must assume that it is booting a legacy kernel and only 896 bytes are
available.
The removing of trailing whitespace in head.S is also removed because
code to do this is already present in setup_boot_command_line().
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of adding support for command lines with variable
sizes on s390, the check whether the new kernel image is at least HEAD_END
bytes long isn't correct. Move the check to kexec_file_add_components()
so we can get the size of the parm area and check the size there.
The '.org HEAD_END' directive can now also be removed from head.S. This
was used in the past to reserve space for the early sccb buffer, but with
commit 9a5131b87cac1 ("s390/boot: move sclp early buffer from fixed address
in asm to C") this is no longer required.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Some applications map the same memory area for DMA multiple times while
also mapping significant amounts of memory. With our current DMA code
these applications will run out of DMA addresses after mapping half of
the available memory because the number of DMA mappings is constrained
by the number of concurrently active DMA addresses we support which in
turn is limited by the minimum of hardware constraints and high_memory.
Limiting the number of active DMA addresses to high_memory is only
a heuristic to save memory used by the iommu_bitmap and DMA page tables
however. This was added under the assumption that it rarely makes sense
to DMA map more than system memory.
To accommodate special applications which insist on double mapping, which
works on other platforms, allow specifying a factor of how many times
installed memory is available as DMA address space. Use 0 as a special
value to apply no constraints beyond what hardware dictates at the
expense of significantly more memory use.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The generic version of strlcpy is identical to the architecure
specific variant.
Therefore use the generic variant.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Use generic strrchr instead of an optimized architecture specific
variant. Performance of strrchr is not relevant for real life
workloads, since the only user which may call this more frequently
would be kbasename().
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/lkml/CAHk-=whoe211F8ND-9hZvfnib0UA4gga8DZJ+YaBZNbE4fubdg@mail.gmail.com/
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Slight rework of function __ap_revise_reserved()
because of unused variable warning when build with W=1.
This patch introduces an additional debug feature warning
message when device_reprobe() returns with failure.
However, the return value of __ap_revise_reserved()
is still hard coded to 0 as this is a callback function
to be used together with bus_for_each_dev() and thus
the return value indicates to go on with the
bus_for_each_dev() loop and not apport on a failure
of something within this function.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Since commit 48720ba568 ("virtio/s390: use DMA memory for ccw I/O and
classic notifiers") we were supposed to make sure that
virtio_ccw_release_dev() completes before the ccw device and the
attached dma pool are torn down, but unfortunately we did not. Before
that commit it used to be OK to delay cleaning up the memory allocated
by virtio-ccw indefinitely (which isn't really intuitive for guys used
to destruction happens in reverse construction order), but now we
trigger a BUG_ON if the genpool is destroyed before all memory allocated
from it is deallocated. Which brings down the guest. We can observe this
problem, when unregister_virtio_device() does not give up the last
reference to the virtio_device (e.g. because a virtio-scsi attached scsi
disk got removed without previously unmounting its previously mounted
partition).
To make sure that the genpool is only destroyed after all the necessary
freeing is done let us take a reference on the ccw device on each
ccw_device_dma_zalloc() and give it up on each ccw_device_dma_free().
Actually there are multiple approaches to fixing the problem at hand
that can work. The upside of this one is that it is the safest one while
remaining simple. We don't crash the guest even if the driver does not
pair allocations and frees. The downside is the reference counting
overhead, that the reference counting for ccw devices becomes more
complex, in a sense that we need to pair the calls to the aforementioned
functions for it to be correct, and that if we happen to leak, we leak
more than necessary (the whole ccw device instead of just the genpool).
Some alternatives to this approach are taking a reference in
virtio_ccw_online() and giving it up in virtio_ccw_release_dev() or
making sure virtio_ccw_release_dev() completes its work before
virtio_ccw_remove() returns. The downside of these approaches is that
these are less safe against programming errors.
Cc: <stable@vger.kernel.org> # v5.3
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Fixes: 48720ba568 ("virtio/s390: use DMA memory for ccw I/O and classic notifiers")
Reported-by: bfu@redhat.com
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Fixes the kernel-doc warnings in the following source files:
* drivers/s390/crypto/vfio_ap_private.h
* drivers/s390/crypto/vfio_ap_drv.c
* drivers/s390/crypto/vfio_ap_ops.c
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This patch introduces a new AP module option to be able to
control if the ap bus code is using interrupts or not.
By default if the interrupt support is available it is used.
This option makes it possible to disable interrupt use even
when interrupt support is available.
It should be obvious that this option can't magically enable
interrupt support when the hardware or hypervisor layer does
not support AP interrupts.
On the kernel command line use ap.useirq=0 or ap.useirq=1
to disable or enable (that's the default) interrupt use.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Commit a029a4eab3 ("s390/cpumf: Allow concurrent access for CPU Measurement Counter Facility")
added CPU Measurement counter facility access to multiple consumers.
It allows concurrent access to the CPU Measurement counter facility
via several perf_event_open() system call invocations and via ioctl()
system call of device /dev/hwc. However the access via device /dev/hwc
was exclusive, only one process was able to open this device.
The patch removes this restriction. Now multiple invocations of lshwc
can execute in parallel. They can access different CPUs and counter
sets or CPUs and counter set can overlap.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The Breaking-Event-Address-Register (BEAR) stores the address of the
last breaking event instruction. Breaking events are usually instructions
that change the program flow - for example branches, and instructions
that modify the address in the PSW like lpswe. This is useful for debugging
wild branches, because one could easily figure out where the wild branch
was originating from.
What is problematic is that lpswe is considered a breaking event, and
therefore overwrites BEAR on kernel exit. The BEAR enhancement facility
adds new instructions that allow to save/restore BEAR and also an lpswey
instruction that doesn't cause a breaking event. So we can save BEAR on
kernel entry and restore it on exit to user space.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
and replace all of the "__is_defined(CC_USING_EXPOLINE) && !nospec_disable"
occurrences.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
With the upcoming BEAR enhancements last_break isn't really
unique, so rename it to pgm_last_break. This way it should
be more obvious that this is the last_break value that is
written by the hardware when a program check occurs.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Instead of using args[0] for the value of the last breaking event
address register, add a member to make things more obvious.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Provide physical addresses whenever the hardware interface
expects it or a 32-bit value used for tracking.
Variable sclp_early_sccb gets initialized in the decompressor
and points to an address in physcal memory. Yet, it is used
as virtual memory pointer and therefore should be converted.
Note, the other two __bootdata variables sclp_info_sccb and
sclp_info_sccb_valid contain plain data, but no pointers and
do need any special care.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Variables initrd_start and initrd_end are expected to hold
virtual memory pointers, not physical.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
memblock_reserve() function accepts physcal address of a memory
block to be reserved, but provided with virtual memory pointers.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Instructions IPTE, IDTE and CRDTE accept Page-Table Origin
as one of the arguments, but instead the pgtable virtual
address is passed. Fix that and also update the crdte()
prototype to conform to csp() and cspg() friends.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This patch reworks all the debug feature invocations to be
more uniform. All invocations now use the macro with the
level already part of the macro name. All messages now start
with %s filled with __func__ (well there are still some
exceptions), and some message text has been shortened or
reworked.
There is no functional code touched with this patch.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
When a queue is switched to soft offline during heavy load and later
switched to soft online again and now used, it may be that the caller
is blocked forever in the ioctl call.
The failure occurs because there is a pending reply after the queue(s)
have been switched to offline. This orphaned reply is received when
the queue is switched to online and is accidentally counted for the
outstanding replies. So when there was a valid outstanding reply and
this orphaned reply is received it counts as the outstanding one thus
dropping the outstanding counter to 0. Voila, with this counter the
receive function is not called any more and the real outstanding reply
is never received (until another request comes in...) and the ioctl
blocks.
The fix is simple. However, instead of readjusting the counter when an
orphaned reply is detected, I check the queue status for not empty and
compare this to the outstanding counter. So if the queue is not empty
then the counter must not drop to 0 but at least have a value of 1.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
pci and string functions changes on features depend on changes from the
fixes branch.
* fixes:
s390: add Alexander Gordeev as reviewer
s390: fix strrchr() implementation
vfio-ccw: step down as maintainer
KVM: s390: remove myself as reviewer
s390/pci: fix zpci_zdev_put() on reserve
bpf, s390: Fix potential memory leak about jit_data
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add s390 support for ftrace direct call samples, which also enables
ftrace direct call selftests within ftrace selftests.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211012133802.2460757-5-hca@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add HAVE_SAMPLE_FTRACE_DIRECT config option which can be selected by
architectures which have support for ftrace direct call samples.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211012133802.2460757-4-hca@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Make STACK_FRAME_OVERHEAD available via asm-offsets.h. This allows to
add s390 specific asm code to e.g. ftrace samples, without requiring
to add random header files, which might cause all sort of problems on
other architectures. asm-offsets.h can be assumed to be non-problematic.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211012133802.2460757-3-hca@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Fix two problems found in the strrchr() implementation for s390
architectures: evaluate empty strings (return the string address instead of
NULL, if '\0' is passed as second argument); evaluate the first character
of non-empty strings (the current implementation stops at the second).
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reported-by: Heiko Carstens <hca@linux.ibm.com> (incorrect behavior with empty strings)
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Link: https://lore.kernel.org/r/20211005120836.60630-1-roberto.sassu@huawei.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
I currently don't have time to act as vfio-ccw maintainer
anymore, but I trust that I leave it in capable hands.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Acked-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20211006160120.217636-3-cohuck@redhat.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
I currently don't have time anymore to review KVM/s390
code.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20211006160120.217636-2-cohuck@redhat.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add regs_get_kernel_argument() which returns Nth argument of a
function call.
This enables ftrace kprobe events to access kernel function arguments
via $argN syntax.
This is the s390 variant of commit a823c35ff2 ("arm64: ptrace: Add
function argument access API").
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This is the s390 variant of commit 9855c4626c ("selftests/ftrace:
Add ppc support for kprobe args tests").
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
ftrace_regs_caller is an alias to ftrace_caller - making ftrace_caller
quite heavyweight. Split the function and provide an ftrace_caller
implementation which comes with fewer instructions. Especially getting
rid of 'stosm' on each function entry should help here, e.g. to
have less performance impact on live patched functions.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add ftrace_instruction_pointer_set() helper function to match x86.
See commit 2860cd8a23 ("livepatch: Use the default ftrace_ops
instead of REGS when ARGS is available").
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add HAVE_DYNAMIC_FTRACE_WITH_ARGS support similar to commit 02a474ca26
("ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default").
s390's ftrace implementation always provides all registers with
pt_regs, therefore this is trivial.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Trivial patch just to get rid of the leading underscores.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Specify HAVE_JUMP_LABEL_BATCH in header file. This allows to make use
of the arch_jump_label_transform_queue()/arch_jump_label_transform_apply()
mechanism.
However unlike on x86, which currently is the only user of this
mechanism, the to be patched instructions are still directly
modified. The only difference to before is that serialization is only
done after all instructions have been modified. This way the number of
serialization/synchronization events is reduced.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
CPUs must be serialized also when ftrace_graph_caller gets patched.
This is missing since ftrace function graph support was added on s390.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Introduce a text_poke_sync() similar to what x86 has. This can be
used to execute a serializing instruction on all CPUs (including
the current one).
Note: according to the Principles of Operation an IPI (= interrupt)
will already serialize a CPU, however it is better to be explicit. In
addition on_each_cpu() makes sure that also the current CPU get
serialized - just to make sure that possible preemption can prevent
some theoretical case where a CPU will not be serialized.
Therefore text_poke_sync() has to be used whenever code got modified,
just to avoid to rely on implicit serialization.
Also introduce text_poke_sync_lock() which will also disable CPU
hotplug, to prevent that any CPU is just going online with a
prefetched old version of a modified instruction.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
