The e7 opcode table does not have an end marker. Hence when trying to
find an unknown e7 instruction the code will access memory behind the
table until it finds something that matches the opcode, or the kernel
crashes, whatever comes first.
This affects not only the in-kernel disassembler but also uprobes and
kprobes which refuse to set a probe on unknown instructions, and
therefore search the opcode tables to figure out if instructions are
known or not.
Cc: <stable@vger.kernel.org> # v3.18+
Fixes: 3585cb0280654 ("s390/disassembler: add vector instructions")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The queued spinlock code for s390 follows the principles of the common
code qspinlock implementation but with a few notable differences.
The format of the spinlock_t locking word differs, s390 needs to store
the logical CPU number of the lock holder in the spinlock_t to be able
to use the diagnose 9c directed yield hypervisor call.
The inline code sequences for spin_lock and spin_unlock are nice and
short. The inline portion of a spin_lock now typically looks like this:
lhi %r0,0 # 0 indicates an empty lock
l %r1,0x3a0 # CPU number + 1 from lowcore
cs %r0,%r1,<some_lock> # lock operation
jnz call_wait # on failure call wait function
locked:
...
call_wait:
la %r2,<some_lock>
brasl %r14,arch_spin_lock_wait
j locked
A spin_unlock is as simple as before:
lhi %r0,0
sth %r0,2(%r2) # unlock operation
After a CPU has queued itself it may not enable interrupts again for the
arch_spin_lock_flags() variant. The arch_spin_lock_wait_flags wait function
is removed.
To improve performance the code implements opportunistic lock stealing.
If the wait function finds a spinlock_t that indicates that the lock is
free but there are queued waiters, the CPU may steal the lock up to three
times without queueing itself. The lock stealing update the steal counter
in the lock word to prevent more than 3 steals. The counter is reset at
the time the CPU next in the queue successfully takes the lock.
While the queued spinlocks improve performance in a system with dedicated
CPUs, in a virtualized environment with continuously overcommitted CPUs
the queued spinlocks can have a negative effect on performance. This
is due to the fact that a queued CPU that is preempted by the hypervisor
will block the queue at some point even without holding the lock. With
the classic spinlock it does not matter if a CPU is preempted that waits
for the lock. Therefore use the queued spinlock code only if the system
runs with dedicated CPUs and fall back to classic spinlocks when running
with shared CPUs.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The topology information returned by STSI 15.x.x contains a flag
if the CPUs of a topology-list are dedicated or shared. Make this
information available if the machine provides topology information.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Paul Burton reported that the nr_cpumask_bits check
within cpumsf_pmu_event_init() is not necessary.
Actually there is already a prior check within
perf_event_alloc(). Therefore remove the check.
Reported-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add runtime instrumention register get and set which allows to read
and modify the runtime instrumention control block.
Signed-off-by: Alice Frosi <alice@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Update runtime_instr_cb structure to be consistent with the runtime
instrumentation documentation.
Signed-off-by: Alice Frosi <alice@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This is the quite trivial backend for s390 which is required to enable
FORTIFY_SOURCE support.
See commit 6974f0c4555e ("include/linux/string.h: add the option of
fortified string.h functions") for more details.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
exit_thread() is empty now. Therefore remove it and get rid of a
pointless branch.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Free data structures required for guarded storage from
arch_release_task_struct(). This allows to simplify the code a bit,
and also makes the semantics a bit easier: arch_release_task_struct()
is never called from the task that is being removed.
In addition this allows to get rid of exit_thread() in a later patch.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If the guarded storage regset for current is supposed to be changed,
the regset from user space is copied directly into the guarded storage
control block.
If then the process gets scheduled away while the control block is
being copied and before the new control block has been loaded, the
result is random: the process can be scheduled away due to a page
fault or preemption. If that happens the already copied parts will be
overwritten by save_gs_cb(), called from switch_to().
Avoid this by copying the data to a temporary buffer on the stack and
do the actual update with preemption disabled.
Fixes: f5bbd7219891 ("s390/ptrace: guarded storage regset for the current task")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
For PREEMPT enabled kernels the guarded storage (GS) code contains a
possible use-after-free bug. If a task that makes use of GS exits, it
will execute do_exit() while still enabled for preemption.
That function will call exit_thread_runtime_instr() via exit_thread().
If exit_thread_gs() gets preempted after the GS control block of the
task has been freed but before the pointer to it is set to NULL, then
save_gs_cb(), called from switch_to(), will write to already freed
memory.
Avoid this and simply disable preemption while freeing the control
block and setting the pointer to NULL.
Fixes: 916cda1aa1b4 ("s390: add a system call for guarded storage")
Cc: <stable@vger.kernel.org> # v4.12+
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Free data structures required for runtime instrumentation from
arch_release_task_struct(). This allows to simplify the code a bit,
and also makes the semantics a bit easier: arch_release_task_struct()
is never called from the task that is being removed.
In addition this allows to get rid of exit_thread() in a later patch.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
For PREEMPT enabled kernels the runtime instrumentation (RI) code
contains a possible use-after-free bug. If a task that makes use of RI
exits, it will execute do_exit() while still enabled for preemption.
That function will call exit_thread_runtime_instr() via
exit_thread(). If exit_thread_runtime_instr() gets preempted after the
RI control block of the task has been freed but before the pointer to
it is set to NULL, then save_ri_cb(), called from switch_to(), will
write to already freed memory.
Avoid this and simply disable preemption while freeing the control
block and setting the pointer to NULL.
Fixes: e4b8b3f33fca ("s390: add support for runtime instrumentation")
Cc: <stable@vger.kernel.org> # v3.7+
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
release_thread() is an empty function that gets called on every task
exit. Move the function to a header file and force inlining of it, so
that the compiler can optimize it away instead of generating a
pointless function call.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a new sysctl file /proc/sys/s390/topology which displays if
topology is on (1) or off (0) as specified by the "topology=" kernel
parameter.
This allows to change topology information during runtime and
configuring it via /etc/sysctl.conf instead of using the kernel line
parameter.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If running on machines that do not provide topology information we
currently generate a "fake" topology which defines the maximum
distance between each cpu: each cpu will be put into an own drawer.
Historically this used to be the best option for (virtual) machines in
overcommited hypervisors.
For some workloads however it is better to generate a different
topology where all cpus are siblings within a package (all cpus are
core siblings). This shows performance improvements of up to 10%,
depending on the workload.
In order to keep the current behaviour, but also allow to switch to
the different core sibling topology use the existing "topology="
kernel parameter:
Specifying "topology=on" on machines without topology information will
generate the core siblings (fake) topology information, instead of the
default topology information where all cpus have the maximum distance.
On machines which provide topology information specifying
"topology=on" does not have any effect.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A per-thread event could not be created correctly like below:
perf record --per-thread -e rB0000 -- sleep 1
Error:
The sys_perf_event_open() syscall returned with 19 (No such device) for event (rB0000).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?
This bug was introduced by:
commit c311c797998c1e70eade463dd60b843da4f1a203
Author: Alexey Dobriyan <adobriyan@gmail.com>
Date: Mon May 8 15:56:15 2017 -0700
cpumask: make "nr_cpumask_bits" unsigned
If a per-thread event is not attached to any CPU, the cpu field
in struct perf_event is -1. The above commit converts the CPU number
to unsigned int, which result in an illegal CPU number.
Fixes: c311c797998c ("cpumask: make "nr_cpumask_bits" unsigned")
Cc: <stable@vger.kernel.org> # v4.12+
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Pu Hou <bjhoupu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull namespace updates from Eric Biederman:
"Life has been busy and I have not gotten half as much done this round
as I would have liked. I delayed it so that a minor conflict
resolution with the mips tree could spend a little time in linux-next
before I sent this pull request.
This includes two long delayed user namespace changes from Kirill
Tkhai. It also includes a very useful change from Serge Hallyn that
allows the security capability attribute to be used inside of user
namespaces. The practical effect of this is people can now untar
tarballs and install rpms in user namespaces. It had been suggested to
generalize this and encode some of the namespace information
information in the xattr name. Upon close inspection that makes the
things that should be hard easy and the things that should be easy
more expensive.
Then there is my bugfix/cleanup for signal injection that removes the
magic encoding of the siginfo union member from the kernel internal
si_code. The mips folks reported the case where I had used FPE_FIXME
me is impossible so I have remove FPE_FIXME from mips, while at the
same time including a return statement in that case to keep gcc from
complaining about unitialized variables.
I almost finished the work to get make copy_siginfo_to_user a trivial
copy to user. The code is available at:
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git neuter-copy_siginfo_to_user-v3
But I did not have time/energy to get the code posted and reviewed
before the merge window opened.
I was able to see that the security excuse for just copying fields
that we know are initialized doesn't work in practice there are buggy
initializations that don't initialize the proper fields in siginfo. So
we still sometimes copy unitialized data to userspace"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
Introduce v3 namespaced file capabilities
mips/signal: In force_fcr31_sig return in the impossible case
signal: Remove kernel interal si_code magic
fcntl: Don't use ambiguous SIG_POLL si_codes
prctl: Allow local CAP_SYS_ADMIN changing exe_file
security: Use user_namespace::level to avoid redundant iterations in cap_capable()
userns,pidns: Verify the userns for new pid namespaces
signal/testing: Don't look for __SI_FAULT in userspace
signal/mips: Document a conflict with SI_USER with SIGFPE
signal/sparc: Document a conflict with SI_USER with SIGFPE
signal/ia64: Document a conflict with SI_USER with SIGFPE
signal/alpha: Document a conflict with SI_USER for SIGTRAP
Unsigned long long and unsigned long were different in size for 31-bit.
For 64-bit the size for both datatypes is 8 Bytes and since the support
for 31-bit is long gone we can clean up a little and change everything
to unsigned long.
Change get_phys_clock() along the way to accept unsigned long as well so
that the DASD code can be consistent.
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
cpuhp_setup_state() returns a state number on CPUHP_AP_ONLINE_DYN if
no error occurred. Therefore convert the return code to zero before
using it as exit code for s390_smp_init().
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Specifying the 'novx' kernel parameter always results in a warning:
Malformed early option 'novx'
The reason for this is that the novx early parameter handling function
always returns a non-zero value which means that an error occurred.
Fix this and return the correct zero value instead.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If memory is fragmented it is unlikely that large order memory
allocations succeed. This has been an issue with the vmcp device
driver since a long time, since it requires large physical contiguous
memory ares for large responses.
To hopefully resolve this issue make use of the contiguous memory
allocator (cma). This patch adds a vmcp specific vmcp cma area with a
default size of 4MB. The size can be changed either via the
VMCP_CMA_SIZE config option at compile time or with the "vmcp_cma"
kernel parameter (e.g. "vmcp_cma=16m").
For any vmcp response buffers larger than 16k memory from the cma area
will be allocated. If such an allocation fails, there is a fallback to
the buddy allocator.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
According to the CP Programming Services manual Diagnose Code 8
"Virtual Console Function" can be used in all addressing modes. Also
the input and output buffers do not have a limitation which specifies
they need to be below the 2GB line.
This is true at least since z/VM 5.4.
Therefore remove the sam31/64 instructions and allow for simple
GFP_KERNEL allocations. This makes it easier to allocate a 1MB page
if the user requested such a large return buffer.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add detection for machine type 0x3906 and set the ELF platform name
to z14. Add the miscellaneous-instruction-extension 2 facility to
the list of facilities for z14.
And allow to generate code that only runs on a z14 machine.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The TOD epoch extension adds 8 epoch bits to the TOD clock to provide
a continuous clock after 2042/09/17. The store-clock-extended (STCKE)
instruction will store the epoch index in the first byte of the
16 bytes stored by the instruction. The read_boot_clock64 and the
read_presistent_clock64 functions need to take the additional bits
into account to give the correct result after 2042/09/17.
The clock-comparator register will stay 64 bit wide. The comparison
of the clock-comparator with the TOD clock is limited to bytes
1 to 8 of the extended TOD format. To deal with the overflow problem
due to an epoch change the clock-comparator sign control in CR0 can
be used to switch the comparison of the 64-bit TOD clock with the
clock-comparator to a signed comparison.
The decision between the signed vs. unsigned clock-comparator
comparisons is done at boot time. Only if the TOD clock is in the
second half of a 142 year epoch the signed comparison is used.
This solves the epoch overflow issue as long as the machine is
booted at least once in an epoch.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull s390 fixes from Martin Schwidefsky:
"Three bug fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/mm: set change and reference bit on lazy key enablement
s390: chp: handle CRW_ERC_INIT for channel-path status change
s390/perf: fix problem state detection
The ESSA instruction has a new option that allows to tag pages that
are not used as a page table. Without the tag the hypervisor has to
assume that any guest page could be used in a page table inside the
guest. This forces the hypervisor to flush all guest TLB entries
whenever a host page table entry is invalidated. With the tag
the host can skip the TLB flush if the page is tagged as normal page.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
struct siginfo is a union and the kernel since 2.4 has been hiding a union
tag in the high 16bits of si_code using the values:
__SI_KILL
__SI_TIMER
__SI_POLL
__SI_FAULT
__SI_CHLD
__SI_RT
__SI_MESGQ
__SI_SYS
While this looks plausible on the surface, in practice this situation has
not worked well.
- Injected positive signals are not copied to user space properly
unless they have these magic high bits set.
- Injected positive signals are not reported properly by signalfd
unless they have these magic high bits set.
- These kernel internal values leaked to userspace via ptrace_peek_siginfo
- It was possible to inject these kernel internal values and cause the
the kernel to misbehave.
- Kernel developers got confused and expected these kernel internal values
in userspace in kernel self tests.
- Kernel developers got confused and set si_code to __SI_FAULT which
is SI_USER in userspace which causes userspace to think an ordinary user
sent the signal and that it was not kernel generated.
- The values make it impossible to reorganize the code to transform
siginfo_copy_to_user into a plain copy_to_user. As si_code must
be massaged before being passed to userspace.
So remove these kernel internal si codes and make the kernel code simpler
and more maintainable.
To replace these kernel internal magic si_codes introduce the helper
function siginfo_layout, that takes a signal number and an si_code and
computes which union member of siginfo is being used. Have
siginfo_layout return an enumeration so that gcc will have enough
information to warn if a switch statement does not handle all of union
members.
A couple of architectures have a messed up ABI that defines signal
specific duplications of SI_USER which causes more special cases in
siginfo_layout than I would like. The good news is only problem
architectures pay the cost.
Update all of the code that used the previous magic __SI_ values to
use the new SIL_ values and to call siginfo_layout to get those
values. Escept where not all of the cases are handled remove the
defaults in the switch statements so that if a new case is missed in
the future the lack will show up at compile time.
Modify the code that copies siginfo si_code to userspace to just copy
the value and not cast si_code to a short first. The high bits are no
longer used to hold a magic union member.
Fixup the siginfo header files to stop including the __SI_ values in
their constants and for the headers that were missing it to properly
update the number of si_codes for each signal type.
The fixes to copy_siginfo_from_user32 implementations has the
interesting property that several of them perviously should never have
worked as the __SI_ values they depended up where kernel internal.
With that dependency gone those implementations should work much
better.
The idea of not passing the __SI_ values out to userspace and then
not reinserting them has been tested with criu and criu worked without
changes.
Ref: 2.4.0-test1
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The P sample bit indicates problem state and not PER.
Fixes: commit a752598254 ("s390: rename struct psw_bits members")
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
As Eric said,
"what we need to do is move the variable vmcoreinfo_note out of the
kernel's .bss section. And modify the code to regenerate and keep this
information in something like the control page.
Definitely something like this needs a page all to itself, and ideally
far away from any other kernel data structures. I clearly was not
watching closely the data someone decided to keep this silly thing in
the kernel's .bss section."
This patch allocates extra pages for these vmcoreinfo_XXX variables, one
advantage is that it enhances some safety of vmcoreinfo, because
vmcoreinfo now is kept far away from other kernel data structures.
Link: http://lkml.kernel.org/r/1493281021-20737-1-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Suggested-by: Eric Biederman <ebiederm@xmission.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
"Reasonably busy this cycle, but perhaps not as busy as in the 4.12
merge window:
1) Several optimizations for UDP processing under high load from
Paolo Abeni.
2) Support pacing internally in TCP when using the sch_fq packet
scheduler for this is not practical. From Eric Dumazet.
3) Support mutliple filter chains per qdisc, from Jiri Pirko.
4) Move to 1ms TCP timestamp clock, from Eric Dumazet.
5) Add batch dequeueing to vhost_net, from Jason Wang.
6) Flesh out more completely SCTP checksum offload support, from
Davide Caratti.
7) More plumbing of extended netlink ACKs, from David Ahern, Pablo
Neira Ayuso, and Matthias Schiffer.
8) Add devlink support to nfp driver, from Simon Horman.
9) Add RTM_F_FIB_MATCH flag to RTM_GETROUTE queries, from Roopa
Prabhu.
10) Add stack depth tracking to BPF verifier and use this information
in the various eBPF JITs. From Alexei Starovoitov.
11) Support XDP on qed device VFs, from Yuval Mintz.
12) Introduce BPF PROG ID for better introspection of installed BPF
programs. From Martin KaFai Lau.
13) Add bpf_set_hash helper for TC bpf programs, from Daniel Borkmann.
14) For loads, allow narrower accesses in bpf verifier checking, from
Yonghong Song.
15) Support MIPS in the BPF selftests and samples infrastructure, the
MIPS eBPF JIT will be merged in via the MIPS GIT tree. From David
Daney.
16) Support kernel based TLS, from Dave Watson and others.
17) Remove completely DST garbage collection, from Wei Wang.
18) Allow installing TCP MD5 rules using prefixes, from Ivan
Delalande.
19) Add XDP support to Intel i40e driver, from Björn Töpel
20) Add support for TC flower offload in nfp driver, from Simon
Horman, Pieter Jansen van Vuuren, Benjamin LaHaise, Jakub
Kicinski, and Bert van Leeuwen.
21) IPSEC offloading support in mlx5, from Ilan Tayari.
22) Add HW PTP support to macb driver, from Rafal Ozieblo.
23) Networking refcount_t conversions, From Elena Reshetova.
24) Add sock_ops support to BPF, from Lawrence Brako. This is useful
for tuning the TCP sockopt settings of a group of applications,
currently via CGROUPs"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1899 commits)
net: phy: dp83867: add workaround for incorrect RX_CTRL pin strap
dt-bindings: phy: dp83867: provide a workaround for incorrect RX_CTRL pin strap
cxgb4: Support for get_ts_info ethtool method
cxgb4: Add PTP Hardware Clock (PHC) support
cxgb4: time stamping interface for PTP
nfp: default to chained metadata prepend format
nfp: remove legacy MAC address lookup
nfp: improve order of interfaces in breakout mode
net: macb: remove extraneous return when MACB_EXT_DESC is defined
bpf: add missing break in for the TCP_BPF_SNDCWND_CLAMP case
bpf: fix return in load_bpf_file
mpls: fix rtm policy in mpls_getroute
net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t
net, ax25: convert ax25_route.refcount from atomic_t to refcount_t
net, ax25: convert ax25_uid_assoc.refcount from atomic_t to refcount_t
net, sctp: convert sctp_ep_common.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_transport.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_chunk.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_datamsg.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_auth_bytes.refcnt from atomic_t to refcount_t
...
Pull SMP hotplug updates from Thomas Gleixner:
"This update is primarily a cleanup of the CPU hotplug locking code.
The hotplug locking mechanism is an open coded RWSEM, which allows
recursive locking. The main problem with that is the recursive nature
as it evades the full lockdep coverage and hides potential deadlocks.
The rework replaces the open coded RWSEM with a percpu RWSEM and
establishes full lockdep coverage that way.
The bulk of the changes fix up recursive locking issues and address
the now fully reported potential deadlocks all over the place. Some of
these deadlocks have been observed in the RT tree, but on mainline the
probability was low enough to hide them away."
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
cpu/hotplug: Constify attribute_group structures
powerpc: Only obtain cpu_hotplug_lock if called by rtasd
ARM/hw_breakpoint: Fix possible recursive locking for arch_hw_breakpoint_init
cpu/hotplug: Remove unused check_for_tasks() function
perf/core: Don't release cred_guard_mutex if not taken
cpuhotplug: Link lock stacks for hotplug callbacks
acpi/processor: Prevent cpu hotplug deadlock
sched: Provide is_percpu_thread() helper
cpu/hotplug: Convert hotplug locking to percpu rwsem
s390: Prevent hotplug rwsem recursion
arm: Prevent hotplug rwsem recursion
arm64: Prevent cpu hotplug rwsem recursion
kprobes: Cure hotplug lock ordering issues
jump_label: Reorder hotplug lock and jump_label_lock
perf/tracing/cpuhotplug: Fix locking order
ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus()
PCI: Replace the racy recursion prevention
PCI: Use cpu_hotplug_disable() instead of get_online_cpus()
perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode()
x86/perf: Drop EXPORT of perf_check_microcode
...
Pull s390 updates from Martin Schwidefsky:
"The bulk of the s390 patches for 4.13. Some new things but mostly bug
fixes and cleanups. Noteworthy changes:
- The SCM block driver is converted to blk-mq
- Switch s390 to 5 level page tables. The virtual address space for a
user space process can now have up to 16EB-4KB.
- Introduce a ELF phdr flag for qemu to avoid the global
vm.alloc_pgste which forces all processes to large page tables
- A couple of PCI improvements to improve error recovery
- Included is the merge of the base support for proper machine checks
for KVM"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (52 commits)
s390/dasd: Fix faulty ENODEV for RO sysfs attribute
s390/pci: recognize name clashes with uids
s390/pci: provide more debug information
s390/pci: fix handling of PEC 306
s390/pci: improve pci hotplug
s390/pci: introduce clp_get_state
s390/pci: improve error handling during fmb (de)registration
s390/pci: improve unreg_ioat error handling
s390/pci: improve error handling during interrupt deregistration
s390/pci: don't cleanup in arch_setup_msi_irqs
KVM: s390: Backup the guest's machine check info
s390/nmi: s390: New low level handling for machine check happening in guest
s390/fpu: export save_fpu_regs for all configs
s390/kvm: avoid global config of vm.alloc_pgste=1
s390: rename struct psw_bits members
s390: rename psw_bits enums
s390/mm: use correct address space when enabling DAT
s390/cio: introduce io_subchannel_type
s390/ipl: revert Load Normal semantics for LPAR CCW-type re-IPL
s390/dumpstack: remove raw stack dump
...
- introduce the new uuid_t/guid_t types that are going to replace
the somewhat confusing uuid_be/uuid_le types and make the terminology
fit the various specs, as well as the userspace libuuid library.
(me, based on a previous version from Amir)
- consolidated generic uuid/guid helper functions lifted from XFS
and libnvdimm (Amir and me)
- conversions to the new types and helpers (Amir, Andy and me)
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Merge tag 'uuid-for-4.13' of git://git.infradead.org/users/hch/uuid
Pull uuid subsystem from Christoph Hellwig:
"This is the new uuid subsystem, in which Amir, Andy and I have started
consolidating our uuid/guid helpers and improving the types used for
them. Note that various other subsystems have pulled in this tree, so
I'd like it to go in early.
UUID/GUID summary:
- introduce the new uuid_t/guid_t types that are going to replace the
somewhat confusing uuid_be/uuid_le types and make the terminology
fit the various specs, as well as the userspace libuuid library.
(me, based on a previous version from Amir)
- consolidated generic uuid/guid helper functions lifted from XFS and
libnvdimm (Amir and me)
- conversions to the new types and helpers (Amir, Andy and me)"
* tag 'uuid-for-4.13' of git://git.infradead.org/users/hch/uuid: (34 commits)
ACPI: hns_dsaf_acpi_dsm_guid can be static
mmc: sdhci-pci: make guid intel_dsm_guid static
uuid: Take const on input of uuid_is_null() and guid_is_null()
thermal: int340x_thermal: fix compile after the UUID API switch
thermal: int340x_thermal: Switch to use new generic UUID API
acpi: always include uuid.h
ACPI: Switch to use generic guid_t in acpi_evaluate_dsm()
ACPI / extlog: Switch to use new generic UUID API
ACPI / bus: Switch to use new generic UUID API
ACPI / APEI: Switch to use new generic UUID API
acpi, nfit: Switch to use new generic UUID API
MAINTAINERS: add uuid entry
tmpfs: generate random sb->s_uuid
scsi_debug: switch to uuid_t
nvme: switch to uuid_t
sysctl: switch to use uuid_t
partitions/ldm: switch to use uuid_t
overlayfs: use uuid_t instead of uuid_be
fs: switch ->s_uuid to uuid_t
ima/policy: switch to use uuid_t
...
The only user of thread_saved_pc() in non-arch-specific code was removed
in commit 8243d5597793 ("sched/core: Remove pointless printout in
sched_show_task()"). Remove the implementations as well.
Some architectures use thread_saved_pc() in their arch-specific code.
Leave their thread_saved_pc() intact.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This provides the basic plumbing for handling machine checks when
running guests
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Merge tag 'nmiforkvm' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into features
Pull kvm patches from Christian Borntraeger:
"s390,kvm: provide plumbing for machines checks when running guests"
This provides the basic plumbing for handling machine checks when
running guests
When a machine check happens in the guest, related mcck info (mcic,
external damage code, ...) is stored in the vcpu's lowcore on the host.
Then the machine check handler's low-level part is executed, followed
by the high-level part.
If the high-level part's execution is interrupted by a new machine check
happening on the same vcpu on the host, the mcck info in the lowcore is
overwritten with the new machine check's data.
If the high-level part's execution is scheduled to a different cpu,
the mcck info in the lowcore is uncertain.
Therefore, for both cases, the further reinjection to the guest will use
the wrong data.
Let's backup the mcck info in the lowcore to the sie page
for further reinjection, so that the right data will be used.
Add new member into struct sie_page to store related machine check's
info of mcic, failing storage address and external damage code.
Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Add the logic to check if the machine check happens when the guest is
running. If yes, set the exit reason -EINTR in the machine check's
interrupt handler. Refactor s390_do_machine_check to avoid panicing
the host for some kinds of machine checks which happen
when guest is running.
Reinject the instruction processing damage's machine checks including
Delayed Access Exception instead of damaging the host if it happens
in the guest because it could be caused by improper update on TLB entry
or other software case and impacts the guest only.
Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Implement support for the hypervisor diagnose 0x26c
('Access Certain System Information').
It passes a request buffer and a subfunction code, and receives
a response buffer and a return code.
Also add the scaffolding for the 'MAC Services' subfunction.
It may be used by network devices to obtain a hypervisor-managed
MAC address.
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts the two commits
7afbeb6df2aa ("s390/ipl: always use load normal for CCW-type re-IPL")
0f7451ff3ab8 ("s390/ipl: use load normal for LPAR re-ipl")
The two commits did not take into account that behavior of standby
memory changes fundamentally if the re-IPL method is changed from
Load Clear to Load Normal.
In case of the old re-IPL clear method all memory that was initially
in standby state will be put into standby state again within the
re-IPL process. Or in other words: memory that was brought online
before a re-IPL will be offline again after a reboot.
Given that we use different re-IPL methods depending on the hypervisor
and CCW-type vs SCSI re-IPL it is not easy to tell in advance when and
why memory will stay online or will be offline after a re-IPL.
This does also have other side effects, since memory that is online
from the beginning will be in ZONE_NORMAL by default vs ZONE_MOVABLE
for memory that is offline.
Therefore, before the change, a user could online and offline memory
easily since standby memory was always in ZONE_NORMAL. After the
change, and a re-IPL, this depended on which memory parts were online
before the re-IPL.
From a usability point of view the current behavior is more than
suboptimal. Therefore revert these changes until we have a better
solution and get back to a consistent behavior. The bad thing about
this is that the time required for a re-IPL will be significantly
increased for configurations with several 100GB or 1TB of memory.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The save_fpu_regs function is a general API that is supposed to be
usable for modules as well. Remove the #ifdef that hides the symbol
for CONFIG_KVM=n.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The system control vm.alloc_pgste is used to control the size of the
page tables, either 2K or 4K. The idea is that a KVM host sets the
vm.alloc_pgste control to 1 which causes *all* new processes to run
with 4K page tables. For a non-kvm system the control should stay off
to save on memory used for page tables.
Trouble is that distributions choose to set the control globally to
be able to run KVM guests. This wastes memory on non-KVM systems.
Introduce the PT_S390_PGSTE ELF segment type to "mark" the qemu
executable with it. All executables with this (empty) segment in
its ELF phdr array will be started with 4K page tables. Any executable
without PT_S390_PGSTE will run with the default 2K page tables.
This removes the need to set vm.alloc_pgste=1 for a KVM host and
minimizes the waste of memory for page tables.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Rename a couple of the struct psw_bits members so it is more obvious
for what they are good. Initially I thought using the single character
names from the PoP would be sufficient and obvious, but admittedly
that is not true.
The current implementation is not easy to use, if one has to look into
the source file to figure out which member represents the 'per' bit
(which is the 'r' member).
Therefore rename the members to sane names that are identical to the
uapi psw mask defines:
r -> per
i -> io
e -> ext
t -> dat
m -> mcheck
w -> wait
p -> pstate
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The address space enums that must be used when modifying the address
space part of a psw with the psw_bits() macro can easily be confused
with the psw defines that are used to mask and compare directly the
mask part of a psw.
We have e.g. PSW_AS_PRIMARY vs PSW_ASC_PRIMARY.
To avoid confusion rename the PSW_AS_* enums to PSW_BITS_AS_*.
In addition also rename the PSW_AMODE_* enums, so they also follow the
same naming scheme: PSW_BITS_AMODE_*.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This reverts the two commits
7afbeb6df2aa ("s390/ipl: always use load normal for CCW-type re-IPL")
0f7451ff3ab8 ("s390/ipl: use load normal for LPAR re-ipl")
The two commits did not take into account that behavior of standby
memory changes fundamentally if the re-IPL method is changed from
Load Clear to Load Normal.
In case of the old re-IPL clear method all memory that was initially
in standby state will be put into standby state again within the
re-IPL process. Or in other words: memory that was brought online
before a re-IPL will be offline again after a reboot.
Given that we use different re-IPL methods depending on the hypervisor
and CCW-type vs SCSI re-IPL it is not easy to tell in advance when and
why memory will stay online or will be offline after a re-IPL.
This does also have other side effects, since memory that is online
from the beginning will be in ZONE_NORMAL by default vs ZONE_MOVABLE
for memory that is offline.
Therefore, before the change, a user could online and offline memory
easily since standby memory was always in ZONE_NORMAL. After the
change, and a re-IPL, this depended on which memory parts were online
before the re-IPL.
From a usability point of view the current behavior is more than
suboptimal. Therefore revert these changes until we have a better
solution and get back to a consistent behavior. The bad thing about
this is that the time required for a re-IPL will be significantly
increased for configurations with several 100GB or 1TB of memory.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
