| Age | Commit message (Collapse) | Author | Files | Lines |
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Pull s390 fixes from Martin Schwidefsky:
"Improvements and bug fixes for 5.1-rc2:
- Fix early free of the channel program in vfio
- On AP device removal make sure that all messages are flushed with
the driver still attached that queued the message
- Limit brk randomization to 32MB to reduce the chance that the heap
of ld.so is placed after the main stack
- Add a rolling average for the steal time of a CPU, this will be
needed for KVM to decide when to do busy waiting
- Fix a warning in the CPU-MF code
- Add a notification handler for AP configuration change to react
faster to new AP devices"
* tag 's390-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/cpumf: Fix warning from check_processor_id
zcrypt: handle AP Info notification from CHSC SEI command
vfio: ccw: only free cp on final interrupt
s390/vtime: steal time exponential moving average
s390/zcrypt: revisit ap device remove procedure
s390: limit brk randomization to 32MB
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Function __hw_perf_event_init() used a CPU variable without
ensuring CPU preemption has been disabled. This caused the
following warning in the kernel log:
[ 7.277085] BUG: using smp_processor_id() in preemptible
[00000000] code: cf-csdiag/1892
[ 7.277111] caller is cf_diag_event_init+0x13a/0x338
[ 7.277122] CPU: 10 PID: 1892 Comm: cf-csdiag Not tainted
5.0.0-20190318.rc0.git0.9e1a11e0f602.300.fc29.s390x+debug #1
[ 7.277131] Hardware name: IBM 2964 NC9 712 (LPAR)
[ 7.277139] Call Trace:
[ 7.277150] ([<000000000011385a>] show_stack+0x82/0xd0)
[ 7.277161] [<0000000000b7a71a>] dump_stack+0x92/0xd0
[ 7.277174] [<00000000007b7e9c>] check_preemption_disabled+0xe4/0x100
[ 7.277183] [<00000000001228aa>] cf_diag_event_init+0x13a/0x338
[ 7.277195] [<00000000002cf3aa>] perf_try_init_event+0x72/0xf0
[ 7.277204] [<00000000002d0bba>] perf_event_alloc+0x6fa/0xce0
[ 7.277214] [<00000000002dc4a8>] __s390x_sys_perf_event_open+0x398/0xd50
[ 7.277224] [<0000000000b9e8f0>] system_call+0xdc/0x2d8
[ 7.277233] 2 locks held by cf-csdiag/1892:
[ 7.277241] #0: 00000000976f5510 (&sig->cred_guard_mutex){+.+.},
at: __s390x_sys_perf_event_open+0xd2e/0xd50
[ 7.277257] #1: 00000000363b11bd (&pmus_srcu){....},
at: perf_event_alloc+0x52e/0xce0
The variable is now accessed in proper context. Use
get_cpu_var()/put_cpu_var() pair to disable
preemption during access.
As the hardware authorization settings apply to all CPUs, it
does not matter which CPU is used to check the authorization setting.
Remove the event->count assignment. It is not needed as function
perf_event_alloc() allocates memory for the event with kzalloc() and
thus count is already set to zero.
Fixes: fe5908bccc56 ("s390/cpum_cf_diag: Add support for s390 counter facility diagnostic trace")
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>
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Pull KVM updates from Paolo Bonzini:
"ARM:
- some cleanups
- direct physical timer assignment
- cache sanitization for 32-bit guests
s390:
- interrupt cleanup
- introduction of the Guest Information Block
- preparation for processor subfunctions in cpu models
PPC:
- bug fixes and improvements, especially related to machine checks
and protection keys
x86:
- many, many cleanups, including removing a bunch of MMU code for
unnecessary optimizations
- AVIC fixes
Generic:
- memcg accounting"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (147 commits)
kvm: vmx: fix formatting of a comment
KVM: doc: Document the life cycle of a VM and its resources
MAINTAINERS: Add KVM selftests to existing KVM entry
Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()"
KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char()
KVM: PPC: Fix compilation when KVM is not enabled
KVM: Minor cleanups for kvm_main.c
KVM: s390: add debug logging for cpu model subfunctions
KVM: s390: implement subfunction processor calls
arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2
KVM: arm/arm64: Remove unused timer variable
KVM: PPC: Book3S: Improve KVM reference counting
KVM: PPC: Book3S HV: Fix build failure without IOMMU support
Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()"
x86: kvmguest: use TSC clocksource if invariant TSC is exposed
KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start
KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter
KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns
KVM: x86/mmu: Consolidate kvm_mmu_zap_all() and kvm_mmu_zap_mmio_sptes()
KVM: x86/mmu: WARN if zapping a MMIO spte results in zapping children
...
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Add check for the return value of memblock_alloc*() functions and call
panic() in case of error. The panic message repeats the one used by
panicing memblock allocators with adjustment of parameters to include
only relevant ones.
The replacement was mostly automated with semantic patches like the one
below with manual massaging of format strings.
@@
expression ptr, size, align;
@@
ptr = memblock_alloc(size, align);
+ if (!ptr)
+ panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, size, align);
[anders.roxell@linaro.org: use '%pa' with 'phys_addr_t' type]
Link: http://lkml.kernel.org/r/20190131161046.21886-1-anders.roxell@linaro.org
[rppt@linux.ibm.com: fix format strings for panics after memblock_alloc]
Link: http://lkml.kernel.org/r/1548950940-15145-1-git-send-email-rppt@linux.ibm.com
[rppt@linux.ibm.com: don't panic if the allocation in sparse_buffer_init fails]
Link: http://lkml.kernel.org/r/20190131074018.GD28876@rapoport-lnx
[akpm@linux-foundation.org: fix xtensa printk warning]
Link: http://lkml.kernel.org/r/1548057848-15136-20-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Guo Ren <ren_guo@c-sky.com> [c-sky]
Acked-by: Paul Burton <paul.burton@mips.com> [MIPS]
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390]
Reviewed-by: Juergen Gross <jgross@suse.com> [Xen]
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The memblock_alloc_base() function tries to allocate a memory up to the
limit specified by its max_addr parameter and panics if the allocation
fails. Replace its usage with memblock_phys_alloc_range() and make the
callers check the return value and panic in case of error.
Link: http://lkml.kernel.org/r/1548057848-15136-10-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com> [c-sky]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Juergen Gross <jgross@suse.com> [Xen]
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Make the memblock_phys_alloc() function an inline wrapper for
memblock_phys_alloc_range() and update the memblock_phys_alloc() callers
to check the returned value and panic in case of error.
Link: http://lkml.kernel.org/r/1548057848-15136-8-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com> [c-sky]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Juergen Gross <jgross@suse.com> [Xen]
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge misc updates from Andrew Morton:
- a few misc things
- ocfs2 updates
- most of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (159 commits)
tools/testing/selftests/proc/proc-self-syscall.c: remove duplicate include
proc: more robust bulk read test
proc: test /proc/*/maps, smaps, smaps_rollup, statm
proc: use seq_puts() everywhere
proc: read kernel cpu stat pointer once
proc: remove unused argument in proc_pid_lookup()
fs/proc/thread_self.c: code cleanup for proc_setup_thread_self()
fs/proc/self.c: code cleanup for proc_setup_self()
proc: return exit code 4 for skipped tests
mm,mremap: bail out earlier in mremap_to under map pressure
mm/sparse: fix a bad comparison
mm/memory.c: do_fault: avoid usage of stale vm_area_struct
writeback: fix inode cgroup switching comment
mm/huge_memory.c: fix "orig_pud" set but not used
mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC
mm/memcontrol.c: fix bad line in comment
mm/cma.c: cma_declare_contiguous: correct err handling
mm/page_ext.c: fix an imbalance with kmemleak
mm/compaction: pass pgdat to too_many_isolated() instead of zone
mm: remove zone_lru_lock() function, access ->lru_lock directly
...
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Pull perf updates from Ingo Molnar:
"Lots of tooling updates - too many to list, here's a few highlights:
- Various subcommand updates to 'perf trace', 'perf report', 'perf
record', 'perf annotate', 'perf script', 'perf test', etc.
- CPU and NUMA topology and affinity handling improvements,
- HW tracing and HW support updates:
- Intel PT updates
- ARM CoreSight updates
- vendor HW event updates
- BPF updates
- Tons of infrastructure updates, both on the build system and the
library support side
- Documentation updates.
- ... and lots of other changes, see the changelog for details.
Kernel side updates:
- Tighten up kprobes blacklist handling, reduce the number of places
where developers can install a kprobe and hang/crash the system.
- Fix/enhance vma address filter handling.
- Various PMU driver updates, small fixes and additions.
- refcount_t conversions
- BPF updates
- error code propagation enhancements
- misc other changes"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (238 commits)
perf script python: Add Python3 support to syscall-counts-by-pid.py
perf script python: Add Python3 support to syscall-counts.py
perf script python: Add Python3 support to stat-cpi.py
perf script python: Add Python3 support to stackcollapse.py
perf script python: Add Python3 support to sctop.py
perf script python: Add Python3 support to powerpc-hcalls.py
perf script python: Add Python3 support to net_dropmonitor.py
perf script python: Add Python3 support to mem-phys-addr.py
perf script python: Add Python3 support to failed-syscalls-by-pid.py
perf script python: Add Python3 support to netdev-times.py
perf tools: Add perf_exe() helper to find perf binary
perf script: Handle missing fields with -F +..
perf data: Add perf_data__open_dir_data function
perf data: Add perf_data__(create_dir|close_dir) functions
perf data: Fail check_backup in case of error
perf data: Make check_backup work over directories
perf tools: Add rm_rf_perf_data function
perf tools: Add pattern name checking to rm_rf
perf tools: Add depth checking to rm_rf
perf data: Add global path holder
...
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To be able to judge the current overcommitment ratio for a CPU add
a lowcore field with the exponential moving average of the steal time.
The average is updated every tick.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The VDSO is part of the kernel image and therefore the struct pages are
marked as reserved during boot.
As we install a special mapping, the actual struct pages will never be
exposed to MM via the page tables. We can therefore leave the pages
marked as reserved.
Link: http://lkml.kernel.org/r/20190114125903.24845-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull year 2038 updates from Thomas Gleixner:
"Another round of changes to make the kernel ready for 2038. After lots
of preparatory work this is the first set of syscalls which are 2038
safe:
403 clock_gettime64
404 clock_settime64
405 clock_adjtime64
406 clock_getres_time64
407 clock_nanosleep_time64
408 timer_gettime64
409 timer_settime64
410 timerfd_gettime64
411 timerfd_settime64
412 utimensat_time64
413 pselect6_time64
414 ppoll_time64
416 io_pgetevents_time64
417 recvmmsg_time64
418 mq_timedsend_time64
419 mq_timedreceiv_time64
420 semtimedop_time64
421 rt_sigtimedwait_time64
422 futex_time64
423 sched_rr_get_interval_time64
The syscall numbers are identical all over the architectures"
* 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
riscv: Use latest system call ABI
checksyscalls: fix up mq_timedreceive and stat exceptions
unicore32: Fix __ARCH_WANT_STAT64 definition
asm-generic: Make time32 syscall numbers optional
asm-generic: Drop getrlimit and setrlimit syscalls from default list
32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option
compat ABI: use non-compat openat and open_by_handle_at variants
y2038: add 64-bit time_t syscalls to all 32-bit architectures
y2038: rename old time and utime syscalls
y2038: remove struct definition redirects
y2038: use time32 syscall names on 32-bit
syscalls: remove obsolete __IGNORE_ macros
y2038: syscalls: rename y2038 compat syscalls
x86/x32: use time64 versions of sigtimedwait and recvmmsg
timex: change syscalls to use struct __kernel_timex
timex: use __kernel_timex internally
sparc64: add custom adjtimex/clock_adjtime functions
time: fix sys_timer_settime prototype
time: Add struct __kernel_timex
time: make adjtime compat handling available for 32 bit
...
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Pull s390 updates from Martin Schwidefsky:
- A copy of Arnds compat wrapper generation series
- Pass information about the KVM guest to the host in form the control
program code and the control program version code
- Map IOV resources to support PCI physical functions on s390
- Add vector load and store alignment hints to improve performance
- Use the "jdd" constraint with gcc 9 to make jump labels working again
- Remove amode workaround for old z/VM releases from the DCSS code
- Add support for in-kernel performance measurements using the CPU
measurement counter facility
- Introduce a new PMU device cpum_cf_diag to capture counters and store
thenn as event raw data.
- Bug fixes and cleanups
* tag 's390-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
Revert "s390/cpum_cf: Add kernel message exaplanations"
s390/dasd: fix read device characteristic with CONFIG_VMAP_STACK=y
s390/suspend: fix prefix register reset in swsusp_arch_resume
s390: warn about clearing als implied facilities
s390: allow overriding facilities via command line
s390: clean up redundant facilities list setup
s390/als: remove duplicated in-place implementation of stfle
s390/cio: Use cpa range elsewhere within vfio-ccw
s390/cio: Fix vfio-ccw handling of recursive TICs
s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem
s390/cpum_cf: Handle EBUSY return code from CPU counter facility reservation
s390/cpum_cf: Add kernel message exaplanations
s390/cpum_cf_diag: Add support for s390 counter facility diagnostic trace
s390/cpum_cf: add ctr_stcctm() function
s390/cpum_cf: move common functions into a separate file
s390/cpum_cf: introduce kernel_cpumcf_avail() function
s390/cpu_mf: replace stcctm5() with the stcctm() function
s390/cpu_mf: add store cpu counter multiple instruction support
s390/cpum_cf: Add minimal in-kernel interface for counter measurements
s390/cpum_cf: introduce kernel_cpumcf_alert() to obtain measurement alerts
...
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The reset of the prefix to zero in swsusp_arch_resume uses a 4 byte stack
slot. With CONFIG_VMAP_STACK=y this is now in the vmalloc area, this works
only with DAT enabled. Move the DAT disable in swsusp_arch_resume after
the prefix reset.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Facilities list in the lowcore is initially set up by verify_facilities
from als.c and later initializations are redundant, so cleaning them up.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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KVM: s390: Features for 5.1
- Clarify KVM related kernel messages
- Interrupt cleanup
- Introduction of the Guest Information Block (GIB)
- Preparation for processor subfunctions in cpu model
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Rservation of the CPU Measurement Counter facility may fail if
it is already in use by the cf_diag device driver.
This is indicated by a non zero return code (-EBUSY).
However this return code is ignored and the counter facility
may be used in parallel by different device drivers.
Handle the failing reservation and return an error to the
caller.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Introduce a PMU device named cpum_cf_diag. It extracts the
values of all counters in all authorized counter sets and stores
them as event raw data. This is done with the STORE CPU COUNTER
MULTIPLE instruction to speed up access. All counter sets
fit into one buffer. The values of each counter are taken
when the event is started on the performance sub-system and when
the event is stopped.
This results in counter values available at the start and
at the end of the measurement time frame. The difference is
calculated for each counter. The differences of all
counters are then saved as event raw data in the perf.data
file.
The counter values are accompanied by the time stamps
when the counter set was started and when the counter set
was stopped. This data is part of a trailer entry which
describes the time frame, counter set version numbers,
CPU speed, and machine type for later analysis.
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>
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Move common functions of the couter facility support into a separate
file.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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A preparation to move out common CPU-MF counter facility support
functions, first introduce a function that indicates whether the
support is ready to use.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Remove the stcctm5() function to extract counters from the MT-diagnostic
counter set with the stcctm() function. For readability, introduce an
enum to map the counter sets names to respective numbers for the stcctm
instruction.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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During a __kernel_cpumcf_begin()/end() session, save measurement alerts
for the counter facility in the per-CPU cpu_cf_events variable.
Users can obtain and, optionally, clear the alerts by calling
kernel_cpumcf_alert() to specifically handle alerts.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
Make the struct cpu_cf_events and the respective per-CPU variable available
to in-kernel users. Access to this per-CPU variable shall be done between
the calls to __kernel_cpumcf_begin() and __kernel_cpumcf_end().
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
Rename the struct cpu_hw_events to cpu_cf_events and also the respective
per-CPU variable to make its name more clear. No functional changes.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
Prepare the counter facility support to be used by other in-kernel
users. The first step introduces the __kernel_cpumcf_begin() and
__kernel_cpumcf_end() functions to reserve the counter facility
for doing measurements and to release after the measurements are
done.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
Move counter set specific controls and functions to the asm/cpu_mcf.h
header file containg all counter facility support definitions. Also
adapt few variable names and header file includes. No functional changes.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
The fix to make WARN work in the early boot code created a problem
on older machines without EDAT-1. The setup_lowcore_dat_on function
uses the pointer from lowcore_ptr[0] to set the DAT bit in the new
PSWs. That does not work if the kernel page table is set up with
4K pages as the prefix address maps to absolute zero.
To make this work the PSWs need to be changed with via address 0 in
form of the S390_lowcore definition.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Cornelia Huck <cohuck@redhat.com>
Fixes: 94f85ed3e2f8 ("s390/setup: fix early warning messages")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
The setup_lowcore() function creates a new prefix page for the boot CPU.
The PSW mask for the system_call, external interrupt, i/o interrupt and
the program check handler have the DAT bit set in this new prefix page.
At the time setup_lowcore is called the system still runs without virtual
address translation, the paging_init() function creates the kernel page
table and loads the CR13 with the kernel ASCE.
Any code between setup_lowcore() and the end of paging_init() that has
a BUG or WARN statement will create a program check that can not be
handled correctly as there is no kernel page table yet.
To allow early WARN statements initially setup the lowcore with DAT off
and set the DAT bit only after paging_init() has completed.
Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
Pull y2038 - time64 system calls from Arnd Bergmann:
This series finally gets us to the point of having system calls with 64-bit
time_t on all architectures, after a long time of incremental preparation
patches.
There was actually one conversion that I missed during the summer,
i.e. Deepa's timex series, which I now updated based the 5.0-rc1 changes
and review comments.
The following system calls are now added on all 32-bit architectures using
the same system call numbers:
403 clock_gettime64
404 clock_settime64
405 clock_adjtime64
406 clock_getres_time64
407 clock_nanosleep_time64
408 timer_gettime64
409 timer_settime64
410 timerfd_gettime64
411 timerfd_settime64
412 utimensat_time64
413 pselect6_time64
414 ppoll_time64
416 io_pgetevents_time64
417 recvmmsg_time64
418 mq_timedsend_time64
419 mq_timedreceiv_time64
420 semtimedop_time64
421 rt_sigtimedwait_time64
422 futex_time64
423 sched_rr_get_interval_time64
Each one of these corresponds directly to an existing system call that
includes a 'struct timespec' argument, or a structure containing a timespec
or (in case of clock_adjtime) timeval. Not included here are new versions
of getitimer/setitimer and getrusage/waitid, which are planned for the
future but only needed to make a consistent API rather than for correct
operation beyond y2038. These four system calls are based on 'timeval', and
it has not been finally decided what the replacement kernel interface will
use instead.
So far, I have done a lot of build testing across most architectures, which
has found a number of bugs. Runtime testing so far included testing LTP on
32-bit ARM with the existing system calls, to ensure we do not regress for
existing binaries, and a test with a 32-bit x86 build of LTP against a
modified version of the musl C library that has been adapted to the new
system call interface [3]. This library can be used for testing on all
architectures supported by musl-1.1.21, but it is not how the support is
getting integrated into the official musl release. Official musl support is
planned but will require more invasive changes to the library.
Link: https://lore.kernel.org/lkml/20190110162435.309262-1-arnd@arndb.de/T/
Link: https://lore.kernel.org/lkml/20190118161835.2259170-1-arnd@arndb.de/
Link: https://git.linaro.org/people/arnd/musl-y2038.git/ [2]
|
|
Pull preparatory work for y2038 changes from Arnd Bergmann:
System call unification and cleanup
The system call tables have diverged a bit over the years, and a number of
the recent additions never made it into all architectures, for one reason
or another.
This is an attempt to clean it up as far as we can without breaking
compatibility, doing a number of steps:
- Add system calls that have not yet been integrated into all architectures
but that we definitely want there. This includes {,f}statfs64() and
get{eg,eu,g,p,u,pp}id() on alpha, which have been missing traditionally.
- The s390 compat syscall handling is cleaned up to be more like what we
do on other architectures, while keeping the 31-bit pointer
extension. This was merged as a shared branch by the s390 maintainers
and is included here in order to base the other patches on top.
- Add the separate ipc syscalls on all architectures that traditionally
only had sys_ipc(). This version is done without support for IPC_OLD
that is we have in sys_ipc. The new semtimedop_time64 syscall will only
be added here, not in sys_ipc
- Add syscall numbers for a couple of syscalls that we probably don't need
everywhere, in particular pkey_* and rseq, for the purpose of symmetry:
if it's in asm-generic/unistd.h, it makes sense to have it everywhere. I
expect that any future system calls will get assigned on all platforms
together, even when they appear to be specific to a single architecture.
- Prepare for having the same system call numbers for any future calls. In
combination with the generated tables, this hopefully makes it easier to
add new calls across all architectures together.
All of the above are technically separate from the y2038 work, but are done
as preparation before we add the new 64-bit time_t system calls everywhere,
providing a common baseline set of system calls.
I expect that glibc and other libraries that want to use 64-bit time_t will
require linux-5.1 kernel headers for building in the future, and at a much
later point may also require linux-5.1 or a later version as the minimum
kernel at runtime. Having a common baseline then allows the removal of many
architecture or kernel version specific workarounds.
|
|
Remove including <linux/version.h> that don't need it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
Remove some dead code from head64.S, which was left over since commit
da292bbe1f62 ("[S390] eliminate ipl_device from lowcore") removed
ipl_device from lowcore.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
The #ifdef CONFIG_DMA_API_DEBUG check in reserve_kernel() is no longer
needed, since commit ea535e418c01 ("dma-debug: switch check from _text
to _stext") changed the logic in lib/dma-debug.c, so remove it.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
This adds 21 new system calls on each ABI that has 32-bit time_t
today. All of these have the exact same semantics as their existing
counterparts, and the new ones all have macro names that end in 'time64'
for clarification.
This gets us to the point of being able to safely use a C library
that has 64-bit time_t in user space. There are still a couple of
loose ends to tie up in various areas of the code, but this is the
big one, and should be entirely uncontroversial at this point.
In particular, there are four system calls (getitimer, setitimer,
waitid, and getrusage) that don't have a 64-bit counterpart yet,
but these can all be safely implemented in the C library by wrapping
around the existing system calls because the 32-bit time_t they
pass only counts elapsed time, not time since the epoch. They
will be dealt with later.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
|
|
A lot of system calls that pass a time_t somewhere have an implementation
using a COMPAT_SYSCALL_DEFINEx() on 64-bit architectures, and have
been reworked so that this implementation can now be used on 32-bit
architectures as well.
The missing step is to redefine them using the regular SYSCALL_DEFINEx()
to get them out of the compat namespace and make it possible to build them
on 32-bit architectures.
Any system call that ends in 'time' gets a '32' suffix on its name for
that version, while the others get a '_time32' suffix, to distinguish
them from the normal version, which takes a 64-bit time argument in the
future.
In this step, only 64-bit architectures are changed, doing this rename
first lets us avoid touching the 32-bit architectures twice.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
|
|
When pmu::setup_aux() is called the coresight PMU needs to know which
sink to use for the session by looking up the information in the
event's attr::config2 field.
As such simply replace the cpu information by the complete perf_event
structure and change all affected customers.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/20190131184714.20388-2-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The patch implements a handler for GIB alert interruptions
on the host. Its task is to alert guests that interrupts are
pending for them.
A GIB alert interrupt statistic counter is added as well:
$ cat /proc/interrupts
CPU0 CPU1
...
GAL: 23 37 [I/O] GIB Alert
...
Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20190131085247.13826-14-mimu@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
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The s390x diagnose 318 instruction sets the control program name code (CPNC)
and control program version code (CPVC) to provide useful information
regarding the OS during debugging. The CPNC is explicitly set to 4 to
indicate a Linux/KVM environment.
The CPVC is a 7-byte value containing:
- 3-byte Linux version code, currently set to 0
- 3-byte unique value, currently set to 0
- 1-byte trailing null
Signed-off-by: Collin Walling <walling@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <1544135405-22385-2-git-send-email-walling@linux.ibm.com>
[set version code to 0 until the structure is fully defined]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The patch that added support for the virtually mapped kernel stacks changed
swsusp_arch_suspend to switch to the nodat-stack as the vmap stack is not
available while going in and out of suspend.
Unfortunately the switch to the nodat-stack is incorrect which breaks
suspend to disk.
Cc: stable@vger.kernel.org # v4.20
Fixes: ce3dc447493f ("s390: add support for virtually mapped kernel stacks")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
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Most architectures define system call numbers for the rseq and pkey system
calls, even when they don't support the features, and perhaps never will.
Only a few architectures are missing these, so just define them anyway
for consistency. If we decide to add them later to one of these, the
system call numbers won't get out of sync then.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
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The IPC system call handling is highly inconsistent across architectures,
some use sys_ipc, some use separate calls, and some use both. We also
have some architectures that require passing IPC_64 in the flags, and
others that set it implicitly.
For the addition of a y2038 safe semtimedop() system call, I chose to only
support the separate entry points, but that requires first supporting
the regular ones with their own syscall numbers.
The IPC_64 is now implied by the new semctl/shmctl/msgctl system
calls even on the architectures that require passing it with the ipc()
multiplexer.
I'm not adding the new semtimedop() or semop() on 32-bit architectures,
those will get implemented using the new semtimedop_time64() version
that gets added along with the other time64 calls.
Three 64-bit architectures (powerpc, s390 and sparc) get semtimedop().
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
|
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Now that all these wrappers are automatically generated, we can
remove the entire file, and instead point to the regualar syscalls
like all other architectures do.
The 31-bit pointer extension is now handled in the __s390_sys_*()
wrappers.
Link: https://lore.kernel.org/lkml/20190116131527.2071570-6-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
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Any system call that takes a pointer argument on s390 requires
a wrapper function to do a 31-to-64 zero-extension, these are
currently generated in arch/s390/kernel/compat_wrapper.c.
On arm64 and x86, we already generate similar wrappers for all
system calls in the place of their definition, just for a different
purpose (they load the arguments from pt_regs).
We can do the same thing here, by adding an asm/syscall_wrapper.h
file with a copy of all the relevant macros to override the generic
version. Besides the addition of the compat entry point, these also
rename the entry points with a __s390_ or __s390x_ prefix, similar
to what we do on arm64 and x86. This in turn requires renaming
a few things, and adding a proper ni_syscall() entry point.
In order to still compile system call definitions that pass an
loff_t argument, the __SC_COMPAT_CAST() macro checks for that
and forces an -ENOSYS error, which was the best I could come up
with. Those functions must obviously not get called from user
space, but instead require hand-written compat_sys_*() handlers,
which fortunately already exist.
Link: https://lore.kernel.org/lkml/20190116131527.2071570-5-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
[heiko.carstens@de.ibm.com: compile fix for !CONFIG_COMPAT]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
s390 has an almost identical copy of the code in kernel/uid16.c.
The problem here is that it requires calling the regular system calls,
which the generic implementation handles correctly, but the internal
interfaces are not declared in a global header for this.
The best way forward here seems to be to just use the generic code and
delete the s390 specific implementation.
I keep the changes to uapi/asm/posix_types.h inside of an #ifdef check
so user space does not observe any changes. As some of the system calls
pass pointers, we also need wrappers in compat_wrapper.c, which I add
for all calls with at least one argument. All those wrappers can be
removed in a later step.
Link: https://lore.kernel.org/lkml/20190116131527.2071570-4-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
The sys_ipc() and compat_ksys_ipc() functions are meant to only
be used from the system call table, not called by another function.
Introduce ksys_*() interfaces for this purpose, as we have done
for many other system calls.
Link: https://lore.kernel.org/lkml/20190116131527.2071570-3-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
[heiko.carstens@de.ibm.com: compile fix for !CONFIG_COMPAT]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
Patch series "s390: rework compat wrapper generation".
As promised, I gave this a go and changed the SYSCALL_DEFINEx()
infrastructure to always include the wrappers for doing the
31-bit argument conversion on s390 compat mode.
This does three main things:
- The UID16 rework saved a lot of duplicated code, and would
probably make sense by itself, but is also required as
we can no longer call sys_*() functions directly after the
last step.
- Removing the compat_wrapper.c file is of course the main
goal here, in order to remove the need to maintain the
compat_wrapper.c file when new system calls get added.
Unfortunately, this requires adding some complexity in
syscall_wrapper.h, and trades a small reduction in source
code lines for a small increase in binary size for
unused wrappers.
- As an added benefit, the use of syscall_wrapper.h now makes
it easy to change the syscall wrappers so they no longer
see all user space register contents, similar to changes
done in commits fa697140f9a2 ("syscalls/x86: Use 'struct pt_regs'
based syscall calling convention for 64-bit syscalls") and
4378a7d4be30 ("arm64: implement syscall wrappers").
I leave the actual implementation of this for you, if you
want to do it later.
I did not test the changes at runtime, but I looked at the
generated object code, which seems fine here and includes
the same conversions as before.
This patch(of 5):
The sys_personality function is not meant to be called from other system
calls. We could introduce an intermediate ksys_personality function,
but it does almost nothing, so this just moves the implementation into
the caller.
Link: https://lore.kernel.org/lkml/20190116131527.2071570-1-arnd@arndb.de
Link: https://lore.kernel.org/lkml/20190116131527.2071570-2-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
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When calling smp_call_ipl_cpu() from the IPL CPU, we will try to read
from pcpu_devices->lowcore. However, due to prefixing, that will result
in reading from absolute address 0 on that CPU. We have to go via the
actual lowcore instead.
This means that right now, we will read lc->nodat_stack == 0 and
therfore work on a very wrong stack.
This BUG essentially broke rebooting under QEMU TCG (which will report
a low address protection exception). And checking under KVM, it is
also broken under KVM. With 1 VCPU it can be easily triggered.
:/# echo 1 > /proc/sys/kernel/sysrq
:/# echo b > /proc/sysrq-trigger
[ 28.476745] sysrq: SysRq : Resetting
[ 28.476793] Kernel stack overflow.
[ 28.476817] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
[ 28.476820] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
[ 28.476826] Krnl PSW : 0400c00180000000 0000000000115c0c (pcpu_delegate+0x12c/0x140)
[ 28.476861] R:0 T:1 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
[ 28.476863] Krnl GPRS: ffffffffffffffff 0000000000000000 000000000010dff8 0000000000000000
[ 28.476864] 0000000000000000 0000000000000000 0000000000ab7090 000003e0006efbf0
[ 28.476864] 000000000010dff8 0000000000000000 0000000000000000 0000000000000000
[ 28.476865] 000000007fffc000 0000000000730408 000003e0006efc58 0000000000000000
[ 28.476887] Krnl Code: 0000000000115bfe: 4170f000 la %r7,0(%r15)
[ 28.476887] 0000000000115c02: 41f0a000 la %r15,0(%r10)
[ 28.476887] #0000000000115c06: e370f0980024 stg %r7,152(%r15)
[ 28.476887] >0000000000115c0c: c0e5fffff86e brasl %r14,114ce8
[ 28.476887] 0000000000115c12: 41f07000 la %r15,0(%r7)
[ 28.476887] 0000000000115c16: a7f4ffa8 brc 15,115b66
[ 28.476887] 0000000000115c1a: 0707 bcr 0,%r7
[ 28.476887] 0000000000115c1c: 0707 bcr 0,%r7
[ 28.476901] Call Trace:
[ 28.476902] Last Breaking-Event-Address:
[ 28.476920] [<0000000000a01c4a>] arch_call_rest_init+0x22/0x80
[ 28.476927] Kernel panic - not syncing: Corrupt kernel stack, can't continue.
[ 28.476930] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
[ 28.476932] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
[ 28.476932] Call Trace:
Fixes: 2f859d0dad81 ("s390/smp: reduce size of struct pcpu")
Cc: stable@vger.kernel.org # 4.0+
Reported-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|
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While "s390/vdso: avoid 64-bit vdso mapping for compat tasks" fixed
64-bit vdso mapping for compat tasks under gdb it introduced another
problem. "compat_mm" flag is not inherited during fork and when
31-bit process forks a child (but does not perform exec) it ends up
with 64-bit vdso. To address that, init_new_context (which is called
during fork and exec) now initialize compat_mm based on thread TIF_31BIT
flag. Later compat_mm is adjusted in arch_setup_additional_pages, which
is called during exec.
Fixes: d1befa65823e ("s390/vdso: avoid 64-bit vdso mapping for compat tasks")
Reported-by: Stefan Liebler <stli@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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smp_rescan_cpus() is called without the device_hotplug_lock, which can lead
to a dedlock when a new CPU is found and immediately set online by a udev
rule.
This was observed on an older kernel version, where the cpu_hotplug_begin()
loop was still present, and it resulted in hanging chcpu and systemd-udev
processes. This specific deadlock will not show on current kernels. However,
there may be other possible deadlocks, and since smp_rescan_cpus() can still
trigger a CPU hotplug operation, the device_hotplug_lock should be held.
For reference, this was the deadlock with the old cpu_hotplug_begin() loop:
chcpu (rescan) systemd-udevd
echo 1 > /sys/../rescan
-> smp_rescan_cpus()
-> (*) get_online_cpus()
(increases refcount)
-> smp_add_present_cpu()
(new CPU found)
-> register_cpu()
-> device_add()
-> udev "add" event triggered -----------> udev rule sets CPU online
-> echo 1 > /sys/.../online
-> lock_device_hotplug_sysfs()
(this is missing in rescan path)
-> device_online()
-> (**) device_lock(new CPU dev)
-> cpu_up()
-> cpu_hotplug_begin()
(loops until refcount == 0)
-> deadlock with (*)
-> bus_probe_device()
-> device_attach()
-> device_lock(new CPU dev)
-> deadlock with (**)
Fix this by taking the device_hotplug_lock in the CPU rescan path.
Cc: <stable@vger.kernel.org>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Linus Torvalds
Thomas Richter
Mike Rapoport
Martin Schwidefsky
David Hildenbrand
Vasily Gorbik
Ingo Molnar
Paolo Bonzini
Hendrik Brueckner
Thomas Gleixner
YueHaibing
Gerald Schaefer
Arnd Bergmann
Mathieu Poirier
Michael Mueller
Greg Kroah-Hartman
Collin Walling