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2019-12-18kvm: x86: Host feature SSBD doesn't imply guest feature AMD_SSBDJim Mattson
The host reports support for the synthetic feature X86_FEATURE_SSBD when any of the three following hardware features are set: CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] CPUID.80000008H:EBX.AMD_SSBD[bit 24] CPUID.80000008H:EBX.VIRT_SSBD[bit 25] Either of the first two hardware features implies the existence of the IA32_SPEC_CTRL MSR, but CPUID.80000008H:EBX.VIRT_SSBD[bit 25] does not. Therefore, CPUID.80000008H:EBX.AMD_SSBD[bit 24] should only be set in the guest if CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] or CPUID.80000008H:EBX.AMD_SSBD[bit 24] is set on the host. Fixes: 4c6903a0f9d76 ("KVM: x86: fix reporting of AMD speculation bug CPUID leaf") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Jacob Xu <jacobhxu@google.com> Reviewed-by: Peter Shier <pshier@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Reported-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-18kvm: x86: Host feature SSBD doesn't imply guest feature SPEC_CTRL_SSBDJim Mattson
The host reports support for the synthetic feature X86_FEATURE_SSBD when any of the three following hardware features are set: CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] CPUID.80000008H:EBX.AMD_SSBD[bit 24] CPUID.80000008H:EBX.VIRT_SSBD[bit 25] Either of the first two hardware features implies the existence of the IA32_SPEC_CTRL MSR, but CPUID.80000008H:EBX.VIRT_SSBD[bit 25] does not. Therefore, CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] should only be set in the guest if CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] or CPUID.80000008H:EBX.AMD_SSBD[bit 24] is set on the host. Fixes: 0c54914d0c52a ("KVM: x86: use Intel speculation bugs and features as derived in generic x86 code") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Jacob Xu <jacobhxu@google.com> Reviewed-by: Peter Shier <pshier@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Reported-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-18KVM: PPC: Book3S HV: Don't do ultravisor calls on systems without ultravisorPaul Mackerras
Commit 22945688acd4 ("KVM: PPC: Book3S HV: Support reset of secure guest") added a call to uv_svm_terminate, which is an ultravisor call, without any check that the guest is a secure guest or even that the system has an ultravisor. On a system without an ultravisor, the ultracall will degenerate to a hypercall, but since we are not in KVM guest context, the hypercall will get treated as a system call, which could have random effects depending on what happens to be in r0, and could also corrupt the current task's kernel stack. Hence this adds a test for the guest being a secure guest before doing uv_svm_terminate(). Fixes: 22945688acd4 ("KVM: PPC: Book3S HV: Support reset of secure guest") Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-12-17Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fix from Ingo Molnar: "Fix kexec booting with certain EFI memory map layouts" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/efi: Update e820 with reserved EFI boot services data to fix kexec breakage
2019-12-17Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: "Add HPET quirks for the Intel 'Coffee Lake H' and 'Ice Lake' platforms" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/intel: Disable HPET on Intel Ice Lake platforms x86/intel: Disable HPET on Intel Coffee Lake H platforms
2019-12-17perf/x86/intel: Fix PT PMI handlingAlexander Shishkin
Commit: ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it") skips the PT/LBR exclusivity check on CPUs where PT and LBRs coexist, but also inadvertently skips the active_events bump for PT in that case, which is a bug. If there aren't any hardware events at the same time as PT, the PMI handler will ignore PT PMIs, as active_events reads zero in that case, resulting in the "Uhhuh" spurious NMI warning and PT data loss. Fix this by always increasing active_events for PT events. Fixes: ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it") Reported-by: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Alexey Budankov <alexey.budankov@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Link: https://lkml.kernel.org/r/20191210105101.77210-1-alexander.shishkin@linux.intel.com
2019-12-17perf/x86/intel/bts: Fix the use of page_private()Alexander Shishkin
Commit 8062382c8dbe2 ("perf/x86/intel/bts: Add BTS PMU driver") brought in a warning with the BTS buffer initialization that is easily tripped with (assuming KPTI is disabled): instantly throwing: > ------------[ cut here ]------------ > WARNING: CPU: 2 PID: 326 at arch/x86/events/intel/bts.c:86 bts_buffer_setup_aux+0x117/0x3d0 > Modules linked in: > CPU: 2 PID: 326 Comm: perf Not tainted 5.4.0-rc8-00291-gceb9e77324fa #904 > RIP: 0010:bts_buffer_setup_aux+0x117/0x3d0 > Call Trace: > rb_alloc_aux+0x339/0x550 > perf_mmap+0x607/0xc70 > mmap_region+0x76b/0xbd0 ... It appears to assume (for lost raisins) that PagePrivate() is set, while later it actually tests for PagePrivate() before using page_private(). Make it consistent and always check PagePrivate() before using page_private(). Fixes: 8062382c8dbe2 ("perf/x86/intel/bts: Add BTS PMU driver") Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Link: https://lkml.kernel.org/r/20191205142853.28894-2-alexander.shishkin@linux.intel.com
2019-12-17perf/x86: Fix potential out-of-bounds accessPeter Zijlstra
UBSAN reported out-of-bound accesses for x86_pmu.event_map(), it's arguments should be < x86_pmu.max_events. Make sure all users observe this constraint. Reported-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Meelis Roos <mroos@linux.ee>
2019-12-17x86/mce: Fix possibly incorrect severity calculation on AMDJan H. Schönherr
The function mce_severity_amd_smca() requires m->bank to be initialized for correct operation. Fix the one case, where mce_severity() is called without doing so. Fixes: 6bda529ec42e ("x86/mce: Grade uncorrected errors for SMCA-enabled systems") Fixes: d28af26faa0b ("x86/MCE: Initialize mce.bank in the case of a fatal error in mce_no_way_out()") Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Cc: Yazen Ghannam <Yazen.Ghannam@amd.com> Link: https://lkml.kernel.org/r/20191210000733.17979-4-jschoenh@amazon.de
2019-12-17x86/MCE/AMD: Allow Reserved types to be overwritten in smca_banks[]Yazen Ghannam
Each logical CPU in Scalable MCA systems controls a unique set of MCA banks in the system. These banks are not shared between CPUs. The bank types and ordering will be the same across CPUs on currently available systems. However, some CPUs may see a bank as Reserved/Read-as-Zero (RAZ) while other CPUs do not. In this case, the bank seen as Reserved on one CPU is assumed to be the same type as the bank seen as a known type on another CPU. In general, this occurs when the hardware represented by the MCA bank is disabled, e.g. disabled memory controllers on certain models, etc. The MCA bank is disabled in the hardware, so there is no possibility of getting an MCA/MCE from it even if it is assumed to have a known type. For example: Full system: Bank | Type seen on CPU0 | Type seen on CPU1 ------------------------------------------------ 0 | LS | LS 1 | UMC | UMC 2 | CS | CS System with hardware disabled: Bank | Type seen on CPU0 | Type seen on CPU1 ------------------------------------------------ 0 | LS | LS 1 | UMC | RAZ 2 | CS | CS For this reason, there is a single, global struct smca_banks[] that is initialized at boot time. This array is initialized on each CPU as it comes online. However, the array will not be updated if an entry already exists. This works as expected when the first CPU (usually CPU0) has all possible MCA banks enabled. But if the first CPU has a subset, then it will save a "Reserved" type in smca_banks[]. Successive CPUs will then not be able to update smca_banks[] even if they encounter a known bank type. This may result in unexpected behavior. Depending on the system configuration, a user may observe issues enumerating the MCA thresholding sysfs interface. The issues may be as trivial as sysfs entries not being available, or as severe as system hangs. For example: Bank | Type seen on CPU0 | Type seen on CPU1 ------------------------------------------------ 0 | LS | LS 1 | RAZ | UMC 2 | CS | CS Extend the smca_banks[] entry check to return if the entry is a non-reserved type. Otherwise, continue so that CPUs that encounter a known bank type can update smca_banks[]. Fixes: 68627a697c19 ("x86/mce/AMD, EDAC/mce_amd: Enumerate Reserved SMCA bank type") Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20191121141508.141273-1-Yazen.Ghannam@amd.com
2019-12-17x86/MCE/AMD: Do not use rdmsr_safe_on_cpu() in smca_configure()Konstantin Khlebnikov
... because interrupts are disabled that early and sending IPIs can deadlock: BUG: sleeping function called from invalid context at kernel/sched/completion.c:99 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1 no locks held by swapper/1/0. irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [<ffffffff8106dda9>] copy_process+0x8b9/0x1ca0 softirqs last enabled at (0): [<ffffffff8106dda9>] copy_process+0x8b9/0x1ca0 softirqs last disabled at (0): [<0000000000000000>] 0x0 Preemption disabled at: [<ffffffff8104703b>] start_secondary+0x3b/0x190 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.5.0-rc2+ #1 Hardware name: GIGABYTE MZ01-CE1-00/MZ01-CE1-00, BIOS F02 08/29/2018 Call Trace: dump_stack ___might_sleep.cold.92 wait_for_completion ? generic_exec_single rdmsr_safe_on_cpu ? wrmsr_on_cpus mce_amd_feature_init mcheck_cpu_init identify_cpu identify_secondary_cpu smp_store_cpu_info start_secondary secondary_startup_64 The function smca_configure() is called only on the current CPU anyway, therefore replace rdmsr_safe_on_cpu() with atomic rdmsr_safe() and avoid the IPI. [ bp: Update commit message. ] Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/157252708836.3876.4604398213417262402.stgit@buzz
2019-12-17KVM: PPC: Book3S HV: Fix regression on big endian hostsMarcus Comstedt
VCPU_CR is the offset of arch.regs.ccr in kvm_vcpu. arch/powerpc/include/asm/kvm_host.h defines arch.regs as a struct pt_regs, and arch/powerpc/include/asm/ptrace.h defines the ccr field of pt_regs as "unsigned long ccr". Since unsigned long is 64 bits, a 64-bit load needs to be used to load it, unless an endianness specific correction offset is added to access the desired subpart. In this case there is no reason to _not_ use a 64 bit load though. Fixes: 6c85b7bc637b ("powerpc/kvm: Use UV_RETURN ucall to return to ultravisor") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Marcus Comstedt <marcus@mc.pp.se> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191215094900.46740-1-marcus@mc.pp.se
2019-12-16Merge tag 'armsoc-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM SoC fixes from Olof Johansson: "I didn't get a batch in this weekend, so here's what we queued up last week and today. - A couple of defconfigs add back debugfs -- it used to be implicitly enabled through CONFIG_TRACING, but 0e4a459f56c32d3e ("tracing: Remove unnecessary DEBUG_FS dependency") removed that. - The rest are mostly minor fixlets of the usual kind; some DT tweaks, a headerfile refactor that needs a build fix now, etc" * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (30 commits) ARM: bcm: Add missing sentinel to bcm2711_compat[] ARM: shmobile: defconfig: Restore debugfs support bus: ti-sysc: Fix missing reset delay handling ARM: imx: Fix boot crash if ocotp is not found ARM: imx_v6_v7_defconfig: Explicitly restore CONFIG_DEBUG_FS ARM: dts: imx6ul-evk: Fix peripheral regulator arm64: dts: ls1028a: fix reboot node ARM: mmp: include the correct cputype.h ARM: dts: am437x-gp/epos-evm: fix panel compatible arm64: dts: ls1028a: fix typo in TMU calibration data ARM: imx: Correct ocotp id for serial number support of i.MX6ULL/ULZ SoCs ARM: dts: bcm283x: Fix critical trip point ARM: omap2plus_defconfig: Add back DEBUG_FS ARM: omap2plus_defconfig: enable NET_SWITCHDEV ARM: dts: am335x-sancloud-bbe: fix phy mode bus: ti-sysc: Fix missing force mstandby quirk handling reset: Do not register resource data for missing resets reset: Fix {of,devm}_reset_control_array_get kerneldoc return types reset: brcmstb: Remove resource checks dt-bindings: reset: Fix brcmstb-reset example ...
2019-12-16Merge tag 'arm-soc/for-5.5/soc-fixes' of ↵Olof Johansson
https://github.com/Broadcom/stblinux into arm/fixes This pull request contains Broadcom ARM-based SoCs machine fixes for 5.5-rc1, please pull the following: - H. Nikolaus adds a missing sentinel entry to the BCM2711 machine descriptor compatible array which would make multiplatform kernels fail to boot * tag 'arm-soc/for-5.5/soc-fixes' of https://github.com/Broadcom/stblinux: ARM: bcm: Add missing sentinel to bcm2711_compat[] Link: https://lore.kernel.org/r/20191216035701.15534-1-f.fainelli@gmail.com Signed-off-by: Olof Johansson <olof@lixom.net>
2019-12-16Merge tag 'samsung-fixes-5.5' of ↵Olof Johansson
https://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux into arm/fixes Samsung fixes for v5.5 1. Restore debugfs support in exynos_defconfig (as now it is not selected as dependency of tracing). Debugfs is required by systemd and several tests. 2. Maintainers updates. * tag 'samsung-fixes-5.5' of https://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux: ARM: exynos_defconfig: Restore debugfs support MAINTAINERS: Include Samsung SoC serial driver in Samsung SoC entry MAINTAINERS: Update Lukasz Luba's email address Link: https://lore.kernel.org/r/20191215121316.32091-1-krzk@kernel.org Signed-off-by: Olof Johansson <olof@lixom.net>
2019-12-16Merge tag 'renesas-fixes-for-v5.5-tag1' of ↵Olof Johansson
git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel into arm/fixes Renesas fixes for v5.5 - Restore debugfs support * tag 'renesas-fixes-for-v5.5-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel: ARM: shmobile: defconfig: Restore debugfs support Link: https://lore.kernel.org/r/20191213213719.18122-1-geert+renesas@glider.be Signed-off-by: Olof Johansson <olof@lixom.net>
2019-12-16powerpc: Fix __clear_user() with KUAP enabledAndrew Donnellan
The KUAP implementation adds calls in clear_user() to enable and disable access to userspace memory. However, it doesn't add these to __clear_user(), which is used in the ptrace regset code. As there's only one direct user of __clear_user() (the regset code), and the time taken to set the AMR for KUAP purposes is going to dominate the cost of a quick access_ok(), there's not much point having a separate path. Rename __clear_user() to __arch_clear_user(), and make __clear_user() just call clear_user(). Reported-by: syzbot+f25ecf4b2982d8c7a640@syzkaller-ppc64.appspotmail.com Reported-by: Daniel Axtens <dja@axtens.net> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection") Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> [mpe: Use __arch_clear_user() for the asm version like arm64 & nds32] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191209132221.15328-1-ajd@linux.ibm.com
2019-12-16powerpc/pseries/cmm: fix managed page counts when migrating pages between zonesDavid Hildenbrand
Commit 63341ab03706 (virtio-balloon: fix managed page counts when migrating pages between zones) fixed a long existing BUG in the virtio-balloon driver when pages would get migrated between zones. I did not try to reproduce on powerpc, but looking at the code, the same should apply to powerpc/cmm ever since it started using the balloon compaction infrastructure (luckily just recently). In case we have to migrate a ballon page to a newpage of another zone, the managed page count of both zones is wrong. Paired with memory offlining (which will adjust the managed page count), we can trigger kernel crashes and all kinds of different symptoms. Fix it by properly adjusting the managed page count when migrating if the zone changed. We'll temporarily modify the totalram page count. If this ever becomes a problem, we can fine tune by providing helpers that don't touch the totalram pages (e.g., adjust_zone_managed_page_count()). Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction") Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191216103058.4958-1-david@redhat.com
2019-12-16powerpc/8xx: fix bogus __init on mmu_mapin_ram_chunk()Christophe Leroy
Remove __init qualifier for mmu_mapin_ram_chunk() as it is called by mmu_mark_initmem_nx() and mmu_mark_rodata_ro() which are not __init functions. At the same time, mark it static as it is only used in this file. Reported-by: kbuild test robot <lkp@intel.com> Fixes: a2227a277743 ("powerpc/32: Don't populate page tables for block mapped pages except on the 8xx") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/56648921986a6b3e7315b1fbbf4684f21bd2dea8.1576310997.git.christophe.leroy@c-s.fr
2019-12-15ARM: bcm: Add missing sentinel to bcm2711_compat[]H. Nikolaus Schaller
commit 781fa0a95424 ("ARM: bcm: Add support for BCM2711 SoC") breaks boot of many other platforms (e.g. OMAP or i.MX6) if CONFIG_ARCH_BCM2835 is enabled in addition to some multiplatform config (e.g. omap2plus_defconfig). The symptom is that the OMAP based board does not show any activity beyond "Starting Kernel ..." even with earlycon. Reverting the mentioned commit makes it work again. The real fix is to add the missing NULL sentinel to the bcm2711_compat[] variable-length array. Fixes: 781fa0a95424 ("ARM: bcm: Add support for BCM2711 SoC") Acked-by: Stefan Wahren <wahrenst@gmx.net> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
2019-12-15Merge tag 'riscv/for-v5.5-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Paul Walmsley: "Two minor build fixes: - Fix builds of the ELF loader when built with 'make -j1' (nommu only) - Fix CONFIG_SOC_SIFIVE builds when CONFIG_TTY is disabled (found during randconfig testing)" * tag 'riscv/for-v5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: only select serial sifive if TTY is enabled riscv: Fix build dependency for loader
2019-12-15parisc: add missing __init annotationSven Schnelle
compilation failed with: MODPOST vmlinux.o WARNING: vmlinux.o(.text.unlikely+0xa0c): Section mismatch in reference from the function walk_lower_bus() to the function .init.text:walk_native_bus() The function walk_lower_bus() references the function __init walk_native_bus(). This is often because walk_lower_bus lacks a __init annotation or the annotation of walk_native_bus is wrong. FATAL: modpost: Section mismatches detected. Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them. make[2]: *** [/home/svens/linux/parisc-linux/src/scripts/Makefile.modpost:64: __modpost] Error 1 make[1]: *** [/home/svens/linux/parisc-linux/src/Makefile:1077: vmlinux] Error 2 make[1]: Leaving directory '/home/svens/linux/parisc-linux/build' make: *** [Makefile:179: sub-make] Error 2 Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de>
2019-12-15parisc: fix compilation when KEXEC=n and KEXEC_FILE=ySven Schnelle
Fix compilation when the CONFIG_KEXEC_FILE=y and CONFIG_KEXEC=n. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de>
2019-12-14Merge tag 'Wimplicit-fallthrough-5.5-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux Pull fall through fix from Gustavo Silva: "Fix compile error on sh by marking expected switch fall-through" * tag 'Wimplicit-fallthrough-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: sh: kgdb: Mark expected switch fall-throughs
2019-12-14Merge tag 'driver-core-5.5-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core fixes from Greg KH: "Here are two small driver core fixes to resolve some reported issues The first is to handle the much-reported (by the build systems) problem that superH does not boot anymore. The second handles an issue in the new platform logic that a number of people ran into with the automated tests in kbuild Both of these have been in linux-next with no reported issues" * tag 'driver-core-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: drivers: Fix boot problem on SuperH of/platform: Unconditionally pause/resume sync state during kernel init
2019-12-14Merge tag 's390-5.5-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add support for KASAN_VMALLOC feature. - Remove the last user of problematic diag 0x44 call. - Adjust sampling interval and avoid sample data block overflow condition on pressure in perf code. - Prefer EOPNOTSUPP over ENOTSUPP and comments fixes. * tag 's390-5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/kasan: add KASAN_VMALLOC support s390: remove last diag 0x44 caller s390/uv: use EOPNOTSUPP instead of ENOTSUPP s390/cpum_sf: Avoid SBD overflow condition in irq handler s390/cpum_sf: Adjust sampling interval to avoid hitting sample limits s390/test_unwind: fix spelling mistake "reqister" -> "register" s390/spinlock: remove confusing comment in arch_spin_lock_wait
2019-12-14Merge branch 'linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto fix from Herbert Xu: "Fix another build problem for Wireguard without Crypto" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: arm/curve25519 - add arch-specific key generation function
2019-12-14x86/boot: kbuild: allow readelf executable to be specifiedDmitry Golovin
Introduce a new READELF variable to top-level Makefile, so the name of readelf binary can be specified. Before this change the name of the binary was hardcoded to "$(CROSS_COMPILE)readelf" which might not be present for every toolchain. This allows to build with LLVM Object Reader by using make parameter READELF=llvm-readelf. Link: https://github.com/ClangBuiltLinux/linux/issues/771 Signed-off-by: Dmitry Golovin <dima@golovin.in> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2019-12-13Merge tag 'nios2-v5.5-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2 Pull nios2 fix from Ley Foon Tan: "Fix nios2 ioremap regression" * tag 'nios2-v5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2: nios2: Fix ioremap
2019-12-13Merge tag 'sizeof_field-v5.5-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull FIELD_SIZEOF conversion from Kees Cook: "A mostly mechanical treewide conversion from FIELD_SIZEOF() to sizeof_field(). This avoids the redundancy of having 2 macros (actually 3) doing the same thing, and consolidates on sizeof_field(). While "field" is not an accurate name, it is the common name used in the kernel, and doesn't result in any unintended innuendo. As there are still users of FIELD_SIZEOF() in -next, I will clean up those during this coming development cycle and send the final old macro removal patch at that time" * tag 'sizeof_field-v5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: treewide: Use sizeof_field() macro MIPS: OCTEON: Replace SIZEOF_FIELD() macro
2019-12-14powerpc/irq: fix stack overflow verificationChristophe Leroy
Before commit 0366a1c70b89 ("powerpc/irq: Run softirqs off the top of the irq stack"), check_stack_overflow() was called by do_IRQ(), before switching to the irq stack. In that commit, do_IRQ() was renamed __do_irq(), and is now executing on the irq stack, so check_stack_overflow() has just become almost useless. Move check_stack_overflow() call in do_IRQ() to do the check while still on the current stack. Fixes: 0366a1c70b89 ("powerpc/irq: Run softirqs off the top of the irq stack") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e033aa8116ab12b7ca9a9c75189ad0741e3b9b5f.1575872340.git.christophe.leroy@c-s.fr
2019-12-13Merge tag 'omap-for-v5.5/fixes-rc1-signed' of ↵Olof Johansson
git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into arm/fixes Fixes for omap variants for v5.5-rc1 cycle This series of changes contains fixes for issues recently noticed: - The ti-sysc interconnect target module driver needs fixes for mstandby quirk handling and reset delay - We need to configure am335x-sancloud-bbe to use rgmii-id mode because of the phy changes done earlier - NET_SWITCHDEV is no longer selected in Kconfig but a dependency and we must enable CONFIG_NET_SWITCHDEV to have TI_CPSW_SWITCHDEV - We are still relying on DEBUG_FS at least for PM configuration, let's add it back - We need to update compatible for am437x-gp/epos-evm because of the recent changes to use generic panels * tag 'omap-for-v5.5/fixes-rc1-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: bus: ti-sysc: Fix missing reset delay handling ARM: dts: am437x-gp/epos-evm: fix panel compatible ARM: omap2plus_defconfig: Add back DEBUG_FS ARM: omap2plus_defconfig: enable NET_SWITCHDEV ARM: dts: am335x-sancloud-bbe: fix phy mode bus: ti-sysc: Fix missing force mstandby quirk handling Link: https://lore.kernel.org/r/pull-1576254925-709310@atomide.com Signed-off-by: Olof Johansson <olof@lixom.net>
2019-12-13ARM: shmobile: defconfig: Restore debugfs supportGeert Uytterhoeven
Since commit 0e4a459f56c32d3e ("tracing: Remove unnecessary DEBUG_FS dependency"), CONFIG_DEBUG_FS is no longer auto-enabled. This breaks booting Debian 9, as systemd needs debugfs: [FAILED] Failed to mount /sys/kernel/debug. See 'systemctl status sys-kernel-debug.mount' for details. [DEPEND] Dependency failed for Local File Systems. ... You are in emergGive root password for maintenance (or press Control-D to continue): Fix this by enabling CONFIG_DEBUG_FS explicitly. See also commit 18977008f44c66bd ("ARM: multi_v7_defconfig: Restore debugfs support"). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Link: https://lore.kernel.org/r/20191209101327.26571-1-geert+renesas@glider.be
2019-12-13powerpc: Ensure that swiotlb buffer is allocated from low memoryMike Rapoport
Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G. If a system has more physical memory than this limit, the swiotlb buffer is not addressable because it is allocated from memblock using top-down mode. Force memblock to bottom-up mode before calling swiotlb_init() to ensure that the swiotlb buffer is DMA-able. Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191204123524.22919-1-rppt@kernel.org
2019-12-13powerpc/shared: Use static key to detect shared processorSrikar Dronamraju
With the static key shared processor available, is_shared_processor() can return without having to query the lppaca structure. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Phil Auld <pauld@redhat.com> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191213035036.6913-2-mpe@ellerman.id.au
2019-12-13powerpc/vcpu: Assume dedicated processors as non-preemptSrikar Dronamraju
With commit 247f2f6f3c70 ("sched/core: Don't schedule threads on pre-empted vCPUs"), the scheduler avoids preempted vCPUs to schedule tasks on wakeup. This leads to wrong choice of CPU, which in-turn leads to larger wakeup latencies. Eventually, it leads to performance regression in latency sensitive benchmarks like soltp, schbench etc. On Powerpc, vcpu_is_preempted() only looks at yield_count. If the yield_count is odd, the vCPU is assumed to be preempted. However yield_count is increased whenever the LPAR enters CEDE state (idle). So any CPU that has entered CEDE state is assumed to be preempted. Even if vCPU of dedicated LPAR is preempted/donated, it should have right of first-use since they are supposed to own the vCPU. On a Power9 System with 32 cores: # lscpu Architecture: ppc64le Byte Order: Little Endian CPU(s): 128 On-line CPU(s) list: 0-127 Thread(s) per core: 8 Core(s) per socket: 1 Socket(s): 16 NUMA node(s): 2 Model: 2.2 (pvr 004e 0202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 32K L1i cache: 32K L2 cache: 512K L3 cache: 10240K NUMA node0 CPU(s): 0-63 NUMA node1 CPU(s): 64-127 # perf stat -a -r 5 ./schbench v5.4 v5.4 + patch Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 45 75.0000th: 62 75.0th: 63 90.0000th: 71 90.0th: 74 95.0000th: 77 95.0th: 78 *99.0000th: 91 *99.0th: 82 99.5000th: 707 99.5th: 83 99.9000th: 6920 99.9th: 86 min=0, max=10048 min=0, max=96 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 46 75.0000th: 61 75.0th: 64 90.0000th: 72 90.0th: 75 95.0000th: 79 95.0th: 79 *99.0000th: 691 *99.0th: 83 99.5000th: 3972 99.5th: 85 99.9000th: 8368 99.9th: 91 min=0, max=16606 min=0, max=117 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 46 75.0000th: 61 75.0th: 64 90.0000th: 71 90.0th: 75 95.0000th: 77 95.0th: 79 *99.0000th: 106 *99.0th: 83 99.5000th: 2364 99.5th: 84 99.9000th: 7480 99.9th: 90 min=0, max=10001 min=0, max=95 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 47 75.0000th: 62 75.0th: 65 90.0000th: 72 90.0th: 75 95.0000th: 78 95.0th: 79 *99.0000th: 93 *99.0th: 84 99.5000th: 108 99.5th: 85 99.9000th: 6792 99.9th: 90 min=0, max=17681 min=0, max=117 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 46 50.0th: 45 75.0000th: 62 75.0th: 64 90.0000th: 73 90.0th: 75 95.0000th: 79 95.0th: 79 *99.0000th: 113 *99.0th: 82 99.5000th: 2724 99.5th: 83 99.9000th: 6184 99.9th: 93 min=0, max=9887 min=0, max=111 Performance counter stats for 'system wide' (5 runs): context-switches 43,373 ( +- 0.40% ) 44,597 ( +- 0.55% ) cpu-migrations 1,211 ( +- 5.04% ) 220 ( +- 6.23% ) page-faults 15,983 ( +- 5.21% ) 15,360 ( +- 3.38% ) Waiman Long suggested using static_keys. Fixes: 247f2f6f3c70 ("sched/core: Don't schedule threads on pre-empted vCPUs") Cc: stable@vger.kernel.org # v4.18+ Reported-by: Parth Shah <parth@linux.ibm.com> Reported-by: Ihor Pasichnyk <Ihor.Pasichnyk@ibm.com> Tested-by: Juri Lelli <juri.lelli@redhat.com> Acked-by: Waiman Long <longman@redhat.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Phil Auld <pauld@redhat.com> Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com> Tested-by: Parth Shah <parth@linux.ibm.com> [mpe: Move the key and setting of the key to pseries/setup.c] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191213035036.6913-1-mpe@ellerman.id.au
2019-12-12Merge tag 'imx-fixes-5.5' of ↵Olof Johansson
git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux into arm/fixes i.MX fixes for 5.5: - Add missing jedec,spi-nor compatible for imx6ul-14x14-evk board, so that SPI NOR device can be probed. - Fix power button of E60K02 board by removing LDORTC2 regulator. - A couple of fixes on serial number support of i.MX6ULL/ULZ SoCs to remove the boot regression caused by 8267ff89b713 ("ARM: imx: Add serial number support for i.MX6/7 SoCs"). - A couple of fixes on LS1028A SoC TMU regarding to calibration data and reboot register configuration. - Fix a regression seen on imx6ul-evk board by marking always-on for the regulator that is shared by many peripherals. - Explicitly restore CONFIG_DEBUG_FS in imx_v6_v7_defconfig. * tag 'imx-fixes-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux: ARM: imx: Fix boot crash if ocotp is not found ARM: imx_v6_v7_defconfig: Explicitly restore CONFIG_DEBUG_FS ARM: dts: imx6ul-evk: Fix peripheral regulator arm64: dts: ls1028a: fix reboot node arm64: dts: ls1028a: fix typo in TMU calibration data ARM: imx: Correct ocotp id for serial number support of i.MX6ULL/ULZ SoCs ARM: dts: e60k02: fix power button ARM: dts: imx6ul: imx6ul-14x14-evk.dtsi: Fix SPI NOR probing Link: https://lore.kernel.org/r/20191212122427.GK15858@dragon Signed-off-by: Olof Johansson <olof@lixom.net>
2019-12-12KVM: arm64: Ensure 'params' is initialised when looking up sys registerWill Deacon
Commit 4b927b94d5df ("KVM: arm/arm64: vgic: Introduce find_reg_by_id()") introduced 'find_reg_by_id()', which looks up a system register only if the 'id' index parameter identifies a valid system register. As part of the patch, existing callers of 'find_reg()' were ported over to the new interface, but this breaks 'index_to_sys_reg_desc()' in the case that the initial lookup in the vCPU target table fails because we will then call into 'find_reg()' for the system register table with an uninitialised 'param' as the key to the lookup. GCC 10 is bright enough to spot this (amongst a tonne of false positives, but hey!): | arch/arm64/kvm/sys_regs.c: In function ‘index_to_sys_reg_desc.part.0.isra’: | arch/arm64/kvm/sys_regs.c:983:33: warning: ‘params.Op2’ may be used uninitialized in this function [-Wmaybe-uninitialized] | 983 | (u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2); | [...] Revert the hunk of 4b927b94d5df which breaks 'index_to_sys_reg_desc()' so that the old behaviour of checking the index upfront is restored. Fixes: 4b927b94d5df ("KVM: arm/arm64: vgic: Introduce find_reg_by_id()") Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191212094049.12437-1-will@kernel.org
2019-12-12nios2: Fix ioremapGuenter Roeck
Commit 5ace77e0b41a ("nios2: remove __ioremap") removed the following code, with the argument that cacheflag is always 0 and the expression would therefore always be false. if (IS_MAPPABLE_UNCACHEABLE(phys_addr) && IS_MAPPABLE_UNCACHEABLE(last_addr) && !(cacheflag & _PAGE_CACHED)) return (void __iomem *)(CONFIG_NIOS2_IO_REGION_BASE + phys_addr); This did not take the "!" in the expression into account. Result is that nios2 images no longer boot. Restoring the removed code fixes the problem. Fixes: 5ace77e0b41a ("nios2: remove __ioremap") Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
2019-12-12crypto: arm/curve25519 - add arch-specific key generation functionJason A. Donenfeld
Somehow this was forgotten when Zinc was being split into oddly shaped pieces, resulting in linker errors. The x86_64 glue has a specific key generation implementation, but the Arm one does not. However, it can still receive the NEON speedups by calling the ordinary DH function using the base point. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-12-12ARM: imx: Fix boot crash if ocotp is not foundLeonard Crestez
The imx_soc_device_init functions tries to fetch the ocotp regmap in order to soc serial number. If regmap fetch fails then a message is printed but regmap_read is called anyway and the system crashes. Failing to lookup ocotp regmap shouldn't be a fatal boot error so check that the pointer is valid. Only side-effect of ocotp lookup failure now is that serial number will be reported as all-zeros which is acceptable. Cc: stable@vger.kernel.org Fixes: 8267ff89b713 ("ARM: imx: Add serial number support for i.MX6/7 SoCs") Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Tested-by: Christoph Niedermaier <cniedermaier@dh-electronics.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-12ARM: imx_v6_v7_defconfig: Explicitly restore CONFIG_DEBUG_FSLeonard Crestez
This is currently off and that's not desirable: default imx config is meant to be generally useful for development and debugging. Running git bisect between v5.4 and v5.5-rc1 finds this started from commit 0e4a459f56c3 ("tracing: Remove unnecessary DEBUG_FS dependency") Explicit CONFIG_DEBUG_FS=y was earlier removed by commit c29d541f590c ("ARM: imx_v6_v7_defconfig: Remove unneeded options") A very similar fix was required before: commit 7e9eb6268809 ("ARM: imx_v6_v7_defconfig: Explicitly restore CONFIG_DEBUG_FS") Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-12ARM: dts: imx6ul-evk: Fix peripheral regulatorLeonard Crestez
Many peripherals are affected by gpio5/2, not just sensors. One of those is ethernet phy so network boot is current broken. Fix by renaming reg_sensors and marking it as "always on". Also add a comment asking for careful testing if this is to be made dynamic in the future. The "peri_3v3" naming is similar to imx6sx-sdb and regulator-name is same string as in schematics (VPERI_3V3). Fixes: 09e2b1048954 ("ARM: dts: imx6ul-14x14-evk: Add sensors' GPIO regulator") Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Reviewed-by: Marco Felsch <m.felsch@pengutronix.de> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-12arm64: dts: ls1028a: fix reboot nodeMichael Walle
The reboot register isn't located inside the DCFG controller, but in its own RST controller. Fix it. Fixes: 8897f3255c9c ("arm64: dts: Add support for NXP LS1028A SoC") Signed-off-by: Michael Walle <michael@walle.cc> Acked-by: Li Yang <leoyang.li@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-11Merge tag 'trace-v5.5-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: - Remove code I accidentally applied when doing a minor fix up to a patch, and then using "git commit -a --amend", which pulled in some other changes I was playing with. - Remove an used variable in trace_events_inject code - Fix function graph tracer when it traces a ftrace direct function. It will now ignore tracing a function that has a ftrace direct tramploine attached. This is needed for eBPF to use the ftrace direct code. * tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Fix function_graph tracer interaction with BPF trampoline tracing: remove set but not used variable 'buffer' module: Remove accidental change of module_enable_x()
2019-12-11s390/kasan: add KASAN_VMALLOC supportVasily Gorbik
Add KASAN_VMALLOC support which now enables vmalloc memory area access checks as well as enables usage of VMAP_STACK under kasan. KASAN_VMALLOC changes the way vmalloc and modules areas shadow memory is handled. With this new approach only top level page tables are pre-populated and lower levels are filled dynamically upon memory allocation. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11s390: remove last diag 0x44 callerHeiko Carstens
diag 0x44 is a voluntary undirected yield of a virtual CPU. This has caused a lot of performance issues in the past. There is only one caller left, and that one is only executed if diag 0x9c (directed yield) is not present. Given that all hypervisors implement diag 0x9c anyway, remove the last diag 0x44 to avoid that more callers will be added. Worst case that could happen now, if diag 0x9c is not present, is that a virtual CPU would loop a bit instead of giving its time slice up. diag 0x44 statistics in debugfs are kept and will always be zero, so that user space can tell that there are no calls. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11s390/uv: use EOPNOTSUPP instead of ENOTSUPPChristian Borntraeger
ENOTSUP is just an internal kernel error and should never reach userspace. The return value of the share function is not exported to userspace, but to avoid giving bad examples let us use EOPNOTSUPP: Suggested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11s390/cpum_sf: Avoid SBD overflow condition in irq handlerThomas Richter
The s390 CPU Measurement sampling facility has an overflow condition which fires when all entries in a SBD are used. The measurement alert interrupt is triggered and reads out all samples in this SDB. It then tests the successor SDB, if this SBD is not full, the interrupt handler does not read any samples at all from this SDB The design waits for the hardware to fill this SBD and then trigger another meassurement alert interrupt. This scheme works nicely until an perf_event_overflow() function call discards the sample due to a too high sampling rate. The interrupt handler has logic to read out a partially filled SDB when the perf event overflow condition in linux common code is met. This causes the CPUM sampling measurement hardware and the PMU device driver to operate on the same SBD's trailer entry. This should not happen. This can be seen here using this trace: cpumsf_pmu_add: tear:0xb5286000 hw_perf_event_update: sdbt 0xb5286000 full 1 over 0 flush_all:0 hw_perf_event_update: sdbt 0xb5286008 full 0 over 0 flush_all:0 above shows 1. interrupt hw_perf_event_update: sdbt 0xb5286008 full 1 over 0 flush_all:0 hw_perf_event_update: sdbt 0xb5286008 full 0 over 0 flush_all:0 above shows 2. interrupt ... this goes on fine until... hw_perf_event_update: sdbt 0xb5286068 full 1 over 0 flush_all:0 perf_push_sample1: overflow one or more samples read from the IRQ handler are rejected by perf_event_overflow() and the IRQ handler advances to the next SDB and modifies the trailer entry of a partially filled SDB. hw_perf_event_update: sdbt 0xb5286070 full 0 over 0 flush_all:1 timestamp: 14:32:52.519953 Next time the IRQ handler is called for this SDB the trailer entry shows an overflow count of 19 missed entries. hw_perf_event_update: sdbt 0xb5286070 full 1 over 19 flush_all:1 timestamp: 14:32:52.970058 Remove access to a follow on SDB when event overflow happened. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11s390/cpum_sf: Adjust sampling interval to avoid hitting sample limitsThomas Richter
Function perf_event_ever_overflow() and perf_event_account_interrupt() are called every time samples are processed by the interrupt handler. However function perf_event_account_interrupt() has checks to avoid being flooded with interrupts (more then 1000 samples are received per task_tick). Samples are then dropped and a PERF_RECORD_THROTTLED is added to the perf data. The perf subsystem limit calculation is: maximum sample frequency := 100000 --> 1 samples per 10 us task_tick = 10ms = 10000us --> 1000 samples per task_tick The work flow is measurement_alert() uses SDBT head and each SBDT points to 511 SDB pages, each with 126 sample entries. After processing 8 SBDs and for each valid sample calling: perf_event_overflow() perf_event_account_interrupts() there is a considerable amount of samples being dropped, especially when the sample frequency is very high and near the 100000 limit. To avoid the high amount of samples being dropped near the end of a task_tick time frame, increment the sampling interval in case of dropped events. The CPU Measurement sampling facility on the s390 supports only intervals, specifiing how many CPU cycles have to be executed before a sample is generated. Increase the interval when the samples being generated hit the task_tick limit. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>