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2020-01-04mm/memory_hotplug: shrink zones when offlining memoryDavid Hildenbrand1-3/+1
We currently try to shrink a single zone when removing memory. We use the zone of the first page of the memory we are removing. If that memmap was never initialized (e.g., memory was never onlined), we will read garbage and can trigger kernel BUGs (due to a stale pointer): BUG: unable to handle page fault for address: 000000000000353d #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP PTI CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.3.0-rc5-next-20190820+ #317 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4 Workqueue: kacpi_hotplug acpi_hotplug_work_fn RIP: 0010:clear_zone_contiguous+0x5/0x10 Code: 48 89 c6 48 89 c3 e8 2a fe ff ff 48 85 c0 75 cf 5b 5d c3 c6 85 fd 05 00 00 01 5b 5d c3 0f 1f 840 RSP: 0018:ffffad2400043c98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000200000000 RCX: 0000000000000000 RDX: 0000000000200000 RSI: 0000000000140000 RDI: 0000000000002f40 RBP: 0000000140000000 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000140000 R13: 0000000000140000 R14: 0000000000002f40 R15: ffff9e3e7aff3680 FS: 0000000000000000(0000) GS:ffff9e3e7bb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000353d CR3: 0000000058610000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __remove_pages+0x4b/0x640 arch_remove_memory+0x63/0x8d try_remove_memory+0xdb/0x130 __remove_memory+0xa/0x11 acpi_memory_device_remove+0x70/0x100 acpi_bus_trim+0x55/0x90 acpi_device_hotplug+0x227/0x3a0 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x221/0x550 worker_thread+0x50/0x3b0 kthread+0x105/0x140 ret_from_fork+0x3a/0x50 Modules linked in: CR2: 000000000000353d Instead, shrink the zones when offlining memory or when onlining failed. Introduce and use remove_pfn_range_from_zone(() for that. We now properly shrink the zones, even if we have DIMMs whereby - Some memory blocks fall into no zone (never onlined) - Some memory blocks fall into multiple zones (offlined+re-onlined) - Multiple memory blocks that fall into different zones Drop the zone parameter (with a potential dubious value) from __remove_pages() and __remove_section(). Link: http://lkml.kernel.org/r/20191006085646.5768-6-david@redhat.com Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319] Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: <stable@vger.kernel.org> [5.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-18s390/ftrace: save traced function callerVasily Gorbik1-0/+1
A typical backtrace acquired from ftraced function currently looks like the following (e.g. for "path_openat"): arch_stack_walk+0x15c/0x2d8 stack_trace_save+0x50/0x68 stack_trace_call+0x15a/0x3b8 ftrace_graph_caller+0x0/0x1c 0x3e0007e3c98 <- ftraced function caller (should be do_filp_open+0x7c/0xe8) do_open_execat+0x70/0x1b8 __do_execve_file.isra.0+0x7d8/0x860 __s390x_sys_execve+0x56/0x68 system_call+0xdc/0x2d8 Note random "0x3e0007e3c98" stack value as ftraced function caller. This value causes either imprecise unwinder result or unwinding failure. That "0x3e0007e3c98" comes from r14 of ftraced function stack frame, which it haven't had a chance to initialize since the very first instruction calls ftrace code ("ftrace_caller"). (ftraced function might never save r14 as well). Nevertheless according to s390 ABI any function is called with stack frame allocated for it and r14 contains return address. "ftrace_caller" itself is called with "brasl %r0,ftrace_caller". So, to fix this issue simply always save traced function caller onto ftraced function stack frame. Reported-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-18s390/unwind: stop gracefully at user mode pt_regs in irq stackVasily Gorbik1-4/+11
Consider reaching user mode pt_regs at the bottom of irq stack graceful unwinder termination. This is the case when irq/mcck/ext interrupt arrives while in user mode. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-18s390/purgatory: do not build purgatory with kcov, kasan and friendsChristian Borntraeger2-2/+7
the purgatory must not rely on functions from the "old" kernel, so we must disable kasan and friends. We also need to have a separate copy of string.c as the default does not build memcmp with KASAN. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-18s390/purgatory: Make sure we fail the build if purgatory has missing symbolsHans de Goede2-3/+11
Since we link purgatory with -r aka we enable "incremental linking" no checks for unresolved symbols are done while linking the purgatory. This commit adds an extra check for unresolved symbols by calling ld without -r before running objcopy to generate purgatory.ro. This will help us catch missing symbols in the purgatory sooner. Note this commit also removes --no-undefined from LDFLAGS_purgatory as that has no effect. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/lkml/20191212205304.191610-1-hdegoede@redhat.com Tested-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-18s390/ftrace: fix endless recursion in function_graph tracerSven Schnelle1-2/+2
The following sequence triggers a kernel stack overflow on s390x: mount -t tracefs tracefs /sys/kernel/tracing cd /sys/kernel/tracing echo function_graph > current_tracer [crash] This is because preempt_count_{add,sub} are in the list of traced functions, which can be demonstrated by: echo preempt_count_add >set_ftrace_filter echo function_graph > current_tracer [crash] The stack overflow happens because get_tod_clock_monotonic() gets called by ftrace but itself calls preempt_{disable,enable}(), which leads to a endless recursion. Fix this by using preempt_{disable,enable}_notrace(). Fixes: 011620688a71 ("s390/time: ensure get_clock_monotonic() returns monotonic values") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11s390/kasan: add KASAN_VMALLOC supportVasily Gorbik2-12/+57
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 Carstens3-26/+5
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 Borntraeger1-1/+1
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 Richter1-6/+0
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 Richter1-0/+16
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>
2019-12-11s390/test_unwind: fix spelling mistake "reqister" -> "register"Colin Ian King1-1/+1
There is a spelling mistake in a pr_info message. Fix it. Link: https://lkml.kernel.org/r/20191202090215.28766-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11s390/spinlock: remove confusing comment in arch_spin_lock_waitVasily Gorbik1-1/+0
arch_spin_lock_wait does not take steal time into consideration. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-06Merge tag 'powerpc-5.5-2' of ↵Linus Torvalds1-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull more powerpc updates from Michael Ellerman: "A few commits splitting the KASAN instrumented bitops header in three, to match the split of the asm-generic bitops headers. This is needed on powerpc because we use the generic bitops for the non-atomic case only, whereas the existing KASAN instrumented bitops assume all the underlying operations are provided by the arch as arch_foo() versions. Thanks to: Daniel Axtens & Christophe Leroy" * tag 'powerpc-5.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: docs/core-api: Remove possibly confusing sub-headings from Bit Operations powerpc: support KASAN instrumentation of bitops kasan: support instrumented bitops combined with generic bitops
2019-12-04arch: ipcbuf.h: make uapi asm/ipcbuf.h self-containedMasahiro Yamada1-0/+2
Userspace cannot compile <asm/ipcbuf.h> due to some missing type definitions. For example, building it for x86 fails as follows: CC usr/include/asm/ipcbuf.h.s In file included from usr/include/asm/ipcbuf.h:1:0, from <command-line>:32: usr/include/asm-generic/ipcbuf.h:21:2: error: unknown type name `__kernel_key_t' __kernel_key_t key; ^~~~~~~~~~~~~~ usr/include/asm-generic/ipcbuf.h:22:2: error: unknown type name `__kernel_uid32_t' __kernel_uid32_t uid; ^~~~~~~~~~~~~~~~ usr/include/asm-generic/ipcbuf.h:23:2: error: unknown type name `__kernel_gid32_t' __kernel_gid32_t gid; ^~~~~~~~~~~~~~~~ usr/include/asm-generic/ipcbuf.h:24:2: error: unknown type name `__kernel_uid32_t' __kernel_uid32_t cuid; ^~~~~~~~~~~~~~~~ usr/include/asm-generic/ipcbuf.h:25:2: error: unknown type name `__kernel_gid32_t' __kernel_gid32_t cgid; ^~~~~~~~~~~~~~~~ usr/include/asm-generic/ipcbuf.h:26:2: error: unknown type name `__kernel_mode_t' __kernel_mode_t mode; ^~~~~~~~~~~~~~~ usr/include/asm-generic/ipcbuf.h:28:35: error: `__kernel_mode_t' undeclared here (not in a function) unsigned char __pad1[4 - sizeof(__kernel_mode_t)]; ^~~~~~~~~~~~~~~ usr/include/asm-generic/ipcbuf.h:31:2: error: unknown type name `__kernel_ulong_t' __kernel_ulong_t __unused1; ^~~~~~~~~~~~~~~~ usr/include/asm-generic/ipcbuf.h:32:2: error: unknown type name `__kernel_ulong_t' __kernel_ulong_t __unused2; ^~~~~~~~~~~~~~~~ It is just a matter of missing include directive. Include <linux/posix_types.h> to make it self-contained, and add it to the compile-test coverage. Link: http://lkml.kernel.org/r/20191030063855.9989-1-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-03Merge tag 'pci-v5.5-changes' of ↵Linus Torvalds4-18/+15
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "Enumeration: - Warn if a host bridge has no NUMA info (Yunsheng Lin) - Add PCI_STD_NUM_BARS for the number of standard BARs (Denis Efremov) Resource management: - Fix boot-time Embedded Controller GPE storm caused by incorrect resource assignment after ACPI Bus Check Notification (Mika Westerberg) - Protect pci_reassign_bridge_resources() against concurrent addition/removal (Benjamin Herrenschmidt) - Fix bridge dma_ranges resource list cleanup (Rob Herring) - Add "pci=hpmmiosize" and "pci=hpmmioprefsize" parameters to control the MMIO and prefetchable MMIO window sizes of hotplug bridges independently (Nicholas Johnson) - Fix MMIO/MMIO_PREF window assignment that assigned more space than desired (Nicholas Johnson) - Only enforce bus numbers from bridge EA if the bridge has EA devices downstream (Subbaraya Sundeep) - Consolidate DT "dma-ranges" parsing and convert all host drivers to use shared parsing (Rob Herring) Error reporting: - Restore AER capability after resume (Mayurkumar Patel) - Add PoisonTLPBlocked AER counter (Rajat Jain) - Use for_each_set_bit() to simplify AER code (Andy Shevchenko) - Fix AER kernel-doc (Andy Shevchenko) - Add "pcie_ports=dpc-native" parameter to allow native use of DPC even if platform didn't grant control over AER (Olof Johansson) Hotplug: - Avoid returning prematurely from sysfs requests to enable or disable a PCIe hotplug slot (Lukas Wunner) - Don't disable interrupts twice when suspending hotplug ports (Mika Westerberg) - Fix deadlocks when PCIe ports are hot-removed while suspended (Mika Westerberg) Power management: - Remove unnecessary ASPM locking (Bjorn Helgaas) - Add support for disabling L1 PM Substates (Heiner Kallweit) - Allow re-enabling Clock PM after it has been disabled (Heiner Kallweit) - Add sysfs attributes for controlling ASPM link states (Heiner Kallweit) - Remove CONFIG_PCIEASPM_DEBUG, including "link_state" and "clk_ctl" sysfs files (Heiner Kallweit) - Avoid AMD FCH XHCI USB PME# from D0 defect that prevents wakeup on USB 2.0 or 1.1 connect events (Kai-Heng Feng) - Move power state check out of pci_msi_supported() (Bjorn Helgaas) - Fix incorrect MSI-X masking on resume and revert related nvme quirk for Kingston NVME SSD running FW E8FK11.T (Jian-Hong Pan) - Always return devices to D0 when thawing to fix hibernation with drivers like mlx4 that used legacy power management (previously we only did it for drivers with new power management ops) (Dexuan Cui) - Clear PCIe PME Status even for legacy power management (Bjorn Helgaas) - Fix PCI PM documentation errors (Bjorn Helgaas) - Use dev_printk() for more power management messages (Bjorn Helgaas) - Apply D2 delay as milliseconds, not microseconds (Bjorn Helgaas) - Convert xen-platform from legacy to generic power management (Bjorn Helgaas) - Removed unused .resume_early() and .suspend_late() legacy power management hooks (Bjorn Helgaas) - Rearrange power management code for clarity (Rafael J. Wysocki) - Decode power states more clearly ("4" or "D4" really refers to "D3cold") (Bjorn Helgaas) - Notice when reading PM Control register returns an error (~0) instead of interpreting it as being in D3hot (Bjorn Helgaas) - Add missing link delays required by the PCIe spec (Mika Westerberg) Virtualization: - Move pci_prg_resp_pasid_required() to CONFIG_PCI_PRI (Bjorn Helgaas) - Allow VFs to use PRI (the PF PRI is shared by the VFs, but the code previously didn't recognize that) (Kuppuswamy Sathyanarayanan) - Allow VFs to use PASID (the PF PASID capability is shared by the VFs, but the code previously didn't recognize that) (Kuppuswamy Sathyanarayanan) - Disconnect PF and VF ATS enablement, since ATS in PFs and associated VFs can be enabled independently (Kuppuswamy Sathyanarayanan) - Cache PRI and PASID capability offsets (Kuppuswamy Sathyanarayanan) - Cache the PRI PRG Response PASID Required bit (Bjorn Helgaas) - Consolidate ATS declarations in linux/pci-ats.h (Krzysztof Wilczynski) - Remove unused PRI and PASID stubs (Bjorn Helgaas) - Removed unnecessary EXPORT_SYMBOL_GPL() from ATS, PRI, and PASID interfaces that are only used by built-in IOMMU drivers (Bjorn Helgaas) - Hide PRI and PASID state restoration functions used only inside the PCI core (Bjorn Helgaas) - Add a DMA alias quirk for the Intel VCA NTB (Slawomir Pawlowski) - Serialize sysfs sriov_numvfs reads vs writes (Pierre Crégut) - Update Cavium ACS quirk for ThunderX2 and ThunderX3 (George Cherian) - Fix the UPDCR register address in the Intel ACS quirk (Steffen Liebergeld) - Unify ACS quirk implementations (Bjorn Helgaas) Amlogic Meson host bridge driver: - Fix meson PERST# GPIO polarity problem (Remi Pommarel) - Add DT bindings for Amlogic Meson G12A (Neil Armstrong) - Fix meson clock names to match DT bindings (Neil Armstrong) - Add meson support for Amlogic G12A SoC with separate shared PHY (Neil Armstrong) - Add meson extended PCIe PHY functions for Amlogic G12A USB3+PCIe combo PHY (Neil Armstrong) - Add arm64 DT for Amlogic G12A PCIe controller node (Neil Armstrong) - Add commented-out description of VIM3 USB3/PCIe mux in arm64 DT (Neil Armstrong) Broadcom iProc host bridge driver: - Invalidate iProc PAXB address mapping before programming it (Abhishek Shah) - Fix iproc-msi and mvebu __iomem annotations (Ben Dooks) Cadence host bridge driver: - Refactor Cadence PCIe host controller to use as a library for both host and endpoint (Tom Joseph) Freescale Layerscape host bridge driver: - Add layerscape LS1028a support (Xiaowei Bao) Intel VMD host bridge driver: - Add VMD bus 224-255 restriction decode (Jon Derrick) - Add VMD 8086:9A0B device ID (Jon Derrick) - Remove Keith from VMD maintainer list (Keith Busch) Marvell ARMADA 3700 / Aardvark host bridge driver: - Use LTSSM state to build link training flag since Aardvark doesn't implement the Link Training bit (Remi Pommarel) - Delay before training Aardvark link in case PERST# was asserted before the driver probe (Remi Pommarel) - Fix Aardvark issues with Root Control reads and writes (Remi Pommarel) - Don't rely on jiffies in Aardvark config access path since interrupts may be disabled (Remi Pommarel) - Fix Aardvark big-endian support (Grzegorz Jaszczyk) Marvell ARMADA 370 / XP host bridge driver: - Make mvebu_pci_bridge_emul_ops static (Ben Dooks) Microsoft Hyper-V host bridge driver: - Add hibernation support for Hyper-V virtual PCI devices (Dexuan Cui) - Track Hyper-V pci_protocol_version per-hbus, not globally (Dexuan Cui) - Avoid kmemleak false positive on hv hbus buffer (Dexuan Cui) Mobiveil host bridge driver: - Change mobiveil csr_read()/write() function names that conflict with riscv arch functions (Kefeng Wang) NVIDIA Tegra host bridge driver: - Fix Tegra CLKREQ dependency programming (Vidya Sagar) Renesas R-Car host bridge driver: - Remove unnecessary header include from rcar (Andrew Murray) - Tighten register index checking for rcar inbound range programming (Marek Vasut) - Fix rcar inbound range alignment calculation to improve packing of multiple entries (Marek Vasut) - Update rcar MACCTLR setting to match documentation (Yoshihiro Shimoda) - Clear bit 0 of MACCTLR before PCIETCTLR.CFINIT per manual (Yoshihiro Shimoda) - Add Marek Vasut and Yoshihiro Shimoda as R-Car maintainers (Simon Horman) Rockchip host bridge driver: - Make rockchip 0V9 and 1V8 power regulators non-optional (Robin Murphy) Socionext UniPhier host bridge driver: - Set uniphier to host (RC) mode always (Kunihiko Hayashi) Endpoint drivers: - Fix endpoint driver sign extension problem when shifting page number to phys_addr_t (Alan Mikhak) Misc: - Add NumaChip SPDX header (Krzysztof Wilczynski) - Replace EXTRA_CFLAGS with ccflags-y (Krzysztof Wilczynski) - Remove unused includes (Krzysztof Wilczynski) - Removed unused sysfs attribute groups (Ben Dooks) - Remove PTM and ASPM dependencies on PCIEPORTBUS (Bjorn Helgaas) - Add PCIe Link Control 2 register field definitions to replace magic numbers in AMDGPU and Radeon CIK/SI (Bjorn Helgaas) - Fix incorrect Link Control 2 Transmit Margin usage in AMDGPU and Radeon CIK/SI PCIe Gen3 link training (Bjorn Helgaas) - Use pcie_capability_read_word() instead of pci_read_config_word() in AMDGPU and Radeon CIK/SI (Frederick Lawler) - Remove unused pci_irq_get_node() Greg Kroah-Hartman) - Make asm/msi.h mandatory and simplify PCI_MSI_IRQ_DOMAIN Kconfig (Palmer Dabbelt, Michal Simek) - Read all 64 bits of Switchtec part_event_bitmap (Logan Gunthorpe) - Fix erroneous intel-iommu dependency on CONFIG_AMD_IOMMU (Bjorn Helgaas) - Fix bridge emulation big-endian support (Grzegorz Jaszczyk) - Fix dwc find_next_bit() usage (Niklas Cassel) - Fix pcitest.c fd leak (Hewenliang) - Fix typos and comments (Bjorn Helgaas) - Fix Kconfig whitespace errors (Krzysztof Kozlowski)" * tag 'pci-v5.5-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (160 commits) PCI: Remove PCI_MSI_IRQ_DOMAIN architecture whitelist asm-generic: Make msi.h a mandatory include/asm header Revert "nvme: Add quirk for Kingston NVME SSD running FW E8FK11.T" PCI/MSI: Fix incorrect MSI-X masking on resume PCI/MSI: Move power state check out of pci_msi_supported() PCI/MSI: Remove unused pci_irq_get_node() PCI: hv: Avoid a kmemleak false positive caused by the hbus buffer PCI: hv: Change pci_protocol_version to per-hbus PCI: hv: Add hibernation support PCI: hv: Reorganize the code in preparation of hibernation MAINTAINERS: Remove Keith from VMD maintainer PCI/ASPM: Remove PCIEASPM_DEBUG Kconfig option and related code PCI/ASPM: Add sysfs attributes for controlling ASPM link states PCI: Fix indentation drm/radeon: Prefer pcie_capability_read_word() drm/radeon: Replace numbers with PCI_EXP_LNKCTL2 definitions drm/radeon: Correct Transmit Margin masks drm/amdgpu: Prefer pcie_capability_read_word() PCI: uniphier: Set mode register to host mode drm/amdgpu: Replace numbers with PCI_EXP_LNKCTL2 definitions ...
2019-12-03Merge tag 's390-5.5-2' of ↵Linus Torvalds34-768/+625
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Vasily Gorbik: - Make stack unwinder reliable and suitable for livepatching. Add unwinder testing module. - Fixes for CALL_ON_STACK helper used for stack switching. - Fix unwinding from bpf code. - Fix getcpu and remove compat support in vdso code. - Fix address space control registers initialization. - Save KASLR offset for early dumps. - Handle new FILTERED_BY_HYPERVISOR reply code in crypto code. - Minor perf code cleanup and potential memory leak fix. - Add couple of error messages for corner cases during PCI device creation. * tag 's390-5.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (33 commits) s390: remove compat vdso code s390/livepatch: Implement reliable stack tracing for the consistency model s390/unwind: add stack pointer alignment sanity checks s390/unwind: filter out unreliable bogus %r14 s390/unwind: start unwinding from reliable state s390/test_unwind: add program check context tests s390/test_unwind: add irq context tests s390/test_unwind: print verbose unwinding results s390/test_unwind: add CALL_ON_STACK tests s390: fix register clobbering in CALL_ON_STACK s390/test_unwind: require that unwinding ended successfully s390/unwind: add a test for the internal API s390/unwind: always inline get_stack_pointer s390/pci: add error message on device number limit s390/pci: add error message for UID collision s390/cpum_sf: Check for SDBT and SDB consistency s390/cpum_sf: Use TEAR_REG macro consistantly s390/cpum_sf: Remove unnecessary check for pending SDBs s390/cpum_sf: Replace function name in debug statements s390/kaslr: store KASLR offset for early dumps ...
2019-12-01s390: remove compat vdso codeHeiko Carstens13-638/+3
Remove compat vdso code, since there is hardly any compat user space left. Still existing compat user space will have to use system calls instead. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30Merge tag 'seccomp-v5.5-rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull seccomp updates from Kees Cook: "Mostly this is implementing the new flag SECCOMP_USER_NOTIF_FLAG_CONTINUE, but there are cleanups as well. - implement SECCOMP_USER_NOTIF_FLAG_CONTINUE (Christian Brauner) - fixes to selftests (Christian Brauner) - remove secure_computing() argument (Christian Brauner)" * tag 'seccomp-v5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: seccomp: rework define for SECCOMP_USER_NOTIF_FLAG_CONTINUE seccomp: fix SECCOMP_USER_NOTIF_FLAG_CONTINUE test seccomp: simplify secure_computing() seccomp: test SECCOMP_USER_NOTIF_FLAG_CONTINUE seccomp: add SECCOMP_USER_NOTIF_FLAG_CONTINUE seccomp: avoid overflow in implicit constant conversion
2019-11-30s390/livepatch: Implement reliable stack tracing for the consistency modelMiroslav Benes2-0/+44
The livepatch consistency model requires reliable stack tracing architecture support in order to work properly. In order to achieve this, two main issues have to be solved. First, reliable and consistent call chain backtracing has to be ensured. Second, the unwinder needs to be able to detect stack corruptions and return errors. The "zSeries ELF Application Binary Interface Supplement" says: "The stack pointer points to the first word of the lowest allocated stack frame. If the "back chain" is implemented this word will point to the previously allocated stack frame (towards higher addresses), except for the first stack frame, which shall have a back chain of zero (NULL). The stack shall grow downwards, in other words towards lower addresses." "back chain" is optional. GCC option -mbackchain enables it. Quoting Martin Schwidefsky [1]: "The compiler is called with the -mbackchain option, all normal C function will store the backchain in the function prologue. All functions written in assembler code should do the same, if you find one that does not we should fix that. The end result is that a task that *voluntarily* called schedule() should have a proper backchain at all times. Dependent on the use case this may or may not be enough. Asynchronous interrupts may stop the CPU at the beginning of a function, if kernel preemption is enabled we can end up with a broken backchain. The production kernels for IBM Z are all compiled *without* kernel preemption. So yes, we might get away without the objtool support. On a side-note, we do have a line item to implement the ORC unwinder for the kernel, that includes the objtool support. Once we have that we can drop the -mbackchain option for the kernel build. That gives us a nice little performance benefit. I hope that the change from backchain to the ORC unwinder will not be too hard to implement in the livepatch tools." Since -mbackchain is enabled by default when the kernel is compiled, the call chain backtracing should be currently ensured and objtool should not be necessary for livepatch purposes. Regarding the second issue, stack corruptions and non-reliable states have to be recognized by the unwinder. Mainly it means to detect preemption or page faults, the end of the task stack must be reached, return addresses must be valid text addresses and hacks like function graph tracing and kretprobes must be properly detected. Unwinding a running task's stack is not a problem, because there is a livepatch requirement that every checked task is blocked, except for the current task. Due to that, the implementation can be much simpler compared to the existing non-reliable infrastructure. We can consider a task's kernel/thread stack only and skip the other stacks. [1] 20180912121106.31ffa97c@mschwideX1 [not archived on lore.kernel.org] Link: https://lkml.kernel.org/r/20191106095601.29986-5-mbenes@suse.cz Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: add stack pointer alignment sanity checksMiroslav Benes2-0/+8
ABI requires SP to be aligned 8 bytes, report unwinding error otherwise. Link: https://lkml.kernel.org/r/20191106095601.29986-5-mbenes@suse.cz Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: filter out unreliable bogus %r14Vasily Gorbik1-0/+5
Currently unwinder unconditionally returns %r14 from the first frame pointed by %r15 from pt_regs. A task could be interrupted when a function already allocated this frame (if it needs it) for its callees or to store local variables. In that case this frame would contain random values from stack or values stored there by a callee. As we are only interested in %r14 to get potential return address, skip bogus return addresses which doesn't belong to kernel text. This helps to avoid duplicating filtering logic in unwider users, most of which use unwind_get_return_address() and would choke on bogus 0 address returned by it otherwise. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: start unwinding from reliable stateVasily Gorbik2-17/+31
A comment in arch/s390/include/asm/unwind.h says: > If 'first_frame' is not zero unwind_start skips unwind frames until it > reaches the specified stack pointer. > The end of the unwinding is indicated with unwind_done, this can be true > right after unwind_start, e.g. with first_frame!=0 that can not be found. > unwind_next_frame skips to the next frame. > Once the unwind is completed unwind_error() can be used to check if there > has been a situation where the unwinder could not correctly understand > the tasks call chain. With this change backchain unwinder now comply with behaviour described. As well as matches orc unwinder implementation. Now unwinder starts from reliable state, i.e. __unwind_start own stack frame is taken or stack frame generated by __switch_to (ksp) - both known to be valid. In case of pt_regs %r15 is better match for pt_regs psw, than sometimes random "sp" caller passed. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: add program check context testsVasily Gorbik1-0/+47
Add unwinding from program check handler tests. Unwinder should be able to unwind through pt_regs stored by program check handler on task stack. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: add irq context testsVasily Gorbik1-0/+45
Add unwinding from irq context tests. Unwinder should be able to unwind through irq stack to task stack up to task pt_regs. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: print verbose unwinding resultsVasily Gorbik2-2/+11
Add stack name, sp and reliable information into test unwinding results. Also consider ip outside of kernel text as failure if the state is reported reliable. Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: add CALL_ON_STACK testsVasily Gorbik1-7/+19
Add CALL_ON_STACK helper testing. Tests make sure that we can unwind from switched stack to original one up to task pt_regs (nodat -> task stack). UWM_SWITCH_STACK could not be used together with UWM_THREAD because get_stack_info explicitly restricts unwinding to task stack if task != current. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390: fix register clobbering in CALL_ON_STACKVasily Gorbik1-2/+2
CALL_ON_STACK defines and initializes register variables. Inline assembly which follows might trigger compiler to generate memory access for "stack" argument (e.g. in case of S390_lowcore.nodat_stack). This memory access produces a function call under kasan with outline instrumentation which clobbers registers. Switch "stack" argument in CALL_ON_STACK helper to use memory reference constraint and perform load instead. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: require that unwinding ended successfullyVasily Gorbik1-0/+4
Currently unwinder test passes if unwinding results contain unwindme_func2 and unwindme_func1 functions. Now that unwinder reports success upon reaching task pt_regs, check that unwinding ended successfully in every test. Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: add a test for the internal APIIlya Leoshkevich3-0/+248
unwind_for_each_frame can take at least 8 different sets of parameters. Add a test to make sure they all are handled in a sane way. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Co-developed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: always inline get_stack_pointerVasily Gorbik1-2/+2
Always inline get_stack_pointer() to avoid potential problems due to compiler inlining decisions, i.e. getting stack pointer of get_stack_pointer() itself which is later reused. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/pci: add error message on device number limitNiklas Schnelle1-0/+2
The config option CONFIG_PCI_NR_FUNCTIONS sets a limit on the number of PCI functions we can support. Previously on reaching this limit there was no indication why newly attached devices are not recognized by Linux which could be quite confusing. Thus this patch adds a pr_err() for this case. Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/pci: add error message for UID collisionNiklas Schnelle1-0/+3
When UID checking was turned off during runtime in the underlying hypervisor, a PCI device may be attached with the same UID. This is already detected but happens silently. Add an error message so it can more easily be understood why a device was not added. Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/cpum_sf: Check for SDBT and SDB consistencyThomas Richter1-2/+15
Each SBDT is located at a 4KB page and contains 512 entries. Each entry of a SDBT points to a SDB, a 4KB page containing sampled data. The last entry is a link to another SDBT page. When an event is created the function sequence executed is: __hw_perf_event_init() +--> allocate_buffers() +--> realloc_sampling_buffers() +---> alloc_sample_data_block() Both functions realloc_sampling_buffers() and alloc_sample_data_block() allocate pages and the allocation can fail. This is handled correctly and all allocated pages are freed and error -ENOMEM is returned to the top calling function. Finally the event is not created. Once the event has been created, the amount of initially allocated SDBT and SDB can be too low. This is detected during measurement interrupt handling, where the amount of lost samples is calculated. If the number of lost samples is too high considering sampling frequency and already allocated SBDs, the number of SDBs is enlarged during the next execution of cpumsf_pmu_enable(). If more SBDs need to be allocated, functions realloc_sampling_buffers() +---> alloc-sample_data_block() are called to allocate more pages. Page allocation may fail and the returned error is ignored. A SDBT and SDB setup already exists. However the modified SDBTs and SDBs might end up in a situation where the first entry of an SDBT does not point to an SDB, but another SDBT, basicly an SBDT without payload. This can not be handled by the interrupt handler, where an SDBT must have at least one entry pointing to an SBD. Add a check to avoid SDBTs with out payload (SDBs) when enlarging the buffer setup. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/cpum_sf: Use TEAR_REG macro consistantlyThomas Richter1-8/+1
The macro TEAR_REG() saves the last used SDBT address in the perf_hw_event structure. This is also done by function hw_reset_registers() which is a one-liner and simply uses macro TEAR_REG(). Remove function hw_reset_registers(), which is only used one time and use macro TEAR_REG() instead. This macro is used throughout the code anyway. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/cpum_sf: Remove unnecessary check for pending SDBsThomas Richter1-2/+1
In interrupt handling the function extend_sampling_buffer() is called after checking for a possibly extension. This check is not necessary as the called function itself performs this check again. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/cpum_sf: Replace function name in debug statementsThomas Richter2-52/+57
Replace hard coded function names in debug statements by the "%s ...", __func__ construct suggested by checkpatch.pl script. Use consistent debug print format of the form variable blank value. Also add leading 0x for all hex values. Print allocated page addresses consistantly as hex numbers with leading 0x. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/kaslr: store KASLR offset for early dumpsGerald Schaefer2-1/+6
The KASLR offset is added to vmcoreinfo in arch_crash_save_vmcoreinfo(), so that it can be found by crash when processing kernel dumps. However, arch_crash_save_vmcoreinfo() is called during a subsys_initcall, so if the kernel crashes before that, we have no vmcoreinfo and no KASLR offset. Fix this by storing the KASLR offset in the lowcore, where the vmcore_info pointer will be stored, and where it can be found by crash. In order to make it distinguishable from a real vmcore_info pointer, mark it as uneven (KASLR offset itself is aligned to THREAD_SIZE). When arch_crash_save_vmcoreinfo() stores the real vmcore_info pointer in the lowcore, it overwrites the KASLR offset. At that point, the KASLR offset is not yet added to vmcoreinfo, so we also need to move the mem_assign_absolute() behind the vmcoreinfo_append_str(). Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)") Cc: <stable@vger.kernel.org> # v5.2+ Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: stop gracefully at task pt_regsVasily Gorbik1-1/+7
Consider reaching task pt_regs graceful unwinder termination. Task pt_regs itself never contains a valid state to which a task might return within the kernel context (user task pt_regs is a special case). Since we already avoid printing user task pt_regs and in most cases we don't even bother filling task pt_regs psw and r15 with something reasonable simply skip task pt_regs altogether. With this change unwind_error() now accurately represent whether unwinder reached task pt_regs successfully or failed along the way. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/head64: correct init_task stack setupVasily Gorbik1-1/+1
Add missing allocation of pt_regs at the bottom of the stack. This makes it consistent with other stack setup cases and also what stack unwinder expects. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: make reuse_sp default when unwinding pt_regsVasily Gorbik2-15/+7
Currently unwinder yields 2 entries when pt_regs are met: sp="address of pt_regs itself" ip=pt_regs->psw sp=pt_regs->gprs[15] ip="r14 from stack frame pointed by pt_regs->gprs[15]" And neither of those 2 states (combination of sp and ip) ever happened. reuse_sp has been introduced by commit a1d863ac3e10 ("s390/unwind: fix mixing regs and sp"). reuse_sp=true makes unwinder keen to produce the following result, when pt_regs are given (as an arg to unwind_start): sp=pt_regs->gprs[15] ip=pt_regs->psw sp=pt_regs->gprs[15] ip="r14 from stack frame pointed by pt_regs->gprs[15]" The first state is an actual state in which a task was when pt_regs were collected. The second state is marked unreliable and is for debugging purposes to cover the case when a task has been interrupted in between stack frame allocation and writing back_chain - in this case r14 might show an actual caller. Make unwinder behaviour enabled via reuse_sp=true default and drop the special case handling. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: report an error if pt_regs are not on stackVasily Gorbik1-1/+1
If unwinder is looking at pt_regs which is not on stack then something went wrong and an error has to be reported rather than successful unwinding termination. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390: avoid misusing CALL_ON_STACK for task stack setupVasily Gorbik3-9/+13
CALL_ON_STACK is intended to be used for temporary stack switching with potential return to the caller. When CALL_ON_STACK is misused to switch from nodat stack to task stack back_chain information would later lead stack unwinder from task stack into (per cpu) nodat stack which is reused for other purposes. This would yield confusing unwinding result or errors. To avoid that introduce CALL_ON_STACK_NORETURN to be used instead. It makes sure that back_chain is zeroed and unwinder finishes gracefully ending up at task pt_regs. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390: correct CALL_ON_STACK back_chain savingVasily Gorbik1-1/+14
Currently CALL_ON_STACK saves r15 as back_chain in the first stack frame of the stack we about to switch to. But if a function which uses CALL_ON_STACK calls other function it allocates a stack frame for a callee. In this case r15 is pointing to a callee stack frame and not a stack frame of function itself. This results in dummy unwinding entry with random sp and ip values. Introduce and utilize current_frame_address macro to get an address of actual function stack frame. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: unify task is current checksVasily Gorbik3-6/+3
Avoid mixture of task == NULL and task == current meaning the same thing and simply always initialize task with current in unwind_start. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390: disable preemption when switching to nodat stack with CALL_ON_STACKVasily Gorbik2-3/+11
Make sure preemption is disabled when temporary switching to nodat stack with CALL_ON_STACK helper, because nodat stack is per cpu. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390: always inline disabled_waitVasily Gorbik1-1/+1
disabled_wait uses _THIS_IP_ and assumes that compiler would inline it. Make sure this assumption is always correct by utilizing __always_inline. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/vdso: fix getcpuHeiko Carstens4-10/+14
getcpu reads the required values for cpu and node with two instructions. This might lead to an inconsistent result if user space gets preempted and migrated to a different CPU between the two instructions. Fix this by using just a single instruction to read both values at once. This is currently rather a theoretical bug, since there is no real NUMA support available (except for NUMA emulation). Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/smp,vdso: fix ASCE handlingHeiko Carstens1-0/+5
When a secondary CPU is brought up it must initialize its control registers. CPU A which triggers that a secondary CPU B is brought up stores its control register contents into the lowcore of new CPU B, which then loads these values on startup. This is problematic in various ways: the control register which contains the home space ASCE will correctly contain the kernel ASCE; however control registers for primary and secondary ASCEs are initialized with whatever values were present in CPU A. Typically: - the primary ASCE will contain the user process ASCE of the process that triggered onlining of CPU B. - the secondary ASCE will contain the percpu VDSO ASCE of CPU A. Due to lazy ASCE handling we may also end up with other combinations. When then CPU B switches to a different process (!= idle) it will fixup the primary ASCE. However the problem is that the (wrong) ASCE from CPU A was loaded into control register 1: as soon as an ASCE is attached (aka loaded) a CPU is free to generate TLB entries using that address space. Even though it is very unlikey that CPU B will actually generate such entries, this could result in TLB entries of the address space of the process that ran on CPU A. These entries shouldn't exist at all and could cause problems later on. Furthermore the secondary ASCE of CPU B will not be updated correctly. This means that processes may see wrong results or even crash if they access VDSO data on CPU B. The correct VDSO ASCE will eventually be loaded on return to user space as soon as the kernel executed a call to strnlen_user or an atomic futex operation on CPU B. Fix both issues by intializing the to be loaded control register contents with the correct ASCEs and also enforce (re-)loading of the ASCEs upon first context switch and return to user space. Fixes: 0aaba41b58bc ("s390: remove all code using the access register mode") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390: implement perf_arch_fetch_caller_regsIlya Leoshkevich1-0/+7
On s390 bpf_get_stack_raw_tp() returns 0 entries for both kernel and user stacks. While there is no practical unwinding solution for userspace on s390 at this moment, there certainly is a kernel unwinder. However, it is not properly integrated with BPF. In order to start unwinding, bpf_get_stack_raw_tp() obtains the current kernel register values using perf_fetch_caller_regs(), which is not implemented for s390. The actual unwinding then happens by passing those registers to perf_callchain_kernel(). Implement perf_arch_fetch_caller_regs() for s390, where __builtin_frame_address(0) points to back_chain. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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