1. 15 Jun, 2017 4 commits
  2. 12 Jun, 2017 9 commits
  3. 07 Jun, 2017 2 commits
    • Ard Biesheuvel's avatar
      arm64: ftrace: add support for far branches to dynamic ftrace · e71a4e1b
      Ard Biesheuvel authored
      Currently, dynamic ftrace support in the arm64 kernel assumes that all
      core kernel code is within range of ordinary branch instructions that
      occur in module code, which is usually the case, but is no longer
      guaranteed now that we have support for module PLTs and address space
      randomization.
      
      Since on arm64, all patching of branch instructions involves function
      calls to the same entry point [ftrace_caller()], we can emit the modules
      with a trampoline that has unlimited range, and patch both the trampoline
      itself and the branch instruction to redirect the call via the trampoline.
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      [will: minor clarification to smp_wmb() comment]
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      e71a4e1b
    • Ard Biesheuvel's avatar
      arm64: ftrace: don't validate branch via PLT in ftrace_make_nop() · f8af0b36
      Ard Biesheuvel authored
      When turning branch instructions into NOPs, we attempt to validate the
      action by comparing the old value at the call site with the opcode of
      a direct relative branch instruction pointing at the old target.
      
      However, these call sites are statically initialized to call _mcount(),
      and may be redirected via a PLT entry if the module is loaded far away
      from the kernel text, leading to false negatives and spurious errors.
      
      So skip the validation if CONFIG_ARM64_MODULE_PLTS is configured.
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      f8af0b36
  4. 06 Jun, 2017 1 commit
  5. 05 Jun, 2017 1 commit
  6. 01 Jun, 2017 1 commit
    • Ard Biesheuvel's avatar
      arm64: kernel: restrict /dev/mem read() calls to linear region · 1151f838
      Ard Biesheuvel authored
      When running lscpu on an AArch64 system that has SMBIOS version 2.0
      tables, it will segfault in the following way:
      
        Unable to handle kernel paging request at virtual address ffff8000bfff0000
        pgd = ffff8000f9615000
        [ffff8000bfff0000] *pgd=0000000000000000
        Internal error: Oops: 96000007 [#1] PREEMPT SMP
        Modules linked in:
        CPU: 0 PID: 1284 Comm: lscpu Not tainted 4.11.0-rc3+ #103
        Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
        task: ffff8000fa78e800 task.stack: ffff8000f9780000
        PC is at __arch_copy_to_user+0x90/0x220
        LR is at read_mem+0xcc/0x140
      
      This is caused by the fact that lspci issues a read() on /dev/mem at the
      offset where it expects to find the SMBIOS structure array. However, this
      region is classified as EFI_RUNTIME_SERVICE_DATA (as per the UEFI spec),
      and so it is omitted from the linear mapping.
      
      So let's restrict /dev/mem read/write access to those areas that are
      covered by the linear region.
      Reported-by: default avatarAlexander Graf <agraf@suse.de>
      Fixes: 4dffbfc4 ("arm64/efi: mark UEFI reserved regions as MEMBLOCK_NOMAP")
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      1151f838
  7. 30 May, 2017 8 commits
    • Lorenzo Pieralisi's avatar
      ARM64/PCI: Set root bus NUMA node on ACPI systems · db46a72b
      Lorenzo Pieralisi authored
      PCI core requires the NUMA node for the struct pci_host_bridge.dev to
      be set by using the pcibus_to_node(struct pci_bus*) API, that on ARM64
      systems relies on the struct pci_host_bridge->bus.dev NUMA node.
      
      The struct pci_host_bridge.dev NUMA node is then propagated through
      the PCI device hierarchy as PCI devices (and bridges) are enumerated
      under it.
      
      Therefore, in order to set-up the PCI NUMA hierarchy appropriately, the
      struct pci_host_bridge->bus.dev NUMA node must be set before core
      code calls pcibus_to_node(struct pci_bus*) on it so that PCI core can
      retrieve the NUMA node for the struct pci_host_bridge.dev device and can
      propagate it through the PCI bus tree.
      
      On ARM64 ACPI based systems the struct pci_host_bridge->bus.dev NUMA
      node can be set-up in pcibios_root_bridge_prepare() by parsing the root
      bridge ACPI device firmware binding.
      
      Add code to the pcibios_root_bridge_prepare() that, when booting with
      ACPI, parse the root bridge ACPI device companion NUMA binding and set
      the corresponding struct pci_host_bridge->bus.dev NUMA node
      appropriately.
      
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Reviewed-by: default avatarRobert Richter <rrichter@cavium.com>
      Tested-by: default avatarRobert Richter <rrichter@cavium.com>
      Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      db46a72b
    • Will Deacon's avatar
      arm64: futex: Fix undefined behaviour with FUTEX_OP_OPARG_SHIFT usage · 5f16a046
      Will Deacon authored
      FUTEX_OP_OPARG_SHIFT instructs the futex code to treat the 12-bit oparg
      field as a shift value, potentially leading to a left shift value that
      is negative or with an absolute value that is significantly larger then
      the size of the type. UBSAN chokes with:
      
      ================================================================================
      UBSAN: Undefined behaviour in ./arch/arm64/include/asm/futex.h:60:13
      shift exponent -1 is negative
      CPU: 1 PID: 1449 Comm: syz-executor0 Not tainted 4.11.0-rc4-00005-g977eb52-dirty #11
      Hardware name: linux,dummy-virt (DT)
      Call trace:
      [<ffff200008094778>] dump_backtrace+0x0/0x538 arch/arm64/kernel/traps.c:73
      [<ffff200008094cd0>] show_stack+0x20/0x30 arch/arm64/kernel/traps.c:228
      [<ffff200008c194a8>] __dump_stack lib/dump_stack.c:16 [inline]
      [<ffff200008c194a8>] dump_stack+0x120/0x188 lib/dump_stack.c:52
      [<ffff200008cc24b8>] ubsan_epilogue+0x18/0x98 lib/ubsan.c:164
      [<ffff200008cc3098>] __ubsan_handle_shift_out_of_bounds+0x250/0x294 lib/ubsan.c:421
      [<ffff20000832002c>] futex_atomic_op_inuser arch/arm64/include/asm/futex.h:60 [inline]
      [<ffff20000832002c>] futex_wake_op kernel/futex.c:1489 [inline]
      [<ffff20000832002c>] do_futex+0x137c/0x1740 kernel/futex.c:3231
      [<ffff200008320504>] SYSC_futex kernel/futex.c:3281 [inline]
      [<ffff200008320504>] SyS_futex+0x114/0x268 kernel/futex.c:3249
      [<ffff200008084770>] el0_svc_naked+0x24/0x28
      ================================================================================
      syz-executor1 uses obsolete (PF_INET,SOCK_PACKET)
      sock: process `syz-executor0' is using obsolete setsockopt SO_BSDCOMPAT
      
      This patch attempts to fix some of this by:
      
        * Making encoded_op an unsigned type, so we can shift it left even if
          the top bit is set.
      
        * Casting to signed prior to shifting right when extracting oparg
          and cmparg
      
        * Consider only the bottom 5 bits of oparg when using it as a left-shift
          value.
      
      Whilst I think this catches all of the issues, I'd much prefer to remove
      this stuff, as I think it's unused and the bugs are copy-pasted between
      a bunch of architectures.
      Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      5f16a046
    • Kefeng Wang's avatar
      arm64: check return value of of_flat_dt_get_machine_name · 690e95dd
      Kefeng Wang authored
      It's useless to print machine name and setup arch-specific system
      identifiers if of_flat_dt_get_machine_name() return NULL, especially
      when ACPI-based boot.
      Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
      Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      690e95dd
    • Will Deacon's avatar
      arm64: cpufeature: Don't dump useless backtrace on CPU_OUT_OF_SPEC · 3fde2999
      Will Deacon authored
      Unfortunately, it turns out that mismatched CPU features in big.LITTLE
      systems are starting to appear in the wild. Whilst we should continue to
      taint the kernel with CPU_OUT_OF_SPEC for features that differ in ways
      that we can't fix up, dumping a useless backtrace out of the cpufeature
      code is pointless and irritating.
      
      This patch removes the backtrace from the taint.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      3fde2999
    • Tobias Klauser's avatar
      arm64: mm: explicity include linux/vmalloc.h · 6efd8499
      Tobias Klauser authored
      arm64's mm/mmu.c uses vm_area_add_early, struct vm_area and other
      definitions  but relies on implict inclusion of linux/vmalloc.h which
      means that changes in other headers could break the build. Thus, add an
      explicit include.
      Acked-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarTobias Klauser <tklauser@distanz.ch>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      6efd8499
    • Kefeng Wang's avatar
      arm64: Add dump_backtrace() in show_regs · 1149aad1
      Kefeng Wang authored
      Generic code expects show_regs() to dump the stack, but arm64's
      show_regs() does not. This makes it hard to debug softlockups and
      other issues that result in show_regs() being called.
      
      This patch updates arm64's show_regs() to dump the stack, as common
      code expects.
      Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      [will: folded in bug_handler fix from mrutland]
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      1149aad1
    • Kefeng Wang's avatar
      arm64: Call __show_regs directly · c07ab957
      Kefeng Wang authored
      Generic code expects show_regs() to also dump the stack, but arm64's
      show_reg() does not do this. Some arm64 callers of show_regs() *only*
      want the registers dumped, without the stack.
      
      To enable generic code to work as expected, we need to make
      show_regs() dump the stack. Where we only want the registers dumped,
      we must use __show_regs().
      
      This patch updates code to use __show_regs() where only registers are
      desired. A subsequent patch will modify show_regs().
      Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      c07ab957
    • Dong Bo's avatar
      arm64: Preventing READ_IMPLIES_EXEC propagation · 48f99c8e
      Dong Bo authored
      Like arch/arm/, we inherit the READ_IMPLIES_EXEC personality flag across
      fork(). This is undesirable for a number of reasons:
      
        * ELF files that don't require executable stack can end up with it
          anyway
      
        * We end up performing un-necessary I-cache maintenance when mapping
          what should be non-executable pages
      
        * Restricting what is executable is generally desirable when defending
          against overflow attacks
      
      This patch clears the personality flag when setting up the personality for
      newly spwaned native tasks. Given that semi-recent AArch64 toolchains emit
      a non-executable PT_GNU_STACK header, userspace applications can already
      not rely on READ_IMPLIES_EXEC so shouldn't be adversely affected by this
      change.
      
      Cc: <stable@vger.kernel.org>
      Reported-by: default avatarPeter Maydell <peter.maydell@linaro.org>
      Signed-off-by: default avatarDong Bo <dongbo4@huawei.com>
      [will: added comment to compat code, rewrote commit message]
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      48f99c8e
  8. 29 May, 2017 1 commit
  9. 28 May, 2017 1 commit
  10. 27 May, 2017 12 commits
    • Linus Torvalds's avatar
      Merge tag 'tty-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty · 249f1efd
      Linus Torvalds authored
      Pull tty/serial fixes from Greg KH:
       "Here are some serial and tty fixes for 4.12-rc3. They are a bit bigger
        than normal, which is why I had them bake in linux-next for a few
        weeks and didn't send them to you for -rc2.
      
        They revert a few of the serdev patches from 4.12-rc1, and bring
        things back to how they were in 4.11, to try to make things a bit more
        stable there. Rob and Johan both agree that this is the way forward,
        so this isn't people squabbling over semantics. Other than that, just
        a few minor serial driver fixes that people have had problems with.
      
        All of these have been in linux-next for a few weeks with no reported
        issues"
      
      * tag 'tty-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
        serial: altera_uart: call iounmap() at driver remove
        serial: imx: ensure UCR3 and UFCR are setup correctly
        MAINTAINERS/serial: Change maintainer of jsm driver
        serial: enable serdev support
        tty/serdev: add serdev registration interface
        serdev: Restore serdev_device_write_buf for atomic context
        serial: core: fix crash in uart_suspend_port
        tty: fix port buffer locking
        tty: ehv_bytechan: clean up init error handling
        serial: ifx6x60: fix use-after-free on module unload
        serial: altera_jtaguart: adding iounmap()
        serial: exar: Fix stuck MSIs
        serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'
        serdev: fix tty-port client deregistration
        Revert "tty_port: register tty ports with serdev bus"
        drivers/tty: 8250: only call fintek_8250_probe when doing port I/O
      249f1efd
    • Linus Torvalds's avatar
      Merge tag 'powerpc-4.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 6f68a6ae
      Linus Torvalds authored
      Pull powerpc fixes from Michael Ellerman:
       "Fix running SPU programs on Cell, and a few other minor fixes.
      
        Thanks to Alistair Popple, Jeremy Kerr, Michael Neuling, Nicholas
        Piggin"
      
      * tag 'powerpc-4.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        powerpc: Add PPC_FEATURE userspace bits for SCV and DARN instructions
        powerpc/spufs: Fix hash faults for kernel regions
        powerpc: Fix booting P9 hash with CONFIG_PPC_RADIX_MMU=N
        powerpc/powernv/npu-dma.c: Fix opal_npu_destroy_context() call
        selftests/powerpc: Fix TM resched DSCR test with some compilers
      6f68a6ae
    • Linus Torvalds's avatar
      Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 38e6bf23
      Linus Torvalds authored
      Pull x86 fixes from Thomas Gleixner:
       "A series of fixes for X86:
      
         - The final fix for the end-of-stack issue in the unwinder
         - Handle non PAT systems gracefully
         - Prevent access to uninitiliazed memory
         - Move early delay calaibration after basic init
         - Fix Kconfig help text
         - Fix a cross compile issue
         - Unbreak older make versions"
      
      * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/timers: Move simple_udelay_calibration past init_hypervisor_platform
        x86/alternatives: Prevent uninitialized stack byte read in apply_alternatives()
        x86/PAT: Fix Xorg regression on CPUs that don't support PAT
        x86/watchdog: Fix Kconfig help text file path reference to lockup watchdog documentation
        x86/build: Permit building with old make versions
        x86/unwind: Add end-of-stack check for ftrace handlers
        Revert "x86/entry: Fix the end of the stack for newly forked tasks"
        x86/boot: Use CROSS_COMPILE prefix for readelf
      38e6bf23
    • Linus Torvalds's avatar
      Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 39b8ab31
      Linus Torvalds authored
      Pull timer fixlet from Thomas Gleixner:
       "Silence dmesg spam by making the posix cpu timer printks depend on
        print_fatal_signals"
      
      * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        posix-timers: Make signal printks conditional
      39b8ab31
    • Linus Torvalds's avatar
      Merge branch 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · de0b9d75
      Linus Torvalds authored
      Pull RAS fixes from Thomas Gleixner:
       "Two fixlets for RAS:
      
         - Export memory_error() so the NFIT module can utilize it
      
         - Handle memory errors in NFIT correctly"
      
      * 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        acpi, nfit: Fix the memory error check in nfit_handle_mce()
        x86/MCE: Export memory_error()
      de0b9d75
    • Linus Torvalds's avatar
      Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · fac3fcae
      Linus Torvalds authored
      Pull perf tooling fixes from Thomas Gleixner:
      
       - Synchronization of tools and kernel headers
      
       - A series of fixes for perf report addressing various failures:
          * Handle invalid maps proper
          * Plug a memory leak
          * Handle frames and callchain order correctly
      
       - Fixes for handling inlines and children mode
      
      * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        tools/include: Sync kernel ABI headers with tooling headers
        perf tools: Put caller above callee in --children mode
        perf report: Do not drop last inlined frame
        perf report: Always honor callchain order for inlined nodes
        perf script: Add --inline option for debugging
        perf report: Fix off-by-one for non-activation frames
        perf report: Fix memory leak in addr2line when called by addr2inlines
        perf report: Don't crash on invalid maps in `-g srcline` mode
      fac3fcae
    • Linus Torvalds's avatar
      Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 805f2869
      Linus Torvalds authored
      Pull locking fix from Thomas Gleixner:
       "A fix for a state leak which was introduced in the recent rework of
        futex/rtmutex interaction"
      
      * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock()
      805f2869
    • Linus Torvalds's avatar
      Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · d024baa5
      Linus Torvalds authored
      Pull kthread fix from Thomas Gleixner:
       "A single fix which prevents a use after free when kthread fork fails"
      
      * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        kthread: Fix use-after-free if kthread fork fails
      d024baa5
    • Linus Torvalds's avatar
      Merge tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · 77d64656
      Linus Torvalds authored
      Pull ftrace fixes from Steven Rostedt:
       "There's been a few memory issues found with ftrace.
      
        One was simply a memory leak where not all was being freed that should
        have been in releasing a file pointer on set_graph_function.
      
        Then Thomas found that the ftrace trampolines were marked for
        read/write as well as execute. To shrink the possible attack surface,
        he added calls to set them to ro. Which also uncovered some other
        issues with freeing module allocated memory that had its permissions
        changed.
      
        Kprobes had a similar issue which is fixed and a selftest was added to
        trigger that issue again"
      
      * tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
        x86/ftrace: Make sure that ftrace trampolines are not RWX
        x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range()
        selftests/ftrace: Add a testcase for many kprobe events
        kprobes/x86: Fix to set RWX bits correctly before releasing trampoline
        ftrace: Fix memory leak in ftrace_graph_release()
      77d64656
    • Thomas Gleixner's avatar
      x86/ftrace: Make sure that ftrace trampolines are not RWX · 6ee98ffe
      Thomas Gleixner authored
      ftrace use module_alloc() to allocate trampoline pages. The mapping of
      module_alloc() is RWX, which makes sense as the memory is written to right
      after allocation. But nothing makes these pages RO after writing to them.
      
      Add proper set_memory_rw/ro() calls to protect the trampolines after
      modification.
      
      Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705251056410.1862@nanosSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      6ee98ffe
    • Steven Rostedt (VMware)'s avatar
      x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range() · a53276e2
      Steven Rostedt (VMware) authored
      With function tracing starting in early bootup and having its trampoline
      pages being read only, a bug triggered with the following:
      
      kernel BUG at arch/x86/mm/pageattr.c:189!
      invalid opcode: 0000 [#1] SMP
      Modules linked in:
      CPU: 0 PID: 0 Comm: swapper Not tainted 4.12.0-rc2-test+ #3
      Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
      task: ffffffffb4222500 task.stack: ffffffffb4200000
      RIP: 0010:change_page_attr_set_clr+0x269/0x302
      RSP: 0000:ffffffffb4203c88 EFLAGS: 00010046
      RAX: 0000000000000046 RBX: 0000000000000000 RCX: 00000001b6000000
      RDX: ffffffffb4203d40 RSI: 0000000000000000 RDI: ffffffffb4240d60
      RBP: ffffffffb4203d18 R08: 00000001b6000000 R09: 0000000000000001
      R10: ffffffffb4203aa8 R11: 0000000000000003 R12: ffffffffc029b000
      R13: ffffffffb4203d40 R14: 0000000000000001 R15: 0000000000000000
      FS:  0000000000000000(0000) GS:ffff9a639ea00000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: ffff9a636b384000 CR3: 00000001ea21d000 CR4: 00000000000406b0
      Call Trace:
       change_page_attr_clear+0x1f/0x21
       set_memory_ro+0x1e/0x20
       arch_ftrace_update_trampoline+0x207/0x21c
       ? ftrace_caller+0x64/0x64
       ? 0xffffffffc029b000
       ftrace_startup+0xf4/0x198
       register_ftrace_function+0x26/0x3c
       function_trace_init+0x5e/0x73
       tracer_init+0x1e/0x23
       tracing_set_tracer+0x127/0x15a
       register_tracer+0x19b/0x1bc
       init_function_trace+0x90/0x92
       early_trace_init+0x236/0x2b3
       start_kernel+0x200/0x3f5
       x86_64_start_reservations+0x29/0x2b
       x86_64_start_kernel+0x17c/0x18f
       secondary_startup_64+0x9f/0x9f
       ? secondary_startup_64+0x9f/0x9f
      
      Interrupts should not be enabled at this early in the boot process. It is
      also fine to leave interrupts enabled during this time as there's only one
      CPU running, and on_each_cpu() means to only run on the current CPU.
      
      If early_boot_irqs_disabled is set, it is safe to run cpu_flush_range() with
      interrupts disabled. Don't trigger a BUG_ON() in that case.
      
      Link: http://lkml.kernel.org/r/20170526093717.0be3b849@gandalf.local.homeSuggested-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      a53276e2
    • Masami Hiramatsu's avatar
      selftests/ftrace: Add a testcase for many kprobe events · bdd7e3d6
      Masami Hiramatsu authored
      Add a testcase to test kprobes via ftrace interface
      with many concurrent kprobe events.
      
      This tries to add many kprobe events (up to 256) on
      kernel functions. To avoid making ftrace-based
      kprobes (kprobes on fentry), it skips first N bytes
      (on x86 N=5, on ppc or arm N=4) of function entry.
      After that, it enables all those events, disable it,
      and remove it.
      
      Since the unoptimization buffer reclaiming will
      be delayed, after removing events, it will wait
      enough time.
      
      Link: http://lkml.kernel.org/r/149577388470.11702.11832460851769204511.stgit@devboxSigned-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
      Suggested-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      bdd7e3d6