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  1. Apr 12, 2019
    • Will Deacon's avatar
      arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value · 045afc24
      Will Deacon authored
      
      Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't
      explicitly set the return value on the non-faulting path and instead
      leaves it holding the result of the underlying atomic operation. This
      means that any FUTEX_WAKE_OP atomic operation which computes a non-zero
      value will be reported as having failed. Regrettably, I wrote the buggy
      code back in 2011 and it was upstreamed as part of the initial arm64
      support in 2012.
      
      The reasons we appear to get away with this are:
      
        1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get
           exercised by futex() test applications
      
        2. If the result of the atomic operation is zero, the system call
           behaves correctly
      
        3. Prior to version 2.25, the only operation used by GLIBC set the
           futex to zero, and therefore worked as expected. From 2.25 onwards,
           FUTEX_WAKE_OP is not used by GLIBC at all.
      
      Fix the implementation by ensuring that the return value is either 0
      to indicate that the atomic operation completed successfully, or -EFAULT
      if we encountered a fault when accessing the user mapping.
      
      Cc: <stable@kernel.org>
      Fixes: 6170a974 ("arm64: Atomic operations")
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      045afc24
  2. Apr 10, 2019
    • Christoph Hellwig's avatar
      sparc64/pci_sun4v: fix ATU checks for large DMA masks · 2a29e9f6
      Christoph Hellwig authored
      
      Now that we allow drivers to always need to set larger than required
      DMA masks we need to be a little more careful in the sun4v PCI iommu
      driver to chose when to select the ATU support - a larger DMA mask
      can be set even when the platform does not support ATU, so we always
      have to check if it is avaiable before using it.  Add a little helper
      for that and use it in all the places where we make ATU usage decisions
      based on the DMA mask.
      
      Fixes: 24132a41 ("sparc64/pci_sun4v: allow large DMA masks")
      Reported-by: default avatarMeelis Roos <mroos@linux.ee>
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Tested-by: default avatarMeelis Roos <mroos@linux.ee>
      Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
      2a29e9f6
    • Lendacky, Thomas's avatar
      x86/perf/amd: Remove need to check "running" bit in NMI handler · 3966c3fe
      Lendacky, Thomas authored
      
      Spurious interrupt support was added to perf in the following commit, almost
      a decade ago:
      
        63e6be6d ("perf, x86: Catch spurious interrupts after disabling counters")
      
      The two previous patches (resolving the race condition when disabling a
      PMC and NMI latency mitigation) allow for the removal of this older
      spurious interrupt support.
      
      Currently in x86_pmu_stop(), the bit for the PMC in the active_mask bitmap
      is cleared before disabling the PMC, which sets up a race condition. This
      race condition was mitigated by introducing the running bitmap. That race
      condition can be eliminated by first disabling the PMC, waiting for PMC
      reset on overflow and then clearing the bit for the PMC in the active_mask
      bitmap. The NMI handler will not re-enable a disabled counter.
      
      If x86_pmu_stop() is called from the perf NMI handler, the NMI latency
      mitigation support will guard against any unhandled NMI messages.
      
      Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: <stable@vger.kernel.org> # 4.14.x-
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Link: https://lkml.kernel.org/r/Message-ID
      
      :
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      3966c3fe
    • Michael Ellerman's avatar
      powerpc/mm: Define MAX_PHYSMEM_BITS for all 64-bit configs · cf7cf697
      Michael Ellerman authored
      
      The recent commit 8bc08689 ("powerpc/mm: Only define
      MAX_PHYSMEM_BITS in SPARSEMEM configurations") removed our definition
      of MAX_PHYSMEM_BITS when SPARSEMEM is disabled.
      
      This inadvertently broke some 64-bit FLATMEM using configs with eg:
      
        arch/powerpc/include/asm/book3s/64/mmu-hash.h:584:6: error: "MAX_PHYSMEM_BITS" is not defined, evaluates to 0
         #if (MAX_PHYSMEM_BITS > MAX_EA_BITS_PER_CONTEXT)
              ^~~~~~~~~~~~~~~~
      
      Fix it by making sure we define MAX_PHYSMEM_BITS for all 64-bit
      configs regardless of SPARSEMEM.
      
      Fixes: 8bc08689 ("powerpc/mm: Only define MAX_PHYSMEM_BITS in SPARSEMEM configurations")
      Reported-by: default avatarAndreas Schwab <schwab@linux-m68k.org>
      Reported-by: default avatarHugh Dickins <hughd@google.com>
      Reviewed-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      cf7cf697
  3. Apr 08, 2019
  4. Apr 07, 2019
    • Arnd Bergmann's avatar
      ARM: milbeaut: fix build with !CONFIG_HOTPLUG_CPU · 9a8f3203
      Arnd Bergmann authored
      
      When HOTPLUG_CPU is disabled, some fields in the smp operations
      are not available or needed:
      
      arch/arm/mach-milbeaut/platsmp.c:90:3: error: field designator 'cpu_die' does not refer to any field in type
            'struct smp_operations'
              .cpu_die                = m10v_cpu_die,
               ^
      arch/arm/mach-milbeaut/platsmp.c:91:3: error: field designator 'cpu_kill' does not refer to any field in type
            'struct smp_operations'
              .cpu_kill               = m10v_cpu_kill,
               ^
      
      Hide them in an #ifdef like the other platforms do.
      
      Fixes: 9fb29c73 ("ARM: milbeaut: Add basic support for Milbeaut m10v SoC")
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      9a8f3203
    • Arnd Bergmann's avatar
      ARM: iop: don't use using 64-bit DMA masks · 2125801c
      Arnd Bergmann authored
      
      clang warns about statically defined DMA masks from the DMA_BIT_MASK
      macro with length 64:
      
       arch/arm/mach-iop13xx/setup.c:303:35: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
       static u64 iop13xx_adma_dmamask = DMA_BIT_MASK(64);
                                        ^~~~~~~~~~~~~~~~
       include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK'
       #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
                                                            ^ ~~~
      
      The ones in iop shouldn't really be 64 bit masks, so changing them
      to what the driver can support avoids the warning.
      
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      2125801c
    • Arnd Bergmann's avatar
      ARM: orion: don't use using 64-bit DMA masks · cd92d74d
      Arnd Bergmann authored
      
      clang warns about statically defined DMA masks from the DMA_BIT_MASK
      macro with length 64:
      
      arch/arm/plat-orion/common.c:625:29: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
                      .coherent_dma_mask      = DMA_BIT_MASK(64),
                                                ^~~~~~~~~~~~~~~~
      include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK'
       #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
      
      The ones in orion shouldn't really be 64 bit masks, so changing them
      to what the driver can support avoids the warning.
      
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      cd92d74d
    • Olof Johansson's avatar
      Revert "ARM: dts: nomadik: Fix polarity of SPI CS" · fbe8758f
      Olof Johansson authored
      
      This reverts commit fa946356.
      
      Per Linus Walleij:
      
      Dear ARM SoC maintainers,
      
      can you please revert this patch. It was the wrong solution to the
      wrong problem, and I must have acted in stress. Andrey fixed the
      real bug in a proper way in these commits:
      
      commit e5545c94
      "gpio: of: Check propname before applying "cs-gpios" quirks"
      commit 7ce40277
      "gpio: of: Check for "spi-cs-high" in child instead of parent node"
      
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      fbe8758f
    • Christophe Leroy's avatar
      powerpc/vdso32: fix CLOCK_MONOTONIC on PPC64 · dd9a994f
      Christophe Leroy authored
      
      Commit b5b4453e ("powerpc/vdso64: Fix CLOCK_MONOTONIC
      inconsistencies across Y2038") changed the type of wtom_clock_sec
      to s64 on PPC64. Therefore, VDSO32 needs to read it with a 4 bytes
      shift in order to retrieve the lower part of it.
      
      Fixes: b5b4453e ("powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038")
      Reported-by: default avatarChristian Zigotzky <chzigotzky@xenosoft.de>
      Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      dd9a994f
  5. Apr 06, 2019
    • Helge Deller's avatar
      parisc: Detect QEMU earlier in boot process · d006e95b
      Helge Deller authored
      
      While adding LASI support to QEMU, I noticed that the QEMU detection in
      the kernel happens much too late. For example, when a LASI chip is found
      by the kernel, it registers the LASI LED driver as well.  But when we
      run on QEMU it makes sense to avoid spending unnecessary CPU cycles, so
      we need to access the running_on_QEMU flag earlier than before.
      
      This patch now makes the QEMU detection the fist task of the Linux
      kernel by moving it to where the kernel enters the C-coding.
      
      Fixes: 310d8278 ("parisc: qemu idle sleep support")
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Cc: stable@vger.kernel.org # v4.14+
      d006e95b
    • Sven Schnelle's avatar
      parisc: also set iaoq_b in instruction_pointer_set() · f324fa58
      Sven Schnelle authored
      
      When setting the instruction pointer on PA-RISC we also need
      to set the back of the instruction queue to the new offset, otherwise
      we will execute on instruction from the new location, and jumping
      back to the old location stored in iaoq_b.
      
      Signed-off-by: default avatarSven Schnelle <svens@stackframe.org>
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Fixes: 75ebedf1 ("parisc: Add HAVE_REGS_AND_STACK_ACCESS_API feature")
      Cc: stable@vger.kernel.org # 4.19+
      f324fa58
    • Sven Schnelle's avatar
      parisc: regs_return_value() should return gpr28 · 45efd871
      Sven Schnelle authored
      
      While working on kretprobes for PA-RISC I was wondering while the
      kprobes sanity test always fails on kretprobes. This is caused by
      returning gpr20 instead of gpr28.
      
      Signed-off-by: default avatarSven Schnelle <svens@stackframe.org>
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Cc: stable@vger.kernel.org # 4.14+
      45efd871
    • Alexander Potapenko's avatar
      x86/asm: Use stricter assembly constraints in bitops · 5b77e95d
      Alexander Potapenko authored
      There's a number of problems with how arch/x86/include/asm/bitops.h
      is currently using assembly constraints for the memory region
      bitops are modifying:
      
      1) Use memory clobber in bitops that touch arbitrary memory
      
      Certain bit operations that read/write bits take a base pointer and an
      arbitrarily large offset to address the bit relative to that base.
      Inline assembly constraints aren't expressive enough to tell the
      compiler that the assembly directive is going to touch a specific memory
      location of unknown size, therefore we have to use the "memory" clobber
      to indicate that the assembly is going to access memory locations other
      than those listed in the inputs/outputs.
      
      To indicate that BTR/BTS instructions don't necessarily touch the first
      sizeof(long) bytes of the argument, we also move the address to assembly
      inputs.
      
      This particular change leads to size increase of 124 kernel functions in
      a defconfig build. For some of them the diff is in NOP operations, other
      end up re-reading values from memory and may potentially slow down the
      execution. But without these clobbers the compiler is free to cache
      the contents of the bitmaps and use them as if they weren't changed by
      the inline assembly.
      
      2) Use byte-sized arguments for operations touching single bytes.
      
      Passing a long value to ANDB/ORB/XORB instructions makes the compiler
      treat sizeof(long) bytes as being clobbered, which isn't the case. This
      may theoretically lead to worse code in the case of heavy optimization.
      
      Practical impact:
      
      I've built a defconfig kernel and looked through some of the functions
      generated by GCC 7.3.0 with and without this clobber, and didn't spot
      any miscompilations.
      
      However there is a (trivial) theoretical case where this code leads to
      miscompilation:
      
        https://lkml.org/lkml/2019/3/28/393
      
      
      
      using just GCC 8.3.0 with -O2.  It isn't hard to imagine someone writes
      such a function in the kernel someday.
      
      So the primary motivation is to fix an existing misuse of the asm
      directive, which happens to work in certain configurations now, but
      isn't guaranteed to work under different circumstances.
      
      [ --mingo: Added -stable tag because defconfig only builds a fraction
        of the kernel and the trivial testcase looks normal enough to
        be used in existing or in-development code. ]
      
      Signed-off-by: default avatarAlexander Potapenko <glider@google.com>
      Cc: <stable@vger.kernel.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: James Y Knight <jyknight@google.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Paul E. McKenney <paulmck@linux.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20190402112813.193378-1-glider@google.com
      
      
      [ Edited the changelog, tidied up one of the defines. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      5b77e95d
    • Randy Dunlap's avatar
      sh: fix multiple function definition build errors · acaf892e
      Randy Dunlap authored
      Many of the sh CPU-types have their own plat_irq_setup() and
      arch_init_clk_ops() functions, so these same (empty) functions in
      arch/sh/boards/of-generic.c are not needed and cause build errors.
      
      If there is some case where these empty functions are needed, they can
      be retained by marking them as "__weak" while at the same time making
      builds that do not need them succeed.
      
      Fixes these build errors:
      
      arch/sh/boards/of-generic.o: In function `plat_irq_setup':
      (.init.text+0x134): multiple definition of `plat_irq_setup'
      arch/sh/kernel/cpu/sh2/setup-sh7619.o:(.init.text+0x30): first defined here
      arch/sh/boards/of-generic.o: In function `arch_init_clk_ops':
      (.init.text+0x118): multiple definition of `arch_init_clk_ops'
      arch/sh/kernel/cpu/sh2/clock-sh7619.o:(.init.text+0x0): first defined here
      
      Link: http://lkml.kernel.org/r/9ee4e0c5-f100-86a2-bd4d-1d3287ceab31@infradead.org
      
      
      Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
      Reported-by: default avatarkbuild test robot <lkp@intel.com>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Rich Felker <dalias@libc.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      acaf892e
    • Catalin Marinas's avatar
      kmemleak: powerpc: skip scanning holes in the .bss section · 298a32b1
      Catalin Marinas authored
      Commit 2d4f5671 ("KVM: PPC: Introduce kvm_tmp framework") adds
      kvm_tmp[] into the .bss section and then free the rest of unused spaces
      back to the page allocator.
      
      kernel_init
        kvm_guest_init
          kvm_free_tmp
            free_reserved_area
              free_unref_page
                free_unref_page_prepare
      
      With DEBUG_PAGEALLOC=y, it will unmap those pages from kernel.  As the
      result, kmemleak scan will trigger a panic when it scans the .bss
      section with unmapped pages.
      
      This patch creates dedicated kmemleak objects for the .data, .bss and
      potentially .data..ro_after_init sections to allow partial freeing via
      the kmemleak_free_part() in the powerpc kvm_free_tmp() function.
      
      Link: http://lkml.kernel.org/r/20190321171917.62049-1-catalin.marinas@arm.com
      
      
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Reported-by: default avatarQian Cai <cai@lca.pw>
      Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Tested-by: default avatarQian Cai <cai@lca.pw>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krcmar <rkrcmar@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      298a32b1
  6. Apr 05, 2019
    • Marc Orr's avatar
      KVM: x86: nVMX: fix x2APIC VTPR read intercept · c73f4c99
      Marc Orr authored
      
      Referring to the "VIRTUALIZING MSR-BASED APIC ACCESSES" chapter of the
      SDM, when "virtualize x2APIC mode" is 1 and "APIC-register
      virtualization" is 0, a RDMSR of 808H should return the VTPR from the
      virtual APIC page.
      
      However, for nested, KVM currently fails to disable the read intercept
      for this MSR. This means that a RDMSR exit takes precedence over
      "virtualize x2APIC mode", and KVM passes through L1's TPR to L2,
      instead of sourcing the value from L2's virtual APIC page.
      
      This patch fixes the issue by disabling the read intercept, in VMCS02,
      for the VTPR when "APIC-register virtualization" is 0.
      
      The issue described above and fix prescribed here, were verified with
      a related patch in kvm-unit-tests titled "Test VMX's virtualize x2APIC
      mode w/ nested".
      
      Signed-off-by: default avatarMarc Orr <marcorr@google.com>
      Reviewed-by: default avatarJim Mattson <jmattson@google.com>
      Fixes: c992384b ("KVM: vmx: speed up MSR bitmap merge")
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      c73f4c99
    • Marc Orr's avatar
      KVM: x86: nVMX: close leak of L0's x2APIC MSRs (CVE-2019-3887) · acff7847
      Marc Orr authored
      
      The nested_vmx_prepare_msr_bitmap() function doesn't directly guard the
      x2APIC MSR intercepts with the "virtualize x2APIC mode" MSR. As a
      result, we discovered the potential for a buggy or malicious L1 to get
      access to L0's x2APIC MSRs, via an L2, as follows.
      
      1. L1 executes WRMSR(IA32_SPEC_CTRL, 1). This causes the spec_ctrl
      variable, in nested_vmx_prepare_msr_bitmap() to become true.
      2. L1 disables "virtualize x2APIC mode" in VMCS12.
      3. L1 enables "APIC-register virtualization" in VMCS12.
      
      Now, KVM will set VMCS02's x2APIC MSR intercepts from VMCS12, and then
      set "virtualize x2APIC mode" to 0 in VMCS02. Oops.
      
      This patch closes the leak by explicitly guarding VMCS02's x2APIC MSR
      intercepts with VMCS12's "virtualize x2APIC mode" control.
      
      The scenario outlined above and fix prescribed here, were verified with
      a related patch in kvm-unit-tests titled "Add leak scenario to
      virt_x2apic_mode_test".
      
      Note, it looks like this issue may have been introduced inadvertently
      during a merge---see 15303ba5.
      
      Signed-off-by: default avatarMarc Orr <marcorr@google.com>
      Reviewed-by: default avatarJim Mattson <jmattson@google.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      acff7847
    • David Rientjes's avatar
      KVM: SVM: prevent DBG_DECRYPT and DBG_ENCRYPT overflow · b86bc285
      David Rientjes authored
      
      This ensures that the address and length provided to DBG_DECRYPT and
      DBG_ENCRYPT do not cause an overflow.
      
      At the same time, pass the actual number of pages pinned in memory to
      sev_unpin_memory() as a cleanup.
      
      Reported-by: default avatarCfir Cohen <cfir@google.com>
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      b86bc285
    • David Rientjes's avatar
      kvm: svm: fix potential get_num_contig_pages overflow · ede885ec
      David Rientjes authored
      
      get_num_contig_pages() could potentially overflow int so make its type
      consistent with its usage.
      
      Reported-by: default avatarCfir Cohen <cfir@google.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      ede885ec
    • Steven Rostedt (VMware)'s avatar
      syscalls: Remove start and number from syscall_set_arguments() args · 32d92586
      Steven Rostedt (VMware) authored
      After removing the start and count arguments of syscall_get_arguments() it
      seems reasonable to remove them from syscall_set_arguments(). Note, as of
      today, there are no users of syscall_set_arguments(). But we are told that
      there will be soon. But for now, at least make it consistent with
      syscall_get_arguments().
      
      Link: http://lkml.kernel.org/r/20190327222014.GA32540@altlinux.org
      
      
      
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dominik Brodowski <linux@dominikbrodowski.net>
      Cc: Dave Martin <dave.martin@arm.com>
      Cc: "Dmitry V. Levin" <ldv@altlinux.org>
      Cc: x86@kernel.org
      Cc: linux-snps-arc@lists.infradead.org
      Cc: linux-kernel@vger.kernel.org
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: linux-c6x-dev@linux-c6x.org
      Cc: uclinux-h8-devel@lists.sourceforge.jp
      Cc: linux-hexagon@vger.kernel.org
      Cc: linux-ia64@vger.kernel.org
      Cc: linux-mips@vger.kernel.org
      Cc: nios2-dev@lists.rocketboards.org
      Cc: openrisc@lists.librecores.org
      Cc: linux-parisc@vger.kernel.org
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: linux-riscv@lists.infradead.org
      Cc: linux-s390@vger.kernel.org
      Cc: linux-sh@vger.kernel.org
      Cc: sparclinux@vger.kernel.org
      Cc: linux-um@lists.infradead.org
      Cc: linux-xtensa@linux-xtensa.org
      Cc: linux-arch@vger.kernel.org
      Acked-by: Max Filippov <jcmvbkbc@gmail.com> # For xtensa changes
      Acked-by: Will Deacon <will.deacon@arm.com> # For the arm64 bits
      Reviewed-by: Thomas Gleixner <tglx@linutronix.de> # for x86
      Reviewed-by: default avatarDmitry V. Levin <ldv@altlinux.org>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      32d92586
    • Steven Rostedt (Red Hat)'s avatar
      syscalls: Remove start and number from syscall_get_arguments() args · b35f549d
      Steven Rostedt (Red Hat) authored
      At Linux Plumbers, Andy Lutomirski approached me and pointed out that the
      function call syscall_get_arguments() implemented in x86 was horribly
      written and not optimized for the standard case of passing in 0 and 6 for
      the starting index and the number of system calls to get. When looking at
      all the users of this function, I discovered that all instances pass in only
      0 and 6 for these arguments. Instead of having this function handle
      different cases that are never used, simply rewrite it to return the first 6
      arguments of a system call.
      
      This should help out the performance of tracing system calls by ptrace,
      ftrace and perf.
      
      Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org
      
      
      
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dominik Brodowski <linux@dominikbrodowski.net>
      Cc: Dave Martin <dave.martin@arm.com>
      Cc: "Dmitry V. Levin" <ldv@altlinux.org>
      Cc: x86@kernel.org
      Cc: linux-snps-arc@lists.infradead.org
      Cc: linux-kernel@vger.kernel.org
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: linux-c6x-dev@linux-c6x.org
      Cc: uclinux-h8-devel@lists.sourceforge.jp
      Cc: linux-hexagon@vger.kernel.org
      Cc: linux-ia64@vger.kernel.org
      Cc: linux-mips@vger.kernel.org
      Cc: nios2-dev@lists.rocketboards.org
      Cc: openrisc@lists.librecores.org
      Cc: linux-parisc@vger.kernel.org
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: linux-riscv@lists.infradead.org
      Cc: linux-s390@vger.kernel.org
      Cc: linux-sh@vger.kernel.org
      Cc: sparclinux@vger.kernel.org
      Cc: linux-um@lists.infradead.org
      Cc: linux-xtensa@linux-xtensa.org
      Cc: linux-arch@vger.kernel.org
      Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts
      Acked-by: Max Filippov <jcmvbkbc@gmail.com> # For xtensa changes
      Acked-by: Will Deacon <will.deacon@arm.com> # For the arm64 bits
      Reviewed-by: Thomas Gleixner <tglx@linutronix.de> # for x86
      Reviewed-by: default avatarDmitry V. Levin <ldv@altlinux.org>
      Reported-by: default avatarAndy Lutomirski <luto@amacapital.net>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      b35f549d
    • Dan Carpenter's avatar
      xen: Prevent buffer overflow in privcmd ioctl · 42d8644b
      Dan Carpenter authored
      
      The "call" variable comes from the user in privcmd_ioctl_hypercall().
      It's an offset into the hypercall_page[] which has (PAGE_SIZE / 32)
      elements.  We need to put an upper bound on it to prevent an out of
      bounds access.
      
      Cc: stable@vger.kernel.org
      Fixes: 1246ae0b ("xen: add variable hypercall caller")
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
      Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
      42d8644b
    • Max Filippov's avatar
      xtensa: fix format string warning in init_pmd · ecae26fa
      Max Filippov authored
      
      Use %lu instead of %zu to fix the following warning introduced with
      recent memblock refactoring:
        xtensa/mm/mmu.c:36:9: warning: format '%zu' expects argument of type
        'size_t', but argument 3 has type 'long unsigned int
      
      Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
      ecae26fa
  7. Apr 04, 2019
  8. Apr 03, 2019
    • Lendacky, Thomas's avatar
      x86/perf/amd: Resolve NMI latency issues for active PMCs · 6d3edaae
      Lendacky, Thomas authored
      
      On AMD processors, the detection of an overflowed PMC counter in the NMI
      handler relies on the current value of the PMC. So, for example, to check
      for overflow on a 48-bit counter, bit 47 is checked to see if it is 1 (not
      overflowed) or 0 (overflowed).
      
      When the perf NMI handler executes it does not know in advance which PMC
      counters have overflowed. As such, the NMI handler will process all active
      PMC counters that have overflowed. NMI latency in newer AMD processors can
      result in multiple overflowed PMC counters being processed in one NMI and
      then a subsequent NMI, that does not appear to be a back-to-back NMI, not
      finding any PMC counters that have overflowed. This may appear to be an
      unhandled NMI resulting in either a panic or a series of messages,
      depending on how the kernel was configured.
      
      To mitigate this issue, add an AMD handle_irq callback function,
      amd_pmu_handle_irq(), that will invoke the common x86_pmu_handle_irq()
      function and upon return perform some additional processing that will
      indicate if the NMI has been handled or would have been handled had an
      earlier NMI not handled the overflowed PMC. Using a per-CPU variable, a
      minimum value of the number of active PMCs or 2 will be set whenever a
      PMC is active. This is used to indicate the possible number of NMIs that
      can still occur. The value of 2 is used for when an NMI does not arrive
      at the LAPIC in time to be collapsed into an already pending NMI. Each
      time the function is called without having handled an overflowed counter,
      the per-CPU value is checked. If the value is non-zero, it is decremented
      and the NMI indicates that it handled the NMI. If the value is zero, then
      the NMI indicates that it did not handle the NMI.
      
      Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: <stable@vger.kernel.org> # 4.14.x-
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Link: https://lkml.kernel.org/r/Message-ID
      
      :
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      6d3edaae
    • Lendacky, Thomas's avatar
      x86/perf/amd: Resolve race condition when disabling PMC · 914123fa
      Lendacky, Thomas authored
      
      On AMD processors, the detection of an overflowed counter in the NMI
      handler relies on the current value of the counter. So, for example, to
      check for overflow on a 48 bit counter, bit 47 is checked to see if it
      is 1 (not overflowed) or 0 (overflowed).
      
      There is currently a race condition present when disabling and then
      updating the PMC. Increased NMI latency in newer AMD processors makes this
      race condition more pronounced. If the counter value has overflowed, it is
      possible to update the PMC value before the NMI handler can run. The
      updated PMC value is not an overflowed value, so when the perf NMI handler
      does run, it will not find an overflowed counter. This may appear as an
      unknown NMI resulting in either a panic or a series of messages, depending
      on how the kernel is configured.
      
      To eliminate this race condition, the PMC value must be checked after
      disabling the counter. Add an AMD function, amd_pmu_disable_all(), that
      will wait for the NMI handler to reset any active and overflowed counter
      after calling x86_pmu_disable_all().
      
      Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: <stable@vger.kernel.org> # 4.14.x-
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Link: https://lkml.kernel.org/r/Message-ID
      
      :
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      914123fa
    • Peter Zijlstra's avatar
      perf/x86/intel: Initialize TFA MSR · d7262457
      Peter Zijlstra authored
      
      Stephane reported that the TFA MSR is not initialized by the kernel,
      but the TFA bit could set by firmware or as a leftover from a kexec,
      which makes the state inconsistent.
      
      Reported-by: default avatarStephane Eranian <eranian@google.com>
      Tested-by: default avatarNelson DSouza <nelson.dsouza@intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Cc: tonyj@suse.com
      Link: https://lkml.kernel.org/r/20190321123849.GN6521@hirez.programming.kicks-ass.net
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      d7262457
    • Stephane Eranian's avatar
      perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS · 583feb08
      Stephane Eranian authored
      
      When an event is programmed with attr.wakeup_events=N (N>0), it means
      the caller is interested in getting a user level notification after
      N samples have been recorded in the kernel sampling buffer.
      
      With precise events on Intel processors, the kernel uses PEBS.
      The kernel tries minimize sampling overhead by verifying
      if the event configuration is compatible with multi-entry PEBS mode.
      If so, the kernel is notified only when the buffer has reached its threshold.
      Other PEBS operates in single-entry mode, the kenrel is notified for each
      PEBS sample.
      
      The problem is that the current implementation look at frequency
      mode and event sample_type but ignores the wakeup_events field. Thus,
      it may not be possible to receive a notification after each precise event.
      
      This patch fixes this problem by disabling multi-entry PEBS if wakeup_events
      is non-zero.
      
      Signed-off-by: default avatarStephane Eranian <eranian@google.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Reviewed-by: default avatarAndi Kleen <ak@linux.intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Cc: kan.liang@intel.com
      Link: https://lkml.kernel.org/r/20190306195048.189514-1-eranian@google.com
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      583feb08
  9. Apr 01, 2019
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