1. 10 5月, 2015 2 次提交
  2. 08 5月, 2015 6 次提交
    • D
      x86/entry: Define 'cpu_current_top_of_stack' for 64-bit code · 3a23208e
      Denys Vlasenko 提交于
      32-bit code has PER_CPU_VAR(cpu_current_top_of_stack).
      64-bit code uses somewhat more obscure: PER_CPU_VAR(cpu_tss + TSS_sp0).
      
      Define the 'cpu_current_top_of_stack' macro on CONFIG_X86_64
      as well so that the PER_CPU_VAR(cpu_current_top_of_stack)
      expression can be used in both 32-bit and 64-bit code.
      Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
      Cc: Alexei Starovoitov <ast@plumgrid.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Will Drewry <wad@chromium.org>
      Link: http://lkml.kernel.org/r/1429889495-27850-3-git-send-email-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      3a23208e
    • D
      x86/entry: Remove unused 'kernel_stack' per-cpu variable · fed7c3f0
      Denys Vlasenko 提交于
      Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
      Acked-by: NAndy Lutomirski <luto@kernel.org>
      Cc: Alexei Starovoitov <ast@plumgrid.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Will Drewry <wad@chromium.org>
      Link: http://lkml.kernel.org/r/1429889495-27850-2-git-send-email-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      fed7c3f0
    • D
      x86/entry: Stop using PER_CPU_VAR(kernel_stack) · 63332a84
      Denys Vlasenko 提交于
      PER_CPU_VAR(kernel_stack) is redundant:
      
        - On the 64-bit build, we can use PER_CPU_VAR(cpu_tss + TSS_sp0).
        - On the 32-bit build, we can use PER_CPU_VAR(cpu_current_top_of_stack).
      
      PER_CPU_VAR(kernel_stack) will be deleted by a separate change.
      Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
      Cc: Alexei Starovoitov <ast@plumgrid.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Will Drewry <wad@chromium.org>
      Link: http://lkml.kernel.org/r/1429889495-27850-1-git-send-email-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      63332a84
    • D
      x86: Force inlining of atomic ops · 2a4e90b1
      Denys Vlasenko 提交于
      With both gcc 4.7.2 and 4.9.2, sometimes gcc mysteriously
      doesn't inline very small functions we expect to be inlined:
      
      $ nm --size-sort vmlinux | grep -iF ' t ' | uniq -c | grep -v '^
      *1 ' | sort -rn     473 000000000000000b t spin_unlock_irqrestore
          449 000000000000005f t rcu_read_unlock
          355 0000000000000009 t atomic_inc                <== THIS
          353 000000000000006e t rcu_read_lock
          350 0000000000000075 t rcu_read_lock_sched_held
          291 000000000000000b t spin_unlock
          266 0000000000000019 t arch_local_irq_restore
          215 000000000000000b t spin_lock
          180 0000000000000011 t kzalloc
          165 0000000000000012 t list_add_tail
          161 0000000000000019 t arch_local_save_flags
          153 0000000000000016 t test_and_set_bit
          134 000000000000000b t spin_unlock_irq
          134 0000000000000009 t atomic_dec                <== THIS
          130 000000000000000b t spin_unlock_bh
          122 0000000000000010 t brelse
          120 0000000000000016 t test_and_clear_bit
          120 000000000000000b t spin_lock_irq
          119 000000000000001e t get_dma_ops
          117 0000000000000053 t cpumask_next
          116 0000000000000036 t kref_get
          114 000000000000001a t schedule_work
          106 000000000000000b t spin_lock_bh
          103 0000000000000019 t arch_local_irq_disable
      ...
      
      Note sizes of marked functions. They are merely 9 bytes long!
      Selecting function with 'atomic' in their names:
      
          355 0000000000000009 t atomic_inc
          134 0000000000000009 t atomic_dec
           98 0000000000000014 t atomic_dec_and_test
           31 000000000000000e t atomic_add_return
           27 000000000000000a t atomic64_inc
           26 000000000000002f t kmap_atomic
           24 0000000000000009 t atomic_add
           12 0000000000000009 t atomic_sub
           10 0000000000000021 t __atomic_add_unless
           10 000000000000000a t atomic64_add
            5 000000000000001f t __atomic_add_unless.constprop.7
            5 000000000000000a t atomic64_dec
            4 000000000000001f t __atomic_add_unless.constprop.18
            4 000000000000001f t __atomic_add_unless.constprop.12
            4 000000000000001f t __atomic_add_unless.constprop.10
            3 000000000000001f t __atomic_add_unless.constprop.13
            3 0000000000000011 t atomic64_add_return
            2 000000000000001f t __atomic_add_unless.constprop.9
            2 000000000000001f t __atomic_add_unless.constprop.8
            2 000000000000001f t __atomic_add_unless.constprop.6
            2 000000000000001f t __atomic_add_unless.constprop.5
            2 000000000000001f t __atomic_add_unless.constprop.3
            2 000000000000001f t __atomic_add_unless.constprop.22
            2 000000000000001f t __atomic_add_unless.constprop.14
            2 000000000000001f t __atomic_add_unless.constprop.11
            2 000000000000001e t atomic_dec_if_positive
            2 0000000000000014 t atomic_inc_and_test
            2 0000000000000011 t atomic_add_return.constprop.4
            2 0000000000000011 t atomic_add_return.constprop.17
            2 0000000000000011 t atomic_add_return.constprop.16
            2 000000000000000d t atomic_inc.constprop.4
            2 000000000000000c t atomic_cmpxchg
      
      This patch fixes this for x86 atomic ops via
      s/inline/__always_inline/. This decreases allyesconfig kernel by
      about 25k:
      
          text     data      bss       dec     hex filename
      82399481 22255416 20627456 125282353 777a831 vmlinux.before
      82375570 22255544 20627456 125258570 7774b4a vmlinux
      Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
      Cc: Alexei Starovoitov <ast@plumgrid.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Will Drewry <wad@chromium.org>
      Link: http://lkml.kernel.org/r/1431080762-17797-1-git-send-email-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      2a4e90b1
    • D
      x86/asm/entry/64: Clean up usage of TEST insns · 03335e95
      Denys Vlasenko 提交于
      By the nature of TEST operation, it is often possible
      to test a narrower part of the operand:
      
          "testl $3, mem"  -> "testb $3, mem"
      
      This results in shorter insns, because TEST insn has no
      sign-entending byte-immediate forms unlike other ALU ops.
      
         text	   data	    bss	    dec	    hex	filename
        11674	      0	      0	  11674	   2d9a	entry_64.o.before
        11658	      0	      0	  11658	   2d8a	entry_64.o
      
      Changes in object code:
      
      -	f7 84 24 88 00 00 00 03 00 00 00 	testl  $0x3,0x88(%rsp)
      +	f6 84 24 88 00 00 00 03	         	testb  $0x3,0x88(%rsp)
      -	f7 44 24 68 03 00 00 00          	testl  $0x3,0x68(%rsp)
      +	f6 44 24 68 03                  	testb  $0x3,0x68(%rsp)
      -	f7 84 24 90 00 00 00 03 00 00 00	testl  $0x3,0x90(%rsp)
      +	f6 84 24 90 00 00 00 03         	testb  $0x3,0x90(%rsp)
      Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
      Acked-by: NAndy Lutomirski <luto@kernel.org>
      Cc: Alexei Starovoitov <ast@plumgrid.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Will Drewry <wad@chromium.org>
      Link: http://lkml.kernel.org/r/1430140912-7960-2-git-send-email-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      03335e95
    • D
      x86/asm/entry/64: Tidy up JZ insns after TESTs · dde74f2e
      Denys Vlasenko 提交于
      After TESTs, use logically correct JZ/JNZ mnemonics instead of
      JE/JNE. This doesn't change code.
      Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
      Acked-by: NAndy Lutomirski <luto@kernel.org>
      Cc: Alexei Starovoitov <ast@plumgrid.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Will Drewry <wad@chromium.org>
      Link: http://lkml.kernel.org/r/1430140912-7960-1-git-send-email-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      dde74f2e
  3. 06 5月, 2015 6 次提交
  4. 05 5月, 2015 1 次提交
  5. 01 5月, 2015 5 次提交
    • S
      powerpc/powernv: Restore non-volatile CRs after nap · 0aab3747
      Sam Bobroff 提交于
      Patches 7cba160a "powernv/cpuidle: Redesign idle states management"
      and 77b54e9f "powernv/powerpc: Add winkle support for offline cpus"
      use non-volatile condition registers (cr2, cr3 and cr4) early in the system
      reset interrupt handler (system_reset_pSeries()) before it has been determined
      if state loss has occurred. If state loss has not occurred, control returns via
      the power7_wakeup_noloss() path which does not restore those condition
      registers, leaving them corrupted.
      
      Fix this by restoring the condition registers in the power7_wakeup_noloss()
      case.
      
      This is apparent when running a KVM guest on hardware that does not
      support winkle or sleep and the guest makes use of secondary threads. In
      practice this means Power7 machines, though some early unreleased Power8
      machines may also be susceptible.
      
      The secondary CPUs are taken off line before the guest is started and
      they call pnv_smp_cpu_kill_self(). This checks support for sleep
      states (in this case there is no support) and power7_nap() is called.
      
      When the CPU is woken, power7_nap() returns and because the CPU is
      still off line, the main while loop executes again. The sleep states
      support test is executed again, but because the tested values cannot
      have changed, the compiler has optimized the test away and instead we
      rely on the result of the first test, which has been left in cr3
      and/or cr4. With the result overwritten, the wrong branch is taken and
      power7_winkle() is called on a CPU that does not support it, leading
      to it stalling.
      
      Fixes: 7cba160a ("powernv/cpuidle: Redesign idle states management")
      Fixes: 77b54e9f ("powernv/powerpc: Add winkle support for offline cpus")
      [mpe: Massage change log a bit more]
      Signed-off-by: NSam Bobroff <sam.bobroff@au1.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      0aab3747
    • G
      powerpc/eeh: Delay probing EEH device during hotplug · d91dafc0
      Gavin Shan 提交于
      Commit 1c509148b ("powerpc/eeh: Do probe on pci_dn") probes EEH
      devices in early stage, which is reasonable to pSeries platform.
      However, it's wrong for PowerNV platform because the PE# isn't
      determined until the resources (IO and MMIO) are assigned to
      PE in hotplug case. So we have to delay probing EEH devices
      for PowerNV platform until the PE# is assigned.
      
      Fixes: ff57b454 ("powerpc/eeh: Do probe on pci_dn")
      Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      d91dafc0
    • G
      powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state() · 1ae79b78
      Gavin Shan 提交于
      When asserting reset in pcibios_set_pcie_reset_state(), the PE
      is enforced to (hardware) frozen state in order to drop unexpected
      PCI transactions (except PCI config read/write) automatically by
      hardware during reset, which would cause recursive EEH error.
      However, the (software) frozen state EEH_PE_ISOLATED is missed.
      When users get 0xFF from PCI config or MMIO read, EEH_PE_ISOLATED
      is set in PE state retrival backend. Unfortunately, nobody (the
      reset handler or the EEH recovery functinality in host) will clear
      EEH_PE_ISOLATED when the PE has been passed through to guest.
      
      The patch sets and clears EEH_PE_ISOLATED properly during reset
      in function pcibios_set_pcie_reset_state() to fix the issue.
      
      Fixes: 28158cd1 ("Enhance pcibios_set_pcie_reset_state()")
      Reported-by: NCarol L. Soto <clsoto@us.ibm.com>
      Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
      Tested-by: NCarol L. Soto <clsoto@us.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      1ae79b78
    • N
      powerpc/pseries: Correct cpu affinity for dlpar added cpus · f32393c9
      Nathan Fontenot 提交于
      The incorrect ordering of operations during cpu dlpar add results in invalid
      affinity for the cpu being added. The ibm,associativity property in the
      device tree is populated with all zeroes for the added cpu which results in
      invalid affinity mappings and all cpus appear to belong to node 0.
      
      This occurs because rtas configure-connector is called prior to making the
      rtas set-indicator calls. Phyp does not assign affinity information
      for a cpu until the rtas set-indicator calls are made to set the isolation
      and allocation state.
      
      Correct the order of operations to make the rtas set-indicator
      calls (done in dlpar_acquire_drc) before calling rtas configure-connector.
      
      Fixes: 1a8061c4 ("powerpc/pseries: Add kernel based CPU DLPAR handling")
      Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      f32393c9
    • J
      x86/PCI/ACPI: Make all resources except [io 0xcf8-0xcff] available on PCI bus · 2c62e849
      Jiang Liu 提交于
      An IO port or MMIO resource assigned to a PCI host bridge may be
      consumed by the host bridge itself or available to its child
      bus/devices. The ACPI specification defines a bit (Producer/Consumer)
      to tell whether the resource is consumed by the host bridge itself,
      but firmware hasn't used that bit consistently, so we can't rely on it.
      
      Before commit 593669c2 ("x86/PCI/ACPI: Use common ACPI resource
      interfaces to simplify implementation"), arch/x86/pci/acpi.c ignored
      all IO port resources defined by acpi_resource_io and
      acpi_resource_fixed_io to filter out IO ports consumed by the host
      bridge itself.
      
      Commit 593669c2 ("x86/PCI/ACPI: Use common ACPI resource interfaces
      to simplify implementation") started accepting all IO port and MMIO
      resources, which caused a regression that IO port resources consumed
      by the host bridge itself became available to its child devices.
      
      Then commit 63f1789e ("x86/PCI/ACPI: Ignore resources consumed by
      host bridge itself") ignored resources consumed by the host bridge
      itself by checking the IORESOURCE_WINDOW flag, which accidently removed
      MMIO resources defined by acpi_resource_memory24, acpi_resource_memory32
      and acpi_resource_fixed_memory32.
      
      On x86 and IA64 platforms, all IO port and MMIO resources are assumed
      to be available to child bus/devices except one special case:
          IO port [0xCF8-0xCFF] is consumed by the host bridge itself
          to access PCI configuration space.
      
      So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF]. This solution
      will also ease the way to consolidate ACPI PCI host bridge common code
      from x86, ia64 and ARM64.
      
      Related ACPI table are archived at:
      https://bugzilla.kernel.org/show_bug.cgi?id=94221
      
      Related discussions at:
      http://patchwork.ozlabs.org/patch/461633/
      https://lkml.org/lkml/2015/3/29/304
      
      Fixes: 63f1789e (Ignore resources consumed by host bridge itself)
      Reported-by: NBernhard Thaler <bernhard.thaler@wvnet.at>
      Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
      Cc: 4.0+ <stable@vger.kernel.org> # 4.0+
      Reviewed-by: NBjorn Helgaas <bhelgaas@google.com>
      Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      2c62e849
  6. 30 4月, 2015 5 次提交
  7. 29 4月, 2015 2 次提交
  8. 28 4月, 2015 1 次提交
  9. 27 4月, 2015 6 次提交
  10. 24 4月, 2015 6 次提交
    • L
      x86: fix special __probe_kernel_write() tail zeroing case · d869844b
      Linus Torvalds 提交于
      Commit cae2a173 ("x86: clean up/fix 'copy_in_user()' tail zeroing")
      fixed the failure case tail zeroing of one special case of the x86-64
      generic user-copy routine, namely when used for the user-to-user case
      ("copy_in_user()").
      
      But in the process it broke an even more unusual case: using the user
      copy routine for kernel-to-kernel copying.
      
      Now, normally kernel-kernel copies are obviously done using memcpy(),
      but we have a couple of special cases when we use the user-copy
      functions.  One is when we pass a kernel buffer to a regular user-buffer
      routine, using set_fs(KERNEL_DS).  That's a "normal" case, and continued
      to work fine, because it never takes any faults (with the possible
      exception of a silent and successful vmalloc fault).
      
      But Jan Beulich pointed out another, very unusual, special case: when we
      use the user-copy routines not because it's a path that expects a user
      pointer, but for a couple of ftrace/kgdb cases that want to do a kernel
      copy, but do so using "unsafe" buffers, and use the user-copy routine to
      gracefully handle faults.  IOW, for probe_kernel_write().
      
      And that broke for the case of a faulting kernel destination, because we
      saw the kernel destination and wanted to try to clear the tail of the
      buffer.  Which doesn't work, since that's what faults.
      
      This only triggers for things like kgdb and ftrace users (eg trying
      setting a breakpoint on read-only memory), but it's definitely a bug.
      The fix is to not compare against the kernel address start (TASK_SIZE),
      but instead use the same limits "access_ok()" uses.
      Reported-and-tested-by: NJan Beulich <jbeulich@suse.com>
      Cc: stable@vger.kernel.org # 4.0
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d869844b
    • A
      crypto: x86/sha512_ssse3 - fixup for asm function prototype change · 00425bb1
      Ard Biesheuvel 提交于
      Patch e68410eb ("crypto: x86/sha512_ssse3 - move SHA-384/512
      SSSE3 implementation to base layer") changed the prototypes of the
      core asm SHA-512 implementations so that they are compatible with
      the prototype used by the base layer.
      
      However, in one instance, the register that was used for passing the
      input buffer was reused as a scratch register later on in the code,
      and since the input buffer param changed places with the digest param
      -which needs to be written back before the function returns- this
      resulted in the scratch register to be dereferenced in a memory write
      operation, causing a GPF.
      
      Fix this by changing the scratch register to use the same register as
      the input buffer param again.
      
      Fixes: e68410eb ("crypto: x86/sha512_ssse3 - move SHA-384/512 SSSE3 implementation to base layer")
      Reported-By: NBobby Powers <bobbypowers@gmail.com>
      Tested-By: NBobby Powers <bobbypowers@gmail.com>
      Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
      00425bb1
    • L
      nios2: rework cache · 1a70db49
      Ley Foon Tan 提交于
      - flush dcache before flush instruction cache
      - remork update_mmu_cache and flush_dcache_page
      - add shmparam.h
      Signed-off-by: NLey Foon Tan <lftan@altera.com>
      1a70db49
    • E
      nios2: Add types.h header required for __u32 type · 2009337e
      Ezequiel Garcia 提交于
      Reported by the header checker (CONFIG_HEADERS_CHECK=y):
      
        CHECK   usr/include/asm/ (31 files)
      ./usr/include/asm/ptrace.h:77: found __[us]{8,16,32,64} type without #include <linux/types.h>
      Signed-off-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
      Acked-by: NLey Foon Tan <lftan@altera.com>
      2009337e
    • S
      d91e14b3
    • C
      blackfin: Wire up missing syscalls · 4f650a59
      Chen Gang 提交于
      The related syscalls are below which may cause samples/kdbus building
      break in next-20150401 tree, the related information and error:
      
          CALL    scripts/checksyscalls.sh
        <stdin>:1223:2: warning: #warning syscall kcmp not implemented [-Wcpp]
        <stdin>:1226:2: warning: #warning syscall finit_module not implemented [-Wcpp]
        <stdin>:1229:2: warning: #warning syscall sched_setattr not implemented [-Wcpp]
        <stdin>:1232:2: warning: #warning syscall sched_getattr not implemented [-Wcpp]
        <stdin>:1235:2: warning: #warning syscall renameat2 not implemented [-Wcpp]
        <stdin>:1238:2: warning: #warning syscall seccomp not implemented [-Wcpp]
        <stdin>:1241:2: warning: #warning syscall getrandom not implemented [-Wcpp]
        <stdin>:1244:2: warning: #warning syscall memfd_create not implemented [-Wcpp]
        <stdin>:1247:2: warning: #warning syscall bpf not implemented [-Wcpp]
        <stdin>:1250:2: warning: #warning syscall execveat not implemented [-Wcpp]
        [...]
          HOSTCC  samples/kdbus/kdbus-workers
        samples/kdbus/kdbus-workers.c: In function ‘prime_new’:
        samples/kdbus/kdbus-workers.c:930:18: error: ‘__NR_memfd_create’ undeclared (first use in this function)
          p->fd = syscall(__NR_memfd_create, "prime-area", MFD_CLOEXEC);
                          ^
        samples/kdbus/kdbus-workers.c:930:18: note: each undeclared identifier is reported only once for each function it appears in
      Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
      4f650a59