1. 01 10月, 2014 4 次提交
    • L
      of/pci: Add pci_get_new_domain_nr() and of_get_pci_domain_nr() · 41e5c0f8
      Liviu Dudau 提交于
      Add pci_get_new_domain_nr() to allocate a new domain number and
      of_get_pci_domain_nr() to retrieve the PCI domain number of a given device
      from DT.  Host bridge drivers or architecture-specific code can choose to
      implement their PCI domain number policy using these two functions.
      
      Using of_get_pci_domain_nr() guarantees a stable PCI domain number on every
      boot provided that all host bridge controllers are assigned a number in the
      device tree using "linux,pci-domain" property.  Mixing use of
      pci_get_new_domain_nr() and of_get_pci_domain_nr() is not recommended as it
      can lead to potentially conflicting domain numbers being assigned to root
      buses behind different host bridges.
      Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>
      Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      CC: Arnd Bergmann <arnd@arndb.de>
      CC: Grant Likely <grant.likely@linaro.org>
      CC: Rob Herring <robh+dt@kernel.org>
      CC: Catalin Marinas <catalin.marinas@arm.com>
      41e5c0f8
    • C
      PCI: Add generic domain handling · 670ba0c8
      Catalin Marinas 提交于
      The handling of PCI domains (or PCI segments in ACPI speak) is usually a
      straightforward affair but its implementation is currently left to the
      architectural code, with pci_domain_nr(b) querying the value of the domain
      associated with bus b.
      
      This patch introduces CONFIG_PCI_DOMAINS_GENERIC as an option that can be
      selected if an architecture wants a simple implementation where the value
      of the domain associated with a bus is stored in struct pci_bus.
      
      The architectures that select CONFIG_PCI_DOMAINS_GENERIC will then have to
      implement pci_bus_assign_domain_nr() as a way of setting the domain number
      associated with a root bus.  All child buses except the root bus will
      inherit the domain_nr value from their parent.
      Signed-off-by: NCatalin Marinas <Catalin.Marinas@arm.com>
      [Renamed pci_set_domain_nr() to pci_bus_assign_domain_nr()]
      Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>
      Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      CC: Arnd Bergmann <arnd@arndb.de>
      670ba0c8
    • L
      of/pci: Fix the conversion of IO ranges into IO resources · 0b0b0893
      Liviu Dudau 提交于
      The ranges property for a host bridge controller in DT describes the
      mapping between the PCI bus address and the CPU physical address.  The
      resources framework however expects that the IO resources start at a pseudo
      "port" address 0 (zero) and have a maximum size of IO_SPACE_LIMIT.  The
      conversion from PCI ranges to resources failed to take that into account,
      returning a CPU physical address instead of a port number.
      
      Also fix all the drivers that depend on the old behaviour by fetching the
      CPU physical address based on the port number where it is being needed.
      Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>
      Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      Acked-by: NLinus Walleij <linus.walleij@linaro.org>
      CC: Grant Likely <grant.likely@linaro.org>
      CC: Rob Herring <robh+dt@kernel.org>
      CC: Arnd Bergmann <arnd@arndb.de>
      CC: Thierry Reding <thierry.reding@gmail.com>
      CC: Simon Horman <horms@verge.net.au>
      CC: Catalin Marinas <catalin.marinas@arm.com>
      0b0b0893
    • L
      of/pci: Move of_pci_range_to_resource() to of/address.c · 83bbde1c
      Liviu Dudau 提交于
      We need to enhance of_pci_range_to_resources() enough that it won't make
      sense for it to be inline anymore.  Move it to drivers/of/address.c, under
      #ifdef CONFIG_PCI.
      
      of_address.h previously implemented of_pci_range_to_resources()
      unconditionally, regardless of any config options.  The implementation in
      address.c is defined only when CONFIG_OF_ADDRESS=y and CONFIG_PCI=y,
      so add a dummy version to avoid build errors when CONFIG_OF or
      CONFIG_OF_ADDRESS is not defined.
      
      [bhelgaas: drop extra detail from changelog, move def under CONFIG_PCI,
      add dummy of_pci_range_to_resource() for build errors (from Arnd)]
      Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>
      Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      CC: Grant Likely <grant.likely@linaro.org>
      CC: Rob Herring <robh+dt@kernel.org>
      CC: Arnd Bergmann <arnd@arndb.de>
      CC: Catalin Marinas <catalin.marinas@arm.com>
      83bbde1c
  2. 30 9月, 2014 1 次提交
    • L
      of/pci: Add pci_register_io_range() and pci_pio_to_address() · 41f8bba7
      Liviu Dudau 提交于
      Some architectures do not have a simple view of the PCI I/O space and
      instead use a range of CPU addresses that map to bus addresses.  For some
      architectures these ranges will be expressed by OF bindings in a device
      tree file.
      
      This patch introduces a pci_register_io_range() helper function with a
      generic implementation that can be used by such architectures to keep track
      of the I/O ranges described by the PCI bindings.  If the PCI_IOBASE macro
      is not defined, that signals lack of support for PCI and we return an
      error.
      
      In order to retrieve the CPU address associated with an I/O port, a new
      helper function pci_pio_to_address() is introduced.  This will search in
      the list of ranges registered with pci_register_io_range() and return the
      CPU address that corresponds to the given port.
      
      [arnd: add dummy !CONFIG_OF pci_pio_to_address() to fix build errors]
      Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>
      Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
      Acked-by: NRob Herring <robh@kernel.org>
      CC: Grant Likely <grant.likely@linaro.org>
      41f8bba7
  3. 23 8月, 2014 2 次提交
    • W
      nfs: don't sleep with inode lock in lock_and_join_requests · 7c3af975
      Weston Andros Adamson 提交于
      This handles the 'nonblock=false' case in nfs_lock_and_join_requests.
      If the group is already locked and blocking is allowed, drop the inode lock
      and wait for the group lock to be cleared before trying it all again.
      This should fix warnings found in peterz's tree (sched/wait branch), where
      might_sleep() checks are added to wait.[ch].
      Reported-by: NFengguang Wu <fengguang.wu@intel.com>
      Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
      Reviewed-by: NPeng Tao <tao.peng@primarydata.com>
      Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
      7c3af975
    • S
      ftrace: Allow ftrace_ops to use the hashes from other ops · 33b7f99c
      Steven Rostedt (Red Hat) 提交于
      Currently the top level debug file system function tracer shares its
      ftrace_ops with the function graph tracer. This was thought to be fine
      because the tracers are not used together, as one can only enable
      function or function_graph tracer in the current_tracer file.
      
      But that assumption proved to be incorrect. The function profiler
      can use the function graph tracer when function tracing is enabled.
      Since all function graph users uses the function tracing ftrace_ops
      this causes a conflict and when a user enables both function profiling
      as well as the function tracer it will crash ftrace and disable it.
      
      The quick solution so far is to move them as separate ftrace_ops like
      it was earlier. The problem though is to synchronize the functions that
      are traced because both function and function_graph tracer are limited
      by the selections made in the set_ftrace_filter and set_ftrace_notrace
      files.
      
      To handle this, a new structure is made called ftrace_ops_hash. This
      structure will now hold the filter_hash and notrace_hash, and the
      ftrace_ops will point to this structure. That will allow two ftrace_ops
      to share the same hashes.
      
      Since most ftrace_ops do not share the hashes, and to keep allocation
      simple, the ftrace_ops structure will include both a pointer to the
      ftrace_ops_hash called func_hash, as well as the structure itself,
      called local_hash. When the ops are registered, the func_hash pointer
      will be initialized to point to the local_hash within the ftrace_ops
      structure. Some of the ftrace internal ftrace_ops will be initialized
      statically. This will allow for the function and function_graph tracer
      to have separate ops but still share the same hash tables that determine
      what functions they trace.
      
      Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
      Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      33b7f99c
  4. 21 8月, 2014 1 次提交
  5. 19 8月, 2014 1 次提交
  6. 17 8月, 2014 1 次提交
  7. 15 8月, 2014 3 次提交
  8. 13 8月, 2014 1 次提交
  9. 12 8月, 2014 1 次提交
    • V
      net: Always untag vlan-tagged traffic on input. · 0d5501c1
      Vlad Yasevich 提交于
      Currently the functionality to untag traffic on input resides
      as part of the vlan module and is build only when VLAN support
      is enabled in the kernel.  When VLAN is disabled, the function
      vlan_untag() turns into a stub and doesn't really untag the
      packets.  This seems to create an interesting interaction
      between VMs supporting checksum offloading and some network drivers.
      
      There are some drivers that do not allow the user to change
      tx-vlan-offload feature of the driver.  These drivers also seem
      to assume that any VLAN-tagged traffic they transmit will
      have the vlan information in the vlan_tci and not in the vlan
      header already in the skb.  When transmitting skbs that already
      have tagged data with partial checksum set, the checksum doesn't
      appear to be updated correctly by the card thus resulting in a
      failure to establish TCP connections.
      
      The following is a packet trace taken on the receiver where a
      sender is a VM with a VLAN configued.  The host VM is running on
      doest not have VLAN support and the outging interface on the
      host is tg3:
      10:12:43.503055 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q
      (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27243,
      offset 0, flags [DF], proto TCP (6), length 60)
          10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect
      -> 0x48d9), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val
      4294837885 ecr 0,nop,wscale 7], length 0
      10:12:44.505556 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q
      (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27244,
      offset 0, flags [DF], proto TCP (6), length 60)
          10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect
      -> 0x44ee), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val
      4294838888 ecr 0,nop,wscale 7], length 0
      
      This connection finally times out.
      
      I've only access to the TG3 hardware in this configuration thus have
      only tested this with TG3 driver.  There are a lot of other drivers
      that do not permit user changes to vlan acceleration features, and
      I don't know if they all suffere from a similar issue.
      
      The patch attempt to fix this another way.  It moves the vlan header
      stipping code out of the vlan module and always builds it into the
      kernel network core.  This way, even if vlan is not supported on
      a virtualizatoin host, the virtual machines running on top of such
      host will still work with VLANs enabled.
      
      CC: Patrick McHardy <kaber@trash.net>
      CC: Nithin Nayak Sujir <nsujir@broadcom.com>
      CC: Michael Chan <mchan@broadcom.com>
      CC: Jiri Pirko <jiri@resnulli.us>
      Signed-off-by: NVladislav Yasevich <vyasevic@redhat.com>
      Acked-by: NJiri Pirko <jiri@resnulli.us>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0d5501c1
  10. 11 8月, 2014 1 次提交
  11. 09 8月, 2014 24 次提交
    • V
      kexec: verify the signature of signed PE bzImage · 8e7d8381
      Vivek Goyal 提交于
      This is the final piece of the puzzle of verifying kernel image signature
      during kexec_file_load() syscall.
      
      This patch calls into PE file routines to verify signature of bzImage.  If
      signature are valid, kexec_file_load() succeeds otherwise it fails.
      
      Two new config options have been introduced.  First one is
      CONFIG_KEXEC_VERIFY_SIG.  This option enforces that kernel has to be
      validly signed otherwise kernel load will fail.  If this option is not
      set, no signature verification will be done.  Only exception will be when
      secureboot is enabled.  In that case signature verification should be
      automatically enforced when secureboot is enabled.  But that will happen
      when secureboot patches are merged.
      
      Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG.  This option
      enables signature verification support on bzImage.  If this option is not
      set and previous one is set, kernel image loading will fail because kernel
      does not have support to verify signature of bzImage.
      
      I tested these patches with both "pesign" and "sbsign" signed bzImages.
      
      I used signing_key.priv key and signing_key.x509 cert for signing as
      generated during kernel build process (if module signing is enabled).
      
      Used following method to sign bzImage.
      
      pesign
      ======
      - Convert DER format cert to PEM format cert
      openssl x509 -in signing_key.x509 -inform DER -out signing_key.x509.PEM -outform
      PEM
      
      - Generate a .p12 file from existing cert and private key file
      openssl pkcs12 -export -out kernel-key.p12 -inkey signing_key.priv -in
      signing_key.x509.PEM
      
      - Import .p12 file into pesign db
      pk12util -i /tmp/kernel-key.p12 -d /etc/pki/pesign
      
      - Sign bzImage
      pesign -i /boot/vmlinuz-3.16.0-rc3+ -o /boot/vmlinuz-3.16.0-rc3+.signed.pesign
      -c "Glacier signing key - Magrathea" -s
      
      sbsign
      ======
      sbsign --key signing_key.priv --cert signing_key.x509.PEM --output
      /boot/vmlinuz-3.16.0-rc3+.signed.sbsign /boot/vmlinuz-3.16.0-rc3+
      
      Patch details:
      
      Well all the hard work is done in previous patches.  Now bzImage loader
      has just call into that code and verify whether bzImage signature are
      valid or not.
      
      Also create two config options.  First one is CONFIG_KEXEC_VERIFY_SIG.
      This option enforces that kernel has to be validly signed otherwise kernel
      load will fail.  If this option is not set, no signature verification will
      be done.  Only exception will be when secureboot is enabled.  In that case
      signature verification should be automatically enforced when secureboot is
      enabled.  But that will happen when secureboot patches are merged.
      
      Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG.  This option
      enables signature verification support on bzImage.  If this option is not
      set and previous one is set, kernel image loading will fail because kernel
      does not have support to verify signature of bzImage.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Matt Fleming <matt@console-pimps.org>
      Cc: David Howells <dhowells@redhat.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8e7d8381
    • V
      kexec: support kexec/kdump on EFI systems · 6a2c20e7
      Vivek Goyal 提交于
      This patch does two things.  It passes EFI run time mappings to second
      kernel in bootparams efi_info.  Second kernel parse this info and create
      new mappings in second kernel.  That means mappings in first and second
      kernel will be same.  This paves the way to enable EFI in kexec kernel.
      
      This patch also prepares and passes EFI setup data through bootparams.
      This contains bunch of information about various tables and their
      addresses.
      
      These information gathering and passing has been written along the lines
      of what current kexec-tools is doing to make kexec work with UEFI.
      
      [akpm@linux-foundation.org: s/get_efi/efi_get/g, per Matt]
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Matt Fleming <matt@console-pimps.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6a2c20e7
    • V
      kexec-bzImage64: support for loading bzImage using 64bit entry · 27f48d3e
      Vivek Goyal 提交于
      This is loader specific code which can load bzImage and set it up for
      64bit entry.  This does not take care of 32bit entry or real mode entry.
      
      32bit mode entry can be implemented if somebody needs it.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      27f48d3e
    • V
      kexec: load and relocate purgatory at kernel load time · 12db5562
      Vivek Goyal 提交于
      Load purgatory code in RAM and relocate it based on the location.
      Relocation code has been inspired by module relocation code and purgatory
      relocation code in kexec-tools.
      
      Also compute the checksums of loaded kexec segments and store them in
      purgatory.
      
      Arch independent code provides this functionality so that arch dependent
      bootloaders can make use of it.
      
      Helper functions are provided to get/set symbol values in purgatory which
      are used by bootloaders later to set things like stack and entry point of
      second kernel etc.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      12db5562
    • V
      kexec: implementation of new syscall kexec_file_load · cb105258
      Vivek Goyal 提交于
      Previous patch provided the interface definition and this patch prvides
      implementation of new syscall.
      
      Previously segment list was prepared in user space.  Now user space just
      passes kernel fd, initrd fd and command line and kernel will create a
      segment list internally.
      
      This patch contains generic part of the code.  Actual segment preparation
      and loading is done by arch and image specific loader.  Which comes in
      next patch.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cb105258
    • V
      kexec: new syscall kexec_file_load() declaration · f0895685
      Vivek Goyal 提交于
      This is the new syscall kexec_file_load() declaration/interface.  I have
      reserved the syscall number only for x86_64 so far.  Other architectures
      (including i386) can reserve syscall number when they enable the support
      for this new syscall.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f0895685
    • V
      kexec: make kexec_segment user buffer pointer a union · 815d5704
      Vivek Goyal 提交于
      So far kexec_segment->buf was always a user space pointer as user space
      passed the array of kexec_segment structures and kernel copied it.
      
      But with new system call, list of kexec segments will be prepared by
      kernel and kexec_segment->buf will point to a kernel memory.
      
      So while I was adding code where I made assumption that ->buf is pointing
      to kernel memory, sparse started giving warning.
      
      Make ->buf a union.  And where a user space pointer is expected, access it
      using ->buf and where a kernel space pointer is expected, access it using
      ->kbuf.  That takes care of sparse warnings.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      815d5704
    • V
      resource: provide new functions to walk through resources · 8c86e70a
      Vivek Goyal 提交于
      I have added two more functions to walk through resources.
      
      Currently walk_system_ram_range() deals with pfn and /proc/iomem can
      contain partial pages.  By dealing in pfn, callback function loses the
      info that last page of a memory range is a partial page and not the full
      page.  So I implemented walk_system_ram_res() which returns u64 values to
      callback functions and now it properly return start and end address.
      
      walk_system_ram_range() uses find_next_system_ram() to find the next ram
      resource.  This in turn only travels through siblings of top level child
      and does not travers through all the nodes of the resoruce tree.  I also
      need another function where I can walk through all the resources, for
      example figure out where "GART" aperture is.  Figure out where ACPI memory
      is.
      
      So I wrote another function walk_iomem_res() which walks through all
      /proc/iomem resources and returns matches as asked by caller.  Caller can
      specify "name" of resource, start and end and flags.
      
      Got rid of find_next_system_ram_res() and instead implemented more generic
      find_next_iomem_res() which can be used to traverse top level children
      only based on an argument.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8c86e70a
    • V
      kexec: rename unusebale_pages to unusable_pages · 7d3e2bca
      Vivek Goyal 提交于
      Let's use the more common "unusable".
      
      This patch was originally written and posted by Boris. I am including it
      in this patch series.
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7d3e2bca
    • D
      shm: add memfd_create() syscall · 9183df25
      David Herrmann 提交于
      memfd_create() is similar to mmap(MAP_ANON), but returns a file-descriptor
      that you can pass to mmap().  It can support sealing and avoids any
      connection to user-visible mount-points.  Thus, it's not subject to quotas
      on mounted file-systems, but can be used like malloc()'ed memory, but with
      a file-descriptor to it.
      
      memfd_create() returns the raw shmem file, so calls like ftruncate() can
      be used to modify the underlying inode.  Also calls like fstat() will
      return proper information and mark the file as regular file.  If you want
      sealing, you can specify MFD_ALLOW_SEALING.  Otherwise, sealing is not
      supported (like on all other regular files).
      
      Compared to O_TMPFILE, it does not require a tmpfs mount-point and is not
      subject to a filesystem size limit.  It is still properly accounted to
      memcg limits, though, and to the same overcommit or no-overcommit
      accounting as all user memory.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: NHugh Dickins <hughd@google.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Ryan Lortie <desrt@desrt.ca>
      Cc: Lennart Poettering <lennart@poettering.net>
      Cc: Daniel Mack <zonque@gmail.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9183df25
    • D
      shm: add sealing API · 40e041a2
      David Herrmann 提交于
      If two processes share a common memory region, they usually want some
      guarantees to allow safe access. This often includes:
        - one side cannot overwrite data while the other reads it
        - one side cannot shrink the buffer while the other accesses it
        - one side cannot grow the buffer beyond previously set boundaries
      
      If there is a trust-relationship between both parties, there is no need
      for policy enforcement.  However, if there's no trust relationship (eg.,
      for general-purpose IPC) sharing memory-regions is highly fragile and
      often not possible without local copies.  Look at the following two
      use-cases:
      
        1) A graphics client wants to share its rendering-buffer with a
           graphics-server. The memory-region is allocated by the client for
           read/write access and a second FD is passed to the server. While
           scanning out from the memory region, the server has no guarantee that
           the client doesn't shrink the buffer at any time, requiring rather
           cumbersome SIGBUS handling.
        2) A process wants to perform an RPC on another process. To avoid huge
           bandwidth consumption, zero-copy is preferred. After a message is
           assembled in-memory and a FD is passed to the remote side, both sides
           want to be sure that neither modifies this shared copy, anymore. The
           source may have put sensible data into the message without a separate
           copy and the target may want to parse the message inline, to avoid a
           local copy.
      
      While SIGBUS handling, POSIX mandatory locking and MAP_DENYWRITE provide
      ways to achieve most of this, the first one is unproportionally ugly to
      use in libraries and the latter two are broken/racy or even disabled due
      to denial of service attacks.
      
      This patch introduces the concept of SEALING.  If you seal a file, a
      specific set of operations is blocked on that file forever.  Unlike locks,
      seals can only be set, never removed.  Hence, once you verified a specific
      set of seals is set, you're guaranteed that no-one can perform the blocked
      operations on this file, anymore.
      
      An initial set of SEALS is introduced by this patch:
        - SHRINK: If SEAL_SHRINK is set, the file in question cannot be reduced
                  in size. This affects ftruncate() and open(O_TRUNC).
        - GROW: If SEAL_GROW is set, the file in question cannot be increased
                in size. This affects ftruncate(), fallocate() and write().
        - WRITE: If SEAL_WRITE is set, no write operations (besides resizing)
                 are possible. This affects fallocate(PUNCH_HOLE), mmap() and
                 write().
        - SEAL: If SEAL_SEAL is set, no further seals can be added to a file.
                This basically prevents the F_ADD_SEAL operation on a file and
                can be set to prevent others from adding further seals that you
                don't want.
      
      The described use-cases can easily use these seals to provide safe use
      without any trust-relationship:
      
        1) The graphics server can verify that a passed file-descriptor has
           SEAL_SHRINK set. This allows safe scanout, while the client is
           allowed to increase buffer size for window-resizing on-the-fly.
           Concurrent writes are explicitly allowed.
        2) For general-purpose IPC, both processes can verify that SEAL_SHRINK,
           SEAL_GROW and SEAL_WRITE are set. This guarantees that neither
           process can modify the data while the other side parses it.
           Furthermore, it guarantees that even with writable FDs passed to the
           peer, it cannot increase the size to hit memory-limits of the source
           process (in case the file-storage is accounted to the source).
      
      The new API is an extension to fcntl(), adding two new commands:
        F_GET_SEALS: Return a bitset describing the seals on the file. This
                     can be called on any FD if the underlying file supports
                     sealing.
        F_ADD_SEALS: Change the seals of a given file. This requires WRITE
                     access to the file and F_SEAL_SEAL may not already be set.
                     Furthermore, the underlying file must support sealing and
                     there may not be any existing shared mapping of that file.
                     Otherwise, EBADF/EPERM is returned.
                     The given seals are _added_ to the existing set of seals
                     on the file. You cannot remove seals again.
      
      The fcntl() handler is currently specific to shmem and disabled on all
      files. A file needs to explicitly support sealing for this interface to
      work. A separate syscall is added in a follow-up, which creates files that
      support sealing. There is no intention to support this on other
      file-systems. Semantics are unclear for non-volatile files and we lack any
      use-case right now. Therefore, the implementation is specific to shmem.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: NHugh Dickins <hughd@google.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Ryan Lortie <desrt@desrt.ca>
      Cc: Lennart Poettering <lennart@poettering.net>
      Cc: Daniel Mack <zonque@gmail.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      40e041a2
    • D
      mm: allow drivers to prevent new writable mappings · 4bb5f5d9
      David Herrmann 提交于
      This patch (of 6):
      
      The i_mmap_writable field counts existing writable mappings of an
      address_space.  To allow drivers to prevent new writable mappings, make
      this counter signed and prevent new writable mappings if it is negative.
      This is modelled after i_writecount and DENYWRITE.
      
      This will be required by the shmem-sealing infrastructure to prevent any
      new writable mappings after the WRITE seal has been set.  In case there
      exists a writable mapping, this operation will fail with EBUSY.
      
      Note that we rely on the fact that iff you already own a writable mapping,
      you can increase the counter without using the helpers.  This is the same
      that we do for i_writecount.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: NHugh Dickins <hughd@google.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Ryan Lortie <desrt@desrt.ca>
      Cc: Lennart Poettering <lennart@poettering.net>
      Cc: Daniel Mack <zonque@gmail.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4bb5f5d9
    • A
      arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area · a6c19dfe
      Andy Lutomirski 提交于
      The core mm code will provide a default gate area based on
      FIXADDR_USER_START and FIXADDR_USER_END if
      !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
      
      This default is only useful for ia64.  arm64, ppc, s390, sh, tile, 64-bit
      UML, and x86_32 have their own code just to disable it.  arm, 32-bit UML,
      and x86_64 have gate areas, but they have their own implementations.
      
      This gets rid of the default and moves the code into ia64.
      
      This should save some code on architectures without a gate area: it's now
      possible to inline the gate_area functions in the default case.
      Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
      Acked-by: NNathan Lynch <nathan_lynch@mentor.com>
      Acked-by: NH. Peter Anvin <hpa@linux.intel.com>
      Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [in principle]
      Acked-by: Richard Weinberger <richard@nod.at> [for um]
      Acked-by: Will Deacon <will.deacon@arm.com> [for arm64]
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Nathan Lynch <Nathan_Lynch@mentor.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a6c19dfe
    • L
      lib/scatterlist: make ARCH_HAS_SG_CHAIN an actual Kconfig · 308c09f1
      Laura Abbott 提交于
      Rather than have architectures #define ARCH_HAS_SG_CHAIN in an
      architecture specific scatterlist.h, make it a proper Kconfig option and
      use that instead.  At same time, remove the header files are are now
      mostly useless and just include asm-generic/scatterlist.h.
      
      [sfr@canb.auug.org.au: powerpc files now need asm/dma.h]
      Signed-off-by: NLaura Abbott <lauraa@codeaurora.org>
      Acked-by: Thomas Gleixner <tglx@linutronix.de>			[x86]
      Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>	[powerpc]
      Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      308c09f1
    • J
      shm: remove unneeded extern for function · 2f137d66
      Jack Miller 提交于
      A small cleanup while changing adjacent code.  Extern is not needed for
      functions and only one declaration had it so remove it from the odd line.
      Signed-off-by: NMilton Miller <miltonm@bga.com>
      Signed-off-by: NJack Miller <millerjo@us.ibm.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: Anton Blanchard <anton@samba.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2f137d66
    • J
      shm: make exit_shm work proportional to task activity · ab602f79
      Jack Miller 提交于
      This is small set of patches our team has had kicking around for a few
      versions internally that fixes tasks getting hung on shm_exit when there
      are many threads hammering it at once.
      
      Anton wrote a simple test to cause the issue:
      
        http://ozlabs.org/~anton/junkcode/bust_shm_exit.c
      
      Before applying this patchset, this test code will cause either hanging
      tracebacks or pthread out of memory errors.
      
      After this patchset, it will still produce output like:
      
        root@somehost:~# ./bust_shm_exit 1024 160
        ...
        INFO: rcu_sched detected stalls on CPUs/tasks: {} (detected by 116, t=2111 jiffies, g=241, c=240, q=7113)
        INFO: Stall ended before state dump start
        ...
      
      But the task will continue to run along happily, so we consider this an
      improvement over hanging, even if it's a bit noisy.
      
      This patch (of 3):
      
      exit_shm obtains the ipc_ns shm rwsem for write and holds it while it
      walks every shared memory segment in the namespace.  Thus the amount of
      work is related to the number of shm segments in the namespace not the
      number of segments that might need to be cleaned.
      
      In addition, this occurs after the task has been notified the thread has
      exited, so the number of tasks waiting for the ns shm rwsem can grow
      without bound until memory is exausted.
      
      Add a list to the task struct of all shmids allocated by this task.  Init
      the list head in copy_process.  Use the ns->rwsem for locking.  Add
      segments after id is added, remove before removing from id.
      
      On unshare of NEW_IPCNS orphan any ids as if the task had exited, similar
      to handling of semaphore undo.
      
      I chose a define for the init sequence since its a simple list init,
      otherwise it would require a function call to avoid include loops between
      the semaphore code and the task struct.  Converting the list_del to
      list_del_init for the unshare cases would remove the exit followed by
      init, but I left it blow up if not inited.
      Signed-off-by: NMilton Miller <miltonm@bga.com>
      Signed-off-by: NJack Miller <millerjo@us.ibm.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: Anton Blanchard <anton@samba.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ab602f79
    • Y
      initramfs: support initramfs that is bigger than 2GiB · d97b07c5
      Yinghai Lu 提交于
      Now with 64bit bzImage and kexec tools, we support ramdisk that size is
      bigger than 2g, as we could put it above 4G.
      
      Found compressed initramfs image could not be decompressed properly.  It
      turns out that image length is int during decompress detection, and it
      will become < 0 when length is more than 2G.  Furthermore, during
      decompressing len as int is used for inbuf count, that has problem too.
      
      Change len to long, that should be ok as on 32 bit platform long is
      32bits.
      
      Tested with following compressed initramfs image as root with kexec.
      	gzip, bzip2, xz, lzma, lzop, lz4.
      run time for populate_rootfs():
         size        name       Nehalem-EX  Westmere-EX  Ivybridge-EX
       9034400256 root_img     :   26s           24s          30s
       3561095057 root_img.lz4 :   28s           27s          27s
       3459554629 root_img.lzo :   29s           29s          28s
       3219399480 root_img.gz  :   64s           62s          49s
       2251594592 root_img.xz  :  262s          260s         183s
       2226366598 root_img.lzma:  386s          376s         277s
       2901482513 root_img.bz2 :  635s          599s
      Signed-off-by: NYinghai Lu <yinghai@kernel.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Rashika Kheria <rashika.kheria@gmail.com>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Cc: Kyungsik Lee <kyungsik.lee@lge.com>
      Cc: P J P <ppandit@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
      Cc: "Daniel M. Weeks" <dan@danweeks.net>
      Cc: Alexandre Courbot <acourbot@nvidia.com>
      Cc: Jan Beulich <JBeulich@suse.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d97b07c5
    • J
      panic: add TAINT_SOFTLOCKUP · 69361eef
      Josh Hunt 提交于
      This taint flag will be set if the system has ever entered a softlockup
      state.  Similar to TAINT_WARN it is useful to know whether or not the
      system has been in a softlockup state when debugging.
      
      [akpm@linux-foundation.org: apply the taint before calling panic()]
      Signed-off-by: NJosh Hunt <johunt@akamai.com>
      Cc: Jason Baron <jbaron@akamai.com>
      Cc: Randy Dunlap <rdunlap@infradead.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      69361eef
    • J
      sysctl: remove typedef ctl_table · e5eea098
      Joe Perches 提交于
      Remove the final user, and the typedef itself.
      Signed-off-by: NJoe Perches <joe@perches.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e5eea098
    • A
      rapidio: add new RapidIO DMA interface routines · 4aff1ce7
      Alexandre Bounine 提交于
      Add RapidIO DMA interface routines that directly use reference to the mport
      device object and/or target device destination ID as parameters.
      This allows to perform RapidIO DMA transfer requests by modules that do not
      have an access to the RapidIO device list.
      Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
      Cc: Matt Porter <mporter@kernel.crashing.org>
      Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
      Cc: Stef van Os <stef.van.os@prodrive-technologies.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4aff1ce7
    • V
      kernel/fork.c: make mm_init_owner static · 33144e84
      Vladimir Davydov 提交于
      It's only used in fork.c:mm_init().
      Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      33144e84
    • V
      fork/exec: cleanup mm initialization · 41f727fd
      Vladimir Davydov 提交于
      mm initialization on fork/exec is spread all over the place, which makes
      the code look inconsistent.
      
      We have mm_init(), which is supposed to init/nullify mm's internals, but
      it doesn't init all the fields it should:
      
       - on fork ->mmap,mm_rb,vmacache_seqnum,map_count,mm_cpumask,locked_vm
         are zeroed in dup_mmap();
      
       - on fork ->pmd_huge_pte is zeroed in dup_mm(), immediately before
         calling mm_init();
      
       - ->cpu_vm_mask_var ptr is initialized by mm_init_cpumask(), which is
         called before mm_init() on both fork and exec;
      
       - ->context is initialized by init_new_context(), which is called after
         mm_init() on both fork and exec;
      
      Let's consolidate all the initializations in mm_init() to make the code
      look cleaner.
      Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Christoph Lameter <cl@linux.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      41f727fd
    • F
      proc: constify seq_operations · ccf94f1b
      Fabian Frederick 提交于
      proc_uid_seq_operations, proc_gid_seq_operations and
      proc_projid_seq_operations are only called in proc_id_map_open with
      seq_open as const struct seq_operations so we can constify the 3
      structures and update proc_id_map_open prototype.
      
         text    data     bss     dec     hex filename
         6817     404    1984    9205    23f5 kernel/user_namespace.o-before
         6913     308    1984    9205    23f5 kernel/user_namespace.o-after
      Signed-off-by: NFabian Frederick <fabf@skynet.be>
      Cc: Joe Perches <joe@perches.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ccf94f1b
    • G
      memcg: remove lookup_cgroup_page() prototype · 3cbb0187
      Greg Thelen 提交于
      Commit 6b208e3f ("mm: memcg: remove unused node/section info from
      pc->flags") deleted lookup_cgroup_page() but left a prototype for it.
      
      Kill the vestigial prototype.
      Signed-off-by: NGreg Thelen <gthelen@google.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3cbb0187