1. 03 4月, 2018 16 次提交
  2. 21 2月, 2018 1 次提交
  3. 06 2月, 2018 3 次提交
    • M
      membarrier: Provide core serializing command, *_SYNC_CORE · 70216e18
      Mathieu Desnoyers 提交于
      Provide core serializing membarrier command to support memory reclaim
      by JIT.
      
      Each architecture needs to explicitly opt into that support by
      documenting in their architecture code how they provide the core
      serializing instructions required when returning from the membarrier
      IPI, and after the scheduler has updated the curr->mm pointer (before
      going back to user-space). They should then select
      ARCH_HAS_MEMBARRIER_SYNC_CORE to enable support for that command on
      their architecture.
      
      Architectures selecting this feature need to either document that
      they issue core serializing instructions when returning to user-space,
      or implement their architecture-specific sync_core_before_usermode().
      Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Acked-by: NThomas Gleixner <tglx@linutronix.de>
      Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andrea Parri <parri.andrea@gmail.com>
      Cc: Andrew Hunter <ahh@google.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Avi Kivity <avi@scylladb.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Boqun Feng <boqun.feng@gmail.com>
      Cc: Dave Watson <davejwatson@fb.com>
      Cc: David Sehr <sehr@google.com>
      Cc: Greg Hackmann <ghackmann@google.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Maged Michael <maged.michael@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-api@vger.kernel.org
      Cc: linux-arch@vger.kernel.org
      Link: http://lkml.kernel.org/r/20180129202020.8515-9-mathieu.desnoyers@efficios.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      70216e18
    • M
      locking: Introduce sync_core_before_usermode() · e61938a9
      Mathieu Desnoyers 提交于
      Introduce an architecture function that ensures the current CPU
      issues a core serializing instruction before returning to usermode.
      
      This is needed for the membarrier "sync_core" command.
      
      Architectures defining the sync_core_before_usermode() static inline
      need to select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE.
      Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Acked-by: NThomas Gleixner <tglx@linutronix.de>
      Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andrea Parri <parri.andrea@gmail.com>
      Cc: Andrew Hunter <ahh@google.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Avi Kivity <avi@scylladb.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Boqun Feng <boqun.feng@gmail.com>
      Cc: Dave Watson <davejwatson@fb.com>
      Cc: David Sehr <sehr@google.com>
      Cc: Greg Hackmann <ghackmann@google.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Maged Michael <maged.michael@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-api@vger.kernel.org
      Cc: linux-arch@vger.kernel.org
      Link: http://lkml.kernel.org/r/20180129202020.8515-7-mathieu.desnoyers@efficios.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      e61938a9
    • M
      powerpc, membarrier: Skip memory barrier in switch_mm() · 3ccfebed
      Mathieu Desnoyers 提交于
      Allow PowerPC to skip the full memory barrier in switch_mm(), and
      only issue the barrier when scheduling into a task belonging to a
      process that has registered to use expedited private.
      
      Threads targeting the same VM but which belong to different thread
      groups is a tricky case. It has a few consequences:
      
      It turns out that we cannot rely on get_nr_threads(p) to count the
      number of threads using a VM. We can use
      (atomic_read(&mm->mm_users) == 1 && get_nr_threads(p) == 1)
      instead to skip the synchronize_sched() for cases where the VM only has
      a single user, and that user only has a single thread.
      
      It also turns out that we cannot use for_each_thread() to set
      thread flags in all threads using a VM, as it only iterates on the
      thread group.
      
      Therefore, test the membarrier state variable directly rather than
      relying on thread flags. This means
      membarrier_register_private_expedited() needs to set the
      MEMBARRIER_STATE_PRIVATE_EXPEDITED flag, issue synchronize_sched(), and
      only then set MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY which allows
      private expedited membarrier commands to succeed.
      membarrier_arch_switch_mm() now tests for the
      MEMBARRIER_STATE_PRIVATE_EXPEDITED flag.
      Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Acked-by: NThomas Gleixner <tglx@linutronix.de>
      Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Andrea Parri <parri.andrea@gmail.com>
      Cc: Andrew Hunter <ahh@google.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Avi Kivity <avi@scylladb.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Boqun Feng <boqun.feng@gmail.com>
      Cc: Dave Watson <davejwatson@fb.com>
      Cc: David Sehr <sehr@google.com>
      Cc: Greg Hackmann <ghackmann@google.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Maged Michael <maged.michael@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-api@vger.kernel.org
      Cc: linux-arch@vger.kernel.org
      Cc: linuxppc-dev@lists.ozlabs.org
      Link: http://lkml.kernel.org/r/20180129202020.8515-3-mathieu.desnoyers@efficios.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      3ccfebed
  4. 17 1月, 2018 3 次提交
  5. 10 1月, 2018 2 次提交
    • D
      Construct init thread stack in the linker script rather than by union · 0500871f
      David Howells 提交于
      Construct the init thread stack in the linker script rather than doing it
      by means of a union so that ia64's init_task.c can be got rid of.
      
      The following symbols are then made available from INIT_TASK_DATA() linker
      script macro:
      
      	init_thread_union
      	init_stack
      
      INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
      size of the init stack.  init_thread_union is given its own section so that
      it can be placed into the stack space in the right order.  I'm assuming
      that the ia64 ordering is correct and that the task_struct is first and the
      thread_info second.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Tested-by: NTony Luck <tony.luck@intel.com>
      Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
      Tested-by: NPalmer Dabbelt <palmer@sifive.com>
      Acked-by: NThomas Gleixner <tglx@linutronix.de>
      0500871f
    • A
      bpf: introduce BPF_JIT_ALWAYS_ON config · 290af866
      Alexei Starovoitov 提交于
      The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715.
      
      A quote from goolge project zero blog:
      "At this point, it would normally be necessary to locate gadgets in
      the host kernel code that can be used to actually leak data by reading
      from an attacker-controlled location, shifting and masking the result
      appropriately and then using the result of that as offset to an
      attacker-controlled address for a load. But piecing gadgets together
      and figuring out which ones work in a speculation context seems annoying.
      So instead, we decided to use the eBPF interpreter, which is built into
      the host kernel - while there is no legitimate way to invoke it from inside
      a VM, the presence of the code in the host kernel's text section is sufficient
      to make it usable for the attack, just like with ordinary ROP gadgets."
      
      To make attacker job harder introduce BPF_JIT_ALWAYS_ON config
      option that removes interpreter from the kernel in favor of JIT-only mode.
      So far eBPF JIT is supported by:
      x64, arm64, arm32, sparc64, s390, powerpc64, mips64
      
      The start of JITed program is randomized and code page is marked as read-only.
      In addition "constant blinding" can be turned on with net.core.bpf_jit_harden
      
      v2->v3:
      - move __bpf_prog_ret0 under ifdef (Daniel)
      
      v1->v2:
      - fix init order, test_bpf and cBPF (Daniel's feedback)
      - fix offloaded bpf (Jakub's feedback)
      - add 'return 0' dummy in case something can invoke prog->bpf_func
      - retarget bpf tree. For bpf-next the patch would need one extra hunk.
        It will be sent when the trees are merged back to net-next
      
      Considered doing:
        int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT;
      but it seems better to land the patch as-is and in bpf-next remove
      bpf_jit_enable global variable from all JITs, consolidate in one place
      and remove this jit_init() function.
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      290af866
  6. 09 1月, 2018 1 次提交
  7. 24 12月, 2017 1 次提交
    • T
      x86/mm/pti: Add infrastructure for page table isolation · aa8c6248
      Thomas Gleixner 提交于
      Add the initial files for kernel page table isolation, with a minimal init
      function and the boot time detection for this misfeature.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      aa8c6248
  8. 23 12月, 2017 1 次提交
    • T
      init: Invoke init_espfix_bsp() from mm_init() · 613e396b
      Thomas Gleixner 提交于
      init_espfix_bsp() needs to be invoked before the page table isolation
      initialization. Move it into mm_init() which is the place where pti_init()
      will be added.
      
      While at it get rid of the #ifdeffery and provide proper stub functions.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      613e396b
  9. 18 12月, 2017 1 次提交
    • F
      sched/isolation: Enable CONFIG_CPU_ISOLATION=y by default · 2c43838c
      Frederic Weisbecker 提交于
      The "isolcpus=" boot parameter support was always built-in before we
      moved the related code under CONFIG_CPU_ISOLATION. Having it disabled by
      default is very confusing for people accustomed to use this parameter.
      
      So enable it by dafault to keep the previous behaviour but keep it
      optable for those who want to tinify their kernels.
      Signed-off-by: NFrederic Weisbecker <frederic@kernel.org>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: John Stultz <john.stultz@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Luiz Capitulino <lcapitulino@redhat.com>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Wanpeng Li <kernellwp@gmail.com>
      Cc: kernel test robot <xiaolong.ye@intel.com>
      Link: http://lkml.kernel.org/r/1513275507-29200-3-git-send-email-frederic@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      2c43838c
  10. 28 11月, 2017 1 次提交
  11. 18 11月, 2017 5 次提交
  12. 16 11月, 2017 3 次提交
  13. 08 11月, 2017 1 次提交
  14. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318