1. 08 Nov, 2019 2 commits
  2. 07 Oct, 2019 1 commit
    • Will Deacon's avatar
      ARM: 8898/1: mm: Don't treat faults reported from cache maintenance as writes · 6a684e00
      Will Deacon authored
      [ Upstream commit 83402036
      
       ]
      
      Translation faults arising from cache maintenance instructions are
      rather unhelpfully reported with an FSR value where the WnR field is set
      to 1, indicating that the faulting access was a write. Since cache
      maintenance instructions on 32-bit ARM do not require any particular
      permissions, this can cause our private 'cacheflush' system call to fail
      spuriously if a translation fault is generated due to page aging when
      targetting a read-only VMA.
      
      In this situation, we will return -EFAULT to userspace, although this is
      unfortunately suppressed by the popular '__builtin___clear_cache()'
      intrinsic provided by GCC, which returns void.
      
      Although it's tempting to write this off as a userspace issue, we can
      actually do a little bit better on CPUs that support LPAE, even if the
      short-descriptor format is in use. On these CPUs, cache maintenance
      faults additionally set the CM field in the FSR, which we can use to
      suppress the write permission checks in the page fault handler and
      succeed in performing cache maintenance to read-only areas even in the
      presence of a translation fault.
      Reported-by: default avatarOrion Hodson <oth@google.com>
      Signed-off-by: default avatarWill Deacon <will@kernel.org>
      Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      6a684e00
  3. 17 Aug, 2018 1 commit
    • Souptick Joarder's avatar
      mm: convert return type of handle_mm_fault() caller to vm_fault_t · 50a7ca3c
      Souptick Joarder authored
      Use new return type vm_fault_t for fault handler.  For now, this is just
      documenting that the function returns a VM_FAULT value rather than an
      errno.  Once all instances are converted, vm_fault_t will become a
      distinct type.
      
      Ref-> commit 1c8f4220 ("mm: change return type to vm_fault_t")
      
      In this patch all the caller of handle_mm_fault() are changed to return
      vm_fault_t type.
      
      Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC
      
      Signed-off-by: default avatarSouptick Joarder <jrdr.linux@gmail.com>
      Cc: Matthew Wilcox <willy@infradead.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Michal Simek <monstr@monstr.eu>...
      50a7ca3c
  4. 31 May, 2018 1 commit
  5. 25 Apr, 2018 1 commit
    • Eric W. Biederman's avatar
      signal: Ensure every siginfo we send has all bits initialized · 3eb0f519
      Eric W. Biederman authored
      
      
      Call clear_siginfo to ensure every stack allocated siginfo is properly
      initialized before being passed to the signal sending functions.
      
      Note: It is not safe to depend on C initializers to initialize struct
      siginfo on the stack because C is allowed to skip holes when
      initializing a structure.
      
      The initialization of struct siginfo in tracehook_report_syscall_exit
      was moved from the helper user_single_step_siginfo into
      tracehook_report_syscall_exit itself, to make it clear that the local
      variable siginfo gets fully initialized.
      
      In a few cases the scope of struct siginfo has been reduced to make it
      clear that siginfo siginfo is not used on other paths in the function
      in which it is declared.
      
      Instances of using memset to initialize siginfo have been replaced
      with calls clear_siginfo for clarity.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      3eb0f519
  6. 17 Dec, 2017 1 commit
  7. 29 Aug, 2017 1 commit
    • Mark Rutland's avatar
      ARM: 8692/1: mm: abort uaccess retries upon fatal signal · 746a272e
      Mark Rutland authored
      
      
      When there's a fatal signal pending, arm's do_page_fault()
      implementation returns 0. The intent is that we'll return to the
      faulting userspace instruction, delivering the signal on the way.
      
      However, if we take a fatal signal during fixing up a uaccess, this
      results in a return to the faulting kernel instruction, which will be
      instantly retried, resulting in the same fault being taken forever. As
      the task never reaches userspace, the signal is not delivered, and the
      task is left unkillable. While the task is stuck in this state, it can
      inhibit the forward progress of the system.
      
      To avoid this, we must ensure that when a fatal signal is pending, we
      apply any necessary fixup for a faulting kernel instruction. Thus we
      will return to an error path, and it is up to that code to make forward
      progress towards delivering the fatal signal.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Reviewed-by: default avatarSteve Capper <steve.capper@arm.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
      746a272e
  8. 02 Mar, 2017 2 commits
  9. 30 Jan, 2017 1 commit
  10. 24 Jan, 2017 1 commit
  11. 26 Jul, 2016 1 commit
  12. 17 Mar, 2016 1 commit
  13. 19 Oct, 2015 1 commit
  14. 19 May, 2015 1 commit
    • David Hildenbrand's avatar
      mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler · 70ffdb93
      David Hildenbrand authored
      
      
      Introduce faulthandler_disabled() and use it to check for irq context and
      disabled pagefaults (via pagefault_disable()) in the pagefault handlers.
      
      Please note that we keep the in_atomic() checks in place - to detect
      whether in irq context (in which case preemption is always properly
      disabled).
      
      In contrast, preempt_disable() should never be used to disable pagefaults.
      With !CONFIG_PREEMPT_COUNT, preempt_disable() doesn't modify the preempt
      counter, and therefore the result of in_atomic() differs.
      We validate that condition by using might_fault() checks when calling
      might_sleep().
      
      Therefore, add a comment to faulthandler_disabled(), describing why this
      is needed.
      
      faulthandler_disabled() and pagefault_disable() are defined in
      linux/uaccess.h, so let's properly add that include to all relevant files.
      
      This patch is based on a patch from Thomas Gleixner.
      Reviewed-and-tested-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Sign...
      70ffdb93
  15. 10 Mar, 2015 1 commit
  16. 21 Nov, 2014 1 commit
  17. 12 Sep, 2013 2 commits
  18. 29 Jun, 2013 1 commit
  19. 09 Oct, 2012 1 commit
  20. 16 May, 2012 1 commit
  21. 05 May, 2012 1 commit
  22. 10 Apr, 2012 1 commit
  23. 28 Mar, 2012 1 commit
  24. 24 Mar, 2012 1 commit
  25. 08 Dec, 2011 2 commits
  26. 06 Dec, 2011 1 commit
  27. 17 Oct, 2011 1 commit
  28. 19 Jul, 2011 1 commit
  29. 02 Jul, 2011 1 commit
  30. 01 Jul, 2011 1 commit
    • Peter Zijlstra's avatar
      perf: Remove the nmi parameter from the swevent and overflow interface · a8b0ca17
      Peter Zijlstra authored
      
      
      The nmi parameter indicated if we could do wakeups from the current
      context, if not, we would set some state and self-IPI and let the
      resulting interrupt do the wakeup.
      
      For the various event classes:
      
        - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
          the PMI-tail (ARM etc.)
        - tracepoint: nmi=0; since tracepoint could be from NMI context.
        - software: nmi=[0,1]; some, like the schedule thing cannot
          perform wakeups, and hence need 0.
      
      As one can see, there is very little nmi=1 usage, and the down-side of
      not using it is that on some platforms some software events can have a
      jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).
      
      The up-side however is that we can remove the nmi parameter and save a
      bunch of conditionals in fast paths.
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Michael Cree <mcree@orcon.net.nz>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
      Cc: Anton Blanchard <anton@samba.org>
      Cc: Eric B Munson <emunson@mgebm.net>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jason Wessel <jason.wessel@windriver.com>
      Cc: Don Zickus <dzickus@redhat.com>
      Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
      
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      a8b0ca17
  31. 21 Feb, 2011 1 commit
  32. 15 Feb, 2011 1 commit
  33. 22 Dec, 2010 1 commit
    • Russell King's avatar
      ARM: pgtable: switch order of Linux vs hardware page tables · d30e45ee
      Russell King authored
      
      
      This switches the ordering of the Linux vs hardware page tables in
      each page, thereby eliminating some of the arithmetic in the page
      table walks.  As we now place the Linux page table at the beginning
      of the page, we can deal with the offset in the pgt by simply masking
      it away, along with the other control bits.
      
      This also makes the arithmetic all be positive, rather than a mixture.
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      d30e45ee
  34. 08 Sep, 2010 1 commit
  35. 27 Jul, 2010 2 commits