1. 15 Sep, 2016 5 commits
    • Ingo Molnar's avatar
      d4b80afb
    • Josh Poimboeuf's avatar
      x86/dumpstack: Add recursion checking for all stacks · fcd709ef
      Josh Poimboeuf authored
      in_exception_stack() has some recursion checking which makes sure the
      stack trace code never traverses a given exception stack more than once.
      This prevents an infinite loop if corruption somehow causes a stack's
      "next stack" pointer to point to itself (directly or indirectly).
      
      The recursion checking can be useful for other stacks in addition to the
      exception stack, so extend it to work for all stacks.
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Byungchul Park <byungchul.park@lge.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.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: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/95de5db4cfe111754845a5cef04e20630d01423f.1473905218.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      fcd709ef
    • Josh Poimboeuf's avatar
      x86/dumpstack: Add support for unwinding empty IRQ stacks · 5fe599e0
      Josh Poimboeuf authored
      When an interrupt happens in entry code while running on a software IRQ
      stack, and the IRQ stack was empty, regs->sp will contain the stack end
      address (e.g., irq_stack_ptr).  If the regs are passed to dump_trace(),
      get_stack_info() will report STACK_TYPE_UNKNOWN, causing dump_trace() to
      return prematurely without trying to go to the next stack.
      
      Update the bounds checking for software interrupt stacks so that the
      ending address is now considered part of the stack.
      
      This means that it's now possible for the 'walk_stack' callbacks --
      print_context_stack() and print_context_stack_bp() -- to be called with
      an empty stack.  But that's fine; they're already prepared to deal with
      that due to their on_stack() checks.
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Byungchul Park <byungchul.park@lge.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.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: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/5a5e5de92dcf11e8dc6b6e8e50ad7639d067830b.1473905218.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      5fe599e0
    • Josh Poimboeuf's avatar
      x86/dumpstack: Add get_stack_info() interface · cb76c939
      Josh Poimboeuf authored
      valid_stack_ptr() is buggy: it assumes that all stacks are of size
      THREAD_SIZE, which is not true for exception stacks.  So the
      walk_stack() callbacks will need to know the location of the beginning
      of the stack as well as the end.
      
      Another issue is that in general the various features of a stack (type,
      size, next stack pointer, description string) are scattered around in
      various places throughout the stack dump code.
      
      Encapsulate all that information in a single place with a new stack_info
      struct and a get_stack_info() interface.
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Byungchul Park <byungchul.park@lge.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.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: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/8164dd0db96b7e6a279fa17ae5e6dc375eecb4a9.1473905218.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      cb76c939
    • Josh Poimboeuf's avatar
      x86/dumpstack: Simplify in_exception_stack() · 9c003907
      Josh Poimboeuf authored
      in_exception_stack() does some bad, bad things just so the unwinder can
      print different values for different areas of the debug exception stack.
      
      There's no need to clarify where exactly on the stack it is.  Just print
      "#DB" and be done with it.
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Byungchul Park <byungchul.park@lge.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.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: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/e91cb410169dd576678dd427c35efb716fd0cee1.1473905218.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      9c003907
  2. 14 Sep, 2016 5 commits
    • Linus Torvalds's avatar
      Merge tag 'pci-v4.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci · 4cea8776
      Linus Torvalds authored
      Pull PCI fixes from Bjorn Helgaas:
       "Here are two changes for v4.8.  The first fixes a "[Firmware Bug]: reg
        0x10: invalid BAR (can't size)" warning on Haswell, and the second
        fixes a problem in some new runtime suspend functionality we merged
        for v4.8.  Summary:
      
        Enumeration:
          Mark Haswell Power Control Unit as having non-compliant BARs (Bjorn Helgaas)
      
        Power management:
          Fix bridge_d3 update on device removal (Lukas Wunner)"
      
      * tag 'pci-v4.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
        PCI: Fix bridge_d3 update on device removal
        PCI: Mark Haswell Power Control Unit as having non-compliant BARs
      4cea8776
    • Linus Torvalds's avatar
      Merge branch 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · 77e5bdf9
      Linus Torvalds authored
      Pull uaccess fixes from Al Viro:
       "Fixes for broken uaccess primitives - mostly lack of proper zeroing
        in copy_from_user()/get_user()/__get_user(), but for several
        architectures there's more (broken clear_user() on frv and
        strncpy_from_user() on hexagon)"
      
      * 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
        avr32: fix copy_from_user()
        microblaze: fix __get_user()
        microblaze: fix copy_from_user()
        m32r: fix __get_user()
        blackfin: fix copy_from_user()
        sparc32: fix copy_from_user()
        sh: fix copy_from_user()
        sh64: failing __get_user() should zero
        score: fix copy_from_user() and friends
        score: fix __get_user/get_user
        s390: get_user() should zero on failure
        ppc32: fix copy_from_user()
        parisc: fix copy_from_user()
        openrisc: fix copy_from_user()
        nios2: fix __get_user()
        nios2: copy_from_user() should zero the tail of destination
        mn10300: copy_from_user() should zero on access_ok() failure...
        mn10300: failing __get_user() and get_user() should zero
        mips: copy_from_user() must zero the destination on access_ok() failure
        ARC: uaccess: get_user to zero out dest in cause of fault
        ...
      77e5bdf9
    • Linus Torvalds's avatar
      Merge tag 'for-linus-4.8b-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip · b8f26e88
      Linus Torvalds authored
      Pull xen regression fix from David Vrabel:
       "Fix SMP boot in arm guests"
      
      * tag 'for-linus-4.8b-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
        arm/xen: fix SMP guests boot
      b8f26e88
    • Josh Poimboeuf's avatar
      x86/dumpstack: Allow preemption in show_stack_log_lvl() and dump_trace() · cfeeed27
      Josh Poimboeuf authored
      show_stack_log_lvl() and dump_trace() are already preemption safe:
      
      - If they're running in irq or exception context, preemption is already
        disabled and the percpu stack pointers can be trusted.
      
      - If they're running with preemption enabled, they must be running on
        the task stack anyway, so it doesn't matter if they're comparing the
        stack pointer against a percpu stack pointer from this CPU or another
        one: either way it won't match.
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Byungchul Park <byungchul.park@lge.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.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: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/a0ca0b1044eca97d4f0ec7c1619cf80b3b65560d.1473371307.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      cfeeed27
    • Vitaly Kuznetsov's avatar
      arm/xen: fix SMP guests boot · de75abbe
      Vitaly Kuznetsov authored
      Commit 88e957d6 ("xen: introduce xen_vcpu_id mapping") broke SMP
      ARM guests on Xen. When FIFO-based event channels are in use (this is
      the default), evtchn_fifo_alloc_control_block() is called on
      CPU_UP_PREPARE event and this happens before we set up xen_vcpu_id
      mapping in xen_starting_cpu. Temporary fix the issue by setting direct
      Linux CPU id <-> Xen vCPU id mapping for all possible CPUs at boot. We
      don't currently support kexec/kdump on Xen/ARM so these ids always
      match.
      
      In future, we have several ways to solve the issue, e.g.:
      
      - Eliminate all hypercalls from CPU_UP_PREPARE, do them from the
        starting CPU. This can probably be done for both x86 and ARM and, if
        done, will allow us to get Xen's idea of vCPU id from CPUID/MPIDR on
        the starting CPU directly, no messing with ACPI/device tree
        required.
      
      - Save vCPU id information from ACPI/device tree on ARM and use it to
        initialize xen_vcpu_id mapping. This is the same trick we currently
        do on x86.
      Reported-by: default avatarJulien Grall <julien.grall@arm.com>
      Tested-by: default avatarWei Chen <Wei.Chen@arm.com>
      Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
      Acked-by: default avatarStefano Stabellini <sstabellini@kernel.org>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      de75abbe
  3. 13 Sep, 2016 30 commits