1. 15 Sep, 2016 4 commits
    • 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 1 commit
    • 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
  3. 13 Sep, 2016 2 commits
  4. 08 Sep, 2016 9 commits
  5. 24 Aug, 2016 20 commits
  6. 21 Aug, 2016 3 commits
  7. 20 Aug, 2016 1 commit
    • Helge Deller's avatar
      parisc: Fix order of EREFUSED define in errno.h · 3eb53b20
      Helge Deller authored
      When building gccgo in userspace, errno.h gets parsed and the go include file
      sysinfo.go is generated.
      
      Since EREFUSED is defined to the same value as ECONNREFUSED, and ECONNREFUSED
      is defined later on in errno.h, this leads to go complaining that EREFUSED
      isn't defined yet.
      
      Fix this trivial problem by moving the define of EREFUSED down after
      ECONNREFUSED in errno.h (and clean up the indenting while touching this line).
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Cc: stable@vger.kernel.org
      3eb53b20