1. 12 1月, 2017 2 次提交
    • J
      x86/unwind: Disable KASAN checks for non-current tasks · 84936118
      Josh Poimboeuf 提交于
      There are a handful of callers to save_stack_trace_tsk() and
      show_stack() which try to unwind the stack of a task other than current.
      In such cases, it's remotely possible that the task is running on one
      CPU while the unwinder is reading its stack from another CPU, causing
      the unwinder to see stack corruption.
      
      These cases seem to be mostly harmless.  The unwinder has checks which
      prevent it from following bad pointers beyond the bounds of the stack.
      So it's not really a bug as long as the caller understands that
      unwinding another task will not always succeed.
      
      In such cases, it's possible that the unwinder may read a KASAN-poisoned
      region of the stack.  Account for that by using READ_ONCE_NOCHECK() when
      reading the stack of another task.
      
      Use READ_ONCE() when reading the stack of the current task, since KASAN
      warnings can still be useful for finding bugs in that case.
      Reported-by: NDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: NJosh 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: Dave Jones <davej@codemonkey.org.uk>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Miroslav Benes <mbenes@suse.cz>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/4c575eb288ba9f73d498dfe0acde2f58674598f1.1483978430.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      84936118
    • J
      x86/unwind: Silence warnings for non-current tasks · 900742d8
      Josh Poimboeuf 提交于
      There are a handful of callers to save_stack_trace_tsk() and
      show_stack() which try to unwind the stack of a task other than current.
      In such cases, it's remotely possible that the task is running on one
      CPU while the unwinder is reading its stack from another CPU, causing
      the unwinder to see stack corruption.
      
      These cases seem to be mostly harmless.  The unwinder has checks which
      prevent it from following bad pointers beyond the bounds of the stack.
      So it's not really a bug as long as the caller understands that
      unwinding another task will not always succeed.
      
      Since stack "corruption" on another task's stack isn't necessarily a
      bug, silence the warnings when unwinding tasks other than current.
      Reported-by: NDave Jones <davej@codemonkey.org.uk>
      Signed-off-by: NJosh 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: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Miroslav Benes <mbenes@suse.cz>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/00d8c50eea3446c1524a2a755397a3966629354c.1483978430.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      900742d8
  2. 10 1月, 2017 5 次提交
  3. 09 1月, 2017 1 次提交
  4. 06 1月, 2017 1 次提交
  5. 05 1月, 2017 19 次提交
  6. 04 1月, 2017 12 次提交