review request Bug 17116 - StackTrace::SlowUnwindStack dead locked

Evgeniy Stepanov eugeni.stepanov at gmail.com
Thu Sep 12 01:20:21 PDT 2013


Thanks. I've replaced Stacktracing with Unwinding and committed as r190590.


On Wed, Sep 11, 2013 at 11:15 PM, Sergey Matveev <earthdok at google.com> wrote:
> Otherwise lgtm.
>
>
> On Wed, Sep 11, 2013 at 3:57 PM, Sergey Matveev <earthdok at google.com> wrote:
>>
>> Stacktrace is not a verb. Can we please call it "isUnwindingStack" etc?
>>
>> I will take a closer look at the code later today.
>>
>>
>> On Wed, Sep 11, 2013 at 3:13 PM, Evgeniy Stepanov
>> <eugeni.stepanov at gmail.com> wrote:
>>>
>>> Now we've got some allocations without stack traces, and it makes LSan
>>> sad.
>>>
>>> One of those is from after the AsanThread object is destroyed:
>>>
>>> #2  0x000000000044593f in __interceptor_malloc () at
>>> ../projects/compiler-rt/lib/asan/asan_malloc_linux.cc:74
>>> #3  0x0000000000459fc6 in key_destructor (arg=<optimized out>)
>>>     at
>>> /code/llvm2/projects/compiler-rt/lib/lsan/lit_tests/TestCases/disabler_in_tsd_destructor.cc:17
>>> #4  0x00007ffff7bc4c83 in __nptl_deallocate_tsd () at
>>> pthread_create.c:156
>>> #5  0x00007ffff7bc4ea8 in start_thread (arg=0x7ffff2fff700) at
>>> pthread_create.c:315
>>> #6  0x00007ffff6cd3ccd in clone () at
>>> ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
>>>
>>> Attached patch makes LSan consider any such allocation reachable.
>>> I'll wait for Sergey to comment on this.
>>>
>>>
>>> On Wed, Sep 11, 2013 at 5:42 AM, 林作健 <manjian2006 at gmail.com> wrote:
>>> > Please review it.
>>> >
>>> >
>>> > Index: lib/asan/asan_thread.h
>>> > ===================================================================
>>> > --- lib/asan/asan_thread.h (revision 190475)
>>> > +++ lib/asan/asan_thread.h (working copy)
>>> > @@ -86,12 +86,19 @@
>>> >      UnmapOrDie(fake_stack_, sizeof(FakeStack));
>>> >    }
>>> >    FakeStack *fake_stack() { return fake_stack_; }
>>> > +  bool isStacktracing() const {
>>> > +    return stacktracing;
>>> > +  }
>>> > +  void setStacktracing(bool b) {
>>> > +    stacktracing = b;
>>> > +  }
>>> >
>>> >    AsanThreadLocalMallocStorage &malloc_storage() { return
>>> > malloc_storage_;
>>> > }
>>> >    AsanStats &stats() { return stats_; }
>>> >
>>> >   private:
>>> > -  AsanThread() {}
>>> > +  AsanThread()
>>> > +       : stacktracing(false) {}
>>> >    void SetThreadStackAndTls();
>>> >    void ClearShadowForThreadStackAndTLS();
>>> >    AsanThreadContext *context_;
>>> > @@ -105,8 +112,23 @@
>>> >    FakeStack *fake_stack_;
>>> >    AsanThreadLocalMallocStorage malloc_storage_;
>>> >    AsanStats stats_;
>>> > +  bool stacktracing;
>>> >  };
>>> >
>>> > +// ScopedStacktracing is a scope for stacktracing member of a context
>>> > +class ScopedStacktracing {
>>> > +  public:
>>> > +    ScopedStacktracing (AsanThread * t)
>>> > +      : thread(t) {
>>> > +        t->setStacktracing(true);
>>> > +    }
>>> > +    ~ScopedStacktracing() {
>>> > +      thread->setStacktracing(false);
>>> > +    }
>>> > +  private:
>>> > +    AsanThread * thread;
>>> > +};
>>> > +
>>> >  struct CreateThreadContextArgs {
>>> >    AsanThread *thread;
>>> >    StackTrace *stack;
>>> > Index: lib/asan/asan_stack.h
>>> > ===================================================================
>>> > --- lib/asan/asan_stack.h (revision 190475)
>>> > +++ lib/asan/asan_stack.h (working copy)
>>> > @@ -36,14 +36,16 @@
>>> >  #define GET_STACK_TRACE_WITH_PC_AND_BP(max_s, pc, bp, fast)     \
>>> >    StackTrace stack;                                             \
>>> >    {                                                             \
>>> > -    uptr stack_top = 0, stack_bottom = 0;                       \
>>> >      AsanThread *t;                                              \
>>> > -    if (asan_inited && (t = GetCurrentThread())) {              \
>>> > -      stack_top = t->stack_top();                               \
>>> > -      stack_bottom = t->stack_bottom();                         \
>>> > +    stack.size = 0;                                             \
>>> > +    if (asan_inited && (t = GetCurrentThread())                 \
>>> > +        && !t->isStacktracing()) {                              \
>>> > +      uptr stack_top = t->stack_top();                          \
>>> > +      uptr stack_bottom = t->stack_bottom();                    \
>>> > +      ScopedStacktracing sink(t);                               \
>>> > +      GetStackTrace(&stack, max_s, pc, bp,                      \
>>> > +                    stack_top, stack_bottom, fast);             \
>>> >      }                                                           \
>>> > -    GetStackTrace(&stack, max_s, pc, bp,                        \
>>> > -                  stack_top, stack_bottom, fast);               \
>>> >    }
>>> >  #endif  // SANITIZER_WINDOWS
>>> >
>>> >
>>> >
>>> >
>>> > 2013/9/10 Evgeniy Stepanov <eugeni.stepanov at gmail.com>
>>> >>
>>> >> On Mon, Sep 9, 2013 at 2:09 PM, 林作健 <manjian2006 at gmail.com> wrote:
>>> >> > Index: lib/asan/asan_thread.h
>>> >> > ===================================================================
>>> >> > --- lib/asan/asan_thread.h (revision 190121)
>>> >> > +++ lib/asan/asan_thread.h (working copy)
>>> >> > @@ -36,10 +36,12 @@
>>> >> >    explicit AsanThreadContext(int tid)
>>> >> >        : ThreadContextBase(tid),
>>> >> >          announced(false),
>>> >> > +        stacktracing(false),
>>> >> >          thread(0) {
>>> >> >      internal_memset(&stack, 0, sizeof(stack));
>>> >> >    }
>>> >> >    bool announced;
>>> >> > +  bool stacktracing;
>>> >>
>>> >> Thread context objects live forever. Please move this to AsanThread.
>>> >>
>>> >> >    StackTrace stack;
>>> >> >    AsanThread *thread;
>>> >> >
>>> >> > @@ -86,6 +88,12 @@
>>> >> >      UnmapOrDie(fake_stack_, sizeof(FakeStack));
>>> >> >    }
>>> >> >    FakeStack *fake_stack() { return fake_stack_; }
>>> >> > +  bool isStacktracing() {
>>> >> > +    if (context()) {
>>> >> > +      return context()->stacktracing;
>>> >> > +    }
>>> >> > +    return false;
>>> >> > +  }
>>> >> >
>>> >> >    AsanThreadLocalMallocStorage &malloc_storage() { return
>>> >> > malloc_storage_;
>>> >> > }
>>> >> >    AsanStats &stats() { return stats_; }
>>> >> > @@ -107,6 +115,24 @@
>>> >> >    AsanStats stats_;
>>> >> >  };
>>> >> >
>>> >> > +// AsanStacktracingSink is a sink for stacktracing member of a
>>> >> > context
>>> >> > +class AsanStacktracingSink {
>>> >>
>>> >> Please call it ScopedSomething. M/b ScopedInStackTrace or
>>> >> ScopedStacktracing.
>>> >>
>>> >> > +  public:
>>> >> > +    AsanStacktracingSink(AsanThread * t)
>>> >> > +      : thread(t) {
>>> >> > +      if(t->context()) {
>>> >> > +        t->context()->stacktracing = true;
>>> >> > +      }
>>> >> > +    }
>>> >> > +    ~AsanStacktracingSink() {
>>> >> > +      if(thread->context()) {
>>> >> > +        thread->context()->stacktracing = false;
>>> >> > +      }
>>> >> > +    }
>>> >> > +  private:
>>> >> > +    AsanThread * thread;
>>> >> > +};
>>> >> > +
>>> >> >  struct CreateThreadContextArgs {
>>> >> >    AsanThread *thread;
>>> >> >    StackTrace *stack;
>>> >> > Index: lib/asan/asan_stack.h
>>> >> > ===================================================================
>>> >> > --- lib/asan/asan_stack.h (revision 190121)
>>> >> > +++ lib/asan/asan_stack.h (working copy)
>>> >> > @@ -36,14 +36,16 @@
>>> >> >  #define GET_STACK_TRACE_WITH_PC_AND_BP(max_s, pc, bp, fast)     \
>>> >> >    StackTrace stack;                                             \
>>> >> >    {                                                             \
>>> >> > -    uptr stack_top = 0, stack_bottom = 0;                       \
>>> >> >      AsanThread *t;                                              \
>>> >> > -    if (asan_inited && (t = GetCurrentThread())) {              \
>>> >> > -      stack_top = t->stack_top();                               \
>>> >> > -      stack_bottom = t->stack_bottom();                         \
>>> >> > +    stack.size = 0;                                             \
>>> >> > +    if (asan_inited && (t = GetCurrentThread())                 \
>>> >> > +        && !t->isStacktracing()) {                              \
>>> >> > +      uptr stack_top = t->stack_top();                          \
>>> >> > +      uptr stack_bottom = t->stack_bottom();                    \
>>> >> > +      AsanStacktracingSink sink(t);                             \
>>> >> > +      GetStackTrace(&stack, max_s, pc, bp,                      \
>>> >> > +                    stack_top, stack_bottom, fast);             \
>>> >> >      }                                                           \
>>> >> > -    GetStackTrace(&stack, max_s, pc, bp,                        \
>>> >> > -                  stack_top, stack_bottom, fast);               \
>>> >> >    }
>>> >> >  #endif  // SANITIZER_WINDOWS
>>> >> >
>>> >> >
>>> >> > _______________________________________________
>>> >> > llvm-commits mailing list
>>> >> > llvm-commits at cs.uiuc.edu
>>> >> > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>> >> >
>>> >
>>> >
>>
>>
>




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