review request Bug 17116 - StackTrace::SlowUnwindStack dead locked

Sergey Matveev earthdok at google.com
Wed Sep 11 12:15:17 PDT 2013


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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