[llvm] r246449 - Repress sanitization on User dtor. Modify msan macros for applying attribute

[Naomi Musgrave via llvm-commits]

I'm not entirely sure if the compile and runtime options for use-after-dtor
poisoning will be fully integrated into MSan or not when I leave. To
clarify, are you reccommending leaving these as distinct options?

On Mon, Aug 31, 2015 at 12:22 PM, Eric Christopher <echristo at gmail.com>
wrote:

>
>
> On Mon, Aug 31, 2015 at 10:36 AM Naomi Musgrave <nmusgrave at google.com>
> wrote:
>
>> I have looked repeatedly into a fix for this bug, with no progress yet.
>> I'm currently repressing it to be able to proceed with investigating other
>> bugs.
>>
>
> OK. That seems reasonable.
>
>
>> If I have not resolved this issue before my internship is over, I think
>> it may be better to file bugs against these issues.
>>
>>
> *nod* Might be worth an option to disable the feature in general so we
> don't need the source annotations?
>
> -eric
>
>
>> Note: commit reverted in rL246450 due to it breaking a flaky build.
>>
>> On Mon, Aug 31, 2015 at 9:23 AM, Eric Christopher <echristo at gmail.com>
>> wrote:
>>
>>>
>>>
>>>> Summary: In response to bug 24578, reported against failing LLVM test.
>>>>
>>>>
>>> FWIW we generally just say "PR24578"
>>>
>>> So, hrm, how long do we expect the "workaround" annotation to be in the
>>> source?
>>>
>>> -eric
>>>
>>>
>>>
>>>> Reviewers: chandlerc, rsmith, eugenis
>>>>
>>>> Subscribers: llvm-commits
>>>>
>>>> Differential Revision: http://reviews.llvm.org/D12335
>>>>
>>>> Modified:
>>>>     llvm/trunk/include/llvm/IR/User.h
>>>>     llvm/trunk/include/llvm/Support/Compiler.h
>>>>     llvm/trunk/lib/IR/Metadata.cpp
>>>>     llvm/trunk/lib/IR/User.cpp
>>>>
>>>> Modified: llvm/trunk/include/llvm/IR/User.h
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/User.h?rev=246449&r1=246448&r2=246449&view=diff
>>>>
>>>> ==============================================================================
>>>> --- llvm/trunk/include/llvm/IR/User.h (original)
>>>> +++ llvm/trunk/include/llvm/IR/User.h Mon Aug 31 10:57:40 2015
>>>> @@ -72,8 +72,7 @@ protected:
>>>>    void growHungoffUses(unsigned N, bool IsPhi = false);
>>>>
>>>>  public:
>>>> -  ~User() override {
>>>> -  }
>>>> +  ~User() override {}
>>>>    /// \brief Free memory allocated for User and Use objects.
>>>>    void operator delete(void *Usr);
>>>>    /// \brief Placement delete - required by std, but never called.
>>>>
>>>> Modified: llvm/trunk/include/llvm/Support/Compiler.h
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/Compiler.h?rev=246449&r1=246448&r2=246449&view=diff
>>>>
>>>> ==============================================================================
>>>> --- llvm/trunk/include/llvm/Support/Compiler.h (original)
>>>> +++ llvm/trunk/include/llvm/Support/Compiler.h Mon Aug 31 10:57:40 2015
>>>> @@ -323,10 +323,12 @@
>>>>  #if __has_feature(memory_sanitizer)
>>>>  # define LLVM_MEMORY_SANITIZER_BUILD 1
>>>>  # include <sanitizer/msan_interface.h>
>>>> +# define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE
>>>> __attribute__((no_sanitize_memory))
>>>>  #else
>>>>  # define LLVM_MEMORY_SANITIZER_BUILD 0
>>>>  # define __msan_allocated_memory(p, size)
>>>>  # define __msan_unpoison(p, size)
>>>> +# define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE
>>>>  #endif
>>>>
>>>>  /// \macro LLVM_ADDRESS_SANITIZER_BUILD
>>>>
>>>> Modified: llvm/trunk/lib/IR/Metadata.cpp
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Metadata.cpp?rev=246449&r1=246448&r2=246449&view=diff
>>>>
>>>> ==============================================================================
>>>> --- llvm/trunk/lib/IR/Metadata.cpp (original)
>>>> +++ llvm/trunk/lib/IR/Metadata.cpp Mon Aug 31 10:57:40 2015
>>>> @@ -401,7 +401,9 @@ void *MDNode::operator new(size_t Size,
>>>>    return Ptr;
>>>>  }
>>>>
>>>> -void MDNode::operator delete(void *Mem) {
>>>> +// Repress memory sanitization, due to use-after-destroy by operator
>>>> +// delete. Bug report 24578 identifies this issue.
>>>> +LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE void MDNode::operator delete(void
>>>> *Mem) {
>>>>    MDNode *N = static_cast<MDNode *>(Mem);
>>>>    size_t OpSize = N->NumOperands * sizeof(MDOperand);
>>>>    OpSize = RoundUpToAlignment(OpSize, llvm::alignOf<uint64_t>());
>>>>
>>>> Modified: llvm/trunk/lib/IR/User.cpp
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/User.cpp?rev=246449&r1=246448&r2=246449&view=diff
>>>>
>>>> ==============================================================================
>>>> --- llvm/trunk/lib/IR/User.cpp (original)
>>>> +++ llvm/trunk/lib/IR/User.cpp Mon Aug 31 10:57:40 2015
>>>> @@ -118,7 +118,9 @@ void *User::operator new(size_t Size) {
>>>>  //                         User operator delete Implementation
>>>>
>>>>  //===----------------------------------------------------------------------===//
>>>>
>>>> -void User::operator delete(void *Usr) {
>>>> +// Repress memory sanitization, due to use-after-destroy by operator
>>>> +// delete. Bug report 24578 identifies this issue.
>>>> +LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE void User::operator delete(void
>>>> *Usr) {
>>>>    // Hung off uses use a single Use* before the User, while other
>>>> subclasses
>>>>    // use a Use[] allocated prior to the user.
>>>>    User *Obj = static_cast<User *>(Usr);
>>>>
>>>>
>>>> _______________________________________________
>>>> llvm-commits mailing list
>>>> llvm-commits at lists.llvm.org
>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>>
>>>
>>
>>
>> --
>> - Naomi Musgrave
>>
>>


-- 
- Naomi Musgrave
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