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

Mon Aug 31 12:36:23 PDT 2015

Right, but sooner or later should probably mean "when we're clean" and not
at other times? Or am I missing something?

-eric

On Mon, Aug 31, 2015 at 12:35 PM Evgenii Stepanov <eugenis at google.com>
wrote:

> We have the options, and they are off by default at this point. But we
> want to enable them on the sanitizer bootstrap bot sooner or later.
>
>
> On Mon, Aug 31, 2015 at 12:26 PM, Naomi Musgrave <nmusgrave at google.com>
> wrote:
> > 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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