[compiler-rt] r184849 - [lsan] Define interceptors more correctly. Also, always clear allocated memory.

[Sergey Matveev]

Yes, this should theoretically help against false negatives. Also, ASan
does the same.


On Tue, Jun 25, 2013 at 6:28 PM, Dmitry Vyukov <dvyukov at google.com> wrote:

> On Tue, Jun 25, 2013 at 6:05 PM, Sergey Matveev <earthdok at google.com>
> wrote:
> > Author: smatveev
> > Date: Tue Jun 25 09:05:52 2013
> > New Revision: 184849
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=184849&view=rev
> > Log:
> > [lsan] Define interceptors more correctly. Also, always clear allocated
> memory.
> >
> > Modified:
> >     compiler-rt/trunk/lib/lsan/lsan_interceptors.cc
> >
> > Modified: compiler-rt/trunk/lib/lsan/lsan_interceptors.cc
> > URL:
> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/lsan/lsan_interceptors.cc?rev=184849&r1=184848&r2=184849&view=diff
> >
> ==============================================================================
> > --- compiler-rt/trunk/lib/lsan/lsan_interceptors.cc (original)
> > +++ compiler-rt/trunk/lib/lsan/lsan_interceptors.cc Tue Jun 25 09:05:52
> 2013
> > @@ -51,6 +51,8 @@ int pthread_setspecific(unsigned key, co
> >
> >  ///// Malloc/free interceptors. /////
> >
> > +const bool kAlwaysClearMemory = true;
> > +
> >  namespace std {
> >    struct nothrow_t;
> >  }
> > @@ -58,7 +60,7 @@ namespace std {
> >  INTERCEPTOR(void*, malloc, uptr size) {
> >    Init();
> >    GET_STACK_TRACE;
> > -  return Allocate(stack, size, 1, false);
> > +  return Allocate(stack, size, 1, kAlwaysClearMemory);
>
> Do I read this correctly that malloc() now clears memory?
>
>
> >  }
> >
> >  INTERCEPTOR(void, free, void *p) {
> > @@ -83,13 +85,13 @@ INTERCEPTOR(void*, realloc, void *q, upt
> >  INTERCEPTOR(void*, memalign, uptr alignment, uptr size) {
> >    Init();
> >    GET_STACK_TRACE;
> > -  return Allocate(stack, size, alignment, false);
> > +  return Allocate(stack, size, alignment, kAlwaysClearMemory);
> >  }
> >
> >  INTERCEPTOR(int, posix_memalign, void **memptr, uptr alignment, uptr
> size) {
> >    Init();
> >    GET_STACK_TRACE;
> > -  *memptr = Allocate(stack, size, alignment, false);
> > +  *memptr = Allocate(stack, size, alignment, kAlwaysClearMemory);
> >    // FIXME: Return ENOMEM if user requested more than max alloc size.
> >    return 0;
> >  }
> > @@ -99,7 +101,7 @@ INTERCEPTOR(void*, valloc, uptr size) {
> >    GET_STACK_TRACE;
> >    if (size == 0)
> >      size = GetPageSizeCached();
> > -  return Allocate(stack, size, GetPageSizeCached(), false);
> > +  return Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory);
> >  }
> >
> >  INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
> > @@ -121,28 +123,52 @@ INTERCEPTOR(int, mallopt, int cmd, int v
> >    return -1;
> >  }
> >
> > -void *operator new(uptr size) ALIAS("malloc")
> SANITIZER_INTERFACE_ATTRIBUTE;
> > -void *operator new[](uptr size) ALIAS("malloc")
> SANITIZER_INTERFACE_ATTRIBUTE;
> > -void *operator new(uptr size, std::nothrow_t const&) ALIAS("malloc")
> > -    SANITIZER_INTERFACE_ATTRIBUTE;
> > -void *operator new[](uptr size, std::nothrow_t const&) ALIAS("malloc")
> > -    SANITIZER_INTERFACE_ATTRIBUTE;
> > -void operator delete(void *ptr) ALIAS("free")
> SANITIZER_INTERFACE_ATTRIBUTE;
> > -void operator delete[](void *ptr) ALIAS("free")
> SANITIZER_INTERFACE_ATTRIBUTE;
> > -void operator delete(void *ptr, std::nothrow_t const&) ALIAS("free")
> > -    SANITIZER_INTERFACE_ATTRIBUTE;
> > -void operator delete[](void *ptr, std::nothrow_t const&) ALIAS("free")
> > -    SANITIZER_INTERFACE_ATTRIBUTE;
> > -
> > -extern "C" {
> > -void cfree(void *p) ALIAS("free") SANITIZER_INTERFACE_ATTRIBUTE;
> > -void *pvalloc(uptr size) ALIAS("valloc")
> > -    SANITIZER_INTERFACE_ATTRIBUTE;
> > +INTERCEPTOR(void*, pvalloc, uptr size) {
> > +  Init();
> > +  GET_STACK_TRACE;
> > +  uptr PageSize = GetPageSizeCached();
> > +  size = RoundUpTo(size, PageSize);
> > +  if (size == 0) {
> > +    // pvalloc(0) should allocate one page.
> > +    size = PageSize;
> > +  }
> > +  return Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory);
> > +}
> > +
> > +INTERCEPTOR(void, cfree, void *p) ALIAS("free");
> > +
> > +#define OPERATOR_NEW_BODY                              \
> > +  Init();                                              \
> > +  GET_STACK_TRACE;                                     \
> > +  return Allocate(stack, size, 1, kAlwaysClearMemory);
> > +
> > +INTERCEPTOR_ATTRIBUTE
> > +void *operator new(uptr size) { OPERATOR_NEW_BODY; }
> > +INTERCEPTOR_ATTRIBUTE
> > +void *operator new[](uptr size) { OPERATOR_NEW_BODY; }
> > +INTERCEPTOR_ATTRIBUTE
> > +void *operator new(uptr size, std::nothrow_t const&) {
> OPERATOR_NEW_BODY; }
> > +INTERCEPTOR_ATTRIBUTE
> > +void *operator new[](uptr size, std::nothrow_t const&) {
> OPERATOR_NEW_BODY; }
> > +
> > +#define OPERATOR_DELETE_BODY \
> > +  Init();                    \
> > +  Deallocate(ptr);
> > +
> > +INTERCEPTOR_ATTRIBUTE
> > +void operator delete(void *ptr) { OPERATOR_DELETE_BODY; }
> > +INTERCEPTOR_ATTRIBUTE
> > +void operator delete[](void *ptr) { OPERATOR_DELETE_BODY; }
> > +INTERCEPTOR_ATTRIBUTE
> > +void operator delete(void *ptr, std::nothrow_t const&) {
> OPERATOR_DELETE_BODY; }
> > +INTERCEPTOR_ATTRIBUTE
> > +void operator delete[](void *ptr, std::nothrow_t const &) {
> > +  OPERATOR_DELETE_BODY;
> > +}
> > +
> >  // We need this to intercept the __libc_memalign calls that are used to
> >  // allocate dynamic TLS space in ld-linux.so.
> > -void *__libc_memalign(uptr alignment, uptr size)
> > -    ALIAS("memalign") SANITIZER_INTERFACE_ATTRIBUTE;
> > -}
> > +INTERCEPTOR(void *, __libc_memalign, uptr align, uptr s)
> ALIAS("memalign");
> >
> >  ///// Thread initialization and finalization. /////
> >
> > @@ -231,12 +257,14 @@ namespace __lsan {
> >  void InitializeInterceptors() {
> >    INTERCEPT_FUNCTION(malloc);
> >    INTERCEPT_FUNCTION(free);
> > +  INTERCEPT_FUNCTION(cfree);
> >    INTERCEPT_FUNCTION(calloc);
> >    INTERCEPT_FUNCTION(realloc);
> >    INTERCEPT_FUNCTION(memalign);
> >    INTERCEPT_FUNCTION(posix_memalign);
> > -  INTERCEPT_FUNCTION(memalign);
> > +  INTERCEPT_FUNCTION(__libc_memalign);
> >    INTERCEPT_FUNCTION(valloc);
> > +  INTERCEPT_FUNCTION(pvalloc);
> >    INTERCEPT_FUNCTION(malloc_usable_size);
> >    INTERCEPT_FUNCTION(mallinfo);
> >    INTERCEPT_FUNCTION(mallopt);
> >
> >
> > _______________________________________________
> > llvm-commits mailing list
> > llvm-commits at cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>
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