[PATCH] D119816: [SanitizerBounds] Add support for NoSanitizeBounds function

[Tong Zhang via Phabricator via cfe-commits]

ztong0001 added inline comments.


================
Comment at: clang/lib/CodeGen/CodeGenFunction.cpp:757
         SanOpts.set(SanitizerKind::HWAddress, false);
+      if (mask & SanitizerKind::LocalBounds)
+        Fn->addFnAttr(llvm::Attribute::NoSanitizeBounds);
----------------
melver wrote:
> ztong0001 wrote:
> > ztong0001 wrote:
> > > melver wrote:
> > > > These 2 checks can be reduced to 1 due to SanitizerKind::Bounds including both. However, as noted, this only affects local-bounds, so I'm not sure if we want to include both -- perhaps for completeness it makes sense, but in the array-bounds only case this attribute will be a nop (AFAIK).
> > > > 
> > > > Also, I think we don't want to attach the attribute if bounds checking isn't enabled -- at least it seems unnecessary to do so.
> > > > 
> > > > See the following suggested change:
> > > > 
> > > > ```
> > > > diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
> > > > index 842ce0245d45..c1f3a3014a19 100644
> > > > --- a/clang/lib/CodeGen/CodeGenFunction.cpp
> > > > +++ b/clang/lib/CodeGen/CodeGenFunction.cpp
> > > > @@ -740,6 +740,7 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
> > > >    } while (false);
> > > >  
> > > >    if (D) {
> > > > +    const bool SanitizeBounds = SanOpts.hasOneOf(SanitizerKind::Bounds);
> > > >      bool NoSanitizeCoverage = false;
> > > >  
> > > >      for (auto Attr : D->specific_attrs<NoSanitizeAttr>()) {
> > > > @@ -754,16 +755,15 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
> > > >          SanOpts.set(SanitizerKind::KernelHWAddress, false);
> > > >        if (mask & SanitizerKind::KernelHWAddress)
> > > >          SanOpts.set(SanitizerKind::HWAddress, false);
> > > > -      if (mask & SanitizerKind::LocalBounds)
> > > > -        Fn->addFnAttr(llvm::Attribute::NoSanitizeBounds);
> > > > -      if (mask & SanitizerKind::ArrayBounds)
> > > > -        Fn->addFnAttr(llvm::Attribute::NoSanitizeBounds);
> > > >  
> > > >        // SanitizeCoverage is not handled by SanOpts.
> > > >        if (Attr->hasCoverage())
> > > >          NoSanitizeCoverage = true;
> > > >      }
> > > >  
> > > > +    if (SanitizeBounds && !SanOpts.hasOneOf(SanitizerKind::Bounds))
> > > > +      Fn->addFnAttr(llvm::Attribute::NoSanitizeBounds);
> > > > +
> > > >      if (NoSanitizeCoverage && CGM.getCodeGenOpts().hasSanitizeCoverage())
> > > >        Fn->addFnAttr(llvm::Attribute::NoSanitizeCoverage);
> > > >    }
> > > > 
> > > > ```
> > > Agreed. I will revise patch and commit description.
> > BTW: Just to double check we are on the same page
> > 
> > when no_sanitize(bounds) is provided, fsanitize=array-bounds is also disabled -- right ? I can confirm this attribute is also affecting array-bounds as this is handled in clang side and we are setting llvm::Attribute::NoSanitizeBounds so that clang's array-bounds can also see this.
> > 
> > I will also add another test for -fsanitize=array-bounds
> Well, no_sanitize("bounds") already worked for array-bounds before this patch. But adding more tests never hurt.
Got it. Thanks!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D119816/new/

https://reviews.llvm.org/D119816