asan: fix kernel callback naming in instrumentation module

[andreyknvl]

Summary

Right now clang uses "_n" suffix for some user space callbacks and "N" for the matching kernel ones. There's no need for this and it actually breaks kernel build with inline instrumentation. Use the same callback names for user space and the kernel (and also make them consistent with the names GCC uses).

[eugenis]

Please fix hwasan as well.

[andreyknvl]

In D42423#985333, @eugenis wrote:

Please fix hwasan as well.

AFAICS hwasan always uses the same suffix. You want me to make it use "_n" instead of "N"?

[eugenis]

Yes, the same as asan.

[andreyknvl]

Asan uses "asan_loadN" and "asan_storeN" and hwasan now has "hwasan_loadN" and "hwasan_storeN", so both use "N" and this is consistent as is.

Asan however has "__asan_report_store_n_noabort" (and others based on "kAsanReportErrorTemplate"), which uses "_n", but hwasan doesn't have those as of yet.

[eugenis]

Ah, ok. It's strange to have different suffixes for error vs access callbacks. Is that for GCC compatibility?

[andreyknvl]

It is strange indeed.

GCC does the same, but I'm not sure who started doing it first.

[andreyknvl]

Could you commit this?

llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp

 void AddressSanitizer::initializeCallbacks(Module &M) {
   IRBuilder<> IRB(*C);
   // Create __asan_report* callbacks.
   // IsWrite, TypeSize and Exp are encoded in the function name.
   for (int Exp = 0; Exp < 2; Exp++) {
     for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
       const std::string TypeStr = AccessIsWrite ? "store" : "load";
       const std::string ExpStr = Exp ? "exp_" : "";
-      const std::string SuffixStr = CompileKernel ? "N" : "_n";
       const std::string EndingStr = Recover ? "_noabort" : "";
 
       SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
       SmallVector<Type *, 2> Args1{1, IntptrTy};
       if (Exp) {
         Type *ExpType = Type::getInt32Ty(*C);
         Args2.push_back(ExpType);
         Args1.push_back(ExpType);
       }
       AsanErrorCallbackSized[AccessIsWrite][Exp] =
           checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-              kAsanReportErrorTemplate + ExpStr + TypeStr + SuffixStr +
-                  EndingStr,
+              kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
               FunctionType::get(IRB.getVoidTy(), Args2, false)));
 
       AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] =
           checkSanitizerInterfaceFunction(M.getOrInsertFunction(
               ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
               FunctionType::get(IRB.getVoidTy(), Args2, false)));
 
       for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;