[PATCH] D107850: [asan] Implemented intrinsic for the custom calling convention similar used by HWASan for X86.

[Vitaly Buka via Phabricator via llvm-commits]

vitalybuka added inline comments.


================
Comment at: llvm/include/llvm/IR/Intrinsics.td:1640
 
+def int_asan_check_memaccess :
+  Intrinsic<[],[llvm_ptr_ty, llvm_i8_ty, llvm_i8_ty],
----------------
pcc wrote:
> eugenis wrote:
> > vitalybuka wrote:
> > > kstoimenov wrote:
> > > > vitalybuka wrote:
> > > > > vitalybuka wrote:
> > > > > > PTAL at lvm.read_register.i32
> > > > > > 
> > > > > > How about:
> > > > > > 
> > > > > > llvm.asan.check.memaccess ->
> > > > > >   lvm.asan.check_read
> > > > > >   lvm.asan.check_write
> > > > > >   lvm.asan.kernel.check_read
> > > > > >   lvm.asan.kernel.check_write
> > > > > > 
> > > > > > Even better
> > > > > >   lvm.asan.check_read.{i8, i16, i32, ...}
> > > > > >   lvm.asan.check_write.{i8, i16, i32, ...}
> > > > > >   lvm.asan.kernel.check_read.{i8, i16, i32, ...}
> > > > > >   lvm.asan.kernel.check_write.{i8, i16, i32, ...}
> > > > > > 
> > > > > Looks like underscore is not used in intrinsic names, so essentially the same with dots.
> > > > Sounds good to me. I do the full expansion so there will be 20 intrinsics altogether. I will update the code and ping you when done. 
> > > @pcc @eugenis 
> > > WDYT, I think later we can do the same for HWASAN?
> > I don't see what these multiple intrinsics give us that a single memaccess one does not provide?
> > 
> > As long as access type and similar arguments are immediates.
> > 
> Agree with @eugenis - these sorts of intrinsic variants are typically used for distinguishing different pointer element types and we're in the process of getting rid of those anyway.
@pcc @eugenis Then do you prefer to encode is_write+size+kernel into non-human unreadable AccessInfo, like hwasan, or separate 0/1 arguments.
I probably prefer AccessInfo, as they both unreadable, but the hwasan version is shorter.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D107850/new/

https://reviews.llvm.org/D107850