[PATCH] D68720: Support -fstack-clash-protection for x86

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serge-sans-paille created this revision.
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Herald added projects: clang, LLVM.

Implement protection against the stack clash attack [0].

Probe stack allocation every PAGE_SIZE during frame lowering or dynamic allocation to make sure the  page guard, if any, is touched when touching the stack, in a similar manner to GCC[1].

If possible, use MOV already present in the entry block instead of generating new ones.

Only implemented for x86.

[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D68720

Files:
  clang/include/clang/Basic/CodeGenOptions.def
  clang/include/clang/Basic/DiagnosticFrontendKinds.td
  clang/include/clang/Basic/TargetInfo.h
  clang/include/clang/Driver/CC1Options.td
  clang/include/clang/Driver/Options.td
  clang/lib/Basic/Targets/X86.h
  clang/lib/CodeGen/BackendUtil.cpp
  clang/lib/CodeGen/CGStmt.cpp
  clang/lib/Driver/ToolChains/Clang.cpp
  clang/lib/Frontend/CompilerInvocation.cpp
  clang/test/CodeGen/stack-clash-protection.c
  clang/test/Driver/stack-clash-protection.c
  llvm/include/llvm/CodeGen/CommandFlags.inc
  llvm/include/llvm/Target/TargetOptions.h
  llvm/lib/Target/X86/X86FrameLowering.cpp
  llvm/lib/Target/X86/X86FrameLowering.h
  llvm/lib/Target/X86/X86ISelLowering.cpp
  llvm/lib/Target/X86/X86ISelLowering.h
  llvm/lib/Target/X86/X86InstrCompiler.td
  llvm/lib/Target/X86/X86InstrInfo.td
  llvm/test/CodeGen/X86/stack-clash-dynamic-alloca.ll
  llvm/test/CodeGen/X86/stack-clash-medium-natural-probes.ll
  llvm/test/CodeGen/X86/stack-clash-medium.ll
  llvm/test/CodeGen/X86/stack-clash-small.ll

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