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Document types of linking of runtimes.

    1: Sanitizers for NetBSD
    2: 
    3: # Current status
    4: 
    5: Summary of the current status of sanitizers on a NetBSD host.
    6: 
    7: # What are sanitizers?
    8: 
    9: Sanitizer is a programming tool that detects computer program bugs such as buffer overflows, signed integer overflow, uninitialized memory read etc.
   10: 
   11: Sanitizers are developed in LLVM, and a downstream port exists to GCC.
   12: 
   13: # Types of sanitizers
   14: 
   15: There are various types of sanitizers.
   16: 
   17: A sanitizer is composed of an instrumentation part builtin into a compiler's code generation part.
   18: 
   19: The instrumentation part emitted by a compiler requires a runtime library, that is shipped with compiler-rt.
   20: 
   21:  * Undefined Behavior Sanitizer (UBSan)
   22:  * Undefined Behavior with minimal runtime (UBSan_minimal)
   23:  * Address Sanitizer (ASan)
   24:  * Hardware Assisted Address Sanitizer (HWASan)
   25:  * Thread Sanitizer (TSan)
   26:  * Memory Sanitizer (MSan)
   27:  * Efficiency Sanitizer (ESan)
   28:  * Data Flow Sanitizer (DFSan)
   29:  * Leak Sanitizer (LSan)
   30: 
   31: Additionally there are the following features shipped together with sanitizers:
   32: 
   33:  * profile
   34:  * SafeStack
   35:  * Control Flow Integrity
   36:  * Scudo Hardened Allocator
   37:  * XRay
   38:  * libFuzzer
   39:  * ShadowCallStack
   40: 
   41: The compiler-rt package ships with libBlocksRuntime, builtins etc.
   42: 
   43: As a NetBSD specific extension, there is a micro-UBSan runtime developed and maintained in the NetBSD source code.
   44: It is designed to function inside libc (uUBSan - usermode-UBSan) and inside the kernel (kUBSan - kernel-UBSan).
   45: 
   46: # Types of runtimes
   47: 
   48: There are two types of sanitizer runtimes:
   49: 
   50:  * dynamically linked ones (default in GCC)
   51:  * statically linked ones (default in Clang)
   52: 
   53: Base GCC/NetBSD works with the former, upstream HEAD version of LLVM/NetBSD works with the latter.
   54: 
   55: Both compilers should support both of them, but the other options (GCC/NetBSD & static runtime, LLVM/NetBSD & dynamic runtime) are to be done.
   56: 
   57: # Sanitizers in NetBSD
   58: 
   59: Sanitizers in NetBSD are shipped with the following options:
   60: 
   61:  * together with the toolchain with the default compiler runtime (default),
   62:  * together with the MKSANITIZER option (build the userland with the default compiler sanitizer),
   63:  * together with the MKLIBCSANITIZER option (build the userland with a homegrown sanitizer runtime),
   64:  * together with the NetBSD kernel (build the kernel with a homegrown kernel sanitizer runtime).
   65: 
   66: MKSANITIZER blog entry:
   67: 
   68: http://blog.netbsd.org/tnf/entry/mksanitizer_bug_detector_software_integration
   69: 
   70: MKLIBCSANITIZER and kernel sanitizer blog entry:
   71: 	
   72: http://blog.netbsd.org/tnf/entry/introduction_to_%C2%B5ubsan_a_clean
   73: 
   74: # Support in NetBSD
   75: 
   76: Currently the main focus is with LLVM and GCC.
   77: 
   78: Generic TODO:
   79: 
   80:  * switch syscall(2)/__syscall(2) to libc calls
   81:  * upstream local patches / rebase to newly developed support in LLVM available in GCC 8.x and newer
   82:  * develop missing interceptors such as fts(3) (mostly MSan-centric)
   83:  * FILE and DIR sanitization (needed by at least: ESan, MSan)
   84:  * improve the framework for ioctl(2) database and handle special cases when a part of a struct can be uninitialized and passed to the kernel (MSan)
   85:  * finish StopTheWorld() and upstream to LLVM
   86:  * port to !x86
   87:  * fixes with the signal code
   88:  * pkgsrc integration
   89:  * finish the support of float128 for Clang/LLVM/libstdc++/libgcc
   90:  * LLVM fixes for shared (dlopen(3)-powered) runtime
   91:  * fix other bugs.
   92: 
   93: ## GCC
   94: 
   95: The GCC compiler assumed the version in distribution.
   96: 
   97: ### GCC with the default runtime
   98: 
   99: Name      | NetBSD status
  100: ----------|---------------------------------
  101: UBSan     | mostly works with all ports
  102: ASan      | mostly works with amd64 and i386
  103: LSan      | might work with amd64 and i386
  104: 
  105: ### GCC with MKSANITIZER
  106: 
  107: Untested.
  108: 
  109: ### GCC with MKLIBCSANITIZER
  110: 
  111: Name      | NetBSD status
  112: ----------|---------------------------------
  113: UBSan     | works with micro-UBSan
  114: 
  115: ### GCC with kernel sanitizers
  116: 
  117: Name      | NetBSD status
  118: ----------|---------------------------------
  119: UBSan     | works with micro-UBSan
  120: 
  121: ## LLVM
  122: 
  123: The LLVM support is available only with the HEAD version of the toolchain and not shipped in the base distribution.
  124: 
  125: ### LLVM with the default runtime
  126: 
  127: Name      | NetBSD status
  128: ----------|---------------------------------
  129: UBSan     | mostly works with all LLVM ports
  130: ASan      | mostly works with amd64 and i386
  131: MSan      | mostly works with amd64
  132: TSan      | mostly works with amd64
  133: 
  134: ### LLVM with MKSANITIZER
  135: 
  136: Name      | NetBSD status
  137: ----------|---------------------------------
  138: UBSan     | mostly works with all LLVM ports
  139: ASan      | mostly works with amd64 and i386
  140: 
  141: ### LLVM with MKLIBCSANITIZER
  142: 
  143: Name      | NetBSD status
  144: ----------|---------------------------------
  145: UBSan     | works with micro-UBSan
  146: 
  147: ### LLVM with kernel sanitizers
  148: 
  149: Name      | NetBSD status
  150: ----------|---------------------------------
  151: UBSan     | works with micro-UBSan