Arch Linux

Description:
Any program built with -fsanitize=memory will fail to run with LLVM 3.7.0 and Linux 4.1.2 and newer. On startup, the program will fail with:

FATAL: Code 0x563b3a270d20 is out of application range. Non-PIE build?
FATAL: MemorySanitizer can not mmap the shadow memory.
FATAL: Make sure to compile with -fPIE and to link with -pie.
FATAL: Disabling ASLR is known to cause this error.
FATAL: If running under GDB, try 'set disable-randomization off'.

Upstream has pushed a fix for this bug (https://llvm.org/bugs/show_bug.cgi?id=24155), but based on their previous release schedules, it will probably take at least until Feb2016 before the fix is shipped with 3.8.0. Can the patch be considered for inclusion? Although an ABI break is mentioned, the kernel incompatibility has been there for almost 4 months (linux 4.1.2-1). There have been other (unsuspecting) reports of this issue as well: https://github.com/golang/go/issues/12898

I have included a squashed patch for the llvm+compiler-rt changes and an unrelated fix for a scan-build issue with cmake+clang (https://llvm.org/bugs/show_bug.cgi?id=13237). They both apply trivially:

# https://llvm.org/bugs/show_bug.cgi?id=24155
patch -Np1 -i ../new-msan-mapping.patch

# https://llvm.org/bugs/show_bug.cgi?id=13237
patch -d tools/clang -Np1 < ../scan-build-clang-fix.patch

Builds for me and is also helpful :) Tip for users: set MSAN_OPTIONS=help prior to running a MSAN-instrumented build for options.

Additional info:
Package versions:
* llvm 3.7.0-4
* linux 4.2.3-1

Steps to reproduce:
echo 'int main(){}' | clang -fsanitize=memory -x c - && ./a.out