This patch enabled msan for aarch64 with 39-bit VMA and 42-bit VMA.
As defined by lib/msan/msan.h the memory layout used is for 39-bit is:
00 0000 0000 - 40 0000 0000: invalid 40 0000 0000 - 43 0000 0000: shadow 43 0000 0000 - 46 0000 0000: origin 46 0000 0000 - 55 0000 0000: invalid 55 0000 0000 - 56 0000 0000: app (low) 56 0000 0000 - 70 0000 0000: invalid 70 0000 0000 - 80 0000 0000: app (high)
And for 42-bit VMA:
000 0000 0000 - 100 0000 0000: invalid 100 0000 0000 - 11b 0000 0000: shadow 11b 0000 0000 - 120 0000 0000: invalid 120 0000 0000 - 13b 0000 0000: origin 13b 0000 0000 - 2aa 0000 0000: invalid 2aa 0000 0000 - 2ab 0000 0000: app (low) 2ab 0000 0000 - 3f0 0000 0000: invalid 3f0 0000 0000 - 400 0000 0000: app (high)
Most of tests are passing with exception of:
- Linux/mallinfo.cc
- chained_origin_limits.cc
- dlerror.cc
- param_tls_limit.cc
- signal_stress_test.cc
- nonnull-arg.cpp
The 'Linux/mallinfo.cc' is due the fact AArch64 returns the sret in 'x8'
instead of default first argument 'x1'. So a function prototype that
aims to mimic (by using first argument as the return of function) won't
work. For GCC one can make a register alias (register var asm ("r8")), but
for clang it detects it an unused variable and generate wrong code.
The 'chained_origin_limits' is probably due a wrong code generation,
since it fails only when origin memory is used
(-fsanitize-memory-track-origins=2) and only in the returned code
(return buf[50]).
The 'signal_streess_test' and 'nonnull-arg' are due currently missing variadic
argument handling in memory sanitizer code instrumentation on LLVM side.
Both 'dlerror' and 'param_tls_test' are unknown failures that require
further investigation.
All the failures are XFAIL for aarch64 for now.
implement this in asm and it will work on both gcc and clang.