Summary: For platforms which support slow unwinder only, we restrict the store context size to 1, basically only storing the current pc. We do this because the slow unwinder which is based on libunwind is not async signal safe and causes random freezes in forking applications as well as in signal handlers.
Reviewed by eugenis.
Differential: D23107
llvm-svn: 289027
These tests were recently enabled and have never worked on this builder.
Three tests were sensitive to line number changes:
test/msan/Linux/obstack.cc
test/msan/chained_origin.cc
test/msan/chained_origin_memcpy.cc
and this sensitivity will be addressed in a follow-up patch. Of these,
obstack.cc's sensitivity to line numbers is unexplained since it already uses
[[@LINE]].
llvm-svn: 278671
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 is 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.
llvm-svn: 247809
Origin history should only be recorded for uninitialized values, because it is
meaningless otherwise. This change moves __msan_chain_origin to the runtime
library side and makes it conditional on the corresponding shadow value.
Previous code was correct, but _very_ inefficient.
llvm-svn: 211700
Generalize StackDepot and create a new specialized instance of it to
efficiently (i.e. without duplicating stack trace data) store the
origin history tree.
This reduces memory usage for chained origins roughly by an order of
magnitude.
Most importantly, this new design allows us to put two limits on
stored history data (exposed in MSAN_OPTIONS) that help avoid
exponential growth in used memory on certain workloads.
See comments in lib/msan/msan_origin.h for more details.
llvm-svn: 209284
Sagar Thakur