First, avoid calling setTailCall(false) on musttail calls. The funciton
prototypes should be "congruent", so the shadow layout should be exactly
the same.
Second, avoid inserting instrumentation after a musttail call to
propagate the return value shadow. We don't need to propagate the
result of a tail call, it should already be in the right place.
Reviewed By: eugenis
Differential Revision: http://reviews.llvm.org/D4331
llvm-svn: 215415
Origin is meaningless for fully initialized values. Avoid
storing origin for function arguments that are known to
be always initialized (i.e. shadow is a compile-time null
constant).
This is not about correctness, but purely an optimization.
Seems to affect compilation time of blacklisted functions
significantly.
llvm-svn: 213239
With this change all values passed through blacklisted functions
become fully initialized. Previous behavior was to initialize all
loads in blacklisted functions, but apply normal shadow propagation
logic for all other operation.
This makes blacklist applicable in a wider range of situations.
It also makes code for blacklisted functions a lot shorter, which
works as yet another workaround for PR17409.
llvm-svn: 212268
Select condition shadow was being ignored resulting in false negatives.
This change OR-s sign-extended condition shadow into the result shadow.
llvm-svn: 189785
The code was erroneously reading overflow area shadow from the TLS slot,
bypassing the local copy. Reading shadow directly from TLS is wrong, because
it can be overwritten by a nested vararg call, if that happens before va_start.
llvm-svn: 189104
Before this change, each module defined a weak_odr global __msan_track_origins
with a value of 1 if origin tracking is enabled, 0 if disabled. If there are
modules with different values, any of them may win. If 0 wins, and there is at
least one module with 1, the program will most likely crash.
With this change, __msan_track_origins is only emitted if origin tracking is
on. Then runtime library detects if there is at least one module with origin
tracking, and enables runtime support for it.
llvm-svn: 182997
Shadow checks are disabled and memory loads always produce fully initialized
values in functions that don't have a sanitize_memory attribute. Value and
argument shadow is propagated as usual.
This change also updates blacklist behaviour to match the above.
llvm-svn: 176247
It is way too slow. Change the default option value to 0.
Always do exact shadow propagation for unsigned ICmp with constants, it is
cheap (under 1% cpu time) and required for correctness.
llvm-svn: 173682
Only for integers, pointers, and vectors of those. No floats.
Instrumentation seems very heavy, and may need to be replaced
with some approximation in the future.
llvm-svn: 173452
This fixes va_start/va_copy of a va_list field which happens to not
be laid out at a 16-byte boundary.
Differential Revision: http://llvm-reviews.chandlerc.com/D276
llvm-svn: 172128
This changes adds shadow and origin propagation for unknown intrinsics
by examining the arguments and ModRef behaviour. For now, only 3 classes
of intrinsics are handled:
- those that look like simple SIMD store
- those that look like simple SIMD load
- those that don't have memory effects and look like arithmetic/logic/whatever
operation on simple types.
llvm-svn: 170530
Instead of unconditionally storing origin with every application store,
only do this when the shadow of the stored value is != 0.
This change also delays instrumentation of stores until after the walk over
function's instructions, because adding new basic blocks confuses InstVisitor.
We only keep 1 origin value per 4 bytes of application memory. This change
fixes the bug when a store of a single clean byte wiped the origin for the
whole 4-byte area.
Since stores of uninitialized values are relatively uncommon, this change
improves performance of track-origins mode by 5% median and by up to 47% on
specs.
llvm-svn: 169490
Chandler Carruth