Other sanitizers (ASan, TSan, see added tests) already handle
memcpy.inline and memset.inline by not relying on InstVisitor to turn
the intrinsics into calls. Only MSan instrumentation currently does not
support them due to missing InstVisitor callbacks.
Fix it by actually making InstVisitor handle Mem*InlineInst.
While the mem*.inline intrinsics promise no calls to external functions
as an optimization, for the sanitizers we need to break this guarantee
since access into the runtime is required either way, and performance
can no longer be guaranteed. All other cases, where generating a call is
incorrect, should instead use no_sanitize.
Fixes: https://github.com/llvm/llvm-project/issues/57048
Reviewed By: vitalybuka, dvyukov
Differential Revision: https://reviews.llvm.org/D131577
Allow receiving memcpy/memset/memmove instrumentation by using __asan or
__hwasan prefixed versions for AddressSanitizer and HWAddressSanitizer
respectively when compiling in kernel mode, by passing params
-asan-kernel-mem-intrinsic-prefix or -hwasan-kernel-mem-intrinsic-prefix.
By default the kernel-specialized versions of both passes drop the
prefixes for calls generated by memintrinsics. This assumes that all
locations that can lower the intrinsics to libcalls can safely be
instrumented. This unfortunately is not the case when implicit calls to
memintrinsics are inserted by the compiler in no_sanitize functions [1].
To solve the issue, normal memcpy/memset/memmove need to be
uninstrumented, and instrumented code should instead use the prefixed
versions. This also aligns with ASan behaviour in user space.
[1] https://lore.kernel.org/lkml/Yj2yYFloadFobRPx@lakrids/
Reviewed By: glider
Differential Revision: https://reviews.llvm.org/D122724
Marco Elver