Hi,
it's been a while since the last libsanitizer merge from upstream into
GCC happened and the library has significantly changed since that time.
The main features to be ported are:
-New common strings interceptors were added.
-Various allocator improvements were performed.
-Improvements for ASan deactivated start were performed.
-TSan and LSan were enabled for Aarch64.
-Fast unwinding was enabled for Aarch64.
-New tsan_unaligned_{load, store}_[n] functions were intoduced.
-asan_stack_malloc_[n] doesn't take a local stack as a second parameter
anymore.
-sanitization for std containers is supported now.
-New interface functions for dynamic allocas and VLA's
poisoning/unpoisoning were introduced.
Some features are not ported for now, by might be enabled in future:
-Embedded UBSan runtime into ASan and TSan ones. I don't enable this
now, because of errors during ASan static linkage: GCC uses
-whole-archive option that would lead to undefined references to C++ stuff.
-UBSan data descriptors for float-cast conversion support location
propagation now. But sometimes we have loc == UNKNOWN_LOCATION in
ubsan_instrument_float_cast, so use old ABI for now. See below for details.
The first patch of the series is the merge itself.
The second one introduces corresponding compiler changes.
Other patches are applied to library and they are GCC-specific:
Patches 3 and 4 are just reapplied David's and Jakub's patches for SPARC
and disabling ODR violation detection respectively.
Patch 5 removes UBSan stubs from ASan and TSan code since we don't
support embedded UBSan runtime into ASan and TSan.
Patch 6 changes heuristic for extracting last PC from stack frame for
ARM in fast unwind routine. More details can be found here
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61771).
Patch 7 forces libsanitizer to use an old ABI for ubsan float cast data
descriptors, because sometimes we can have loc == UNKNOWN_LOCATION in
ubsan_instrument_float_cast e.g. in a such case:
......
volatile double foo; // ubsan_instrument_float_cast is called by convert
function.
......
Since foo is a tcc_declaration, loc is UNKNOWN_LOCATION. I'm actually
not sure about this, perhaps we can fix this in GCC somehow.
I've regtested and {A, UB}San bootstrapped these patches on
x86-64-unknown-linux-gnu and aarch64-linux-gnueabi (Juno board, 39 bit
VA space) and tested for ARM under QEMU-ARM.
Testing ASan under QEMU-AARCH64 revealed many test failures due to LSan
was enabled. In particular, it tries to call internal_clone function in
LSan internals, that in turn calls _NR_clone syscall and than QEMU exits
with EINTR error code (that might be expected, AFAIK QEMU is not very
good with threads). So, I wonder, if I should disable LSan for AArch64 now?
I'm also asking community to help me with testing these patches on
various targets (ARM, PPC, etc) I'm lack of, so could you help me on
this please?
-Maxim
