* The performance is better than the glibc allocator.
* Allocator interface functions, sanitizer allocator options, and
MallocHooks/FreeHooks are supported.
* Shadow memory has specific memory layout requirement. Using libc
allocator could lead to conflicts.
* When we add a mmap interceptor for reliability (the VMA could reuse a
previously released VMA that is poisoned): glibc may invoke an
internal system call to call unmmap, which cannot be intercepted. We
will not be able to return the shadow memory to the OS.
Similar to dfsan https://reviews.llvm.org/D101204 . Also intercept
operator new/delete to be similar to other sanitizers using the
sanitizer allocator. The align_val_t overload of operator new has
slightly less overhead.
Pull Request: https://github.com/llvm/llvm-project/pull/102764
so that `clang -fsanitize=numerical -shared-libsan` will use
`libclang_rt.nsan.so` on Linux.
Shared runtime is preferred for some platforms (Android, Apple, Fuchsia;
though they are not supported yet) and helps plugin use cases (#98302).
* Update `ninja nsan` to build `libclang_rt.nsan.so`
* Fix `nsan.syms.extra`: `nsan_*` is unneeded. Add `__ubsan_*` so that
`-fsanitize=numerical,undefined -shared-libsan` works.
* Move allocation functions to `nsan_malloc_linux.cpp`. While Apple
platforms aren't supported yet, this separation makes it easier to add
Apple support.
* Delete interceptors for very obsoleted pvalloc/valloc but retain
memalign.
* Replace `HandleEarlyAlloc` with `DlsymAlloc`.
Pull Request: https://github.com/llvm/llvm-project/pull/98415
