1 files changed, 93 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/hwasan/hwasan_globals.cpp b/contrib/llvm-project/compiler-rt/lib/hwasan/hwasan_globals.cpp
new file mode 100644
index 000000000000..7e0f3df20dd0
--- /dev/null
+++ b/contrib/llvm-project/compiler-rt/lib/hwasan/hwasan_globals.cpp
@@ -0,0 +1,93 @@
+//===-- hwasan_globals.cpp ------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of HWAddressSanitizer.
+//
+// HWAddressSanitizer globals-specific runtime.
+//===----------------------------------------------------------------------===//
+
+#include "hwasan_globals.h"
+
+#include "sanitizer_common/sanitizer_array_ref.h"
+
+namespace __hwasan {
+
+enum { NT_LLVM_HWASAN_GLOBALS = 3 };
+struct hwasan_global_note {
+  s32 begin_relptr;
+  s32 end_relptr;
+};
+
+// Check that the given library meets the code model requirements for tagged
+// globals. These properties are not checked at link time so they need to be
+// checked at runtime.
+static void CheckCodeModel(ElfW(Addr) base, const ElfW(Phdr) * phdr,
+                           ElfW(Half) phnum) {
+  ElfW(Addr) min_addr = -1ull, max_addr = 0;
+  for (unsigned i = 0; i != phnum; ++i) {
+    if (phdr[i].p_type != PT_LOAD)
+      continue;
+    ElfW(Addr) lo = base + phdr[i].p_vaddr, hi = lo + phdr[i].p_memsz;
+    if (min_addr > lo)
+      min_addr = lo;
+    if (max_addr < hi)
+      max_addr = hi;
+  }
+
+  if (max_addr - min_addr > 1ull << 32) {
+    Report("FATAL: HWAddressSanitizer: library size exceeds 2^32\n");
+    Die();
+  }
+  if (max_addr > 1ull << 48) {
+    Report("FATAL: HWAddressSanitizer: library loaded above address 2^48\n");
+    Die();
+  }
+}
+
+ArrayRef<const hwasan_global> HwasanGlobalsFor(ElfW(Addr) base,
+                                               const ElfW(Phdr) * phdr,
+                                               ElfW(Half) phnum) {
+  // Read the phdrs from this DSO.
+  for (unsigned i = 0; i != phnum; ++i) {
+    if (phdr[i].p_type != PT_NOTE)
+      continue;
+
+    const char *note = reinterpret_cast<const char *>(base + phdr[i].p_vaddr);
+    const char *nend = note + phdr[i].p_memsz;
+
+    // Traverse all the notes until we find a HWASan note.
+    while (note < nend) {
+      auto *nhdr = reinterpret_cast<const ElfW(Nhdr) *>(note);
+      const char *name = note + sizeof(ElfW(Nhdr));
+      const char *desc = name + RoundUpTo(nhdr->n_namesz, 4);
+
+      // Discard non-HWASan-Globals notes.
+      if (nhdr->n_type != NT_LLVM_HWASAN_GLOBALS ||
+          internal_strcmp(name, "LLVM") != 0) {
+        note = desc + RoundUpTo(nhdr->n_descsz, 4);
+        continue;
+      }
+
+      // Only libraries with instrumented globals need to be checked against the
+      // code model since they use relocations that aren't checked at link time.
+      CheckCodeModel(base, phdr, phnum);
+
+      auto *global_note = reinterpret_cast<const hwasan_global_note *>(desc);
+      auto *globals_begin = reinterpret_cast<const hwasan_global *>(
+          note + global_note->begin_relptr);
+      auto *globals_end = reinterpret_cast<const hwasan_global *>(
+          note + global_note->end_relptr);
+
+      return {globals_begin, globals_end};
+    }
+  }
+
+  return {};
+}
+
+}  // namespace __hwasan