1 files changed, 180 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_tls_get_addr.cpp b/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_tls_get_addr.cpp
new file mode 100644
index 000000000000..ee293bbd6887
--- /dev/null
+++ b/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_tls_get_addr.cpp
@@ -0,0 +1,180 @@
+//===-- sanitizer_tls_get_addr.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
+//
+//===----------------------------------------------------------------------===//
+//
+// Handle the __tls_get_addr call.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_tls_get_addr.h"
+
+#include "sanitizer_allocator_interface.h"
+#include "sanitizer_atomic.h"
+#include "sanitizer_flags.h"
+#include "sanitizer_platform_interceptors.h"
+
+namespace __sanitizer {
+#if SANITIZER_INTERCEPT_TLS_GET_ADDR
+
+// The actual parameter that comes to __tls_get_addr
+// is a pointer to a struct with two words in it:
+struct TlsGetAddrParam {
+  uptr dso_id;
+  uptr offset;
+};
+
+// This must be static TLS
+__attribute__((tls_model("initial-exec")))
+static __thread DTLS dtls;
+
+// Make sure we properly destroy the DTLS objects:
+// this counter should never get too large.
+static atomic_uintptr_t number_of_live_dtls;
+
+static const uptr kDestroyedThread = -1;
+
+static void DTLS_Deallocate(DTLS::DTVBlock *block) {
+  VReport(2, "__tls_get_addr: DTLS_Deallocate %p\n", (void *)block);
+  UnmapOrDie(block, sizeof(DTLS::DTVBlock));
+  atomic_fetch_sub(&number_of_live_dtls, 1, memory_order_relaxed);
+}
+
+static DTLS::DTVBlock *DTLS_NextBlock(atomic_uintptr_t *cur) {
+  uptr v = atomic_load(cur, memory_order_acquire);
+  if (v == kDestroyedThread)
+    return nullptr;
+  DTLS::DTVBlock *next = (DTLS::DTVBlock *)v;
+  if (next)
+    return next;
+  DTLS::DTVBlock *new_dtv =
+      (DTLS::DTVBlock *)MmapOrDie(sizeof(DTLS::DTVBlock), "DTLS_NextBlock");
+  uptr prev = 0;
+  if (!atomic_compare_exchange_strong(cur, &prev, (uptr)new_dtv,
+                                      memory_order_seq_cst)) {
+    UnmapOrDie(new_dtv, sizeof(DTLS::DTVBlock));
+    return (DTLS::DTVBlock *)prev;
+  }
+  uptr num_live_dtls =
+      atomic_fetch_add(&number_of_live_dtls, 1, memory_order_relaxed);
+  VReport(2, "__tls_get_addr: DTLS_NextBlock %p %zd\n", (void *)&dtls,
+          num_live_dtls);
+  return new_dtv;
+}
+
+static DTLS::DTV *DTLS_Find(uptr id) {
+  VReport(2, "__tls_get_addr: DTLS_Find %p %zd\n", (void *)&dtls, id);
+  static constexpr uptr kPerBlock = ARRAY_SIZE(DTLS::DTVBlock::dtvs);
+  DTLS::DTVBlock *cur = DTLS_NextBlock(&dtls.dtv_block);
+  if (!cur)
+    return nullptr;
+  for (; id >= kPerBlock; id -= kPerBlock) cur = DTLS_NextBlock(&cur->next);
+  return cur->dtvs + id;
+}
+
+void DTLS_Destroy() {
+  if (!common_flags()->intercept_tls_get_addr) return;
+  VReport(2, "__tls_get_addr: DTLS_Destroy %p\n", (void *)&dtls);
+  DTLS::DTVBlock *block = (DTLS::DTVBlock *)atomic_exchange(
+      &dtls.dtv_block, kDestroyedThread, memory_order_release);
+  while (block) {
+    DTLS::DTVBlock *next =
+        (DTLS::DTVBlock *)atomic_load(&block->next, memory_order_acquire);
+    DTLS_Deallocate(block);
+    block = next;
+  }
+}
+
+#if defined(__powerpc64__) || defined(__mips__)
+// This is glibc's TLS_DTV_OFFSET:
+// "Dynamic thread vector pointers point 0x8000 past the start of each
+//  TLS block." (sysdeps/<arch>/dl-tls.h)
+static const uptr kDtvOffset = 0x8000;
+#elif defined(__riscv)
+// This is glibc's TLS_DTV_OFFSET:
+// "Dynamic thread vector pointers point 0x800 past the start of each
+// TLS block." (sysdeps/riscv/dl-tls.h)
+static const uptr kDtvOffset = 0x800;
+#else
+static const uptr kDtvOffset = 0;
+#endif
+
+extern "C" {
+SANITIZER_WEAK_ATTRIBUTE
+uptr __sanitizer_get_allocated_size(const void *p);
+
+SANITIZER_WEAK_ATTRIBUTE
+const void *__sanitizer_get_allocated_begin(const void *p);
+}
+
+DTLS::DTV *DTLS_on_tls_get_addr(void *arg_void, void *res,
+                                uptr static_tls_begin, uptr static_tls_end) {
+  if (!common_flags()->intercept_tls_get_addr) return 0;
+  TlsGetAddrParam *arg = reinterpret_cast<TlsGetAddrParam *>(arg_void);
+  uptr dso_id = arg->dso_id;
+  DTLS::DTV *dtv = DTLS_Find(dso_id);
+  if (!dtv || dtv->beg)
+    return 0;
+  uptr tls_size = 0;
+  uptr tls_beg = reinterpret_cast<uptr>(res) - arg->offset - kDtvOffset;
+  VReport(2,
+          "__tls_get_addr: %p {0x%zx,0x%zx} => %p; tls_beg: %p; sp: %p "
+          "num_live_dtls %zd\n",
+          (void *)arg, arg->dso_id, arg->offset, res, (void *)tls_beg,
+          (void *)&tls_beg,
+          atomic_load(&number_of_live_dtls, memory_order_relaxed));
+  if (dtls.last_memalign_ptr == tls_beg) {
+    tls_size = dtls.last_memalign_size;
+    VReport(2, "__tls_get_addr: glibc <=2.24 suspected; tls={%p,0x%zx}\n",
+            (void *)tls_beg, tls_size);
+  } else if (tls_beg >= static_tls_begin && tls_beg < static_tls_end) {
+    // This is the static TLS block which was initialized / unpoisoned at thread
+    // creation.
+    VReport(2, "__tls_get_addr: static tls: %p\n", (void *)tls_beg);
+    tls_size = 0;
+  } else if (const void *start =
+                 __sanitizer_get_allocated_begin((void *)tls_beg)) {
+    tls_beg = (uptr)start;
+    tls_size = __sanitizer_get_allocated_size(start);
+    VReport(2, "__tls_get_addr: glibc >=2.25 suspected; tls={%p,0x%zx}\n",
+            (void *)tls_beg, tls_size);
+  } else {
+    VReport(2, "__tls_get_addr: Can't guess glibc version\n");
+    // This may happen inside the DTOR of main thread, so just ignore it.
+    tls_size = 0;
+  }
+  dtv->beg = tls_beg;
+  dtv->size = tls_size;
+  return dtv;
+}
+
+void DTLS_on_libc_memalign(void *ptr, uptr size) {
+  if (!common_flags()->intercept_tls_get_addr) return;
+  VReport(2, "DTLS_on_libc_memalign: %p 0x%zx\n", ptr, size);
+  dtls.last_memalign_ptr = reinterpret_cast<uptr>(ptr);
+  dtls.last_memalign_size = size;
+}
+
+DTLS *DTLS_Get() { return &dtls; }
+
+bool DTLSInDestruction(DTLS *dtls) {
+  return atomic_load(&dtls->dtv_block, memory_order_relaxed) ==
+         kDestroyedThread;
+}
+
+#else
+void DTLS_on_libc_memalign(void *ptr, uptr size) {}
+DTLS::DTV *DTLS_on_tls_get_addr(void *arg, void *res,
+  unsigned long, unsigned long) { return 0; }
+DTLS *DTLS_Get() { return 0; }
+void DTLS_Destroy() {}
+bool DTLSInDestruction(DTLS *dtls) {
+  UNREACHABLE("dtls is unsupported on this platform!");
+}
+
+#endif  // SANITIZER_INTERCEPT_TLS_GET_ADDR
+
+}  // namespace __sanitizer