1 files changed, 0 insertions, 194 deletions
diff --git a/third_party/abseil_cpp/absl/debugging/internal/vdso_support.cc b/third_party/abseil_cpp/absl/debugging/internal/vdso_support.cc
deleted file mode 100644
index 1e8a78ac9c..0000000000
--- a/third_party/abseil_cpp/absl/debugging/internal/vdso_support.cc
+++ /dev/null
@@ -1,194 +0,0 @@
-// Copyright 2017 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Allow dynamic symbol lookup in the kernel VDSO page.
-//
-// VDSOSupport -- a class representing kernel VDSO (if present).
-
-#include "absl/debugging/internal/vdso_support.h"
-
-#ifdef ABSL_HAVE_VDSO_SUPPORT     // defined in vdso_support.h
-
-#include <errno.h>
-#include <fcntl.h>
-#include <sys/syscall.h>
-#include <unistd.h>
-
-#if __GLIBC_PREREQ(2, 16)  // GLIBC-2.16 implements getauxval.
-#include <sys/auxv.h>
-#endif
-
-#include "absl/base/dynamic_annotations.h"
-#include "absl/base/internal/raw_logging.h"
-#include "absl/base/port.h"
-
-#ifndef AT_SYSINFO_EHDR
-#define AT_SYSINFO_EHDR 33  // for crosstoolv10
-#endif
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace debugging_internal {
-
-ABSL_CONST_INIT
-std::atomic<const void *> VDSOSupport::vdso_base_(
-    debugging_internal::ElfMemImage::kInvalidBase);
-
-std::atomic<VDSOSupport::GetCpuFn> VDSOSupport::getcpu_fn_(&InitAndGetCPU);
-VDSOSupport::VDSOSupport()
-    // If vdso_base_ is still set to kInvalidBase, we got here
-    // before VDSOSupport::Init has been called. Call it now.
-    : image_(vdso_base_.load(std::memory_order_relaxed) ==
-                     debugging_internal::ElfMemImage::kInvalidBase
-                 ? Init()
-                 : vdso_base_.load(std::memory_order_relaxed)) {}
-
-// NOTE: we can't use GoogleOnceInit() below, because we can be
-// called by tcmalloc, and none of the *once* stuff may be functional yet.
-//
-// In addition, we hope that the VDSOSupportHelper constructor
-// causes this code to run before there are any threads, and before
-// InitGoogle() has executed any chroot or setuid calls.
-//
-// Finally, even if there is a race here, it is harmless, because
-// the operation should be idempotent.
-const void *VDSOSupport::Init() {
-  const auto kInvalidBase = debugging_internal::ElfMemImage::kInvalidBase;
-#if __GLIBC_PREREQ(2, 16)
-  if (vdso_base_.load(std::memory_order_relaxed) == kInvalidBase) {
-    errno = 0;
-    const void *const sysinfo_ehdr =
-        reinterpret_cast<const void *>(getauxval(AT_SYSINFO_EHDR));
-    if (errno == 0) {
-      vdso_base_.store(sysinfo_ehdr, std::memory_order_relaxed);
-    }
-  }
-#endif  // __GLIBC_PREREQ(2, 16)
-  if (vdso_base_.load(std::memory_order_relaxed) == kInvalidBase) {
-    // Valgrind zaps AT_SYSINFO_EHDR and friends from the auxv[]
-    // on stack, and so glibc works as if VDSO was not present.
-    // But going directly to kernel via /proc/self/auxv below bypasses
-    // Valgrind zapping. So we check for Valgrind separately.
-    if (RunningOnValgrind()) {
-      vdso_base_.store(nullptr, std::memory_order_relaxed);
-      getcpu_fn_.store(&GetCPUViaSyscall, std::memory_order_relaxed);
-      return nullptr;
-    }
-    int fd = open("/proc/self/auxv", O_RDONLY);
-    if (fd == -1) {
-      // Kernel too old to have a VDSO.
-      vdso_base_.store(nullptr, std::memory_order_relaxed);
-      getcpu_fn_.store(&GetCPUViaSyscall, std::memory_order_relaxed);
-      return nullptr;
-    }
-    ElfW(auxv_t) aux;
-    while (read(fd, &aux, sizeof(aux)) == sizeof(aux)) {
-      if (aux.a_type == AT_SYSINFO_EHDR) {
-        vdso_base_.store(reinterpret_cast<void *>(aux.a_un.a_val),
-                         std::memory_order_relaxed);
-        break;
-      }
-    }
-    close(fd);
-    if (vdso_base_.load(std::memory_order_relaxed) == kInvalidBase) {
-      // Didn't find AT_SYSINFO_EHDR in auxv[].
-      vdso_base_.store(nullptr, std::memory_order_relaxed);
-    }
-  }
-  GetCpuFn fn = &GetCPUViaSyscall;  // default if VDSO not present.
-  if (vdso_base_.load(std::memory_order_relaxed)) {
-    VDSOSupport vdso;
-    SymbolInfo info;
-    if (vdso.LookupSymbol("__vdso_getcpu", "LINUX_2.6", STT_FUNC, &info)) {
-      fn = reinterpret_cast<GetCpuFn>(const_cast<void *>(info.address));
-    }
-  }
-  // Subtle: this code runs outside of any locks; prevent compiler
-  // from assigning to getcpu_fn_ more than once.
-  getcpu_fn_.store(fn, std::memory_order_relaxed);
-  return vdso_base_.load(std::memory_order_relaxed);
-}
-
-const void *VDSOSupport::SetBase(const void *base) {
-  ABSL_RAW_CHECK(base != debugging_internal::ElfMemImage::kInvalidBase,
-                 "internal error");
-  const void *old_base = vdso_base_.load(std::memory_order_relaxed);
-  vdso_base_.store(base, std::memory_order_relaxed);
-  image_.Init(base);
-  // Also reset getcpu_fn_, so GetCPU could be tested with simulated VDSO.
-  getcpu_fn_.store(&InitAndGetCPU, std::memory_order_relaxed);
-  return old_base;
-}
-
-bool VDSOSupport::LookupSymbol(const char *name,
-                               const char *version,
-                               int type,
-                               SymbolInfo *info) const {
-  return image_.LookupSymbol(name, version, type, info);
-}
-
-bool VDSOSupport::LookupSymbolByAddress(const void *address,
-                                        SymbolInfo *info_out) const {
-  return image_.LookupSymbolByAddress(address, info_out);
-}
-
-// NOLINT on 'long' because this routine mimics kernel api.
-long VDSOSupport::GetCPUViaSyscall(unsigned *cpu,  // NOLINT(runtime/int)
-                                   void *, void *) {
-#ifdef SYS_getcpu
-  return syscall(SYS_getcpu, cpu, nullptr, nullptr);
-#else
-  // x86_64 never implemented sys_getcpu(), except as a VDSO call.
-  static_cast<void>(cpu);  // Avoid an unused argument compiler warning.
-  errno = ENOSYS;
-  return -1;
-#endif
-}
-
-// Use fast __vdso_getcpu if available.
-long VDSOSupport::InitAndGetCPU(unsigned *cpu,  // NOLINT(runtime/int)
-                                void *x, void *y) {
-  Init();
-  GetCpuFn fn = getcpu_fn_.load(std::memory_order_relaxed);
-  ABSL_RAW_CHECK(fn != &InitAndGetCPU, "Init() did not set getcpu_fn_");
-  return (*fn)(cpu, x, y);
-}
-
-// This function must be very fast, and may be called from very
-// low level (e.g. tcmalloc). Hence I avoid things like
-// GoogleOnceInit() and ::operator new.
-ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY
-int GetCPU() {
-  unsigned cpu;
-  int ret_code = (*VDSOSupport::getcpu_fn_)(&cpu, nullptr, nullptr);
-  return ret_code == 0 ? cpu : ret_code;
-}
-
-// We need to make sure VDSOSupport::Init() is called before
-// InitGoogle() does any setuid or chroot calls.  If VDSOSupport
-// is used in any global constructor, this will happen, since
-// VDSOSupport's constructor calls Init.  But if not, we need to
-// ensure it here, with a global constructor of our own.  This
-// is an allowed exception to the normal rule against non-trivial
-// global constructors.
-static class VDSOInitHelper {
- public:
-  VDSOInitHelper() { VDSOSupport::Init(); }
-} vdso_init_helper;
-
-}  // namespace debugging_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_HAVE_VDSO_SUPPORT