diff options
Diffstat (limited to 'src/third_party/gperftools-2.5/src/base/vdso_support.cc')
| -rw-r--r-- | src/third_party/gperftools-2.5/src/base/vdso_support.cc | 143 |
1 files changed, 0 insertions, 143 deletions
diff --git a/src/third_party/gperftools-2.5/src/base/vdso_support.cc b/src/third_party/gperftools-2.5/src/base/vdso_support.cc deleted file mode 100644 index 730df3011d6..00000000000 --- a/src/third_party/gperftools-2.5/src/base/vdso_support.cc +++ /dev/null @@ -1,143 +0,0 @@ -// Copyright (c) 2008, Google Inc. -// All rights reserved. -// -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following disclaimer -// in the documentation and/or other materials provided with the -// distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - -// --- -// Author: Paul Pluzhnikov -// -// Allow dynamic symbol lookup in the kernel VDSO page. -// -// VDSOSupport -- a class representing kernel VDSO (if present). -// - -#include "base/vdso_support.h" - -#ifdef HAVE_VDSO_SUPPORT // defined in vdso_support.h - -#include <fcntl.h> -#include <stddef.h> // for ptrdiff_t - -#include "base/atomicops.h" // for MemoryBarrier -#include "base/linux_syscall_support.h" -#include "base/logging.h" -#include "base/dynamic_annotations.h" -#include "base/basictypes.h" // for COMPILE_ASSERT - -using base::subtle::MemoryBarrier; - -#ifndef AT_SYSINFO_EHDR -#define AT_SYSINFO_EHDR 33 -#endif - -namespace base { - -const void *VDSOSupport::vdso_base_ = ElfMemImage::kInvalidBase; -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_ == ElfMemImage::kInvalidBase ? Init() : vdso_base_) { -} - -// 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() { - if (vdso_base_ == ElfMemImage::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_ = NULL; - return NULL; - } - int fd = open("/proc/self/auxv", O_RDONLY); - if (fd == -1) { - // Kernel too old to have a VDSO. - vdso_base_ = NULL; - return NULL; - } - ElfW(auxv_t) aux; - while (read(fd, &aux, sizeof(aux)) == sizeof(aux)) { - if (aux.a_type == AT_SYSINFO_EHDR) { - COMPILE_ASSERT(sizeof(vdso_base_) == sizeof(aux.a_un.a_val), - unexpected_sizeof_pointer_NE_sizeof_a_val); - vdso_base_ = reinterpret_cast<void *>(aux.a_un.a_val); - break; - } - } - close(fd); - if (vdso_base_ == ElfMemImage::kInvalidBase) { - // Didn't find AT_SYSINFO_EHDR in auxv[]. - vdso_base_ = NULL; - } - } - return vdso_base_; -} - -const void *VDSOSupport::SetBase(const void *base) { - CHECK(base != ElfMemImage::kInvalidBase); - const void *old_base = vdso_base_; - vdso_base_ = base; - image_.Init(base); - 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); -} - -// We need to make sure VDSOSupport::Init() is called before -// the main() runs, since it might do something like setuid or -// chroot. 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; -} - -#endif // HAVE_VDSO_SUPPORT |