Index: third_party/tcmalloc/chromium/src/base/vdso_support.h |
=================================================================== |
--- third_party/tcmalloc/chromium/src/base/vdso_support.h (revision 124832) |
+++ third_party/tcmalloc/chromium/src/base/vdso_support.h (working copy) |
@@ -1,35 +1,6 @@ |
-// Copyright (c) 2008, Google Inc. |
-// All rights reserved. |
+// Copyright 2008 Google Inc. All Rights Reserved. |
+// Author: ppluzhnikov@google.com (Paul Pluzhnikov) |
// |
-// 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. |
// |
// VDSO stands for "Virtual Dynamic Shared Object" -- a page of |
@@ -56,14 +27,19 @@ |
#define BASE_VDSO_SUPPORT_H_ |
#include <config.h> |
+#ifdef HAVE_FEATURES_H |
+#include <features.h> // for __GLIBC__ |
+#endif |
#include "base/basictypes.h" |
-#include "base/elf_mem_image.h" |
-#ifdef HAVE_ELF_MEM_IMAGE |
+// Maybe one day we can rewrite this file not to require the elf |
+// symbol extensions in glibc, but for right now we need them. |
+#if defined(__ELF__) && defined(__GLIBC__) |
#define HAVE_VDSO_SUPPORT 1 |
#include <stdlib.h> // for NULL |
+#include <link.h> // for ElfW |
namespace base { |
@@ -71,17 +47,45 @@ |
// use any memory allocation routines. |
class VDSOSupport { |
public: |
+ // Sentinel: there could never be a VDSO at this address. |
+ static const void *const kInvalidBase; |
+ |
+ // Information about a single vdso symbol. |
+ // All pointers are into .dynsym, .dynstr, or .text of the VDSO. |
+ // Do not free() them or modify through them. |
+ struct SymbolInfo { |
+ const char *name; // E.g. "__vdso_getcpu" |
+ const char *version; // E.g. "LINUX_2.6", could be "" |
+ // for unversioned symbol. |
+ const void *address; // Relocated symbol address. |
+ const ElfW(Sym) *symbol; // Symbol in the dynamic symbol table. |
+ }; |
+ |
+ // Supports iteration over all dynamic symbols. |
+ class SymbolIterator { |
+ public: |
+ friend class VDSOSupport; |
+ const SymbolInfo *operator->() const; |
+ const SymbolInfo &operator*() const; |
+ SymbolIterator& operator++(); |
+ bool operator!=(const SymbolIterator &rhs) const; |
+ bool operator==(const SymbolIterator &rhs) const; |
+ private: |
+ SymbolIterator(const void *const image, int index); |
+ void Update(int incr); |
+ SymbolInfo info_; |
+ int index_; |
+ const void *const image_; |
+ }; |
+ |
VDSOSupport(); |
- typedef ElfMemImage::SymbolInfo SymbolInfo; |
- typedef ElfMemImage::SymbolIterator SymbolIterator; |
- |
// Answers whether we have a vdso at all. |
bool IsPresent() const { return image_.IsPresent(); } |
// Allow to iterate over all VDSO symbols. |
- SymbolIterator begin() const { return image_.begin(); } |
- SymbolIterator end() const { return image_.end(); } |
+ SymbolIterator begin() const; |
+ SymbolIterator end() const; |
// Look up versioned dynamic symbol in the kernel VDSO. |
// Returns false if VDSO is not present, or doesn't contain given |
@@ -107,6 +111,33 @@ |
static const void *Init(); |
private: |
+ // An in-memory ELF image (may not exist on disk). |
+ class ElfMemImage { |
+ public: |
+ explicit ElfMemImage(const void *base); |
+ void Init(const void *base); |
+ bool IsPresent() const { return ehdr_ != NULL; } |
+ const ElfW(Phdr)* GetPhdr(int index) const; |
+ const ElfW(Sym)* GetDynsym(int index) const; |
+ const ElfW(Versym)* GetVersym(int index) const; |
+ const ElfW(Verdef)* GetVerdef(int index) const; |
+ const ElfW(Verdaux)* GetVerdefAux(const ElfW(Verdef) *verdef) const; |
+ const char* GetDynstr(ElfW(Word) offset) const; |
+ const void* GetSymAddr(const ElfW(Sym) *sym) const; |
+ const char* GetVerstr(ElfW(Word) offset) const; |
+ int GetNumSymbols() const; |
+ private: |
+ const ElfW(Ehdr) *ehdr_; |
+ const ElfW(Sym) *dynsym_; |
+ const ElfW(Versym) *versym_; |
+ const ElfW(Verdef) *verdef_; |
+ const ElfW(Word) *hash_; |
+ const char *dynstr_; |
+ size_t strsize_; |
+ size_t verdefnum_; |
+ ElfW(Addr) link_base_; // Link-time base (p_vaddr of first PT_LOAD). |
+ }; |
+ |
// image_ represents VDSO ELF image in memory. |
// image_.ehdr_ == NULL implies there is no VDSO. |
ElfMemImage image_; |
@@ -150,6 +181,6 @@ |
int GetCPU(); |
} // namespace base |
-#endif // HAVE_ELF_MEM_IMAGE |
+#endif // __ELF__ and __GLIBC__ |
#endif // BASE_VDSO_SUPPORT_H_ |