Index: sandbox/linux/seccomp/maps.cc |
=================================================================== |
--- sandbox/linux/seccomp/maps.cc (revision 57969) |
+++ sandbox/linux/seccomp/maps.cc (working copy) |
@@ -1,267 +0,0 @@ |
-// Copyright (c) 2010 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#include <errno.h> |
-#include <fcntl.h> |
-#include <linux/unistd.h> |
-#include <signal.h> |
-#include <stdarg.h> |
-#include <stdlib.h> |
-#include <sys/ptrace.h> |
-#include <sys/types.h> |
-#include <sys/wait.h> |
- |
-#include "library.h" |
-#include "maps.h" |
-#include "sandbox_impl.h" |
- |
-namespace playground { |
- |
-Maps::Maps(int proc_self_maps) : |
- proc_self_maps_(proc_self_maps), |
- begin_iter_(this, true, false), |
- end_iter_(this, false, true), |
- vsyscall_(0) { |
- Sandbox::SysCalls sys; |
- if (proc_self_maps_ >= 0 && |
- !sys.lseek(proc_self_maps_, 0, SEEK_SET)) { |
- char buf[256] = { 0 }; |
- int len = 0, rc = 1; |
- bool long_line = false; |
- do { |
- if (rc > 0) { |
- rc = Sandbox::read(sys, proc_self_maps_, buf + len, |
- sizeof(buf) - len - 1); |
- if (rc > 0) { |
- len += rc; |
- } |
- } |
- char *ptr = buf; |
- if (!long_line) { |
- long_line = true; |
- unsigned long start = strtoul(ptr, &ptr, 16); |
- unsigned long stop = strtoul(ptr + 1, &ptr, 16); |
- while (*ptr == ' ' || *ptr == '\t') ++ptr; |
- char *perm_ptr = ptr; |
- while (*ptr && *ptr != ' ' && *ptr != '\t') ++ptr; |
- string perm(perm_ptr, ptr - perm_ptr); |
- unsigned long offset = strtoul(ptr, &ptr, 16); |
- while (*ptr == ' ' || *ptr == '\t') ++ptr; |
- char *id_ptr = ptr; |
- while (*ptr && *ptr != ' ' && *ptr != '\t') ++ptr; |
- while (*ptr == ' ' || *ptr == '\t') ++ptr; |
- while (*ptr && *ptr != ' ' && *ptr != '\t') ++ptr; |
- string id(id_ptr, ptr - id_ptr); |
- while (*ptr == ' ' || *ptr == '\t') ++ptr; |
- char *library_ptr = ptr; |
- while (*ptr && *ptr != ' ' && *ptr != '\t' && *ptr != '\n') ++ptr; |
- string library(library_ptr, ptr - library_ptr); |
- bool isVDSO = false; |
- if (library == "[vdso]") { |
- // /proc/self/maps has a misleading file offset in the [vdso] entry. |
- // Override it with a sane value. |
- offset = 0; |
- isVDSO = true; |
- } else if (library == "[vsyscall]") { |
- vsyscall_ = reinterpret_cast<char *>(start); |
- } else if (library.empty() || library[0] == '[') { |
- goto skip_entry; |
- } |
- int prot = 0; |
- if (perm.find('r') != string::npos) { |
- prot |= PROT_READ; |
- } |
- if (perm.find('w') != string::npos) { |
- prot |= PROT_WRITE; |
- } |
- if (perm.find('x') != string::npos) { |
- prot |= PROT_EXEC; |
- } |
- if ((prot & (PROT_EXEC | PROT_READ)) == 0) { |
- goto skip_entry; |
- } |
- Library* lib = &libs_[id + ' ' + library]; |
- lib->setLibraryInfo(this); |
- lib->addMemoryRange(reinterpret_cast<void *>(start), |
- reinterpret_cast<void *>(stop), |
- Elf_Addr(offset), |
- prot, isVDSO); |
- } |
- skip_entry: |
- for (;;) { |
- if (!*ptr || *ptr++ == '\n') { |
- long_line = false; |
- memmove(buf, ptr, len - (ptr - buf)); |
- memset(buf + len - (ptr - buf), 0, ptr - buf); |
- len -= (ptr - buf); |
- break; |
- } |
- } |
- } while (len || long_line); |
- } |
-} |
- |
-Maps::Iterator::Iterator(Maps* maps, bool at_beginning, bool at_end) |
- : maps_(maps), |
- at_beginning_(at_beginning), |
- at_end_(at_end) { |
-} |
- |
-Maps::LibraryMap::iterator& Maps::Iterator::getIterator() const { |
- if (at_beginning_) { |
- iter_ = maps_->libs_.begin(); |
- } else if (at_end_) { |
- iter_ = maps_->libs_.end(); |
- } |
- return iter_; |
-} |
- |
-Maps::Iterator Maps::Iterator::begin() { |
- return maps_->begin_iter_; |
-} |
- |
-Maps::Iterator Maps::Iterator::end() { |
- return maps_->end_iter_; |
-} |
- |
-Maps::Iterator& Maps::Iterator::operator++() { |
- getIterator().operator++(); |
- at_beginning_ = false; |
- return *this; |
-} |
- |
-Maps::Iterator Maps::Iterator::operator++(int i) { |
- getIterator().operator++(i); |
- at_beginning_ = false; |
- return *this; |
-} |
- |
-Library* Maps::Iterator::operator*() const { |
- return &getIterator().operator*().second; |
-} |
- |
-bool Maps::Iterator::operator==(const Maps::Iterator& iter) const { |
- return getIterator().operator==(iter.getIterator()); |
-} |
- |
-bool Maps::Iterator::operator!=(const Maps::Iterator& iter) const { |
- return !operator==(iter); |
-} |
- |
-Maps::string Maps::Iterator::name() const { |
- return getIterator()->first; |
-} |
- |
-// Test whether a line ends with "[stack]"; used for identifying the |
-// stack entry of /proc/self/maps. |
-static bool isStackLine(char* buf, char* end) { |
- char* ptr = buf; |
- for ( ; *ptr != '\n' && ptr < end; ++ptr) |
- ; |
- if (ptr < end && ptr - 7 > buf) { |
- return (memcmp(ptr - 7, "[stack]", 7) == 0); |
- } |
- return false; |
-} |
- |
-char* Maps::allocNearAddr(char* addr_target, size_t size, int prot) const { |
- // We try to allocate memory within 1.5GB of a target address. This means, |
- // we will be able to perform relative 32bit jumps from the target address. |
- const unsigned long kMaxDistance = 1536 << 20; |
- // In most of the code below, we just care about the numeric value of |
- // the address. |
- const long addr = reinterpret_cast<long>(addr_target); |
- size = (size + 4095) & ~4095; |
- Sandbox::SysCalls sys; |
- if (sys.lseek(proc_self_maps_, 0, SEEK_SET)) { |
- return NULL; |
- } |
- |
- // Iterate through lines of /proc/self/maps to consider each mapped |
- // region one at a time, looking for a gap between regions to allocate. |
- char buf[256] = { 0 }; |
- int len = 0, rc = 1; |
- bool long_line = false; |
- unsigned long gap_start = 0x10000; |
- void* new_addr; |
- do { |
- if (rc > 0) { |
- do { |
- rc = Sandbox::read(sys, proc_self_maps_, buf + len, |
- sizeof(buf) - len - 1); |
- if (rc > 0) { |
- len += rc; |
- } |
- } while (rc > 0 && len < (int)sizeof(buf) - 1); |
- } |
- char *ptr = buf; |
- if (!long_line) { |
- long_line = true; |
- // Maps lines have the form "<start address>-<end address> ... <name>". |
- unsigned long gap_end = strtoul(ptr, &ptr, 16); |
- unsigned long map_end = strtoul(ptr + 1, &ptr, 16); |
- |
- // gap_start to gap_end now covers the region of empty space before |
- // the current line. Now we try to see if there's a place within the |
- // gap we can use. |
- |
- if (gap_end - gap_start >= size) { |
- // Is the gap before our target address? |
- if (addr - static_cast<long>(gap_end) >= 0) { |
- if (addr - (gap_end - size) < kMaxDistance) { |
- unsigned long position; |
- if (isStackLine(ptr, buf + len)) { |
- // If we're adjacent to the stack, try to stay away from |
- // the GROWS_DOWN region. Pick the farthest away region that |
- // is still within the gap. |
- |
- if (static_cast<unsigned long>(addr) < kMaxDistance || // Underflow protection. |
- static_cast<unsigned long>(addr) - kMaxDistance < gap_start) { |
- position = gap_start; |
- } else { |
- position = (addr - kMaxDistance) & ~4095; |
- if (position < gap_start) { |
- position = gap_start; |
- } |
- } |
- } else { |
- // Otherwise, take the end of the region. |
- position = gap_end - size; |
- } |
- new_addr = reinterpret_cast<char *>(sys.MMAP |
- (reinterpret_cast<void *>(position), size, prot, |
- MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0)); |
- if (new_addr != MAP_FAILED) { |
- goto done; |
- } |
- } |
- } else if (gap_start + size - addr < kMaxDistance) { |
- // Gap is after the address. Above checks that we can wrap around |
- // through 0 to a space we'd use. |
- new_addr = reinterpret_cast<char *>(sys.MMAP |
- (reinterpret_cast<void *>(gap_start), size, prot, |
- MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1 ,0)); |
- if (new_addr != MAP_FAILED) { |
- goto done; |
- } |
- } |
- } |
- gap_start = map_end; |
- } |
- for (;;) { |
- if (!*ptr || *ptr++ == '\n') { |
- long_line = false; |
- memmove(buf, ptr, len - (ptr - buf)); |
- memset(buf + len - (ptr - buf), 0, ptr - buf); |
- len -= (ptr - buf); |
- break; |
- } |
- } |
- } while (len || long_line); |
- new_addr = NULL; |
-done: |
- return reinterpret_cast<char*>(new_addr); |
-} |
- |
-} // namespace |