diff options
| -rw-r--r-- | sandbox/linux/seccomp/library.h | 21 | ||||
| -rw-r--r-- | sandbox/linux/seccomp/maps.h | 3 | ||||
| -rw-r--r-- | third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h | 20 |
3 files changed, 34 insertions, 10 deletions
diff --git a/sandbox/linux/seccomp/library.h b/sandbox/linux/seccomp/library.h index 29a755e..96ec581 100644 --- a/sandbox/linux/seccomp/library.h +++ b/sandbox/linux/seccomp/library.h @@ -6,6 +6,7 @@ #define LIBRARY_H__ #include <elf.h> +#include <functional> #include <map> #include <set> #include <string> @@ -135,6 +136,9 @@ class Library { private: class GreaterThan : public std::binary_function<Elf_Addr, Elf_Addr, bool> { + // We create the RangeMap with a GreaterThan rather than the default + // comparator, as that allows us to use lower_bound() to find memory + // mappings. public: bool operator() (Elf_Addr s1, Elf_Addr s2) const { return s1 > s2; @@ -149,10 +153,19 @@ class Library { int prot; }; - typedef std::map<Elf_Addr, Range, GreaterThan> RangeMap; - typedef std::map<string, std::pair<int, Elf_Shdr> > SectionTable; - typedef std::map<string, Elf_Sym> SymbolTable; - typedef std::map<string, Elf_Addr> PltTable; + typedef std::map<Elf_Addr, Range, GreaterThan, + SystemAllocator<std::pair<const Elf_Addr, + Range> > > RangeMap; + typedef std::map<string, std::pair<int, Elf_Shdr>, std::less<string>, + SystemAllocator<std::pair<const string, + std::pair<int, Elf_Shdr> > > > + SectionTable; + typedef std::map<string, Elf_Sym, std::less<string>, + SystemAllocator<std::pair<const string, + Elf_Sym> > > SymbolTable; + typedef std::map<string, Elf_Addr, std::less<string>, + SystemAllocator<std::pair<const string, + Elf_Addr> > > PltTable; char* getBytes(char* dst, const char* src, ssize_t len); static bool isSafeInsn(unsigned short insn); diff --git a/sandbox/linux/seccomp/maps.h b/sandbox/linux/seccomp/maps.h index 5f51782..fbcc7672 100644 --- a/sandbox/linux/seccomp/maps.h +++ b/sandbox/linux/seccomp/maps.h @@ -37,7 +37,8 @@ class Maps { // The key is a unique combination of device number, inode number, and // file name. It should be treated as opaque. typedef std::map<string, Library, std::less<string>, - SystemAllocator<string> > LibraryMap; + SystemAllocator<std::pair<const string, + Library> > > LibraryMap; friend class Iterator; class Iterator { friend class Maps; diff --git a/third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h b/third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h index 0df09a3..f7b4a41 100644 --- a/third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h +++ b/third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h @@ -33,12 +33,22 @@ #include <sched.h> #include <time.h> -#include "base/linux_syscall_support.h" #define FUTEX_WAIT 0 #define FUTEX_WAKE 1 #define FUTEX_PRIVATE_FLAG 128 +// Note: Instead of making direct system calls that are inlined, we rely +// on the syscall() function in glibc to do the right thing. This +// is necessary to make the code compatible with the seccomp sandbox, +// which needs to be able to find and patch all places where system +// calls are made. Scanning through and patching glibc is fast, but +// doing so on the entire Chrome binary would be prohibitively +// expensive. +// This is a notable change from the upstream version of tcmalloc, +// which prefers direct system calls in order to improve compatibility +// with older toolchains and runtime libraries. + static bool have_futex; static int futex_private_flag = FUTEX_PRIVATE_FLAG; @@ -49,9 +59,9 @@ static struct InitModule { // futexes are ints, so we can use them only when // that's the same size as the lockword_ in SpinLock. have_futex = (sizeof (Atomic32) == sizeof (int) && - sys_futex(&x, FUTEX_WAKE, 1, 0) >= 0); + syscall(__NR_futex, &x, FUTEX_WAKE, 1, 0) >= 0); if (have_futex && - sys_futex(&x, FUTEX_WAKE | futex_private_flag, 1, 0) < 0) { + syscall(__NR_futex, &x, FUTEX_WAKE | futex_private_flag, 1, 0) < 0) { futex_private_flag = 0; } } @@ -67,7 +77,7 @@ static void SpinLockWait(volatile Atomic32 *w) { tm.tv_nsec = 1000000; // 1ms; really we're trying to sleep for one kernel // clock tick while ((value = base::subtle::Acquire_CompareAndSwap(w, 0, 1)) != 0) { - sys_futex(reinterpret_cast<int *>(const_cast<Atomic32 *>(w)), + syscall(__NR_futex, reinterpret_cast<int *>(const_cast<Atomic32 *>(w)), FUTEX_WAIT | futex_private_flag, value, reinterpret_cast<struct kernel_timespec *>(&tm)); } @@ -85,7 +95,7 @@ static void SpinLockWait(volatile Atomic32 *w) { static void SpinLockWake(volatile Atomic32 *w) { if (have_futex) { - sys_futex(reinterpret_cast<int *>(const_cast<Atomic32 *>(w)), + syscall(__NR_futex, reinterpret_cast<int *>(const_cast<Atomic32 *>(w)), FUTEX_WAKE | futex_private_flag, 1, 0); } } |