From c0dd51efdbc09f42f3f47109ae571ff9f9e1d7f1 Mon Sep 17 00:00:00 2001 From: "jochen@chromium.org" Date: Wed, 25 Jun 2014 08:20:42 +0000 Subject: [PATCH] Remove dependency from platform.h implementations on isolate BUG=none R=bmeurer@chromium.org LOG=n Review URL: https://codereview.chromium.org/347223004 git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21997 ce2b1a6d-e550-0410-aec6-3dcde31c8c00 --- src/platform-posix.cc | 64 ++++++++++++++++++++----------------- src/platform-win32.cc | 47 ++++++++++++++------------- src/platform.h | 4 +++ src/utils/random-number-generator.h | 4 ++- src/v8.cc | 2 ++ 5 files changed, 68 insertions(+), 53 deletions(-) diff --git a/src/platform-posix.cc b/src/platform-posix.cc index fe3feb5..ae47bd4 100644 --- a/src/platform-posix.cc +++ b/src/platform-posix.cc @@ -43,8 +43,9 @@ #include "src/v8.h" -#include "src/isolate-inl.h" +#include "src/base/lazy-instance.h" #include "src/platform.h" +#include "src/utils/random-number-generator.h" #ifdef V8_FAST_TLS_SUPPORTED #include "src/base/atomicops.h" @@ -186,6 +187,15 @@ void OS::Guard(void* address, const size_t size) { } +static base::LazyInstance::type + platform_random_number_generator = LAZY_INSTANCE_INITIALIZER; + + +void OS::SetRandomSeed(int64_t seed) { + platform_random_number_generator.Pointer()->SetSeed(seed); +} + + void* OS::GetRandomMmapAddr() { #if V8_OS_NACL // TODO(bradchen): restore randomization once Native Client gets @@ -198,42 +208,36 @@ void* OS::GetRandomMmapAddr() { // Dynamic tools do not support custom mmap addresses. return NULL; #endif - Isolate* isolate = Isolate::UncheckedCurrent(); - // Note that the current isolate isn't set up in a call path via - // CpuFeatures::Probe. We don't care about randomization in this case because - // the code page is immediately freed. - if (isolate != NULL) { - uintptr_t raw_addr; - isolate->random_number_generator()->NextBytes(&raw_addr, sizeof(raw_addr)); + uintptr_t raw_addr; + platform_random_number_generator.Pointer()->NextBytes(&raw_addr, + sizeof(raw_addr)); #if V8_TARGET_ARCH_X64 - // Currently available CPUs have 48 bits of virtual addressing. Truncate - // the hint address to 46 bits to give the kernel a fighting chance of - // fulfilling our placement request. - raw_addr &= V8_UINT64_C(0x3ffffffff000); + // Currently available CPUs have 48 bits of virtual addressing. Truncate + // the hint address to 46 bits to give the kernel a fighting chance of + // fulfilling our placement request. + raw_addr &= V8_UINT64_C(0x3ffffffff000); #else - raw_addr &= 0x3ffff000; + raw_addr &= 0x3ffff000; # ifdef __sun - // For our Solaris/illumos mmap hint, we pick a random address in the bottom - // half of the top half of the address space (that is, the third quarter). - // Because we do not MAP_FIXED, this will be treated only as a hint -- the - // system will not fail to mmap() because something else happens to already - // be mapped at our random address. We deliberately set the hint high enough - // to get well above the system's break (that is, the heap); Solaris and - // illumos will try the hint and if that fails allocate as if there were - // no hint at all. The high hint prevents the break from getting hemmed in - // at low values, ceding half of the address space to the system heap. - raw_addr += 0x80000000; + // For our Solaris/illumos mmap hint, we pick a random address in the bottom + // half of the top half of the address space (that is, the third quarter). + // Because we do not MAP_FIXED, this will be treated only as a hint -- the + // system will not fail to mmap() because something else happens to already + // be mapped at our random address. We deliberately set the hint high enough + // to get well above the system's break (that is, the heap); Solaris and + // illumos will try the hint and if that fails allocate as if there were + // no hint at all. The high hint prevents the break from getting hemmed in + // at low values, ceding half of the address space to the system heap. + raw_addr += 0x80000000; # else - // The range 0x20000000 - 0x60000000 is relatively unpopulated across a - // variety of ASLR modes (PAE kernel, NX compat mode, etc) and on macos - // 10.6 and 10.7. - raw_addr += 0x20000000; + // The range 0x20000000 - 0x60000000 is relatively unpopulated across a + // variety of ASLR modes (PAE kernel, NX compat mode, etc) and on macos + // 10.6 and 10.7. + raw_addr += 0x20000000; # endif #endif - return reinterpret_cast(raw_addr); - } - return NULL; + return reinterpret_cast(raw_addr); } diff --git a/src/platform-win32.cc b/src/platform-win32.cc index b1e6478..9fe3e14 100644 --- a/src/platform-win32.cc +++ b/src/platform-win32.cc @@ -19,8 +19,9 @@ #include "src/v8.h" -#include "src/isolate-inl.h" +#include "src/base/lazy-instance.h" #include "src/platform.h" +#include "src/utils/random-number-generator.h" #ifdef _MSC_VER @@ -708,31 +709,33 @@ size_t OS::AllocateAlignment() { } +static base::LazyInstance::type + platform_random_number_generator = LAZY_INSTANCE_INITIALIZER; + + +void OS::SetRandomSeed(int64_t seed) { + platform_random_number_generator.Pointer()->SetSeed(seed); +} + + void* OS::GetRandomMmapAddr() { - Isolate* isolate = Isolate::UncheckedCurrent(); - // Note that the current isolate isn't set up in a call path via - // CpuFeatures::Probe. We don't care about randomization in this case because - // the code page is immediately freed. - if (isolate != NULL) { - // The address range used to randomize RWX allocations in OS::Allocate - // Try not to map pages into the default range that windows loads DLLs - // Use a multiple of 64k to prevent committing unused memory. - // Note: This does not guarantee RWX regions will be within the - // range kAllocationRandomAddressMin to kAllocationRandomAddressMax + // The address range used to randomize RWX allocations in OS::Allocate + // Try not to map pages into the default range that windows loads DLLs + // Use a multiple of 64k to prevent committing unused memory. + // Note: This does not guarantee RWX regions will be within the + // range kAllocationRandomAddressMin to kAllocationRandomAddressMax #ifdef V8_HOST_ARCH_64_BIT - static const intptr_t kAllocationRandomAddressMin = 0x0000000080000000; - static const intptr_t kAllocationRandomAddressMax = 0x000003FFFFFF0000; + static const intptr_t kAllocationRandomAddressMin = 0x0000000080000000; + static const intptr_t kAllocationRandomAddressMax = 0x000003FFFFFF0000; #else - static const intptr_t kAllocationRandomAddressMin = 0x04000000; - static const intptr_t kAllocationRandomAddressMax = 0x3FFF0000; + static const intptr_t kAllocationRandomAddressMin = 0x04000000; + static const intptr_t kAllocationRandomAddressMax = 0x3FFF0000; #endif - uintptr_t address = - (isolate->random_number_generator()->NextInt() << kPageSizeBits) | - kAllocationRandomAddressMin; - address &= kAllocationRandomAddressMax; - return reinterpret_cast(address); - } - return NULL; + uintptr_t address = + (platform_random_number_generator.Pointer()->NextInt() << kPageSizeBits) | + kAllocationRandomAddressMin; + address &= kAllocationRandomAddressMax; + return reinterpret_cast(address); } diff --git a/src/platform.h b/src/platform.h index 497e3a8..a8500f0 100644 --- a/src/platform.h +++ b/src/platform.h @@ -212,6 +212,10 @@ class OS { // Assign memory as a guard page so that access will cause an exception. static void Guard(void* address, const size_t size); + // Set a fixed random seed for the random number generator used for + // GetRandomMmapAddr. + static void SetRandomSeed(int64_t seed); + // Generate a random address to be used for hinting mmap(). static void* GetRandomMmapAddr(); diff --git a/src/utils/random-number-generator.h b/src/utils/random-number-generator.h index 5407571..6b077ee 100644 --- a/src/utils/random-number-generator.h +++ b/src/utils/random-number-generator.h @@ -71,13 +71,15 @@ class RandomNumberGenerator V8_FINAL { // Fills the elements of a specified array of bytes with random numbers. void NextBytes(void* buffer, size_t buflen); + // Override the current ssed. + void SetSeed(int64_t seed); + private: static const int64_t kMultiplier = V8_2PART_UINT64_C(0x5, deece66d); static const int64_t kAddend = 0xb; static const int64_t kMask = V8_2PART_UINT64_C(0xffff, ffffffff); int Next(int bits) V8_WARN_UNUSED_RESULT; - void SetSeed(int64_t seed); int64_t seed_; }; diff --git a/src/v8.cc b/src/v8.cc index d3ba9fb..4739205 100644 --- a/src/v8.cc +++ b/src/v8.cc @@ -90,6 +90,8 @@ void V8::InitializeOncePerProcessImpl() { FLAG_max_semi_space_size = 1; } + if (FLAG_random_seed != 0) OS::SetRandomSeed(FLAG_random_seed); + #ifdef V8_USE_DEFAULT_PLATFORM platform_ = new DefaultPlatform; #endif -- 2.7.4