From 0908105c5a7fb5d3f0b644b37811f82934cccf60 Mon Sep 17 00:00:00 2001 From: Yichao Yu Date: Tue, 19 Jul 2022 23:58:46 -0400 Subject: [PATCH 5/5] Backport of 16k page support on aarch64 --- .../address_space_randomization.h | 15 ++++++ .../page_allocator_constants.h | 51 +++++++++++++++++- .../partition_address_space.cc | 6 +++ .../partition_allocator/partition_alloc.cc | 2 +- .../partition_alloc_constants.h | 5 +- .../address_space_randomization.h | 15 ++++++ .../partition_allocator/page_allocator.cc | 8 +++ .../page_allocator_constants.h | 52 ++++++++++++++++++- .../partition_allocator/partition_alloc.cc | 2 +- .../partition_alloc_constants.h | 5 +- 10 files changed, 153 insertions(+), 8 deletions(-) diff --git a/chromium/base/allocator/partition_allocator/address_space_randomization.h b/chromium/base/allocator/partition_allocator/address_space_randomization.h index e77003eab25..31ac05b86f5 100644 --- a/chromium/base/allocator/partition_allocator/address_space_randomization.h +++ b/chromium/base/allocator/partition_allocator/address_space_randomization.h @@ -119,6 +119,21 @@ AslrMask(uintptr_t bits) { return AslrAddress(0x20000000ULL); } + #elif defined(OS_LINUX) + + // Linux on arm64 can use 39, 42, 48, or 52-bit user space, depending on + // page size and number of levels of translation pages used. We use + // 39-bit as base as all setups should support this, lowered to 38-bit + // as ASLROffset() could cause a carry. + PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE uintptr_t + ASLRMask() { + return AslrMask(38); + } + PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE uintptr_t + ASLROffset() { + return AslrAddress(0x1000000000ULL); + } + #else // ARM64 on Linux has 39-bit user space. Use 38 bits since ASLROffset() diff --git a/chromium/base/allocator/partition_allocator/page_allocator_constants.h b/chromium/base/allocator/partition_allocator/page_allocator_constants.h index c42fe2835ff..dc7486608b9 100644 --- a/chromium/base/allocator/partition_allocator/page_allocator_constants.h +++ b/chromium/base/allocator/partition_allocator/page_allocator_constants.h @@ -24,6 +24,31 @@ // elimination. #define PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR __attribute__((const)) +#elif defined(OS_LINUX) && defined(ARCH_CPU_ARM64) +// This should work for all POSIX (if needed), but currently all other +// supported OS/architecture combinations use either hard-coded values +// (such as x86) or have means to determine these values without needing +// atomics (such as macOS on arm64). + +// Page allocator constants are run-time constant +#define PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR __attribute__((const)) + +#include +#include + +namespace base::internal { + +// Holds the current page size and shift, where size = 1 << shift +// Use PageAllocationGranularity(), PageAllocationGranularityShift() +// to initialize and retrieve these values safely. +struct PageCharacteristics { + std::atomic size; + std::atomic shift; +}; +extern PageCharacteristics page_characteristics; + +} // namespace base::internal + #else // When defined, page size constants are fixed at compile time. When not @@ -36,11 +61,17 @@ #endif +namespace base { +// Forward declaration, implementation below +PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE size_t +PageAllocationGranularity(); +} + namespace { #if !defined(OS_APPLE) -constexpr ALWAYS_INLINE int PageAllocationGranularityShift() { +PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE int PageAllocationGranularityShift() { #if defined(OS_WIN) || defined(ARCH_CPU_PPC64) // Modern ppc64 systems support 4kB (shift = 12) and 64kB (shift = 16) page // sizes. Since 64kB is the de facto standard on the platform and binaries @@ -49,6 +80,15 @@ constexpr ALWAYS_INLINE int PageAllocationGranularityShift() { return 16; // 64kB #elif defined(_MIPS_ARCH_LOONGSON) return 14; // 16kB +#elif defined(OS_LINUX) && defined(ARCH_CPU_ARM64) + // arm64 supports 4kb (shift = 12), 16kb (shift = 14), and 64kb (shift = 16) + // page sizes. Retrieve from or initialize cache. + int shift = base::internal::page_characteristics.shift.load(std::memory_order_relaxed); + if (UNLIKELY(shift == 0)) { + shift = __builtin_ctz((int)base::PageAllocationGranularity()); + base::internal::page_characteristics.shift.store(shift, std::memory_order_relaxed); + } + return shift; #else return 12; // 4kB #endif @@ -64,6 +104,15 @@ PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE size_t PageAllocationGranularity() { #if defined(OS_APPLE) return vm_page_size; +#elif defined(OS_LINUX) && defined(ARCH_CPU_ARM64) + // arm64 supports 4kb, 16kb, and 64kb page sizes. Retrieve from or + // initialize cache. + int size = internal::page_characteristics.size.load(std::memory_order_relaxed); + if (UNLIKELY(size == 0)) { + size = getpagesize(); + internal::page_characteristics.size.store(size, std::memory_order_relaxed); + } + return size; #else return 1ULL << PageAllocationGranularityShift(); #endif diff --git a/chromium/base/allocator/partition_allocator/partition_address_space.cc b/chromium/base/allocator/partition_allocator/partition_address_space.cc index 03883bcb113..90efc51c838 100644 --- a/chromium/base/allocator/partition_allocator/partition_address_space.cc +++ b/chromium/base/allocator/partition_allocator/partition_address_space.cc @@ -75,6 +75,12 @@ void PartitionAddressSpace::UninitForTesting() { internal::AddressPoolManager::GetInstance()->ResetForTesting(); } +#if defined(OS_LINUX) && defined(ARCH_CPU_ARM64) + +PageCharacteristics page_characteristics; + +#endif // defined(OS_LINUX) && defined(ARCH_CPU_ARM64) + #endif // defined(PA_HAS_64_BITS_POINTERS) } // namespace internal diff --git a/chromium/base/allocator/partition_allocator/partition_alloc.cc b/chromium/base/allocator/partition_allocator/partition_alloc.cc index daeb6d5cb17..7c434b5e697 100644 --- a/chromium/base/allocator/partition_allocator/partition_alloc.cc +++ b/chromium/base/allocator/partition_allocator/partition_alloc.cc @@ -522,7 +522,7 @@ static size_t PartitionPurgePage(internal::PartitionPage* page, #if defined(PAGE_ALLOCATOR_CONSTANTS_ARE_CONSTEXPR) constexpr size_t kMaxSlotCount = (PartitionPageSize() * kMaxPartitionPagesPerSlotSpan) / SystemPageSize(); -#elif defined(OS_APPLE) +#elif defined(OS_APPLE) || (defined(OS_LINUX) && defined(ARCH_CPU_ARM64)) // It's better for slot_usage to be stack-allocated and fixed-size, which // demands that its size be constexpr. On OS_APPLE, PartitionPageSize() is // always SystemPageSize() << 2, so regardless of what the run time page size diff --git a/chromium/base/allocator/partition_allocator/partition_alloc_constants.h b/chromium/base/allocator/partition_allocator/partition_alloc_constants.h index c8268ec30a0..f03ba1e4ab4 100644 --- a/chromium/base/allocator/partition_allocator/partition_alloc_constants.h +++ b/chromium/base/allocator/partition_allocator/partition_alloc_constants.h @@ -57,10 +57,11 @@ PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE int PartitionPageShift() { return 18; // 256 KiB } -#elif defined(OS_APPLE) +#elif defined(OS_APPLE) || \ + (defined(OS_LINUX) && defined(ARCH_CPU_ARM64)) PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE int PartitionPageShift() { - return vm_page_shift + 2; + return PageAllocationGranularityShift() + 2; } #else PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE int diff --git a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/address_space_randomization.h b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/address_space_randomization.h index 28c8271fd68..3957e0cdf76 100644 --- a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/address_space_randomization.h +++ b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/address_space_randomization.h @@ -120,6 +120,21 @@ AslrMask(uintptr_t bits) { return AslrAddress(0x20000000ULL); } + #elif defined(OS_LINUX) + + // Linux on arm64 can use 39, 42, 48, or 52-bit user space, depending on + // page size and number of levels of translation pages used. We use + // 39-bit as base as all setups should support this, lowered to 38-bit + // as ASLROffset() could cause a carry. + PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE uintptr_t + ASLRMask() { + return AslrMask(38); + } + PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE uintptr_t + ASLROffset() { + return AslrAddress(0x1000000000ULL); + } + #else // ARM64 on Linux has 39-bit user space. Use 38 bits since kASLROffset diff --git a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/page_allocator.cc b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/page_allocator.cc index 91d00d2fbca..597d5f84cb1 100644 --- a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/page_allocator.cc +++ b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/page_allocator.cc @@ -255,5 +255,13 @@ uint32_t GetAllocPageErrorCode() { return s_allocPageErrorCode; } +#if defined(OS_LINUX) && defined(ARCH_CPU_ARM64) + +namespace internal { +PageCharacteristics page_characteristics; +} + +#endif // defined(OS_LINUX) && defined(ARCH_CPU_ARM64) + } // namespace base } // namespace pdfium diff --git a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/page_allocator_constants.h b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/page_allocator_constants.h index fdc65ac47b7..f826308839d 100644 --- a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/page_allocator_constants.h +++ b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/page_allocator_constants.h @@ -24,6 +24,31 @@ // elimination. #define PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR __attribute__((const)) +#elif defined(OS_LINUX) && defined(ARCH_CPU_ARM64) +// This should work for all POSIX (if needed), but currently all other +// supported OS/architecture combinations use either hard-coded values +// (such as x86) or have means to determine these values without needing +// atomics (such as macOS on arm64). + +// Page allocator constants are run-time constant +#define PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR __attribute__((const)) + +#include +#include + +namespace pdfium::base::internal { + +// Holds the current page size and shift, where size = 1 << shift +// Use PageAllocationGranularity(), PageAllocationGranularityShift() +// to initialize and retrieve these values safely. +struct PageCharacteristics { + std::atomic size; + std::atomic shift; +}; +extern PageCharacteristics page_characteristics; + +} // namespace base::internal + #else // When defined, page size constants are fixed at compile time. When not @@ -37,11 +62,18 @@ #endif namespace pdfium { + +namespace base { +// Forward declaration, implementation below +PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE size_t +PageAllocationGranularity(); +} + namespace { #if !defined(OS_APPLE) -constexpr ALWAYS_INLINE int PageAllocationGranularityShift() { +PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE int PageAllocationGranularityShift() { #if defined(OS_WIN) || defined(ARCH_CPU_PPC64) // Modern ppc64 systems support 4kB (shift = 12) and 64kB (shift = 16) page // sizes. Since 64kB is the de facto standard on the platform and binaries @@ -50,6 +82,15 @@ constexpr ALWAYS_INLINE int PageAllocationGranularityShift() { return 16; // 64kB #elif defined(_MIPS_ARCH_LOONGSON) return 14; // 16kB +#elif defined(OS_LINUX) && defined(ARCH_CPU_ARM64) + // arm64 supports 4kb (shift = 12), 16kb (shift = 14), and 64kb (shift = 16) + // page sizes. Retrieve from or initialize cache. + int shift = base::internal::page_characteristics.shift.load(std::memory_order_relaxed); + if (UNLIKELY(shift == 0)) { + shift = __builtin_ctz((int)base::PageAllocationGranularity()); + base::internal::page_characteristics.shift.store(shift, std::memory_order_relaxed); + } + return shift; #else return 12; // 4kB #endif @@ -65,6 +106,15 @@ PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE size_t PageAllocationGranularity() { #if defined(OS_APPLE) return vm_page_size; +#elif defined(OS_LINUX) && defined(ARCH_CPU_ARM64) + // arm64 supports 4kb, 16kb, and 64kb page sizes. Retrieve from or + // initialize cache. + int size = internal::page_characteristics.size.load(std::memory_order_relaxed); + if (UNLIKELY(size == 0)) { + size = getpagesize(); + internal::page_characteristics.size.store(size, std::memory_order_relaxed); + } + return size; #else return 1ULL << PageAllocationGranularityShift(); #endif diff --git a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/partition_alloc.cc b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/partition_alloc.cc index 2e5e87fa7e6..89b9f6217a6 100644 --- a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/partition_alloc.cc +++ b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/partition_alloc.cc @@ -486,7 +486,7 @@ static size_t PartitionPurgePage(internal::PartitionPage* page, bool discard) { #if defined(PAGE_ALLOCATOR_CONSTANTS_ARE_CONSTEXPR) constexpr size_t kMaxSlotCount = (PartitionPageSize() * kMaxPartitionPagesPerSlotSpan) / SystemPageSize(); -#elif defined(OS_APPLE) +#elif defined(OS_APPLE) || (defined(OS_LINUX) && defined(ARCH_CPU_ARM64)) // It's better for slot_usage to be stack-allocated and fixed-size, which // demands that its size be constexpr. On OS_APPLE, PartitionPageSize() is // always SystemPageSize() << 2, so regardless of what the run time page size diff --git a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/partition_alloc_constants.h b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/partition_alloc_constants.h index 71d63ba4146..a6d83626741 100644 --- a/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/partition_alloc_constants.h +++ b/chromium/third_party/pdfium/third_party/base/allocator/partition_allocator/partition_alloc_constants.h @@ -50,10 +50,11 @@ PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE int PartitionPageShift() { return 18; // 256 KiB } -#elif defined(OS_APPLE) +#elif defined(OS_APPLE) || \ + (defined(OS_LINUX) && defined(ARCH_CPU_ARM64)) PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE int PartitionPageShift() { - return vm_page_shift + 2; + return PageAllocationGranularityShift() + 2; } #else PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE int -- 2.37.0