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Diffstat (limited to 'contrib/compiler-rt/lib/hwasan/hwasan_linux.cc')
| -rw-r--r-- | contrib/compiler-rt/lib/hwasan/hwasan_linux.cc | 416 |
1 files changed, 416 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/hwasan/hwasan_linux.cc b/contrib/compiler-rt/lib/hwasan/hwasan_linux.cc new file mode 100644 index 000000000000..5b0a8b4ac98f --- /dev/null +++ b/contrib/compiler-rt/lib/hwasan/hwasan_linux.cc @@ -0,0 +1,416 @@ +//===-- hwasan_linux.cc -----------------------------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +/// +/// \file +/// This file is a part of HWAddressSanitizer and contains Linux-, NetBSD- and +/// FreeBSD-specific code. +/// +//===----------------------------------------------------------------------===// + +#include "sanitizer_common/sanitizer_platform.h" +#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD + +#include "hwasan.h" +#include "hwasan_dynamic_shadow.h" +#include "hwasan_interface_internal.h" +#include "hwasan_mapping.h" +#include "hwasan_report.h" +#include "hwasan_thread.h" +#include "hwasan_thread_list.h" + +#include <dlfcn.h> +#include <elf.h> +#include <link.h> +#include <pthread.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/resource.h> +#include <sys/time.h> +#include <unistd.h> +#include <unwind.h> + +#include "sanitizer_common/sanitizer_common.h" +#include "sanitizer_common/sanitizer_procmaps.h" + +#if HWASAN_WITH_INTERCEPTORS && !SANITIZER_ANDROID +SANITIZER_INTERFACE_ATTRIBUTE +THREADLOCAL uptr __hwasan_tls; +#endif + +namespace __hwasan { + +static void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name) { + CHECK_EQ((beg % GetMmapGranularity()), 0); + CHECK_EQ(((end + 1) % GetMmapGranularity()), 0); + uptr size = end - beg + 1; + DecreaseTotalMmap(size); // Don't count the shadow against mmap_limit_mb. + if (!MmapFixedNoReserve(beg, size, name)) { + Report( + "ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. " + "Perhaps you're using ulimit -v\n", + size); + Abort(); + } +} + +static void ProtectGap(uptr addr, uptr size) { + if (!size) + return; + void *res = MmapFixedNoAccess(addr, size, "shadow gap"); + if (addr == (uptr)res) + return; + // A few pages at the start of the address space can not be protected. + // But we really want to protect as much as possible, to prevent this memory + // being returned as a result of a non-FIXED mmap(). + if (addr == 0) { + uptr step = GetMmapGranularity(); + while (size > step) { + addr += step; + size -= step; + void *res = MmapFixedNoAccess(addr, size, "shadow gap"); + if (addr == (uptr)res) + return; + } + } + + Report( + "ERROR: Failed to protect shadow gap [%p, %p]. " + "HWASan cannot proceed correctly. ABORTING.\n", (void *)addr, + (void *)(addr + size)); + DumpProcessMap(); + Die(); +} + +static uptr kLowMemStart; +static uptr kLowMemEnd; +static uptr kLowShadowEnd; +static uptr kLowShadowStart; +static uptr kHighShadowStart; +static uptr kHighShadowEnd; +static uptr kHighMemStart; +static uptr kHighMemEnd; + +static void PrintRange(uptr start, uptr end, const char *name) { + Printf("|| [%p, %p] || %.*s ||\n", (void *)start, (void *)end, 10, name); +} + +static void PrintAddressSpaceLayout() { + PrintRange(kHighMemStart, kHighMemEnd, "HighMem"); + if (kHighShadowEnd + 1 < kHighMemStart) + PrintRange(kHighShadowEnd + 1, kHighMemStart - 1, "ShadowGap"); + else + CHECK_EQ(kHighShadowEnd + 1, kHighMemStart); + PrintRange(kHighShadowStart, kHighShadowEnd, "HighShadow"); + if (kLowShadowEnd + 1 < kHighShadowStart) + PrintRange(kLowShadowEnd + 1, kHighShadowStart - 1, "ShadowGap"); + else + CHECK_EQ(kLowMemEnd + 1, kHighShadowStart); + PrintRange(kLowShadowStart, kLowShadowEnd, "LowShadow"); + if (kLowMemEnd + 1 < kLowShadowStart) + PrintRange(kLowMemEnd + 1, kLowShadowStart - 1, "ShadowGap"); + else + CHECK_EQ(kLowMemEnd + 1, kLowShadowStart); + PrintRange(kLowMemStart, kLowMemEnd, "LowMem"); + CHECK_EQ(0, kLowMemStart); +} + +static uptr GetHighMemEnd() { + // HighMem covers the upper part of the address space. + uptr max_address = GetMaxUserVirtualAddress(); + // Adjust max address to make sure that kHighMemEnd and kHighMemStart are + // properly aligned: + max_address |= (GetMmapGranularity() << kShadowScale) - 1; + return max_address; +} + +static void InitializeShadowBaseAddress(uptr shadow_size_bytes) { + __hwasan_shadow_memory_dynamic_address = + FindDynamicShadowStart(shadow_size_bytes); +} + +bool InitShadow() { + // Define the entire memory range. + kHighMemEnd = GetHighMemEnd(); + + // Determine shadow memory base offset. + InitializeShadowBaseAddress(MemToShadowSize(kHighMemEnd)); + + // Place the low memory first. + kLowMemEnd = __hwasan_shadow_memory_dynamic_address - 1; + kLowMemStart = 0; + + // Define the low shadow based on the already placed low memory. + kLowShadowEnd = MemToShadow(kLowMemEnd); + kLowShadowStart = __hwasan_shadow_memory_dynamic_address; + + // High shadow takes whatever memory is left up there (making sure it is not + // interfering with low memory in the fixed case). + kHighShadowEnd = MemToShadow(kHighMemEnd); + kHighShadowStart = Max(kLowMemEnd, MemToShadow(kHighShadowEnd)) + 1; + + // High memory starts where allocated shadow allows. + kHighMemStart = ShadowToMem(kHighShadowStart); + + // Check the sanity of the defined memory ranges (there might be gaps). + CHECK_EQ(kHighMemStart % GetMmapGranularity(), 0); + CHECK_GT(kHighMemStart, kHighShadowEnd); + CHECK_GT(kHighShadowEnd, kHighShadowStart); + CHECK_GT(kHighShadowStart, kLowMemEnd); + CHECK_GT(kLowMemEnd, kLowMemStart); + CHECK_GT(kLowShadowEnd, kLowShadowStart); + CHECK_GT(kLowShadowStart, kLowMemEnd); + + if (Verbosity()) + PrintAddressSpaceLayout(); + + // Reserve shadow memory. + ReserveShadowMemoryRange(kLowShadowStart, kLowShadowEnd, "low shadow"); + ReserveShadowMemoryRange(kHighShadowStart, kHighShadowEnd, "high shadow"); + + // Protect all the gaps. + ProtectGap(0, Min(kLowMemStart, kLowShadowStart)); + if (kLowMemEnd + 1 < kLowShadowStart) + ProtectGap(kLowMemEnd + 1, kLowShadowStart - kLowMemEnd - 1); + if (kLowShadowEnd + 1 < kHighShadowStart) + ProtectGap(kLowShadowEnd + 1, kHighShadowStart - kLowShadowEnd - 1); + if (kHighShadowEnd + 1 < kHighMemStart) + ProtectGap(kHighShadowEnd + 1, kHighMemStart - kHighShadowEnd - 1); + + return true; +} + +void InitThreads() { + CHECK(__hwasan_shadow_memory_dynamic_address); + uptr guard_page_size = GetMmapGranularity(); + uptr thread_space_start = + __hwasan_shadow_memory_dynamic_address - (1ULL << kShadowBaseAlignment); + uptr thread_space_end = + __hwasan_shadow_memory_dynamic_address - guard_page_size; + ReserveShadowMemoryRange(thread_space_start, thread_space_end - 1, + "hwasan threads"); + ProtectGap(thread_space_end, + __hwasan_shadow_memory_dynamic_address - thread_space_end); + InitThreadList(thread_space_start, thread_space_end - thread_space_start); +} + +static void MadviseShadowRegion(uptr beg, uptr end) { + uptr size = end - beg + 1; + if (common_flags()->no_huge_pages_for_shadow) + NoHugePagesInRegion(beg, size); + if (common_flags()->use_madv_dontdump) + DontDumpShadowMemory(beg, size); +} + +void MadviseShadow() { + MadviseShadowRegion(kLowShadowStart, kLowShadowEnd); + MadviseShadowRegion(kHighShadowStart, kHighShadowEnd); +} + +bool MemIsApp(uptr p) { + CHECK(GetTagFromPointer(p) == 0); + return p >= kHighMemStart || (p >= kLowMemStart && p <= kLowMemEnd); +} + +static void HwasanAtExit(void) { + if (flags()->print_stats && (flags()->atexit || hwasan_report_count > 0)) + ReportStats(); + if (hwasan_report_count > 0) { + // ReportAtExitStatistics(); + if (common_flags()->exitcode) + internal__exit(common_flags()->exitcode); + } +} + +void InstallAtExitHandler() { + atexit(HwasanAtExit); +} + +// ---------------------- TSD ---------------- {{{1 + +extern "C" void __hwasan_thread_enter() { + hwasanThreadList().CreateCurrentThread(); +} + +extern "C" void __hwasan_thread_exit() { + Thread *t = GetCurrentThread(); + // Make sure that signal handler can not see a stale current thread pointer. + atomic_signal_fence(memory_order_seq_cst); + if (t) + hwasanThreadList().ReleaseThread(t); +} + +#if HWASAN_WITH_INTERCEPTORS +static pthread_key_t tsd_key; +static bool tsd_key_inited = false; + +void HwasanTSDThreadInit() { + if (tsd_key_inited) + CHECK_EQ(0, pthread_setspecific(tsd_key, + (void *)GetPthreadDestructorIterations())); +} + +void HwasanTSDDtor(void *tsd) { + uptr iterations = (uptr)tsd; + if (iterations > 1) { + CHECK_EQ(0, pthread_setspecific(tsd_key, (void *)(iterations - 1))); + return; + } + __hwasan_thread_exit(); +} + +void HwasanTSDInit() { + CHECK(!tsd_key_inited); + tsd_key_inited = true; + CHECK_EQ(0, pthread_key_create(&tsd_key, HwasanTSDDtor)); +} +#else +void HwasanTSDInit() {} +void HwasanTSDThreadInit() {} +#endif + +#if SANITIZER_ANDROID +uptr *GetCurrentThreadLongPtr() { + return (uptr *)get_android_tls_ptr(); +} +#else +uptr *GetCurrentThreadLongPtr() { + return &__hwasan_tls; +} +#endif + +#if SANITIZER_ANDROID +void AndroidTestTlsSlot() { + uptr kMagicValue = 0x010203040A0B0C0D; + *(uptr *)get_android_tls_ptr() = kMagicValue; + dlerror(); + if (*(uptr *)get_android_tls_ptr() != kMagicValue) { + Printf( + "ERROR: Incompatible version of Android: TLS_SLOT_SANITIZER(6) is used " + "for dlerror().\n"); + Die(); + } +} +#else +void AndroidTestTlsSlot() {} +#endif + +Thread *GetCurrentThread() { + uptr *ThreadLong = GetCurrentThreadLongPtr(); +#if HWASAN_WITH_INTERCEPTORS + if (!*ThreadLong) + __hwasan_thread_enter(); +#endif + auto *R = (StackAllocationsRingBuffer *)ThreadLong; + return hwasanThreadList().GetThreadByBufferAddress((uptr)(R->Next())); +} + +struct AccessInfo { + uptr addr; + uptr size; + bool is_store; + bool is_load; + bool recover; +}; + +static AccessInfo GetAccessInfo(siginfo_t *info, ucontext_t *uc) { + // Access type is passed in a platform dependent way (see below) and encoded + // as 0xXY, where X&1 is 1 for store, 0 for load, and X&2 is 1 if the error is + // recoverable. Valid values of Y are 0 to 4, which are interpreted as + // log2(access_size), and 0xF, which means that access size is passed via + // platform dependent register (see below). +#if defined(__aarch64__) + // Access type is encoded in BRK immediate as 0x900 + 0xXY. For Y == 0xF, + // access size is stored in X1 register. Access address is always in X0 + // register. + uptr pc = (uptr)info->si_addr; + const unsigned code = ((*(u32 *)pc) >> 5) & 0xffff; + if ((code & 0xff00) != 0x900) + return AccessInfo{}; // Not ours. + + const bool is_store = code & 0x10; + const bool recover = code & 0x20; + const uptr addr = uc->uc_mcontext.regs[0]; + const unsigned size_log = code & 0xf; + if (size_log > 4 && size_log != 0xf) + return AccessInfo{}; // Not ours. + const uptr size = size_log == 0xf ? uc->uc_mcontext.regs[1] : 1U << size_log; + +#elif defined(__x86_64__) + // Access type is encoded in the instruction following INT3 as + // NOP DWORD ptr [EAX + 0x40 + 0xXY]. For Y == 0xF, access size is stored in + // RSI register. Access address is always in RDI register. + uptr pc = (uptr)uc->uc_mcontext.gregs[REG_RIP]; + uint8_t *nop = (uint8_t*)pc; + if (*nop != 0x0f || *(nop + 1) != 0x1f || *(nop + 2) != 0x40 || + *(nop + 3) < 0x40) + return AccessInfo{}; // Not ours. + const unsigned code = *(nop + 3); + + const bool is_store = code & 0x10; + const bool recover = code & 0x20; + const uptr addr = uc->uc_mcontext.gregs[REG_RDI]; + const unsigned size_log = code & 0xf; + if (size_log > 4 && size_log != 0xf) + return AccessInfo{}; // Not ours. + const uptr size = + size_log == 0xf ? uc->uc_mcontext.gregs[REG_RSI] : 1U << size_log; + +#else +# error Unsupported architecture +#endif + + return AccessInfo{addr, size, is_store, !is_store, recover}; +} + +static bool HwasanOnSIGTRAP(int signo, siginfo_t *info, ucontext_t *uc) { + AccessInfo ai = GetAccessInfo(info, uc); + if (!ai.is_store && !ai.is_load) + return false; + + InternalMmapVector<BufferedStackTrace> stack_buffer(1); + BufferedStackTrace *stack = stack_buffer.data(); + stack->Reset(); + SignalContext sig{info, uc}; + GetStackTrace(stack, kStackTraceMax, StackTrace::GetNextInstructionPc(sig.pc), + sig.bp, uc, common_flags()->fast_unwind_on_fatal); + + ++hwasan_report_count; + + bool fatal = flags()->halt_on_error || !ai.recover; + ReportTagMismatch(stack, ai.addr, ai.size, ai.is_store, fatal); + +#if defined(__aarch64__) + uc->uc_mcontext.pc += 4; +#elif defined(__x86_64__) +#else +# error Unsupported architecture +#endif + return true; +} + +static void OnStackUnwind(const SignalContext &sig, const void *, + BufferedStackTrace *stack) { + GetStackTrace(stack, kStackTraceMax, StackTrace::GetNextInstructionPc(sig.pc), + sig.bp, sig.context, common_flags()->fast_unwind_on_fatal); +} + +void HwasanOnDeadlySignal(int signo, void *info, void *context) { + // Probably a tag mismatch. + if (signo == SIGTRAP) + if (HwasanOnSIGTRAP(signo, (siginfo_t *)info, (ucontext_t*)context)) + return; + + HandleDeadlySignal(info, context, GetTid(), &OnStackUnwind, nullptr); +} + + +} // namespace __hwasan + +#endif // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD |