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author | nkozlovskiy <nmk@ydb.tech> | 2023-12-04 19:26:35 +0300 |
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committer | nkozlovskiy <nmk@ydb.tech> | 2023-12-05 05:25:43 +0300 |
commit | e62474f851635573f9f6631039e113a02fd50179 (patch) | |
tree | 597d4bc8aad74ef42c55fd062398e93eceebfee3 /contrib/libs/clang16-rt/lib/gwp_asan/optional/segv_handler_posix.cpp | |
parent | e7eddec34be4f360877b46ffa2b70fde8a3a5b8f (diff) | |
download | ydb-e62474f851635573f9f6631039e113a02fd50179.tar.gz |
ydb-oss sync: add clang16-rt/ to additionalPathsToCopy
Diffstat (limited to 'contrib/libs/clang16-rt/lib/gwp_asan/optional/segv_handler_posix.cpp')
-rw-r--r-- | contrib/libs/clang16-rt/lib/gwp_asan/optional/segv_handler_posix.cpp | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/contrib/libs/clang16-rt/lib/gwp_asan/optional/segv_handler_posix.cpp b/contrib/libs/clang16-rt/lib/gwp_asan/optional/segv_handler_posix.cpp new file mode 100644 index 0000000000..e012963bff --- /dev/null +++ b/contrib/libs/clang16-rt/lib/gwp_asan/optional/segv_handler_posix.cpp @@ -0,0 +1,259 @@ +//===-- segv_handler_posix.cpp ----------------------------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "gwp_asan/common.h" +#include "gwp_asan/crash_handler.h" +#include "gwp_asan/guarded_pool_allocator.h" +#include "gwp_asan/optional/segv_handler.h" +#include "gwp_asan/options.h" + +// RHEL creates the PRIu64 format macro (for printing uint64_t's) only when this +// macro is defined before including <inttypes.h>. +#ifndef __STDC_FORMAT_MACROS +#define __STDC_FORMAT_MACROS 1 +#endif + +#include <assert.h> +#include <inttypes.h> +#include <signal.h> +#include <stdio.h> + +using gwp_asan::AllocationMetadata; +using gwp_asan::Error; +using gwp_asan::GuardedPoolAllocator; +using gwp_asan::Printf_t; +using gwp_asan::backtrace::PrintBacktrace_t; +using gwp_asan::backtrace::SegvBacktrace_t; + +namespace { + +struct ScopedEndOfReportDecorator { + ScopedEndOfReportDecorator(gwp_asan::Printf_t Printf) : Printf(Printf) {} + ~ScopedEndOfReportDecorator() { Printf("*** End GWP-ASan report ***\n"); } + gwp_asan::Printf_t Printf; +}; + +// Prints the provided error and metadata information. +void printHeader(Error E, uintptr_t AccessPtr, + const gwp_asan::AllocationMetadata *Metadata, + Printf_t Printf) { + // Print using intermediate strings. Platforms like Android don't like when + // you print multiple times to the same line, as there may be a newline + // appended to a log file automatically per Printf() call. + constexpr size_t kDescriptionBufferLen = 128; + char DescriptionBuffer[kDescriptionBufferLen] = ""; + + bool AccessWasInBounds = false; + if (E != Error::UNKNOWN && Metadata != nullptr) { + uintptr_t Address = __gwp_asan_get_allocation_address(Metadata); + size_t Size = __gwp_asan_get_allocation_size(Metadata); + if (AccessPtr < Address) { + snprintf(DescriptionBuffer, kDescriptionBufferLen, + "(%zu byte%s to the left of a %zu-byte allocation at 0x%zx) ", + Address - AccessPtr, (Address - AccessPtr == 1) ? "" : "s", Size, + Address); + } else if (AccessPtr > Address) { + snprintf(DescriptionBuffer, kDescriptionBufferLen, + "(%zu byte%s to the right of a %zu-byte allocation at 0x%zx) ", + AccessPtr - Address, (AccessPtr - Address == 1) ? "" : "s", Size, + Address); + } else if (E == Error::DOUBLE_FREE) { + snprintf(DescriptionBuffer, kDescriptionBufferLen, + "(a %zu-byte allocation) ", Size); + } else { + AccessWasInBounds = true; + snprintf(DescriptionBuffer, kDescriptionBufferLen, + "(%zu byte%s into a %zu-byte allocation at 0x%zx) ", + AccessPtr - Address, (AccessPtr - Address == 1) ? "" : "s", Size, + Address); + } + } + + // Possible number of digits of a 64-bit number: ceil(log10(2^64)) == 20. Add + // a null terminator, and round to the nearest 8-byte boundary. + uint64_t ThreadID = gwp_asan::getThreadID(); + constexpr size_t kThreadBufferLen = 24; + char ThreadBuffer[kThreadBufferLen]; + if (ThreadID == gwp_asan::kInvalidThreadID) + snprintf(ThreadBuffer, kThreadBufferLen, "<unknown>"); + else + snprintf(ThreadBuffer, kThreadBufferLen, "%" PRIu64, ThreadID); + + const char *OutOfBoundsAndUseAfterFreeWarning = ""; + if (E == Error::USE_AFTER_FREE && !AccessWasInBounds) { + OutOfBoundsAndUseAfterFreeWarning = + " (warning: buffer overflow/underflow detected on a free()'d " + "allocation. This either means you have a buffer-overflow and a " + "use-after-free at the same time, or you have a long-lived " + "use-after-free bug where the allocation/deallocation metadata below " + "has already been overwritten and is likely bogus)"; + } + + Printf("%s%s at 0x%zx %sby thread %s here:\n", gwp_asan::ErrorToString(E), + OutOfBoundsAndUseAfterFreeWarning, AccessPtr, DescriptionBuffer, + ThreadBuffer); +} + +void dumpReport(uintptr_t ErrorPtr, const gwp_asan::AllocatorState *State, + const gwp_asan::AllocationMetadata *Metadata, + SegvBacktrace_t SegvBacktrace, Printf_t Printf, + PrintBacktrace_t PrintBacktrace, void *Context) { + assert(State && "dumpReport missing Allocator State."); + assert(Metadata && "dumpReport missing Metadata."); + assert(Printf && "dumpReport missing Printf."); + assert(__gwp_asan_error_is_mine(State, ErrorPtr) && + "dumpReport() called on a non-GWP-ASan error."); + + uintptr_t InternalErrorPtr = + __gwp_asan_get_internal_crash_address(State, ErrorPtr); + if (InternalErrorPtr) + ErrorPtr = InternalErrorPtr; + + const gwp_asan::AllocationMetadata *AllocMeta = + __gwp_asan_get_metadata(State, Metadata, ErrorPtr); + + // It's unusual for a signal handler to be invoked multiple times for the same + // allocation, but it's possible in various scenarios, like: + // 1. A double-free or invalid-free was invoked in one thread at the same + // time as a buffer-overflow or use-after-free in another thread, or + // 2. Two threads do a use-after-free or buffer-overflow at the same time. + // In these instances, we've already dumped a report for this allocation, so + // skip dumping this issue as well. + if (AllocMeta->HasCrashed) + return; + + Printf("*** GWP-ASan detected a memory error ***\n"); + ScopedEndOfReportDecorator Decorator(Printf); + + Error E = __gwp_asan_diagnose_error(State, Metadata, ErrorPtr); + if (E == Error::UNKNOWN) { + Printf("GWP-ASan cannot provide any more information about this error. " + "This may occur due to a wild memory access into the GWP-ASan pool, " + "or an overflow/underflow that is > 512B in length.\n"); + return; + } + + // Print the error header. + printHeader(E, ErrorPtr, AllocMeta, Printf); + + // Print the fault backtrace. + static constexpr unsigned kMaximumStackFramesForCrashTrace = 512; + uintptr_t Trace[kMaximumStackFramesForCrashTrace]; + size_t TraceLength = + SegvBacktrace(Trace, kMaximumStackFramesForCrashTrace, Context); + + PrintBacktrace(Trace, TraceLength, Printf); + + if (AllocMeta == nullptr) + return; + + // Maybe print the deallocation trace. + if (__gwp_asan_is_deallocated(AllocMeta)) { + uint64_t ThreadID = __gwp_asan_get_deallocation_thread_id(AllocMeta); + if (ThreadID == gwp_asan::kInvalidThreadID) + Printf("0x%zx was deallocated by thread <unknown> here:\n", ErrorPtr); + else + Printf("0x%zx was deallocated by thread %zu here:\n", ErrorPtr, ThreadID); + TraceLength = __gwp_asan_get_deallocation_trace( + AllocMeta, Trace, kMaximumStackFramesForCrashTrace); + PrintBacktrace(Trace, TraceLength, Printf); + } + + // Print the allocation trace. + uint64_t ThreadID = __gwp_asan_get_allocation_thread_id(AllocMeta); + if (ThreadID == gwp_asan::kInvalidThreadID) + Printf("0x%zx was allocated by thread <unknown> here:\n", ErrorPtr); + else + Printf("0x%zx was allocated by thread %zu here:\n", ErrorPtr, ThreadID); + TraceLength = __gwp_asan_get_allocation_trace( + AllocMeta, Trace, kMaximumStackFramesForCrashTrace); + PrintBacktrace(Trace, TraceLength, Printf); +} + +struct sigaction PreviousHandler; +bool SignalHandlerInstalled; +bool RecoverableSignal; +gwp_asan::GuardedPoolAllocator *GPAForSignalHandler; +Printf_t PrintfForSignalHandler; +PrintBacktrace_t PrintBacktraceForSignalHandler; +SegvBacktrace_t BacktraceForSignalHandler; + +static void sigSegvHandler(int sig, siginfo_t *info, void *ucontext) { + const gwp_asan::AllocatorState *State = + GPAForSignalHandler->getAllocatorState(); + void *FaultAddr = info->si_addr; + uintptr_t FaultAddrUPtr = reinterpret_cast<uintptr_t>(FaultAddr); + + if (__gwp_asan_error_is_mine(State, FaultAddrUPtr)) { + GPAForSignalHandler->preCrashReport(FaultAddr); + + dumpReport(FaultAddrUPtr, State, GPAForSignalHandler->getMetadataRegion(), + BacktraceForSignalHandler, PrintfForSignalHandler, + PrintBacktraceForSignalHandler, ucontext); + + if (RecoverableSignal) { + GPAForSignalHandler->postCrashReportRecoverableOnly(FaultAddr); + return; + } + } + + // Process any previous handlers as long as the crash wasn't a GWP-ASan crash + // in recoverable mode. + if (PreviousHandler.sa_flags & SA_SIGINFO) { + PreviousHandler.sa_sigaction(sig, info, ucontext); + } else if (PreviousHandler.sa_handler == SIG_DFL) { + // If the previous handler was the default handler, cause a core dump. + signal(SIGSEGV, SIG_DFL); + raise(SIGSEGV); + } else if (PreviousHandler.sa_handler == SIG_IGN) { + // If the previous segv handler was SIGIGN, crash iff we were responsible + // for the crash. + if (__gwp_asan_error_is_mine(GPAForSignalHandler->getAllocatorState(), + reinterpret_cast<uintptr_t>(info->si_addr))) { + signal(SIGSEGV, SIG_DFL); + raise(SIGSEGV); + } + } else { + PreviousHandler.sa_handler(sig); + } +} +} // anonymous namespace + +namespace gwp_asan { +namespace segv_handler { + +void installSignalHandlers(gwp_asan::GuardedPoolAllocator *GPA, Printf_t Printf, + PrintBacktrace_t PrintBacktrace, + SegvBacktrace_t SegvBacktrace, bool Recoverable) { + assert(GPA && "GPA wasn't provided to installSignalHandlers."); + assert(Printf && "Printf wasn't provided to installSignalHandlers."); + assert(PrintBacktrace && + "PrintBacktrace wasn't provided to installSignalHandlers."); + assert(SegvBacktrace && + "SegvBacktrace wasn't provided to installSignalHandlers."); + GPAForSignalHandler = GPA; + PrintfForSignalHandler = Printf; + PrintBacktraceForSignalHandler = PrintBacktrace; + BacktraceForSignalHandler = SegvBacktrace; + RecoverableSignal = Recoverable; + + struct sigaction Action = {}; + Action.sa_sigaction = sigSegvHandler; + Action.sa_flags = SA_SIGINFO; + sigaction(SIGSEGV, &Action, &PreviousHandler); + SignalHandlerInstalled = true; +} + +void uninstallSignalHandlers() { + if (SignalHandlerInstalled) { + sigaction(SIGSEGV, &PreviousHandler, nullptr); + SignalHandlerInstalled = false; + } +} +} // namespace segv_handler +} // namespace gwp_asan |