diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/debugging/internal/stacktrace_powerpc-inl.inc')
| -rw-r--r-- | third_party/abseil_cpp/absl/debugging/internal/stacktrace_powerpc-inl.inc | 248 |
1 files changed, 0 insertions, 248 deletions
diff --git a/third_party/abseil_cpp/absl/debugging/internal/stacktrace_powerpc-inl.inc b/third_party/abseil_cpp/absl/debugging/internal/stacktrace_powerpc-inl.inc deleted file mode 100644 index 2e7c2f404f..0000000000 --- a/third_party/abseil_cpp/absl/debugging/internal/stacktrace_powerpc-inl.inc +++ /dev/null @@ -1,248 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. -// -// Produce stack trace. I'm guessing (hoping!) the code is much like -// for x86. For apple machines, at least, it seems to be; see -// https://developer.apple.com/documentation/mac/runtimehtml/RTArch-59.html -// https://www.linux-foundation.org/spec/ELF/ppc64/PPC-elf64abi-1.9.html#STACK -// Linux has similar code: http://patchwork.ozlabs.org/linuxppc/patch?id=8882 - -#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_POWERPC_INL_H_ -#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_POWERPC_INL_H_ - -#if defined(__linux__) -#include <asm/ptrace.h> // for PT_NIP. -#include <ucontext.h> // for ucontext_t -#endif - -#include <unistd.h> -#include <cassert> -#include <cstdint> -#include <cstdio> - -#include "absl/base/attributes.h" -#include "absl/base/optimization.h" -#include "absl/base/port.h" -#include "absl/debugging/stacktrace.h" -#include "absl/debugging/internal/address_is_readable.h" -#include "absl/debugging/internal/vdso_support.h" // a no-op on non-elf or non-glibc systems - -// Given a stack pointer, return the saved link register value. -// Note that this is the link register for a callee. -static inline void *StacktracePowerPCGetLR(void **sp) { - // PowerPC has 3 main ABIs, which say where in the stack the - // Link Register is. For DARWIN and AIX (used by apple and - // linux ppc64), it's in sp[2]. For SYSV (used by linux ppc), - // it's in sp[1]. -#if defined(_CALL_AIX) || defined(_CALL_DARWIN) - return *(sp+2); -#elif defined(_CALL_SYSV) - return *(sp+1); -#elif defined(__APPLE__) || defined(__FreeBSD__) || \ - (defined(__linux__) && defined(__PPC64__)) - // This check is in case the compiler doesn't define _CALL_AIX/etc. - return *(sp+2); -#elif defined(__linux) - // This check is in case the compiler doesn't define _CALL_SYSV. - return *(sp+1); -#else -#error Need to specify the PPC ABI for your archiecture. -#endif -} - -// Given a pointer to a stack frame, locate and return the calling -// stackframe, or return null if no stackframe can be found. Perform sanity -// checks (the strictness of which is controlled by the boolean parameter -// "STRICT_UNWINDING") to reduce the chance that a bad pointer is returned. -template<bool STRICT_UNWINDING, bool IS_WITH_CONTEXT> -ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS // May read random elements from stack. -ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY // May read random elements from stack. -static void **NextStackFrame(void **old_sp, const void *uc) { - void **new_sp = (void **) *old_sp; - enum { kStackAlignment = 16 }; - - // Check that the transition from frame pointer old_sp to frame - // pointer new_sp isn't clearly bogus - if (STRICT_UNWINDING) { - // With the stack growing downwards, older stack frame must be - // at a greater address that the current one. - if (new_sp <= old_sp) return nullptr; - // Assume stack frames larger than 100,000 bytes are bogus. - if ((uintptr_t)new_sp - (uintptr_t)old_sp > 100000) return nullptr; - } else { - // In the non-strict mode, allow discontiguous stack frames. - // (alternate-signal-stacks for example). - if (new_sp == old_sp) return nullptr; - // And allow frames upto about 1MB. - if ((new_sp > old_sp) - && ((uintptr_t)new_sp - (uintptr_t)old_sp > 1000000)) return nullptr; - } - if ((uintptr_t)new_sp % kStackAlignment != 0) return nullptr; - -#if defined(__linux__) - enum StackTraceKernelSymbolStatus { - kNotInitialized = 0, kAddressValid, kAddressInvalid }; - - if (IS_WITH_CONTEXT && uc != nullptr) { - static StackTraceKernelSymbolStatus kernel_symbol_status = - kNotInitialized; // Sentinel: not computed yet. - // Initialize with sentinel value: __kernel_rt_sigtramp_rt64 can not - // possibly be there. - static const unsigned char *kernel_sigtramp_rt64_address = nullptr; - if (kernel_symbol_status == kNotInitialized) { - absl::debugging_internal::VDSOSupport vdso; - if (vdso.IsPresent()) { - absl::debugging_internal::VDSOSupport::SymbolInfo - sigtramp_rt64_symbol_info; - if (!vdso.LookupSymbol( - "__kernel_sigtramp_rt64", "LINUX_2.6.15", - absl::debugging_internal::VDSOSupport::kVDSOSymbolType, - &sigtramp_rt64_symbol_info) || - sigtramp_rt64_symbol_info.address == nullptr) { - // Unexpected: VDSO is present, yet the expected symbol is missing - // or null. - assert(false && "VDSO is present, but doesn't have expected symbol"); - kernel_symbol_status = kAddressInvalid; - } else { - kernel_sigtramp_rt64_address = - reinterpret_cast<const unsigned char *>( - sigtramp_rt64_symbol_info.address); - kernel_symbol_status = kAddressValid; - } - } else { - kernel_symbol_status = kAddressInvalid; - } - } - - if (new_sp != nullptr && - kernel_symbol_status == kAddressValid && - StacktracePowerPCGetLR(new_sp) == kernel_sigtramp_rt64_address) { - const ucontext_t* signal_context = - reinterpret_cast<const ucontext_t*>(uc); - void **const sp_before_signal = - reinterpret_cast<void**>(signal_context->uc_mcontext.gp_regs[PT_R1]); - // Check that alleged sp before signal is nonnull and is reasonably - // aligned. - if (sp_before_signal != nullptr && - ((uintptr_t)sp_before_signal % kStackAlignment) == 0) { - // Check that alleged stack pointer is actually readable. This is to - // prevent a "double fault" in case we hit the first fault due to e.g. - // a stack corruption. - if (absl::debugging_internal::AddressIsReadable(sp_before_signal)) { - // Alleged stack pointer is readable, use it for further unwinding. - new_sp = sp_before_signal; - } - } - } - } -#endif - - return new_sp; -} - -// This ensures that absl::GetStackTrace sets up the Link Register properly. -ABSL_ATTRIBUTE_NOINLINE static void AbslStacktracePowerPCDummyFunction() { - ABSL_BLOCK_TAIL_CALL_OPTIMIZATION(); -} - -template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT> -ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS // May read random elements from stack. -ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY // May read random elements from stack. -static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count, - const void *ucp, int *min_dropped_frames) { - void **sp; - // Apple macOS uses an old version of gnu as -- both Darwin 7.9.0 (Panther) - // and Darwin 8.8.1 (Tiger) use as 1.38. This means we have to use a - // different asm syntax. I don't know quite the best way to discriminate - // systems using the old as from the new one; I've gone with __APPLE__. -#ifdef __APPLE__ - __asm__ volatile ("mr %0,r1" : "=r" (sp)); -#else - __asm__ volatile ("mr %0,1" : "=r" (sp)); -#endif - - // On PowerPC, the "Link Register" or "Link Record" (LR), is a stack - // entry that holds the return address of the subroutine call (what - // instruction we run after our function finishes). This is the - // same as the stack-pointer of our parent routine, which is what we - // want here. While the compiler will always(?) set up LR for - // subroutine calls, it may not for leaf functions (such as this one). - // This routine forces the compiler (at least gcc) to push it anyway. - AbslStacktracePowerPCDummyFunction(); - - // The LR save area is used by the callee, so the top entry is bogus. - skip_count++; - - int n = 0; - - // Unlike ABIs of X86 and ARM, PowerPC ABIs say that return address (in - // the link register) of a function call is stored in the caller's stack - // frame instead of the callee's. When we look for the return address - // associated with a stack frame, we need to make sure that there is a - // caller frame before it. So we call NextStackFrame before entering the - // loop below and check next_sp instead of sp for loop termination. - // The outermost frame is set up by runtimes and it does not have a - // caller frame, so it is skipped. - - // The absl::GetStackFrames routine is called when we are in some - // informational context (the failure signal handler for example). - // Use the non-strict unwinding rules to produce a stack trace - // that is as complete as possible (even if it contains a few - // bogus entries in some rare cases). - void **next_sp = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(sp, ucp); - - while (next_sp && n < max_depth) { - if (skip_count > 0) { - skip_count--; - } else { - result[n] = StacktracePowerPCGetLR(sp); - if (IS_STACK_FRAMES) { - if (next_sp > sp) { - sizes[n] = (uintptr_t)next_sp - (uintptr_t)sp; - } else { - // A frame-size of 0 is used to indicate unknown frame size. - sizes[n] = 0; - } - } - n++; - } - - sp = next_sp; - next_sp = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(sp, ucp); - } - - if (min_dropped_frames != nullptr) { - // Implementation detail: we clamp the max of frames we are willing to - // count, so as not to spend too much time in the loop below. - const int kMaxUnwind = 1000; - int j = 0; - for (; next_sp != nullptr && j < kMaxUnwind; j++) { - next_sp = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(next_sp, ucp); - } - *min_dropped_frames = j; - } - return n; -} - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace debugging_internal { -bool StackTraceWorksForTest() { - return true; -} -} // namespace debugging_internal -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_DEBUGGING_INTERNAL_STACKTRACE_POWERPC_INL_H_ |