Move dead submodules in-tree

Signed-off-by: swurl <swurl@swurl.xyz>
2026-05-14 04:17:03 +02:00 · 2025-05-31 02:33:02 -04:00 · 2025-05-31 02:33:02 -04:00 · 6c655321e6
commit 6c655321e6
parent c0cceff365
4081 changed files with 1185566 additions and 45 deletions
--- a/externals/breakpad/src/processor/stackwalker_amd64.cc
+++ b/externals/breakpad/src/processor/stackwalker_amd64.cc
@ -0,0 +1,380 @@
+// Copyright 2010 Google LLC
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google LLC nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// stackwalker_amd64.cc: amd64-specific stackwalker.
+//
+// See stackwalker_amd64.h for documentation.
+//
+// Author: Mark Mentovai, Ted Mielczarek
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>  // Must come first
+#endif
+
+#include <assert.h>
+
+#include "common/scoped_ptr.h"
+#include "google_breakpad/processor/call_stack.h"
+#include "google_breakpad/processor/memory_region.h"
+#include "google_breakpad/processor/source_line_resolver_interface.h"
+#include "google_breakpad/processor/stack_frame_cpu.h"
+#include "google_breakpad/processor/system_info.h"
+#include "processor/cfi_frame_info.h"
+#include "processor/logging.h"
+#include "processor/stackwalker_amd64.h"
+
+namespace google_breakpad {
+
+
+const StackwalkerAMD64::CFIWalker::RegisterSet
+StackwalkerAMD64::cfi_register_map_[] = {
+  // It may seem like $rip and $rsp are callee-saves, because the callee is
+  // responsible for having them restored upon return. But the callee_saves
+  // flags here really means that the walker should assume they're
+  // unchanged if the CFI doesn't mention them --- clearly wrong for $rip
+  // and $rsp.
+  { "$rax", NULL, false,
+    StackFrameAMD64::CONTEXT_VALID_RAX, &MDRawContextAMD64::rax },
+  { "$rdx", NULL, false,
+    StackFrameAMD64::CONTEXT_VALID_RDX, &MDRawContextAMD64::rdx },
+  { "$rcx", NULL, false,
+    StackFrameAMD64::CONTEXT_VALID_RCX, &MDRawContextAMD64::rcx },
+  { "$rbx", NULL, true,
+    StackFrameAMD64::CONTEXT_VALID_RBX, &MDRawContextAMD64::rbx },
+  { "$rsi", NULL, false,
+    StackFrameAMD64::CONTEXT_VALID_RSI, &MDRawContextAMD64::rsi },
+  { "$rdi", NULL, false,
+    StackFrameAMD64::CONTEXT_VALID_RDI, &MDRawContextAMD64::rdi },
+  { "$rbp", NULL, true,
+    StackFrameAMD64::CONTEXT_VALID_RBP, &MDRawContextAMD64::rbp },
+  { "$rsp", ".cfa", false,
+    StackFrameAMD64::CONTEXT_VALID_RSP, &MDRawContextAMD64::rsp },
+  { "$r8", NULL, false,
+    StackFrameAMD64::CONTEXT_VALID_R8,  &MDRawContextAMD64::r8 },
+  { "$r9", NULL, false,
+    StackFrameAMD64::CONTEXT_VALID_R9,  &MDRawContextAMD64::r9 },
+  { "$r10", NULL, false,
+    StackFrameAMD64::CONTEXT_VALID_R10, &MDRawContextAMD64::r10 },
+  { "$r11", NULL, false,
+    StackFrameAMD64::CONTEXT_VALID_R11, &MDRawContextAMD64::r11 },
+  { "$r12", NULL, true,
+    StackFrameAMD64::CONTEXT_VALID_R12, &MDRawContextAMD64::r12 },
+  { "$r13", NULL, true,
+    StackFrameAMD64::CONTEXT_VALID_R13, &MDRawContextAMD64::r13 },
+  { "$r14", NULL, true,
+    StackFrameAMD64::CONTEXT_VALID_R14, &MDRawContextAMD64::r14 },
+  { "$r15", NULL, true,
+    StackFrameAMD64::CONTEXT_VALID_R15, &MDRawContextAMD64::r15 },
+  { "$rip", ".ra", false,
+    StackFrameAMD64::CONTEXT_VALID_RIP, &MDRawContextAMD64::rip },
+};
+
+StackwalkerAMD64::StackwalkerAMD64(const SystemInfo* system_info,
+                                   const MDRawContextAMD64* context,
+                                   MemoryRegion* memory,
+                                   const CodeModules* modules,
+                                   StackFrameSymbolizer* resolver_helper)
+    : Stackwalker(system_info, memory, modules, resolver_helper),
+      context_(context),
+      cfi_walker_(cfi_register_map_,
+                  (sizeof(cfi_register_map_) / sizeof(cfi_register_map_[0]))) {
+}
+
+uint64_t StackFrameAMD64::ReturnAddress() const {
+  assert(context_validity & StackFrameAMD64::CONTEXT_VALID_RIP);
+  return context.rip;
+}
+
+StackFrame* StackwalkerAMD64::GetContextFrame() {
+  if (!context_) {
+    BPLOG(ERROR) << "Can't get context frame without context";
+    return NULL;
+  }
+
+  StackFrameAMD64* frame = new StackFrameAMD64();
+
+  // The instruction pointer is stored directly in a register, so pull it
+  // straight out of the CPU context structure.
+  frame->context = *context_;
+  frame->context_validity = StackFrameAMD64::CONTEXT_VALID_ALL;
+  frame->trust = StackFrame::FRAME_TRUST_CONTEXT;
+  frame->instruction = frame->context.rip;
+
+  return frame;
+}
+
+StackFrameAMD64* StackwalkerAMD64::GetCallerByCFIFrameInfo(
+    const vector<StackFrame*>& frames,
+    CFIFrameInfo* cfi_frame_info) {
+  StackFrameAMD64* last_frame = static_cast<StackFrameAMD64*>(frames.back());
+
+  scoped_ptr<StackFrameAMD64> frame(new StackFrameAMD64());
+  if (!cfi_walker_
+      .FindCallerRegisters(*memory_, *cfi_frame_info,
+                           last_frame->context, last_frame->context_validity,
+                           &frame->context, &frame->context_validity))
+    return NULL;
+
+  // Make sure we recovered all the essentials.
+  static const int essentials = (StackFrameAMD64::CONTEXT_VALID_RIP
+                                 | StackFrameAMD64::CONTEXT_VALID_RSP);
+  if ((frame->context_validity & essentials) != essentials)
+    return NULL;
+
+  if (!frame->context.rip || !frame->context.rsp) {
+    BPLOG(ERROR) << "invalid rip/rsp";
+    return NULL;
+  }
+
+  frame->trust = StackFrame::FRAME_TRUST_CFI;
+  return frame.release();
+}
+
+// Returns true if `ptr` is not in x86-64 canonical form.
+// https://en.wikipedia.org/wiki/X86-64#Virtual_address_space_details
+static bool is_non_canonical(uint64_t ptr) {
+  return ptr > 0x7FFFFFFFFFFF && ptr < 0xFFFF800000000000;
+}
+
+StackFrameAMD64* StackwalkerAMD64::GetCallerByFramePointerRecovery(
+    const vector<StackFrame*>& frames) {
+  StackFrameAMD64* last_frame = static_cast<StackFrameAMD64*>(frames.back());
+  uint64_t last_rbp = last_frame->context.rbp;
+
+  // Assume the presence of a frame pointer. This is not mandated by the
+  // AMD64 ABI, c.f. section 3.2.2 footnote 7, though it is typical for
+  // compilers to still preserve the frame pointer and not treat %rbp as a
+  // general purpose register.
+  //
+  // With this assumption, the CALL instruction pushes the return address
+  // onto the stack and sets %rip to the procedure to enter. The procedure
+  // then establishes the stack frame with a prologue that PUSHes the current
+  // %rbp onto the stack, MOVes the current %rsp to %rbp, and then allocates
+  // space for any local variables. Using this procedure linking information,
+  // it is possible to locate frame information for the callee:
+  //
+  // %caller_rsp = *(%callee_rbp + 16)
+  // %caller_rip = *(%callee_rbp + 8)
+  // %caller_rbp = *(%callee_rbp)
+
+  // If rbp is not 8-byte aligned it can't be a frame pointer.
+  if (last_rbp % 8 != 0) {
+    return NULL;
+  }
+
+  uint64_t caller_rip, caller_rbp;
+  if (memory_->GetMemoryAtAddress(last_rbp + 8, &caller_rip) &&
+      memory_->GetMemoryAtAddress(last_rbp, &caller_rbp)) {
+    uint64_t caller_rsp = last_rbp + 16;
+
+    // If the recovered rip is not a canonical address it can't be
+    // the return address, so rbp must not have been a frame pointer.
+    if (is_non_canonical(caller_rip)) {
+      return NULL;
+    }
+
+    // Check that rbp is within the right frame
+    if (caller_rsp <= last_rbp || caller_rbp < caller_rsp) {
+      return NULL;
+    }
+
+    // Sanity check that resulting rbp is still inside stack memory.
+    uint64_t unused;
+    if (!memory_->GetMemoryAtAddress(caller_rbp, &unused)) {
+      return NULL;
+    }
+
+    StackFrameAMD64* frame = new StackFrameAMD64();
+    frame->trust = StackFrame::FRAME_TRUST_FP;
+    frame->context = last_frame->context;
+    frame->context.rip = caller_rip;
+    frame->context.rsp = caller_rsp;
+    frame->context.rbp = caller_rbp;
+    frame->context_validity = StackFrameAMD64::CONTEXT_VALID_RIP |
+                              StackFrameAMD64::CONTEXT_VALID_RSP |
+                              StackFrameAMD64::CONTEXT_VALID_RBP;
+    return frame;
+  }
+
+  return NULL;
+}
+
+StackFrameAMD64* StackwalkerAMD64::GetCallerBySimulatingReturn(
+    const vector<StackFrame*>& frames) {
+  assert(frames.back()->trust == StackFrame::FRAME_TRUST_CONTEXT);
+  StackFrameAMD64* last_frame = static_cast<StackFrameAMD64*>(frames.back());
+  uint64_t last_rsp = last_frame->context.rsp;
+  uint64_t caller_rip_address, caller_rip;
+  int searchwords = 1;
+  if (!ScanForReturnAddress(last_rsp, &caller_rip_address, &caller_rip,
+                            searchwords)) {
+    // No plausible return address at the top of the stack. Unable to simulate
+    // a return.
+    return NULL;
+  }
+
+  // Create a new stack frame (ownership will be transferred to the caller)
+  // and fill it in.
+  StackFrameAMD64* frame = new StackFrameAMD64();
+
+  frame->trust = StackFrame::FRAME_TRUST_LEAF;
+  frame->context = last_frame->context;
+  frame->context.rip = caller_rip;
+  // The caller's %rsp is directly underneath the return address pushed by
+  // the call.
+  frame->context.rsp = caller_rip_address + 8;
+  frame->context_validity = last_frame->context_validity;
+
+  return frame;
+}
+
+StackFrameAMD64* StackwalkerAMD64::GetCallerByStackScan(
+    const vector<StackFrame*>& frames) {
+  StackFrameAMD64* last_frame = static_cast<StackFrameAMD64*>(frames.back());
+  uint64_t last_rsp = last_frame->context.rsp;
+  uint64_t caller_rip_address, caller_rip;
+
+  if (!ScanForReturnAddress(last_rsp, &caller_rip_address, &caller_rip,
+                            /*is_context_frame=*/last_frame->trust ==
+                                StackFrame::FRAME_TRUST_CONTEXT)) {
+    // No plausible return address was found.
+    return NULL;
+  }
+
+  // Create a new stack frame (ownership will be transferred to the caller)
+  // and fill it in.
+  StackFrameAMD64* frame = new StackFrameAMD64();
+
+  frame->trust = StackFrame::FRAME_TRUST_SCAN;
+  frame->context = last_frame->context;
+  frame->context.rip = caller_rip;
+  // The caller's %rsp is directly underneath the return address pushed by
+  // the call.
+  frame->context.rsp = caller_rip_address + 8;
+  frame->context_validity = StackFrameAMD64::CONTEXT_VALID_RIP |
+                            StackFrameAMD64::CONTEXT_VALID_RSP;
+
+  // Other unwinders give up if they don't have an %rbp value, so see if we
+  // can pass some plausible value on.
+  if (last_frame->context_validity & StackFrameAMD64::CONTEXT_VALID_RBP) {
+    // Functions typically push their caller's %rbp immediately upon entry,
+    // and then set %rbp to point to that. So if the callee's %rbp is
+    // pointing to the first word below the alleged return address, presume
+    // that the caller's %rbp is saved there.
+    if (caller_rip_address - 8 == last_frame->context.rbp) {
+      uint64_t caller_rbp = 0;
+      if (memory_->GetMemoryAtAddress(last_frame->context.rbp, &caller_rbp) &&
+          caller_rbp > caller_rip_address) {
+        frame->context.rbp = caller_rbp;
+        frame->context_validity |= StackFrameAMD64::CONTEXT_VALID_RBP;
+      }
+    } else if (last_frame->context.rbp >= caller_rip_address + 8) {
+      // If the callee's %rbp is plausible as a value for the caller's
+      // %rbp, presume that the callee left it unchanged.
+      frame->context.rbp = last_frame->context.rbp;
+      frame->context_validity |= StackFrameAMD64::CONTEXT_VALID_RBP;
+    }
+  }
+
+  return frame;
+}
+
+StackFrame* StackwalkerAMD64::GetCallerFrame(const CallStack* stack,
+                                             bool stack_scan_allowed) {
+  if (!memory_ || !stack) {
+    BPLOG(ERROR) << "Can't get caller frame without memory or stack";
+    return NULL;
+  }
+
+  const vector<StackFrame*>& frames = *stack->frames();
+  StackFrameAMD64* last_frame = static_cast<StackFrameAMD64*>(frames.back());
+  scoped_ptr<StackFrameAMD64> new_frame;
+
+  // If we have CFI information, use it.
+  scoped_ptr<CFIFrameInfo> cfi_frame_info(
+      frame_symbolizer_->FindCFIFrameInfo(last_frame));
+  if (cfi_frame_info.get())
+    new_frame.reset(GetCallerByCFIFrameInfo(frames, cfi_frame_info.get()));
+
+  // If CFI was not available and this is a Windows x64 stack, check whether
+  // this is a leaf function which doesn't touch any callee-saved registers.
+  // According to https://reviews.llvm.org/D24748, LLVM doesn't generate unwind
+  // info for such functions. According to MSDN, leaf functions can be unwound
+  // simply by simulating a return.
+  if (!new_frame.get() &&
+      last_frame->trust == StackFrame::FRAME_TRUST_CONTEXT &&
+      system_info_->os_short == "windows") {
+    new_frame.reset(GetCallerBySimulatingReturn(frames));
+  }
+
+  // If CFI was not available or failed, try using frame pointer recovery.
+  // Never try to use frame pointer unwinding on Windows x64 stack. MSVC never
+  // generates code that works with frame pointer chasing, and LLVM does the
+  // same. Stack scanning would be better.
+  if (!new_frame.get() && system_info_->os_short != "windows") {
+    new_frame.reset(GetCallerByFramePointerRecovery(frames));
+  }
+
+  // If all else fails, fall back to stack scanning.
+  if (stack_scan_allowed && !new_frame.get()) {
+    new_frame.reset(GetCallerByStackScan(frames));
+  }
+
+  // If nothing worked, tell the caller.
+  if (!new_frame.get())
+    return NULL;
+
+  if (system_info_->os_short == "nacl") {
+    // Apply constraints from Native Client's x86-64 sandbox.  These
+    // registers have the 4GB-aligned sandbox base address (from r15)
+    // added to them, and only the bottom 32 bits are relevant for
+    // stack walking.
+    new_frame->context.rip = static_cast<uint32_t>(new_frame->context.rip);
+    new_frame->context.rsp = static_cast<uint32_t>(new_frame->context.rsp);
+    new_frame->context.rbp = static_cast<uint32_t>(new_frame->context.rbp);
+  }
+
+  // Should we terminate the stack walk? (end-of-stack or broken invariant)
+  if (TerminateWalk(new_frame->context.rip, new_frame->context.rsp,
+                    last_frame->context.rsp,
+                    /*first_unwind=*/last_frame->trust ==
+                        StackFrame::FRAME_TRUST_CONTEXT)) {
+    return NULL;
+  }
+
+  // new_frame->context.rip is the return address, which is the instruction
+  // after the CALL that caused us to arrive at the callee. Set
+  // new_frame->instruction to one less than that, so it points within the
+  // CALL instruction. See StackFrame::instruction for details, and
+  // StackFrameAMD64::ReturnAddress.
+  new_frame->instruction = new_frame->context.rip - 1;
+
+  return new_frame.release();
+}
+
+}  // namespace google_breakpad