Remove obsolete seccomp_unwinder for legacy (pre-BPF) sandbox

src/client/linux/dump_writer_common/seccomp_unwinder.cc

-// Copyright (c) 2014, Google Inc.
-// All rights reserved.
-//
-// 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 Inc. 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.
-
-#include "client/linux/dump_writer_common/seccomp_unwinder.h"
-
-#include <string.h>
-
-#include "google_breakpad/common/minidump_format.h"
-#include "common/linux/linux_libc_support.h"
-
-namespace google_breakpad {
-
-void SeccompUnwinder::PopSeccompStackFrame(RawContextCPU* cpu,
-                                           const MDRawThread& thread,
-                                           uint8_t* stack_copy) {
-#if defined(__x86_64)
-  uint64_t bp = cpu->rbp;
-  uint64_t top = thread.stack.start_of_memory_range;
-  for (int i = 4; i--; ) {
-    if (bp < top ||
-        bp > thread.stack.start_of_memory_range +
-        thread.stack.memory.data_size - sizeof(bp) ||
-        bp & 1) {
-      break;
-    }
-    uint64_t old_top = top;
-    top = bp;
-    uint8_t* bp_addr = stack_copy + bp - thread.stack.start_of_memory_range;
-    my_memcpy(&bp, bp_addr, sizeof(bp));
-    if (bp == 0xDEADBEEFDEADBEEFull) {
-      struct {
-        uint64_t r15;
-        uint64_t r14;
-        uint64_t r13;
-        uint64_t r12;
-        uint64_t r11;
-        uint64_t r10;
-        uint64_t r9;
-        uint64_t r8;
-        uint64_t rdi;
-        uint64_t rsi;
-        uint64_t rdx;
-        uint64_t rcx;
-        uint64_t rbx;
-        uint64_t deadbeef;
-        uint64_t rbp;
-        uint64_t fakeret;
-        uint64_t ret;
-        /* char redzone[128]; */
-      } seccomp_stackframe;
-      if (top - offsetof(__typeof__(seccomp_stackframe), deadbeef) < old_top ||
-          top - offsetof(__typeof__(seccomp_stackframe), deadbeef) +
-          sizeof(seccomp_stackframe) >
-          thread.stack.start_of_memory_range+thread.stack.memory.data_size) {
-        break;
-      }
-      my_memcpy(&seccomp_stackframe,
-                bp_addr - offsetof(__typeof__(seccomp_stackframe), deadbeef),
-                sizeof(seccomp_stackframe));
-      cpu->rbx = seccomp_stackframe.rbx;
-      cpu->rcx = seccomp_stackframe.rcx;
-      cpu->rdx = seccomp_stackframe.rdx;
-      cpu->rsi = seccomp_stackframe.rsi;
-      cpu->rdi = seccomp_stackframe.rdi;
-      cpu->rbp = seccomp_stackframe.rbp;
-      cpu->rsp = top + 4*sizeof(uint64_t) + 128;
-      cpu->r8  = seccomp_stackframe.r8;
-      cpu->r9  = seccomp_stackframe.r9;
-      cpu->r10 = seccomp_stackframe.r10;
-      cpu->r11 = seccomp_stackframe.r11;
-      cpu->r12 = seccomp_stackframe.r12;
-      cpu->r13 = seccomp_stackframe.r13;
-      cpu->r14 = seccomp_stackframe.r14;
-      cpu->r15 = seccomp_stackframe.r15;
-      cpu->rip = seccomp_stackframe.fakeret;
-      return;
-    }
-  }
-#elif defined(__i386__)
-  uint32_t bp = cpu->ebp;
-  uint32_t top = thread.stack.start_of_memory_range;
-  for (int i = 4; i--; ) {
-    if (bp < top ||
-        bp > thread.stack.start_of_memory_range +
-        thread.stack.memory.data_size - sizeof(bp) ||
-        bp & 1) {
-      break;
-    }
-    uint32_t old_top = top;
-    top = bp;
-    uint8_t* bp_addr = stack_copy + bp - thread.stack.start_of_memory_range;
-    my_memcpy(&bp, bp_addr, sizeof(bp));
-    if (bp == 0xDEADBEEFu) {
-      struct {
-        uint32_t edi;
-        uint32_t esi;
-        uint32_t edx;
-        uint32_t ecx;
-        uint32_t ebx;
-        uint32_t deadbeef;
-        uint32_t ebp;
-        uint32_t fakeret;
-        uint32_t ret;
-      } seccomp_stackframe;
-      if (top - offsetof(__typeof__(seccomp_stackframe), deadbeef) < old_top ||
-          top - offsetof(__typeof__(seccomp_stackframe), deadbeef) +
-          sizeof(seccomp_stackframe) >
-          thread.stack.start_of_memory_range+thread.stack.memory.data_size) {
-        break;
-      }
-      my_memcpy(&seccomp_stackframe,
-                bp_addr - offsetof(__typeof__(seccomp_stackframe), deadbeef),
-                sizeof(seccomp_stackframe));
-      cpu->ebx = seccomp_stackframe.ebx;
-      cpu->ecx = seccomp_stackframe.ecx;
-      cpu->edx = seccomp_stackframe.edx;
-      cpu->esi = seccomp_stackframe.esi;
-      cpu->edi = seccomp_stackframe.edi;
-      cpu->ebp = seccomp_stackframe.ebp;
-      cpu->esp = top + 4*sizeof(void*);
-      cpu->eip = seccomp_stackframe.fakeret;
-      return;
-    }
-  }
-#endif
-}
-
-}  // namespace google_breakpad