zircon/system/ulib/inspector/debug-info.cc - fuchsia - Git at Google

 // Copyright 2016 The Fuchsia Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include <inttypes.h>
 #include <lib/backtrace-request/backtrace-request-utils.h>
 #include <lib/zx/process.h>
 #include <lib/zx/thread.h>
 #include <string.h>
 #include <zircon/assert.h>
 #include <zircon/status.h>
 #include <zircon/syscalls.h>
 #include <zircon/syscalls/exception.h>
 #include <zircon/syscalls/policy.h>
 #include <zircon/types.h>

 #include <string>
 #include <vector>

 #include "inspector/inspector.h"
 #include "utils-impl.h"

 namespace inspector {

 #if defined(__x86_64__)
 static const char* kArch = "x86_64";
 #elif defined(__aarch64__)
 static const char* kArch = "aarch64";
 #elif defined(__riscv)
 static const char* kArch = "riscv64";
 #else
 #error unsupported architecture
 #endif

 static const char* excp_type_to_str(const zx_excp_type_t type) {
   switch (type) {
     case ZX_EXCP_GENERAL:
       return "general fault";
     case ZX_EXCP_FATAL_PAGE_FAULT:
       return "fatal page fault";
     case ZX_EXCP_UNDEFINED_INSTRUCTION:
       return "undefined instruction";
     case ZX_EXCP_SW_BREAKPOINT:
       return "sw breakpoint";
     case ZX_EXCP_HW_BREAKPOINT:
       return "hw breakpoint";
     case ZX_EXCP_UNALIGNED_ACCESS:
       return "alignment fault";
     case ZX_EXCP_POLICY_ERROR:
       return "policy error";
     default:
       // Note: To get a compilation failure when a new exception type has
       // been added without having also updated this function, compile with
       // -Wswitch-enum.
       return "<unknown fault>";
   }
 }

 static const char* policy_exception_code_to_str(uint32_t policy_exception_code) {
   switch (policy_exception_code) {
     case ZX_EXCP_POLICY_CODE_BAD_HANDLE:
       return "BAD_HANDLE";
     case ZX_EXCP_POLICY_CODE_WRONG_OBJECT:
       return "WRONG_OBJECT";
     case ZX_EXCP_POLICY_CODE_VMAR_WX:
       return "VMAR_WX";
     case ZX_EXCP_POLICY_CODE_NEW_ANY:
       return "NEW_ANY";
     case ZX_EXCP_POLICY_CODE_NEW_VMO:
       return "NEW_VMO";
     case ZX_EXCP_POLICY_CODE_NEW_CHANNEL:
       return "NEW_CHANNEL";
     case ZX_EXCP_POLICY_CODE_NEW_EVENT:
       return "NEW_EVENT";
     case ZX_EXCP_POLICY_CODE_NEW_EVENTPAIR:
       return "NEW_EVENTPAIR";
     case ZX_EXCP_POLICY_CODE_NEW_PORT:
       return "NEW_PORT";
     case ZX_EXCP_POLICY_CODE_NEW_SOCKET:
       return "NEW_SOCKET";
     case ZX_EXCP_POLICY_CODE_NEW_FIFO:
       return "NEW_FIFO";
     case ZX_EXCP_POLICY_CODE_NEW_TIMER:
       return "NEW_TIMER";
     case ZX_EXCP_POLICY_CODE_NEW_PROCESS:
       return "NEW_PROCESS";
     case ZX_EXCP_POLICY_CODE_NEW_PROFILE:
       return "NEW_PROFILE";
     case ZX_EXCP_POLICY_CODE_AMBIENT_MARK_VMO_EXEC:
       return "AMBIENT_MARK_VMO_EXEC";
     case ZX_EXCP_POLICY_CODE_CHANNEL_FULL_WRITE:
       return "CHANNEL_FULL_WRITE";
     case ZX_EXCP_POLICY_CODE_PORT_TOO_MANY_PACKETS:
       return "PORT_TOO_MANY_PACKETS";
     case ZX_EXCP_POLICY_CODE_BAD_SYSCALL:
       return "BAD_SYSCALL";
     default:
       return "<unknown policy code>";
   }
 }

 // Globs the general registers and the interpretation of them as IP, SP, FP, etc.
 typedef struct decoded_registers_t {
   zx_vaddr_t pc = 0;
   zx_vaddr_t sp = 0;
   zx_vaddr_t fp = 0;
 } decoded_registers;

 decoded_registers_t decode_registers(const zx_thread_state_general_regs* regs) {
   decoded_registers decoded;
 #if defined(__x86_64__)
   decoded.pc = regs->rip;
   decoded.sp = regs->rsp;
   decoded.fp = regs->rbp;
 #elif defined(__aarch64__)
   decoded.pc = regs->pc;
   decoded.sp = regs->sp;
   decoded.fp = regs->r[29];
 #elif defined(__riscv)
 #else
 #error unsupported architecture
 #endif

   return decoded;
 }

 // How much memory to dump, in bytes.
 static constexpr size_t kMemoryDumpSize = 256;

 static zx_koid_t get_koid(zx_handle_t handle) {
   zx_info_handle_basic_t info;
   zx_status_t status =
       zx_object_get_info(handle, ZX_INFO_HANDLE_BASIC, &info, sizeof(info), nullptr, nullptr);
   if (status != ZX_OK) {
     printf("failed to get koid\n");
     return ZX_HANDLE_INVALID;
   }
   return info.koid;
 }

 static void get_name(zx_handle_t handle, char* buf, size_t size) {
   zx_status_t status = zx_object_get_property(handle, ZX_PROP_NAME, buf, size);
   if (status != ZX_OK) {
     strlcpy(buf, "<unknown>", size);
   }
 }

 static void print_exception_report(FILE* out, const zx_exception_report_t& report,
                                    const zx_thread_state_general_regs* regs) {
   inspector::decoded_registers decoded = inspector::decode_registers(regs);

   if (report.header.type == ZX_EXCP_FATAL_PAGE_FAULT) {
     const char* access_type = "<unknown>";
     const char* violation = "<unknown>";
 #if defined(__x86_64__)
     static constexpr uint32_t kErrCodeInstrFetch = (1 << 4);
     static constexpr uint32_t kErrCodeWrite = (1 << 1);
     static constexpr uint32_t kErrCodeProtectionViolation = (1 << 0);
     if (report.context.arch.u.x86_64.err_code & kErrCodeInstrFetch) {
       access_type = "execute";
     } else if (report.context.arch.u.x86_64.err_code & kErrCodeWrite) {
       access_type = "write";
     } else {
       access_type = "read";
     }

     if (report.context.arch.u.x86_64.err_code & kErrCodeProtectionViolation) {
       violation = "protection";
     } else {
       violation = "not-present";
     }
 #elif defined(__aarch64__)
     // The one ec bit that's different between a data and instruction abort
     static constexpr uint32_t kEcDataAbortBit = (1 << 28);
     static constexpr uint32_t kIssCacheOp = (1 << 8);
     static constexpr uint32_t kIssWrite = (1 << 6);
     static constexpr uint32_t kDccNoLvlMask = 0b111100;
     static constexpr uint32_t kDccPermissionFault = 0b001100;
     static constexpr uint32_t kDccTranslationFault = 0b000100;
     static constexpr uint32_t kDccAddressSizeFault = 0b000000;
     static constexpr uint32_t kDccAccessFlagFault = 0b001000;
     static constexpr uint32_t kDccSynchronousExternalFault = 0b010000;

     if (report.context.arch.u.arm_64.esr & kEcDataAbortBit) {
       if (report.context.arch.u.arm_64.esr & kIssWrite &&
           !(report.context.arch.u.arm_64.esr & kIssCacheOp)) {
         access_type = "write";
       } else {
         access_type = "read";
       }
     } else {
       access_type = "execute";
     }

     switch ((report.context.arch.u.arm_64.esr & kDccNoLvlMask)) {
       case kDccPermissionFault:
         violation = "protection";
         break;
       case kDccTranslationFault:
         violation = "not-present";
         break;
       case kDccAddressSizeFault:
         violation = "address-size";
         break;
       case kDccAccessFlagFault:
         violation = "access-flag";
         break;
       case kDccSynchronousExternalFault:
         violation = "external-abort";
         break;
       default:
         violation = "undecoded";
         break;
     }
 #elif defined(__riscv)
 #else
 #error unsupported architecture
 #endif
     fprintf(out, "<== %s %s page fault (error %s), PC at 0x%" PRIxPTR "\n", access_type, violation,
             zx_status_get_string(static_cast<zx_status_t>(report.context.synth_code)), decoded.pc);
   } else if (report.header.type == ZX_EXCP_POLICY_ERROR) {
     switch (report.context.synth_code) {
       case ZX_EXCP_POLICY_CODE_BAD_SYSCALL:
         fprintf(out, "<== policy error: %s (%d, syscall %d), PC at 0x%" PRIxPTR "\n",
                 inspector::policy_exception_code_to_str(report.context.synth_code),
                 report.context.synth_code, report.context.synth_data, decoded.pc);
         break;

       default:
         fprintf(out, "<== policy error: %s (%d), PC at 0x%" PRIxPTR "\n",
                 inspector::policy_exception_code_to_str(report.context.synth_code),
                 report.context.synth_code, decoded.pc);
         break;
     }
   } else {
     fprintf(out, "<== %s, PC at 0x%" PRIxPTR "\n", inspector::excp_type_to_str(report.header.type),
             decoded.pc);
   }
 }

 }  // namespace inspector

 __EXPORT void inspector_print_stack_trace(FILE* out, zx_handle_t process, zx_handle_t thread,
                                           const zx_thread_state_general_regs* regs) {
   inspector_dsoinfo_t* dso_list = inspector_dso_fetch_list(process);
   inspector_print_markup_context(out, process);

   inspector::decoded_registers decoded = inspector::decode_registers(regs);
   inspector_print_backtrace_markup(out, process, thread, dso_list, decoded.pc, decoded.sp,
                                    decoded.fp);
   inspector_dso_free_list(dso_list);
 }

 __EXPORT void inspector_print_debug_info(FILE* out, zx_handle_t process_handle,
                                          zx_handle_t thread_handle) {
   zx_status_t status;
   // If the caller didn't supply |regs| use a local copy.
   zx_thread_state_general_regs_t regs;

   zx::unowned<zx::process> process(process_handle);
   zx_koid_t pid = inspector::get_koid(process->get());
   char process_name[ZX_MAX_NAME_LEN];
   inspector::get_name(process->get(), process_name, sizeof(process_name));

   zx::unowned<zx::thread> thread(thread_handle);
   zx_koid_t tid = inspector::get_koid(thread->get());
   char thread_name[ZX_MAX_NAME_LEN];
   inspector::get_name(thread->get(), thread_name, sizeof(thread_name));

   // Attempt to obtain the registers. If this fails, it means that the thread wasn't provided in a
   // valid state.
   status = inspector_read_general_regs(thread->get(), &regs);
   if (status != ZX_OK) {
     printf("[Process %s, Thread %s] Could not get general registers: %s.\n", process_name,
            thread_name, zx_status_get_string(status));
     return;
   }
   inspector::decoded_registers decoded = inspector::decode_registers(&regs);

   // Backtrace requests are special software breakpoints that get resumed. They need to be clearly
   // differentiable from other exceptions.
   bool backtrace_requested = false;

   // Check if the process is on an exception.
   zx_exception_report_t report;
   if (thread->get_info(ZX_INFO_THREAD_EXCEPTION_REPORT, &report, sizeof(report), nullptr,
                        nullptr) == ZX_OK) {
     // The thread is in a valid exception state.
     if (!ZX_EXCP_IS_ARCH(report.header.type) && report.header.type != ZX_EXCP_POLICY_ERROR) {
       return;
     }

     backtrace_requested = is_backtrace_request(report.header.type, &regs);
     if (backtrace_requested) {
       fprintf(out, "<== BACKTRACE REQUEST: process %s[%" PRIu64 "] thread %s[%" PRIu64 "]\n",
               process_name, pid, thread_name, tid);
     } else {
       // Normal exception.
       fprintf(out, "<== CRASH: process %s[%" PRIu64 "] thread %s[%" PRIu64 "]\n", process_name, pid,
               thread_name, tid);
       inspector::print_exception_report(out, report, &regs);

 #if defined(__x86_64__)
       inspector_print_general_regs(out, &regs, &report.context.arch.u.x86_64);
 #elif defined(__aarch64__)
       inspector_print_general_regs(out, &regs, &report.context.arch.u.arm_64);

       // Only output the Fault address register and ESR if there's a data or
       // alignment fault.
       if (ZX_EXCP_FATAL_PAGE_FAULT == report.header.type ||
           ZX_EXCP_UNALIGNED_ACCESS == report.header.type) {
         fprintf(out, " far %#18" PRIx64 " esr %#18x\n", report.context.arch.u.arm_64.far,
                 report.context.arch.u.arm_64.esr);
       }
 #elif defined(__riscv)
 #else
 #error unsupported architecture
 #endif
     }
   } else {
     // The thread is suspended so we can safely print the stack trace.
     fprintf(out, "<== process %s[%" PRIu64 "] thread %s[%" PRIu64 "]\n", process_name, pid,
             thread_name, tid);
     fprintf(out, "<== PC at 0x%" PRIxPTR "\n", decoded.pc);
     inspector_print_general_regs(out, &regs, nullptr);
   }

   if (!backtrace_requested) {
     // Print the common stack part of the thread.
     fprintf(out, "bottom of user stack:\n");
     inspector_print_memory(out, process->get(), decoded.sp, inspector::kMemoryDumpSize);

     fprintf(out, "arch: %s\n", inspector::kArch);
   }

   inspector_print_stack_trace(out, process->get(), thread->get(), &regs);

   if (inspector::verbosity_level >= 1)
     printf("Done handling thread %" PRIu64 ".%" PRIu64 ".\n", pid, tid);
 }

 // The approach of |inspector_print_debug_info_for_all_threads| is to suspend the process, obtain
 // all threads, go over the ones in an exception first and print them and only then print all the
 // other threads. This permits to have a clearer view between logs and the crash report.
 __EXPORT void inspector_print_debug_info_for_all_threads(FILE* out, zx_handle_t process_handle) {
   zx_status_t status = ZX_ERR_NOT_SUPPORTED;

   zx::unowned<zx::process> process(process_handle);
   char process_name[ZX_MAX_NAME_LEN];
   inspector::get_name(process->get(), process_name, sizeof(process_name));
   zx_koid_t process_koid = inspector::get_koid(process->get());

   // Suspend the process so that each thread is suspended and no more threads get spawned.
   // NOTE: A process cannot suspend itself, so this could fail on some environments (like calling
   //       this function on your process). To support that usecase, this logic will also try to
   //       suspend each thread individually.
   //
   //       The advantages of suspending the process vs each thread individually are:
   //       1. Threads get suspended at a single point in time, which gives a more accurate
   //          representation of what the process is doing at the moment of printing.
   //       2. When a process is suspended, no more threads will be spawned.
   zx::suspend_token process_suspend_token;
   status = process->suspend(&process_suspend_token);
   if (status != ZX_OK) {
     printf("[Process %s (%" PRIu64 ")] Could not suspend process: %s. Continuing anyway.\n ",
            process_name, process_koid, zx_status_get_string(status));
   }

   // Get the thread list.
   // NOTE: This could be skipping threads being created at the moment of this call.
   //       This is an inherent race between suspending a process and a thread being created.
   size_t actual, avail;
   // This is an outrageous amount of threads to output. We mark them all as invalid first.
   constexpr size_t kMaxThreadHandles = 128;
   std::vector<zx_koid_t> thread_koids(kMaxThreadHandles);
   status = process->get_info(ZX_INFO_PROCESS_THREADS, thread_koids.data(),
                              thread_koids.size() * sizeof(zx_koid_t), &actual, &avail);
   if (status != ZX_OK) {
     printf("[Process %s (%" PRIu64 ")] Could not get list of threads: %s.\n", process_name,
            process_koid, zx_status_get_string(status));
     return;
   }

   std::vector<zx::thread> thread_handles(actual);
   std::vector<std::string> thread_names(actual);
   std::vector<zx_info_thread_t> thread_infos(actual);

   // Get the thread associated data.
   for (size_t i = 0; i < actual; i++) {
     // Get the handles.
     zx::thread& child = thread_handles[i];
     status = process->get_child(thread_koids[i], ZX_RIGHT_SAME_RIGHTS, &child);
     if (status != ZX_OK) {
       printf("[Process %s (%" PRIu64 ")] Could not obtain thread handle: %s.\n", process_name,
              process_koid, zx_status_get_string(status));
       continue;
     }

     // Get the name.
     char thread_name[ZX_MAX_NAME_LEN];
     inspector::get_name(child.get(), thread_name, sizeof(thread_name));
     thread_names[i] = thread_name;

     // Get the thread infos.
     zx_info_thread_t thread_info = {};
     status = child.get_info(ZX_INFO_THREAD, &thread_info, sizeof(thread_info), nullptr, nullptr);
     if (status != ZX_OK) {
       printf("[Process %s (%" PRIu64 "), Thread %s (%" PRIu64 ")] Could not obtain info: %s\n",
              process_name, process_koid, thread_names[i].c_str(), thread_koids[i],
              zx_status_get_string(status));
       continue;
     }

     thread_infos[i] = std::move(thread_info);
   }

   // Print the threads in an exception first.
   for (size_t i = 0; i < actual; i++) {
     zx::thread& child = thread_handles[i];
     if (!child.is_valid())
       continue;

     // If the thread is not in an exception, it will be printed on the next loop.
     if (thread_infos[i].state != ZX_THREAD_STATE_BLOCKED_EXCEPTION)
       continue;

     // We print the thread and then mark this koid as empty, so that it won't be printed on the
     // suspended pass. This means we can free the handle after this.
     inspector_print_debug_info(out, process->get(), child.get());
     thread_handles[i].reset();
   }

   // Go over each thread and print them.
   for (size_t i = 0; i < actual; i++) {
     if (!thread_handles[i].is_valid())
       continue;

     // If the thread is in an exception, it was already printed by the previous loop.
     if (thread_infos[i].state == ZX_THREAD_STATE_BLOCKED_EXCEPTION) {
       continue;
     }

     zx::thread& child = thread_handles[i];

     // Wait for the thread to be suspended.
     // We do this regardless of the process suspension. There are legitimate cases where the process
     // suspension would fail, like trying to suspend one's own process. If the process suspension
     // was successful, this is a no-op.
     zx::suspend_token suspend_token;
     status = child.suspend(&suspend_token);
     if (status != ZX_OK) {
       printf("[Process %s (%" PRIu64 "), Thread %s (%" PRIu64 ")] Could not suspend thread: %s.\n",
              process_name, process_koid, thread_names[i].c_str(), thread_koids[i],
              zx_status_get_string(status));
       continue;
     }

     status = child.wait_one(ZX_THREAD_SUSPENDED, zx::deadline_after(zx::msec(100)), nullptr);
     if (status != ZX_OK) {
       printf("[Process %s (%" PRIu64 "), Thread %s (%" PRIu64 ")] Didn't get suspend signal: %s.\n",
              process_name, process_koid, thread_names[i].c_str(), thread_koids[i],
              zx_status_get_string(status));
       continue;
     }

     // We can now print the thread.
     inspector_print_debug_info(out, process->get(), child.get());
   }
 }
	// Copyright 2016 The Fuchsia Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include <inttypes.h>
	#include <lib/backtrace-request/backtrace-request-utils.h>
	#include <lib/zx/process.h>
	#include <lib/zx/thread.h>
	#include <string.h>
	#include <zircon/assert.h>
	#include <zircon/status.h>
	#include <zircon/syscalls.h>
	#include <zircon/syscalls/exception.h>
	#include <zircon/syscalls/policy.h>
	#include <zircon/types.h>

	#include <string>
	#include <vector>

	#include "inspector/inspector.h"
	#include "utils-impl.h"

	namespace inspector {

	#if defined(__x86_64__)
	static const char* kArch = "x86_64";
	#elif defined(__aarch64__)
	static const char* kArch = "aarch64";
	#elif defined(__riscv)
	static const char* kArch = "riscv64";
	#else
	#error unsupported architecture
	#endif

	static const char* excp_type_to_str(const zx_excp_type_t type) {
	switch (type) {
	case ZX_EXCP_GENERAL:
	return "general fault";
	case ZX_EXCP_FATAL_PAGE_FAULT:
	return "fatal page fault";
	case ZX_EXCP_UNDEFINED_INSTRUCTION:
	return "undefined instruction";
	case ZX_EXCP_SW_BREAKPOINT:
	return "sw breakpoint";
	case ZX_EXCP_HW_BREAKPOINT:
	return "hw breakpoint";
	case ZX_EXCP_UNALIGNED_ACCESS:
	return "alignment fault";
	case ZX_EXCP_POLICY_ERROR:
	return "policy error";
	default:
	// Note: To get a compilation failure when a new exception type has
	// been added without having also updated this function, compile with
	// -Wswitch-enum.
	return "<unknown fault>";
	}
	}

	static const char* policy_exception_code_to_str(uint32_t policy_exception_code) {
	switch (policy_exception_code) {
	case ZX_EXCP_POLICY_CODE_BAD_HANDLE:
	return "BAD_HANDLE";
	case ZX_EXCP_POLICY_CODE_WRONG_OBJECT:
	return "WRONG_OBJECT";
	case ZX_EXCP_POLICY_CODE_VMAR_WX:
	return "VMAR_WX";
	case ZX_EXCP_POLICY_CODE_NEW_ANY:
	return "NEW_ANY";
	case ZX_EXCP_POLICY_CODE_NEW_VMO:
	return "NEW_VMO";
	case ZX_EXCP_POLICY_CODE_NEW_CHANNEL:
	return "NEW_CHANNEL";
	case ZX_EXCP_POLICY_CODE_NEW_EVENT:
	return "NEW_EVENT";
	case ZX_EXCP_POLICY_CODE_NEW_EVENTPAIR:
	return "NEW_EVENTPAIR";
	case ZX_EXCP_POLICY_CODE_NEW_PORT:
	return "NEW_PORT";
	case ZX_EXCP_POLICY_CODE_NEW_SOCKET:
	return "NEW_SOCKET";
	case ZX_EXCP_POLICY_CODE_NEW_FIFO:
	return "NEW_FIFO";
	case ZX_EXCP_POLICY_CODE_NEW_TIMER:
	return "NEW_TIMER";
	case ZX_EXCP_POLICY_CODE_NEW_PROCESS:
	return "NEW_PROCESS";
	case ZX_EXCP_POLICY_CODE_NEW_PROFILE:
	return "NEW_PROFILE";
	case ZX_EXCP_POLICY_CODE_AMBIENT_MARK_VMO_EXEC:
	return "AMBIENT_MARK_VMO_EXEC";
	case ZX_EXCP_POLICY_CODE_CHANNEL_FULL_WRITE:
	return "CHANNEL_FULL_WRITE";
	case ZX_EXCP_POLICY_CODE_PORT_TOO_MANY_PACKETS:
	return "PORT_TOO_MANY_PACKETS";
	case ZX_EXCP_POLICY_CODE_BAD_SYSCALL:
	return "BAD_SYSCALL";
	default:
	return "<unknown policy code>";
	}
	}

	// Globs the general registers and the interpretation of them as IP, SP, FP, etc.
	typedef struct decoded_registers_t {
	zx_vaddr_t pc = 0;
	zx_vaddr_t sp = 0;
	zx_vaddr_t fp = 0;
	} decoded_registers;

	decoded_registers_t decode_registers(const zx_thread_state_general_regs* regs) {
	decoded_registers decoded;
	#if defined(__x86_64__)
	decoded.pc = regs->rip;
	decoded.sp = regs->rsp;
	decoded.fp = regs->rbp;
	#elif defined(__aarch64__)
	decoded.pc = regs->pc;
	decoded.sp = regs->sp;
	decoded.fp = regs->r[29];
	#elif defined(__riscv)
	#else
	#error unsupported architecture
	#endif

	return decoded;
	}

	// How much memory to dump, in bytes.
	static constexpr size_t kMemoryDumpSize = 256;

	static zx_koid_t get_koid(zx_handle_t handle) {
	zx_info_handle_basic_t info;
	zx_status_t status =
	zx_object_get_info(handle, ZX_INFO_HANDLE_BASIC, &info, sizeof(info), nullptr, nullptr);
	if (status != ZX_OK) {
	printf("failed to get koid\n");
	return ZX_HANDLE_INVALID;
	}
	return info.koid;
	}

	static void get_name(zx_handle_t handle, char* buf, size_t size) {
	zx_status_t status = zx_object_get_property(handle, ZX_PROP_NAME, buf, size);
	if (status != ZX_OK) {
	strlcpy(buf, "<unknown>", size);
	}
	}

	static void print_exception_report(FILE* out, const zx_exception_report_t& report,
	const zx_thread_state_general_regs* regs) {
	inspector::decoded_registers decoded = inspector::decode_registers(regs);

	if (report.header.type == ZX_EXCP_FATAL_PAGE_FAULT) {
	const char* access_type = "<unknown>";
	const char* violation = "<unknown>";
	#if defined(__x86_64__)
	static constexpr uint32_t kErrCodeInstrFetch = (1 << 4);
	static constexpr uint32_t kErrCodeWrite = (1 << 1);
	static constexpr uint32_t kErrCodeProtectionViolation = (1 << 0);
	if (report.context.arch.u.x86_64.err_code & kErrCodeInstrFetch) {
	access_type = "execute";
	} else if (report.context.arch.u.x86_64.err_code & kErrCodeWrite) {
	access_type = "write";
	} else {
	access_type = "read";
	}

	if (report.context.arch.u.x86_64.err_code & kErrCodeProtectionViolation) {
	violation = "protection";
	} else {
	violation = "not-present";
	}
	#elif defined(__aarch64__)
	// The one ec bit that's different between a data and instruction abort
	static constexpr uint32_t kEcDataAbortBit = (1 << 28);
	static constexpr uint32_t kIssCacheOp = (1 << 8);
	static constexpr uint32_t kIssWrite = (1 << 6);
	static constexpr uint32_t kDccNoLvlMask = 0b111100;
	static constexpr uint32_t kDccPermissionFault = 0b001100;
	static constexpr uint32_t kDccTranslationFault = 0b000100;
	static constexpr uint32_t kDccAddressSizeFault = 0b000000;
	static constexpr uint32_t kDccAccessFlagFault = 0b001000;
	static constexpr uint32_t kDccSynchronousExternalFault = 0b010000;

	if (report.context.arch.u.arm_64.esr & kEcDataAbortBit) {
	if (report.context.arch.u.arm_64.esr & kIssWrite &&
	!(report.context.arch.u.arm_64.esr & kIssCacheOp)) {
	access_type = "write";
	} else {
	access_type = "read";
	}
	} else {
	access_type = "execute";
	}

	switch ((report.context.arch.u.arm_64.esr & kDccNoLvlMask)) {
	case kDccPermissionFault:
	violation = "protection";
	break;
	case kDccTranslationFault:
	violation = "not-present";
	break;
	case kDccAddressSizeFault:
	violation = "address-size";
	break;
	case kDccAccessFlagFault:
	violation = "access-flag";
	break;
	case kDccSynchronousExternalFault:
	violation = "external-abort";
	break;
	default:
	violation = "undecoded";
	break;
	}
	#elif defined(__riscv)
	#else
	#error unsupported architecture
	#endif
	fprintf(out, "<== %s %s page fault (error %s), PC at 0x%" PRIxPTR "\n", access_type, violation,
	zx_status_get_string(static_cast<zx_status_t>(report.context.synth_code)), decoded.pc);
	} else if (report.header.type == ZX_EXCP_POLICY_ERROR) {
	switch (report.context.synth_code) {
	case ZX_EXCP_POLICY_CODE_BAD_SYSCALL:
	fprintf(out, "<== policy error: %s (%d, syscall %d), PC at 0x%" PRIxPTR "\n",
	inspector::policy_exception_code_to_str(report.context.synth_code),
	report.context.synth_code, report.context.synth_data, decoded.pc);
	break;

	default:
	fprintf(out, "<== policy error: %s (%d), PC at 0x%" PRIxPTR "\n",
	inspector::policy_exception_code_to_str(report.context.synth_code),
	report.context.synth_code, decoded.pc);
	break;
	}
	} else {
	fprintf(out, "<== %s, PC at 0x%" PRIxPTR "\n", inspector::excp_type_to_str(report.header.type),
	decoded.pc);
	}
	}

	} // namespace inspector

	__EXPORT void inspector_print_stack_trace(FILE* out, zx_handle_t process, zx_handle_t thread,
	const zx_thread_state_general_regs* regs) {
	inspector_dsoinfo_t* dso_list = inspector_dso_fetch_list(process);
	inspector_print_markup_context(out, process);

	inspector::decoded_registers decoded = inspector::decode_registers(regs);
	inspector_print_backtrace_markup(out, process, thread, dso_list, decoded.pc, decoded.sp,
	decoded.fp);
	inspector_dso_free_list(dso_list);
	}

	__EXPORT void inspector_print_debug_info(FILE* out, zx_handle_t process_handle,
	zx_handle_t thread_handle) {
	zx_status_t status;
	// If the caller didn't supply \|regs\| use a local copy.
	zx_thread_state_general_regs_t regs;

	zx::unowned<zx::process> process(process_handle);
	zx_koid_t pid = inspector::get_koid(process->get());
	char process_name[ZX_MAX_NAME_LEN];
	inspector::get_name(process->get(), process_name, sizeof(process_name));

	zx::unowned<zx::thread> thread(thread_handle);
	zx_koid_t tid = inspector::get_koid(thread->get());
	char thread_name[ZX_MAX_NAME_LEN];
	inspector::get_name(thread->get(), thread_name, sizeof(thread_name));

	// Attempt to obtain the registers. If this fails, it means that the thread wasn't provided in a
	// valid state.
	status = inspector_read_general_regs(thread->get(), &regs);
	if (status != ZX_OK) {
	printf("[Process %s, Thread %s] Could not get general registers: %s.\n", process_name,
	thread_name, zx_status_get_string(status));
	return;
	}
	inspector::decoded_registers decoded = inspector::decode_registers(&regs);

	// Backtrace requests are special software breakpoints that get resumed. They need to be clearly
	// differentiable from other exceptions.
	bool backtrace_requested = false;

	// Check if the process is on an exception.
	zx_exception_report_t report;
	if (thread->get_info(ZX_INFO_THREAD_EXCEPTION_REPORT, &report, sizeof(report), nullptr,
	nullptr) == ZX_OK) {
	// The thread is in a valid exception state.
	if (!ZX_EXCP_IS_ARCH(report.header.type) && report.header.type != ZX_EXCP_POLICY_ERROR) {
	return;
	}

	backtrace_requested = is_backtrace_request(report.header.type, &regs);
	if (backtrace_requested) {
	fprintf(out, "<== BACKTRACE REQUEST: process %s[%" PRIu64 "] thread %s[%" PRIu64 "]\n",
	process_name, pid, thread_name, tid);
	} else {
	// Normal exception.
	fprintf(out, "<== CRASH: process %s[%" PRIu64 "] thread %s[%" PRIu64 "]\n", process_name, pid,
	thread_name, tid);
	inspector::print_exception_report(out, report, &regs);

	#if defined(__x86_64__)
	inspector_print_general_regs(out, &regs, &report.context.arch.u.x86_64);
	#elif defined(__aarch64__)
	inspector_print_general_regs(out, &regs, &report.context.arch.u.arm_64);

	// Only output the Fault address register and ESR if there's a data or
	// alignment fault.
	if (ZX_EXCP_FATAL_PAGE_FAULT == report.header.type \|\|
	ZX_EXCP_UNALIGNED_ACCESS == report.header.type) {
	fprintf(out, " far %#18" PRIx64 " esr %#18x\n", report.context.arch.u.arm_64.far,
	report.context.arch.u.arm_64.esr);
	}
	#elif defined(__riscv)
	#else
	#error unsupported architecture
	#endif
	}
	} else {
	// The thread is suspended so we can safely print the stack trace.
	fprintf(out, "<== process %s[%" PRIu64 "] thread %s[%" PRIu64 "]\n", process_name, pid,
	thread_name, tid);
	fprintf(out, "<== PC at 0x%" PRIxPTR "\n", decoded.pc);
	inspector_print_general_regs(out, &regs, nullptr);
	}

	if (!backtrace_requested) {
	// Print the common stack part of the thread.
	fprintf(out, "bottom of user stack:\n");
	inspector_print_memory(out, process->get(), decoded.sp, inspector::kMemoryDumpSize);

	fprintf(out, "arch: %s\n", inspector::kArch);
	}

	inspector_print_stack_trace(out, process->get(), thread->get(), &regs);

	if (inspector::verbosity_level >= 1)
	printf("Done handling thread %" PRIu64 ".%" PRIu64 ".\n", pid, tid);
	}

	// The approach of \|inspector_print_debug_info_for_all_threads\| is to suspend the process, obtain
	// all threads, go over the ones in an exception first and print them and only then print all the
	// other threads. This permits to have a clearer view between logs and the crash report.
	__EXPORT void inspector_print_debug_info_for_all_threads(FILE* out, zx_handle_t process_handle) {
	zx_status_t status = ZX_ERR_NOT_SUPPORTED;

	zx::unowned<zx::process> process(process_handle);
	char process_name[ZX_MAX_NAME_LEN];
	inspector::get_name(process->get(), process_name, sizeof(process_name));
	zx_koid_t process_koid = inspector::get_koid(process->get());

	// Suspend the process so that each thread is suspended and no more threads get spawned.
	// NOTE: A process cannot suspend itself, so this could fail on some environments (like calling
	// this function on your process). To support that usecase, this logic will also try to
	// suspend each thread individually.
	//
	// The advantages of suspending the process vs each thread individually are:
	// 1. Threads get suspended at a single point in time, which gives a more accurate
	// representation of what the process is doing at the moment of printing.
	// 2. When a process is suspended, no more threads will be spawned.
	zx::suspend_token process_suspend_token;
	status = process->suspend(&process_suspend_token);
	if (status != ZX_OK) {
	printf("[Process %s (%" PRIu64 ")] Could not suspend process: %s. Continuing anyway.\n ",
	process_name, process_koid, zx_status_get_string(status));
	}

	// Get the thread list.
	// NOTE: This could be skipping threads being created at the moment of this call.
	// This is an inherent race between suspending a process and a thread being created.
	size_t actual, avail;
	// This is an outrageous amount of threads to output. We mark them all as invalid first.
	constexpr size_t kMaxThreadHandles = 128;
	std::vector<zx_koid_t> thread_koids(kMaxThreadHandles);
	status = process->get_info(ZX_INFO_PROCESS_THREADS, thread_koids.data(),
	thread_koids.size() * sizeof(zx_koid_t), &actual, &avail);
	if (status != ZX_OK) {
	printf("[Process %s (%" PRIu64 ")] Could not get list of threads: %s.\n", process_name,
	process_koid, zx_status_get_string(status));
	return;
	}

	std::vector<zx::thread> thread_handles(actual);
	std::vector<std::string> thread_names(actual);
	std::vector<zx_info_thread_t> thread_infos(actual);

	// Get the thread associated data.
	for (size_t i = 0; i < actual; i++) {
	// Get the handles.
	zx::thread& child = thread_handles[i];
	status = process->get_child(thread_koids[i], ZX_RIGHT_SAME_RIGHTS, &child);
	if (status != ZX_OK) {
	printf("[Process %s (%" PRIu64 ")] Could not obtain thread handle: %s.\n", process_name,
	process_koid, zx_status_get_string(status));
	continue;
	}

	// Get the name.
	char thread_name[ZX_MAX_NAME_LEN];
	inspector::get_name(child.get(), thread_name, sizeof(thread_name));
	thread_names[i] = thread_name;

	// Get the thread infos.
	zx_info_thread_t thread_info = {};
	status = child.get_info(ZX_INFO_THREAD, &thread_info, sizeof(thread_info), nullptr, nullptr);
	if (status != ZX_OK) {
	printf("[Process %s (%" PRIu64 "), Thread %s (%" PRIu64 ")] Could not obtain info: %s\n",
	process_name, process_koid, thread_names[i].c_str(), thread_koids[i],
	zx_status_get_string(status));
	continue;
	}

	thread_infos[i] = std::move(thread_info);
	}

	// Print the threads in an exception first.
	for (size_t i = 0; i < actual; i++) {
	zx::thread& child = thread_handles[i];
	if (!child.is_valid())
	continue;

	// If the thread is not in an exception, it will be printed on the next loop.
	if (thread_infos[i].state != ZX_THREAD_STATE_BLOCKED_EXCEPTION)
	continue;

	// We print the thread and then mark this koid as empty, so that it won't be printed on the
	// suspended pass. This means we can free the handle after this.
	inspector_print_debug_info(out, process->get(), child.get());
	thread_handles[i].reset();
	}

	// Go over each thread and print them.
	for (size_t i = 0; i < actual; i++) {
	if (!thread_handles[i].is_valid())
	continue;

	// If the thread is in an exception, it was already printed by the previous loop.
	if (thread_infos[i].state == ZX_THREAD_STATE_BLOCKED_EXCEPTION) {
	continue;
	}

	zx::thread& child = thread_handles[i];

	// Wait for the thread to be suspended.
	// We do this regardless of the process suspension. There are legitimate cases where the process
	// suspension would fail, like trying to suspend one's own process. If the process suspension
	// was successful, this is a no-op.
	zx::suspend_token suspend_token;
	status = child.suspend(&suspend_token);
	if (status != ZX_OK) {
	printf("[Process %s (%" PRIu64 "), Thread %s (%" PRIu64 ")] Could not suspend thread: %s.\n",
	process_name, process_koid, thread_names[i].c_str(), thread_koids[i],
	zx_status_get_string(status));
	continue;
	}

	status = child.wait_one(ZX_THREAD_SUSPENDED, zx::deadline_after(zx::msec(100)), nullptr);
	if (status != ZX_OK) {
	printf("[Process %s (%" PRIu64 "), Thread %s (%" PRIu64 ")] Didn't get suspend signal: %s.\n",
	process_name, process_koid, thread_names[i].c_str(), thread_koids[i],
	zx_status_get_string(status));
	continue;
	}

	// We can now print the thread.
	inspector_print_debug_info(out, process->get(), child.get());
	}
	}